Pe d i a t r i c I m a g i n g • O r i g i n a l R e s e a r c h Callahan et al. Survey of Use of Iodinated IV Contrast Media in Pediatric CT
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Pediatric Imaging Original Research
Practice Patterns for the Use of Iodinated IV Contrast Media for Pediatric CT Studies: A Survey of the Society for Pediatric Radiology Michael J. Callahan1 Sabah Servaes 2 Edward Y. Lee 3 Alexander J. Towbin 4 Sjirk J. Westra5 Donald P. Frush 6 Callahan MJ, Servaes S, Lee EY, Towbin AJ, Westra SJ, Frush DP
Keywords: children, CT, IV contrast media DOI:10.2214/AJR.13.11106 Received April 12, 2013; accepted after revision August 4, 2013. A. J. Towbin is an author for Amisys and is a shareholder in Merge Healthcare. 1 Department of Radiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115. Address correspondence to M. J. Callahan ([email protected]). 2 Department of Radiology, Children’s Hospital of Philadelphia, Philadelphia, PA. 3
Department of Radiology and Medicine, Pulmonary Division, Boston Children’s Hospital, Boston, MA. 4
Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. 5
Department Radiology, Massachusetts General Hospital, Boston, MA.
6 Division of Pediatric Radiology, Duke University Medical Center, McGovern-Davison Children’s Health Center, Durham, NC.
Supplemental Data Available online at www.ajronline.org. AJR 2014; 202:872–879 0361–803X/14/2024–872 © American Roentgen Ray Society
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OBJECTIVE. There are limited data available on the use of IV contrast media for CT studies in the pediatric population. The purpose of this study is to determine the practice patterns of IV contrast media usage for pediatric CT by members of the Society for Pediatric Radiology (SPR). MATERIALS AND METHODS. SPR members were surveyed regarding the use of IV contrast media for pediatric CT studies. Questions pertained to information required before administering IV contrast media, types of central catheters for injecting IV contrast media, injection rates based on angiocatheter size and study type, and management of IV contrast media extravasation. RESULTS. The response rate of 6% (88/1545) represented practice patterns of 26% (401/1545) of the SPR membership. Most respondents thought the following clinical information was mandatory before IV contrast media administration: allergy to IV contrast media (97%), renal insufficiency (97%), current metformin use (72%), significant allergies (61%), diabetes (54%), and asthma (52%). Most administered IV contrast media through nonimplanted central venous catheters (78%), implanted venous ports (78%), and peripherally inserted central catheters (72%). The most common maximum IV contrast media injection rates were 5.0 mL/s or greater for a 16-gauge angiocatheter, 4.0 mL/s for an 18-gauge angiocatheter, 3.0 mL/s for a 20-gauge angiocatheter, and 2.0 mL/s for a 22-gauge angiocatheter. For soft-tissue extravasation of IV contrast media, 95% elevate the affected extremity, 76% use ice, and 45% use heat. CONCLUSION. The results of this survey illustrate the collective opinion of a subset of SPR members relating to the use of IV contrast media in pediatric CT, providing guidelines for clinical histories needed before IV contrast media, maximum IV contrast injection rates for standard angiocatheters, contrast media injection rates for specific CT studies, and management of IV contrast media soft-tissue extravasation.
I
odinated IV contrast media is commonly used for pediatric CT studies, but there are relatively few published guidelines on the appropriate administration of iodinated IV contrast media for CT in the pediatric population [1, 2]. The American College of Radiology (ACR) publishes and updates a webbased document, ACR Manual on Contrast Media, which is currently in the ninth edition [1]. This manual was developed by the ACR as a guide for radiologists to promote the safe and effective use of IV contrast media. The manual has a section dedicated to the use of IV contrast media in children, which primarily focuses only on the incidence and treatment of allergic-like reactions and contrastinduced nephropathy.
An anonymous web-based survey was created to determine the broader practice patterns of Society for Pediatric Radiology (SPR) members regarding their use of iodinated IV contrast media for pediatric CT. The survey was performed to identify areas of consensus opinion in the administration of iodinated IV contrast media for pediatric patients. This information can serve as a point of reference for practice development or modification on the use of iodinated IV contrast media in children. Materials and Methods Study approval was granted by the institutional review board of Boston Children’s Hospital. Because the survey was anonymous, institutional review board approval was not required at the other participating institutions.
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Survey of Use of Iodinated IV Contrast Media in Pediatric CT A 15-question survey (Appendix S1, which can be seen in the AJR electronic supplement to this article, available at www.ajronline.org) was created by members of the CT committee of the SPR utilizing an online surveying website (SurveyMonkey.com). The survey questions encompassed a number of topics related to the use of iodinated IV contrast media for pediatric CT, including prescreening questions for administering IV contrast media, the use of central venous catheters, implanted venous ports, and peripherally inserted central catheters (PICCs) for CT studies; preferred routine injection rates of IV contrast media for contrast-enhanced pediatric CT studies (head, chest, abdomen/pelvis, extremities, peripheral CT angiography [CTA], and neurology CTA studies) based on angiocatheter size and study type; and the management of IV contrast media extravasation in children. In addition, questions regarding practice demographics were also included. The majority of survey responses were a multiple-choice or yes-or-no format. In general, respondents were asked to select the single best answer for a given question. For question 3, which related to prescreening questions for IV contrast media, the respondents were asked to respond with one of three choices: “mandatory,” “clinically useful but not mandatory,” or “not necessary.” The survey was distributed electronically via an e-mail. All recipients were informed of the purpose of the study before participation. Those electing to participate in the survey could do so by following a link embedded in the e-mail. All results were anonymous. No incentive was provided to participants, and there was no penalty for not participating. The survey was open for participation between November 2010 and January 2011. Individuals were asked to respond on behalf of their colleagues if applicable, and if they were responding on behalf of multiple colleagues, they were asked to list the number of SPR members in their practice whom the response data represented. All data from the survey were collected via the online survey website, and the data were provided for tabulation of the results. Data were then exported, and descriptive statistics were evaluated in Microsoft Excel. Percentages reported in this article were rounded to the nearest whole number. As a result, not all percentages for a given question may add up to exactly 100%. Not all questions were answered by the survey participants, and, as a result, the denominator will not always be constant for a given question or portion of a question. On the basis of the collective experiences of the authors, an additional review of the data was performed, and additional comments and interpretation of the data are also provided.
Results The survey was sent anonymously to 1545 SPR members. The actual number of recipients was unknown. There were a total of 88 responders (6%). However, 41 of 88 (47%) responded on behalf of a group of colleagues at their institution, which represented the practices of 401 individuals, equaling 26% (401/1545) of the SPR membership. All of those who responded interpret CT studies in children. Of the 88 respondents, 40% (n = 35) practice in a freestanding children’s hospital, 39% (n = 34) practice in a pediatric radiology division of a larger academic medical center, 15% (n = 13) practice at a primarily adult academic hospital without a pediatric division, and 10% (n = 9) practice in a primarily adult private practice hospital. Two respondents practice exclusively in a nonhospital outpatient community-based practice.
Clinical Questions Before Contrast Media Administration Those surveyed were asked to describe the relative importance of certain clinical questions before the administration of iodinated IV contrast media in children. Most responders thought that one or more of the following questions contained mandatory information needed before the administration of IV contrast media: history of allergy to iodinated IV contrast media, 97% (85/88); renal insufficiency or renal disease, 97% (85/88); current use of drugs containing metformin, 72% (62/86); significant allergies (excluding seafood), 61% (54/88); history of diabetes, 54% (46/85); and history of asthma or asthma inhaler use, 52% (46/88). Many responders thought the following questions contained clinically useful, but not mandatory, information: history of liver disease,
TABLE 1: Responses to Survey Question, “Which of the Following Do You Think Are Mandatory Questions Regarding Patient Histories That Must Be Answered Before the Administration of Iodinated IV Contrast Media in Pediatric Patients?” Answer Options
Question Allergy to IV contrast media?
Clinically Useful but Not Not Mandatory Mandatory Necessary
Response Count
85
2
1
88
Significant allergies to other allergens?
54
30
5
88
Asthma or asthma inhaler use?
46
37
5
88
Shellfish allergy?
20
29
36
85
Renal insufficiency or renal disease?
85
3
0
88
Liver disease?
21
47
16
84
Sickle cell disease?
37
35
14
86
Sickle cell crisis?
41
31
14
86
Pheochromocytoma?
30
40
15
85
Myasthenia gravis?
17
46
22
85
Aspiration pneumonia?
5
35
44
84
Diabetes?
46
22
17
85
Hypertension?
16
37
32
85
Thyroid cancer?
15
36
34
85
Hyperthyroidism?
13
37
33
83
Paraproteinemia (e.g., multiple myeloma)?
22
28
35
83
Cardiac dysfunction (acute congestive heart failure, dysrhythmia, unstable angina pectoris, severe aortic stenosis, cardiomyopathy, or pulmonary hypertension)?
33
35
17
85
Metformin use?
62
16
8
86
Aminoglycoside use?
16
40
26
82
Amphotericin B use?
9
42
30
81
Note—Data are no. of responses.
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Callahan et al. 56% (47/84); and history of myasthenia gravis, 54% (46/85). Forty-two percent (36/85) of responders thought a history of shellfish allergy was not clinically relevant in the setting of IV contrast agent administration. Notably, 24% of responders thought a history of shellfish allergy was mandatory before administration of IV contrast media; 34% thought this information was clinically useful, but not mandatory. A relative minority of responders thought that one or more of the following clinical histories was mandatory before administration of iodinated IV contrast media in children: paraproteinemia, 27% (22/83); liver disease, 25% (21/84); myasthenia gravis, 20% (17/85); aminoglycoside use, 20% (16/82); hypertension, 19% (16/85); thyroid cancer, 18% (15/85); hyperthyroidism, 16% (13/83); amphotericin B use, 11% (9/81); and aspiration pneumonia, 6% (5/84). The complete responses to the question regarding what clinical information is needed before administering IV contrast are included in Table 1. Catheter Use The majority of responders (69/88; 78%) administer IV contrast media through nonimplanted central venous catheters (i.e., Broviac and Hickman catheters, Bard Medical) for diagnostic CT studies. Of those who use nonimplanted central venous catheters, 54% (38/71) perform hand injections, 13% (9/71) exclusively use the power injector, and 35% (25/71) perform both hand injections and power injection of IV contrast media. Seventy-eight percent (66/85) of responders use implanted venous ports for IV contrast media injection, and 72% (63/87) of responders are willing to use a PICC. Of those responders who are willing to use PICCs, 74% (57/77) use PICCs specifically designed for CT power injectors, whereas 26% (20/77) report the use of non–power injectable PICCs for diagnostic CT examinations. Seventy-six percent of responders (66/87) routinely use a saline bolus to follow the IV contrast media bolus. Responders were then asked to report the smallest peripheral IV catheter they routinely used with a power injector. Forty-nine percent (40/81) of responders reported a 22 gauge as their smallest-gauge angiocatheter for routine IV contrast media administration via power injector. Thirty-three percent (27/81) answered 24 gauge, 15% (12/81) answered 20 gauge, and 4% (3/81) reported the smallest-gauge angiocatheter they use for power injection is 18 gauge.
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Contrast Media Injection Rates The most common maximum IV contrast injection rates were 5.0 mL/s or greater for a 16-gauge angiocatheter, 4.0 mL/s for 18 gauge, 3.0 mL/s for 20 gauge, and 2.0 mL/s for a 22-gauge angiocatheter (Table 2). Fifty percent (32/64) of responders hand-inject a 24-gauge angiocatheter, but 38% (24/64) use 1.0 mL/s through a power injector as the maximum injection rate for this size of catheter. Most responders routinely administer IV contrast media at a rate of 2.0 mL/s for contrast-enhanced studies of the neck (52%; 35/68), chest (52%; 35/68), and abdomen/ pelvis (49%; 33/68). Eighty-five percent (58/68) of responders use an injection rate of 1.0–2.0 mL/s for neck CT studies, 82% (56/68) of responders use an injection rate of 1.0–2.0 mL/s for chest CT studies, and 79% (54/68) use an injection rate of 1.0– 2.0 mL/s for abdominal/pelvic CT studies (Table 3).
In contrast to body imaging, which often requires a more-rapid bolus, 69% (47/68) of contrast-enhanced head CT studies are performed at an injection rate of 1.0–2.0 mL/s. Twenty-nine percent of responders (20/68) reported a routine injection rate of 2.0 mL/s for contrast-enhanced head CT examinations in children (Table 3), but 22% (15/68) routinely use 1.5 mL/s, and 18% (12/68) perform these studies at 1.0 mL/s. A relatively large percentage of responders (27%; 18/68) hand inject IV contrast media for head CT studies, and in these cases, the exact IV contrast media injection rate is unknown. The majority of responders use 3.0 mL/s for peripheral CTA studies (37%; 25/68), and greater than 3 mL/s for pulmonary CTA studies (44%; 30/68) and head/neck CTA studies (41%; 28/68). However, it should be noted that 70% (48/68) use rates of 2.0–3.0 mL/s, and 35% (24/68) use rates greater than 3.0 mL/s for peripheral CTA studies. For
TABLE 2: Responses to Survey Question, “Please List Your Department’s Maximum Power Injection Rate for Each Size of Peripheral Angiocatheter (IV) in the List Below” Answer Options Not Applicable Angiocatheter (Manual Gauge Injection)
1.0 mL/s
2.0 mL/s
3.0 mL/s
4.0 mL/s
≥ 5.0 mL/s
Response Count
16
3
0
5
10
16
35
68
18
1
1
9
16
25
22
73
20
3
2
21
28
13
7
72
22
4
13
37
14
4
0
70
24
32
24
9
2
0
0
64
Note—Data are no. of responses.
TABLE 3: Responses to Survey Question, “Please List Your Typical IV Contrast Injection Rates for Each of the Following Routine Diagnostic CT Studies if IV Contrast Is Used (If Your Injection Rate Is Different From the Rates Listed Below, Please Give Your Best Estimate)” Answer Options
Type of Study
Not Applicable (Manual Response Injection) 1.0 mL/s 1.5 mL/s 2.0 mL/s 2.5 mL/s 3.0 mL/s > 3.0 mL/s Count
Head CT
18
12
15
20
3
7
1
68
Neck CT
6
10
13
35
5
7
2
68
Chest CT
3
9
12
35
7
8
2
68
Abdomen/pelvis CT
3
9
12
33
8
9
2
68
Peripheral CTA
4
2
3
7
16
25
24
68
Pulmonary CTA
4
2
2
8
12
22
30
68
Head/neck CTA
4
3
3
7
15
19
28
68
Note—Data are no. of responses. CTA = CT angiography.
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pulmonary CTA studies, 62% (42/68) of responders use injection rates of 2.0–3.0 mL/s, and for head/neck CT studies, 60% (41/68) of those surveyed most commonly use injection rates of 2.0–3.0 mL/s. Soft-Tissue Extravasation The majority of responders (81%; 70/87) report that soft-tissue extravasation of iodinated IV contrast media occurs in less than 1% of contrast-enhanced CT examinations. Management of soft-tissue extravasation of IV contrast media is somewhat variable among the SPR membership (Fig. 1); 95% of responders (81/85) elevate the affected extremity after soft-tissue extravasation. All responders (100%; 88/88) monitor these patients with close clinical observation. Different levels of clinical observation were not defined for this survey. Seventy-six percent report using an ice pack (62/82), and 45% report using heat (28/62). Fifty-three percent reported requesting a plastic surgery consultation (42/79). The survey did not specify which type of extravasation would necessitate a plastic surgery consultation. Discussion In this study, we describe the current practice patterns of the SPR membership for the routine use of iodinated IV contrast media for pediatric CT. The purpose of this survey was to provide both pediatric and adult radiologists with a general knowledge of the current SPR membership’s use of iodinated IV contrast media in pediatric patients. This information can serve as a guide for the safe and effective use of IV contrast media for pediatric CT studies in a wide variety of radiology practices. Clinical Questions Before Contrast Media Administration Fortunately, the incidence of allergiclike reactions associated with the administration of iodinated IV contrast media in the pediatric population is very low, with a recently reported incidence between 0.18% and 0.46% [2, 3]. Despite a low overall incidence, a direct relationship between patient age and incidence of contrast agent reactions has been described [3]. In pediatric patients, the incidence of contrast media reactions peaks at 16–18 years of age. Adverse events related to IV contrast media administration are exceedingly uncommon in children younger than 3 years [3]. The ACR lists certain risk factors that increase an individual’s risk of an adverse
No. of Survey Respondents
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Survey of Use of Iodinated IV Contrast Media in Pediatric CT 100 90 80 70 60 50 40 30 20 10 0
No Yes
Elevation of Affected Extremity
Ice Pack
Heat
Close Clinical Observation
Plastic Surgery Consultation
Fig. 1—Responses to survey question, “How do you manage soft-tissue extravasation of IV contrast in pediatric patients? (Please check all that apply).”
event [1]. A history of an allergic reaction to IV contrast media is associated with up to a fivefold increased likelihood of a subsequent reaction. Additional risk factors include history of atopy, especially in patients with a history of anaphylactic responses to one or more allergens [4]. Prior studies have shown that there are no specific allergens, besides iodine and iodinated IV contrast media, that predict a future allergic reaction to the current nonionic iodinated contrast materials [4, 5]. These data generally reflect the practice of the responders to our survey, even though nearly 23% of our survey responders still thought allergy to shellfish was mandatory information before IV contrast media administration. Although a history of asthma may indicate an increased likelihood of a contrast media reaction, the risk is minimal [6], and, in general, a history of allergies or asthma in itself does not require premedication. In a study of greater than 12,000 pediatric patients at a large pediatric tertiary medical center, only 5% (3/57) of patients with documented allergic-like reactions to IV contrast media had a history of asthma in their medical record. However, the total number of patients with a history of asthma in that study population was unknown. Other studies indicate an increased likelihood of contrast agent reaction in asthmatic patients [7, 8]. Trout et al. [9] surveyed the Society of Chairs of Radiology in Children’s Hospitals and found that 2% of respondents premedicated children with a history of mild asthma, 26% premedicated patients with moderate-to-severe asthma, and 41% would premedicate patients with a recent asthma attack. In that same study, 60% of respondents stated that they would either premedicate or avoid IV contrast media administration in patients with a history of life-threatening reaction to other allergens [9].
As expected, the vast majority of respondents (97%; 85/88) thought knowledge of renal insufficiency or renal disease was mandatory before the administration of IV contrast media. Contrast-induced nephropathy is defined as a sudden deterioration in renal function after the recent administration of IV contrast media and is rare in children [2]. Laboratory tests, such as serum creatinine level and glomerular filtration rate, have been used as screening tools for the injection of IV contrast media, but there is no universally accepted threshold of serum creatinine elevation beyond which iodinated IV contrast media should not be given. Fortunately, the risk of clinically relevant renal dysfunction is very low in most situations. However, patients with acute kidney injury, severe chronic renal disease, or patients who receive multiple doses of iodinated IV contrast media over a short period of time are at a higher risk of contrast-induced nephropathy related to the administration of iodinated IV contrast media [2]. Adequate hydration is a major preventive action against contrast-induced nephropathy, because renal blood flow and glomerular filtration rate are diminished in the setting of dehydration. The administration of IV contrast media in patients with sickle cell disease and acute or subacute sickle cell crisis currently remains somewhat controversial. Some authors report no increased risk of adverse events when compared with the general population [10, 11]; however, the results of this survey indicate some variability in opinion throughout the SPR. Forty-eight percent (41/86) of responders think that a current history of sickle cell crisis denotes mandatory clinical information, and 43% (37/86) think that a history of sickle cell disease without history of acute crisis represents mandatory clinical information before administration of IV con-
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Callahan et al. trast media. Only 16% (14/86) of responders think that knowledge of sickle cell disease or sickle cell crisis was not necessary for IV contrast media administration. Almost half of respondents (40/85; 47%) think that knowledge of a history of pheochromocytoma was clinically useful information, and 35% (30/85) thought this information was mandatory. Bessell-Browne and O’Malley [12] reported that nonionic IV contrast material could be safely administered to patients with suspected or known pheochromocytoma or related tumors, and α-blockade is not specifically required for contrast agent administration in this patient population. However, it should be noted that our survey did not specifically address whether the respondents would inject IV contrast media to a patient with known pheochromocytoma, only whether the information is useful before injecting contrast media. Metformin-containing medications are used for diabetes mellitus and polycystic ovary disease. Patients who take metformincontaining medications have an increased risk of developing lactic acidosis if their blood levels of metformin are high. Because nephrotoxicity is associated with the use of iodinated IV contrast agents, it was initially thought that the concomitant use of metformin could lead to an increased risk of lactic acidosis. This has since been disproved empirically. In an effort to be cautious, the package insert for metformin-containing medications states that the drug should be stopped at the time iodinated IV contrast media is administered, and the use of metformin should be held for 48 hours before resuming normal use. In general, metformin is contraindicated in patients with compromised renal function. If a contrast-enhanced CT study is requested in a patient with elevated serum creatinine levels and coexisting metformin use, at the very least the study should be deferred until the referring physician is notified [6, 13]. As expected, the majority (62/86; 72%) of respondents considered a history of current metformin use a mandatory question before iodinated IV contrast media administration. Respondents’ opinions were somewhat mixed on a history of cardiac dysfunction in children. Thirty-nine percent (33/85) thought knowledge of this history was mandatory, 41% (35/85) thought it was clinically useful but not mandatory, and 20% (17/85) thought a history of cardiac dysfunction or disease was unnecessary for IV contrast media administration. ACR guidelines suggest
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that patients with significant cardiac disease (e.g., congestive heart failure, aortic stenosis, pulmonary hypertension, and severe cardiomyopathy) have an increased risk for adverse reactions related to IV contrast media [1]. A history of cardiac disease in itself is not a contraindication for IV contrast media; however, if a pediatric cardiac patient is fluid restricted, care should be taken to minimize IV contrast media and saline bolus volumes. There are scant data on the risks of iodinated IV contrast media administration in patients with myasthenia gravis, but administration has been reported to cause increased weakness in this patient population. Frank et al. [14] reviewed the records of 136 patients with myasthenia gravis who received iodinated IV contrast media and found that five (3.7%) patients had subjective or objective increases in weakness. The authors of that study concluded that IV contrast media is not contraindicated in myasthenia gravis, but extra care should be taken when administered [14]. A majority of responders to our survey (54%; 46/85) thought a history of myasthenia gravis was clinically useful, but not mandatory for IV contrast media administration. Certain patients with hyperthyroidism or thyroid disease can develop iodine-provoked hyperthyroidism 4–6 weeks after IV contrast media administration. This is typically self-limited. Patients with a history of thyroid carcinoma require special consideration when iodinated IV contrast media is being administered. Uptake of 131I in the thyroid gland decreases about 1 week after administration of iodinated IV contrast media but normalizes after a few weeks. A majority of responders to our survey thought a history of hyperthyroidism (45%; 37/83) or thyroid carcinoma (42%; 36/85) was clinically useful but not mandatory for iodinated IV contrast media administration. Catheter Use The majority of respondents, at least 72% depending on type, are willing to administer contrast media through central venous catheters. Of those responders who are willing to use nonimplanted central catheters, a majority prefer to use hand injection (54%; 38/71) or a combination of hand injection and power injection (35%; 25/71). Only 13% (9/71) exclusively use a power injector for nonimplanted central catheters. Although studies exist documenting the safety of injecting contrast agents through certain central catheters, there is a theoretic risk of damaging
central lines during the rapid administration of IV contrast media [15–19], particularly during hand injection [17]. According to ACR guidelines [1], power injection of contrast media through nonimplanted central venous catheters can be performed safely, provided the CT scout scan or a recent chest radiograph confirms a central and intravascular location of the catheter tip, and the catheter tip position is tested for venous backflow. If saline can be injected without abnormal resistance, contrast media can be administered through the central catheter safely. Large-bore (9.5 to 10 French) central venous catheters can be injected using flow rates of up to 2.5 mL/s, which have been shown to generate pressures below the manufacturers’ specified limits. For power injection of contrast media through central venous catheters, the radiologist should consult individual manufacturers’ recommendations. As expected, a majority of those who are willing to use implanted ports or PICCs specifically designed for power injectors use a power injector for administration of IV contrast media for CT studies (74%; 57/77). However, there are many pediatric patients with chronic diseases who have an implanted port or PICC that is not specifically designed for use with a power injector. This presents a dilemma for radiologists because many of these patients have relatively poor peripheral IV access. In addition, because of repeated blood draws and needle sticks, it is the authors’ experience that many of these patients with chronic diseases are “needle phobic,” often to a greater extent than the general pediatric population. As a result, it can be challenging for the radiologist to explain to parents, patients, and referring physicians why placement of a peripheral IV catheter may be required for contrast-enhanced CT studies in children with a preexisting implanted port [20] or PICC. There is variability in the size of the smallest-gauge catheter used for power injection. Forty-nine percent (40/81) report a 22-gauge angiocatheter is the smallest catheter used with a power injector, although up to 33% (27/81) of responders use a power injector for 24-gauge angiocatheters, and this practice is supported in the literature [21]. There was variability in the maximum rate of injection used for different-sized angiocatheters. Twenty-two–gauge catheters can reportedly tolerate flow rates up to 5 mL/s, but a 20-gauge or larger catheter is preferred for flow rates greater than 3 mL/s. Amaral et al.
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Survey of Use of Iodinated IV Contrast Media in Pediatric CT [21] reported maximum power injector rates of 5 mL/s for 18- to 20-gauge angiocatheters, 3 mL/s for a 22-gauge catheter, and 1.5 mL for a 24-gauge angiocatheter. Our results were similar to those reported by Amaral et al. Maximum power injection rates varied by catheter size, and the majority of maximum injection rates ranged from 2.0 to 5.0 mL/s. However, it should be noted that the preferred maximum contrast media injection rates varied substantially for 18-, 20-, and 24-gauge angiocatheters, but were relatively more uniform for 16- and 22-gauge angiocathers (Table 2). It is not clear to the authors why there is relative uniformity in the preferred injection rates for certain catheter sizes and relative heterogeneity for other catheter sizes. Contrast Media Injection Rates Roughly half of responders routinely administer IV contrast agents at 2.0 mL/s for contrast-enhanced studies of the neck, chest, and abdomen/pelvis (Table 3). Although most responders use 2.0 mL/s for routine contrast-enhanced head CT studies, this examination had the most variability of IV contrast media injection rates (Table 3). Contrast media injection rates for CT angiography studies are generally higher than those used for conventional contrast-enhanced CT (Table 3). The details of IV contrast media administration for various imaging studies have been described, and a wide variety of contrast injection rates have been suggested elsewhere [22] and are dependent on the clinical indication. Soft-Tissue Contrast Media Extravasation Extravasation of contrast media into soft tissues is uncommon and is reported to occur in 0.1–0.9% of injections, which was consistent with the reported frequency in our survey. Extravasated iodinated contrast material can be harmful to the surrounding tissues, and some of these patients require close clinical follow-up. Despite the relative risks, most patients who experience soft-tissue extravasation of IV contrast media recover without long-term complications. Treatment depends on the agent administered, the volume extravasated, and the presence or absence of mechanical compression [21]. The most commonly reported severe injury is compartment syndrome. Less-common side effects include tissue ulceration, necrosis, and neurovascular injury. The ACR guidelines state that there is no consensus regarding treatment of contrast
medium extravasation [1]. Ninety-five percent (81/85) of our responders elevate the affected extremity after soft-tissue extravasation (Fig. 1), which decreases capillary hydrostatic pressure and promotes resorption. There is no clear evidence to favor the use of ice or heat compresses. Not unexpectedly, the decision to use ice or heat on the affected extremity resulted in a mixed response in our survey: 76% (62/82) report using an ice pack, and 45% (28/62) report using heat. Given the results, several responders chose both ice and heat in their responses. Those who use cold compresses report that patients have pain relief at the site of extravasation, whereas those who use warm compresses think that it facilitates absorption and improves distal blood flow. Fifty-three percent (42/79) of survey respondents reported requesting a plastic surgery consultation after soft-tissue extravasation of iodinated IV contrast media. The severity of extravasation was not specified in our survey, but surgical consultation is generally recommended in the setting of blistering, altered tissue perfusion, or clinical signs of compartment syndrome. Recommendations We have presented a few practical guidelines for the use of iodinated IV contrast media for CT in children. Many of our suggestions are supported by the literature presented, some are supported by the results of the survey, but most are based on the collective experiences of the authors, all of whom are current members or have been members of the SPR CT committee in the past and have expertise in pediatric CT. At a minimum, we suggest that the following clinical information should be obtained before the administration of iodinated IV contrast media in children: history of allergy to iodinated IV contrast media, history of severe allergies or atopy to other allergens, history of renal insufficiency, and current use of metformin-containing medication. Other clinical information could be obtained at the discretion of the individual practice or institution. A history of, or a potential for, sick-
le cell disease or sickle cell crisis, pheochromocytoma, myasthenia gravis, diabetes mellitus, or medical history of asthma might be clinically useful in certain patients, but a history of one of these disease processes should not affect a radiologist’s decision to administer iodinated IV contrast media for a clinically indicated CT study. The authors’ suggested maximum IV contrast media injection rates for pediatric patients are as follows: 5.0 mL/s for 16- to 18-gauge angiocatheters, 4.0 mL/s for 20-gauge, 2.5 mL/s for 22-gauge, and 1.0 mL/s for 24-gauge angiocatheters (Table 4). It should be noted that the recommendations of the respondents were slightly more conservative than the recommendations of the authors, but the maximum IV contrast media injection rates from our survey (Table 2) would suffice for most clinical applications, particularly routine nonCTA contrast-enhanced CT studies. When peripheral IV access is not possible, central venous catheters are often used for injection of IV contrast media in CT studies. Risk of adverse events has been reported between 0.3% and 1% [17–19]. We endorse the use of implanted ports and PICCs specifically designed for use with power injectors, provided the manufacturers’ rate limits are followed. We also support power injection of nonimplanted central venous catheters, provided certain pressure limits are observed [18]. Particular caution must be exercised when hand injecting central venous catheters [17], because substantial pressure can be generated with a syringe, resulting in a higher risk of subsequent catheter damage. Although there are a range of acceptable IV contrast media injection rates for routine (non-CTA) contrast-enhanced CT studies, the authors suggest 1.0–2.0 mL/s for contrastenhanced head CT studies and 1.0–2.0 mL/s for routine contrast-enhanced neck, chest, extremity, or abdomen/pelvis CT studies (Table 5). Two milliliters per second would be preferable for body CT studies, particularly in older children and adolescents. CTA studies at adult-based practices are often performed with angiocatheters sized
TABLE 4: Maximum Suggested Injection Rates for Pediatric CT Studies Maximum Injection Rate
Catheter Size
5.0 mL/s
16–18 gauge
4.0 mL/s
20 gauge
2.5 mL/s
22 gauge
1.0 mL/s
24 gauge
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Callahan et al. TABLE 5: Suggested IV Contrast Media Injection Rates for Routine (Non–CT Angiography) Contrast-Enhanced CT Studies in Pediatric Patients
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Injection Rate
Study
1.0–2.0 mL/s
Head CT
1.0–2.0 mL/s
Neck, chest, extremity, or abdomen/pelvis CT
Note—Injection rates of less than 1.0 mL/s may be acceptable for certain indications, and some implanted ports, peripherally inserted central catheters, or small-gauge (24-gauge) angiocatheters may necessitate a rate of 1.0 mL/s or less.
20 gauge and larger. It has been the authors’ experience that many pediatric CT angiography studies can be successfully performed in infants and children using a power injector with a 22-gauge angiocatheter at an injection rate of 2.0–2.5 mL/s or with a 24-gauge angiocatheter at an injection rate of 1.0–1.5 mL/s. As such, it is not practical, or even possible, to insert a 20-gauge angiocatheter (or larger) in many pediatric patients. Contrast media injection rates for CTA studies are influenced by the clinical indication, the size of the patient, the volume of contrast agent, the size and stability of the angiocatheter or central catheter, and CT protocol parameters. In general, most pediatric CT angiography studies can be successfully performed at contrast media injection rates of 2.0–4.0 mL/s (Table 6). A rate of 1.0 mL/s is acceptable for very small patients (< 15 kg) using a 24-gauge angiocatheter, often by hand injection. Timing of IV contrast-enhanced CT studies with respect to scan initiation is a complicated topic and is beyond the scope of this article. If soft-tissue extravasation of IV contrast media occurs, the authors suggest an initial clinical evaluation and examination by a radiologist. It is important to estimate how much IV contrast media was extravasated, if possible. If the amount of extravasated contrast media is thought to be clinically significant, the authors suggest elevating the affected extremity and subsequent application of an ice pack. If there is delayed capillary refill or other signs of abnormal tissue perfusion, significant pain, neurologic symptoms, or other signs of compartment syndrome, a plastic surgery consultation is indicated. Surgical consultation is not required for all IV contrast media extravasations, and radiographs are not needed to quantify the volume of IV contrast media extravasation. Our study has limitations. The answers to most of the survey questions are subjective, and the responses would benefit from further discussion or qualification. For instance, it is not practical to provide a list of all relevant
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questions that are necessary before the administration of IV contrast media, and not all responses are straightforward. The circumstances surrounding the decision to inject iodinated IV contrast media are multifactorial and can vary from patient to patient. The survey was sent to 1585 e-mail addresses, but the exact number of recipients was unknown. The responses to this survey represent the collective opinion of our 88 individual respondents; however, 41 respondents answered the survey on behalf of 401 SPR colleagues. The authors acknowledge that more than one member of the same institution may have answered the survey, which could introduce institution bias to a small extent. Nevertheless, the practice patterns of certain individuals within a single institution can vary among the individual radiologists, and it is unlikely that two individuals would fill out the survey exactly the same, even if they are at the same institution. Also, a certain percentage of those responding on behalf of others may be biased by those individuals who are most familiar with the standard techniques. Those who chose not to respond may not know what is used, and these data could affect the numbers recorded. We did not specifically ask the survey participants to list the types of iodinated IV contrast media used in their practice, and we did not address premedication for IV contrast media. Most pediatric practices have used low-osmolar iodinated IV contrast media for years [23]. IV contrast media doses, concentration of iodinated IV contrast media used
for pediatric CT studies, and the use of premedication were not specifically addressed by this study but have been reported in the recent literature [9]. The results of our survey and our suggestions may generate discussion and debate on the appropriate use of IV contrast media for CT studies in children. We hope that this article will stimulate further research on this important topic. Potential areas of future work include determining optimal IV contrast media iodine concentrations for specific pediatric CT studies and creating more-specific guidelines for optimal volumes, timing, and injection rates of IV contrast media required for contrast-enhanced pediatric CT studies and CTA studies. Although premedication for IV contrast media was not specifically addressed in this article, further work on pediatric premedication appropriateness criteria is another potential area of future research that could supplement previous work on this topic [9]. Conclusion The purpose of this survey was to determine the current practice patterns for the administration of iodinated IV contrast media for pediatric CT studies among SPR members and to provide suggestions for the use of IV contrast media on the basis of a combination of the survey results and the authors’ suggestions. The results of this survey show the current opinions of pediatric radiologists relating to information required before administering IV contrast media, methods of administering IV contrast media to children, and methods to treat soft-tissue extravasation of IV contrast media in the pediatric population. Because most pediatric patients are imaged at adult-based radiology practices, we hope that this article will serve as a general guideline for those adult radiologists who occasionally image children and will provide some direction for the effective use of iodinated IV contrast media and management of
TABLE 6: Suggested IV Contrast Media Injection Rates for CT Angiography (CTA) Studies in Pediatric Patients Injection Rate
Study
2.0–4.0 mL/s
Conventional chest, abdomen/pelvis, or extremity CTA (arterial phase)
2.5–4.0 mL/s
Pulmonary CTA
2.0–4.0 mL/s
Head/neck CTA
Note—Many CTA studies can be successfully performed in small children with a 22-gauge angiocatheter at a rate of 2.0 mL/s or less. CTA studies in infants can be performed with a hand injection of a 24-gauge angiocatheter at rates as low as 1 mL/s.
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Survey of Use of Iodinated IV Contrast Media in Pediatric CT
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IV contrast media extravasation for CT studies in children. Acknowledgment We thank Richard Cappock (Children’s Hospital Boston) for his assistance. References 1. American College of Radiology. ACR manual on contrast media, version 9. American College of Radiology website. www.acr.org/~/media/ACR/ Documents/PDF/QualitySafety/Resources/Contrast%20Manual/2013_Contrast_Media.pdf. Published 2013. Accessed December 9, 2013 2. Dillman JR, Strouse PJ, Ellis JH, Cohan RH, Jan SC. Incidence and severity of acute allergic-like reactions to IV nonionic iodinated contrast material in children. AJR 2007; 188:1643–1647 3. Callahan MJ, Poznauskis L, Zurakowski D, Taylor GA. Nonionic iodinated intravenous contrast material-related reactions: incidence in large urban children’s hospital—retrospective analysis of data in 12,494 patients. Radiology 2009; 250:674–681 4. Coakley FV, Panicek DM. Iodine allergy: an oyster without a pearl? AJR 1997; 169:951–952 5. Lieberman PL, Seigle RL. Reactions to radiocontrast material: anaphylactoid events in radiology. Clin Rev Allergy Immunol 1999; 17:469–496 6. Bettmann MA. Frequently asked questions: iodinated contrast agents. RadioGraphics 2004; 24(suppl 1):S3–S10
7. Shehadi WH. Adverse reactions to intravascularly administered contrast media: a comprehensive study based on a prospective survey. Am J Roentgenol Radium Ther Nucl Med 1975; 124:145–152 8. Katayama H, Yamaguchi K, Kozuka T, Takashima T, Seez P, Matsuura K. Adverse reactions to ionic and nonionic contrast media: a report from the Japanese Committee on the Safety of Contrast Media. Radiology 1990; 175:621–628 9. Trout AT, Dillman JR, Ellis JH, Cohan RH, Strouse PJ. Patterns of intravenous contrast material use and corticosteroid premedication in children: a survey of Society of Chairs of Radiology in Children’s Hospitals (SCORCH) member institutions. Pediatr Radiol 2011; 41:1272–1283 10. Rao VM, Rao AK, Steiner RM, Burka ER, Grainger RG, Ballas SK. The effect of ionic and nonionic contrast media on the sickling phenomenon. Radiology 1982; 144:291–293 11. Campbell KL, Hud LM, Adams S, et al. Safety of iodinated intravenous contrast medium administration in sickle cell disease. Am J Med 2012; 125:100.e111–100.e116 12. Bessell-Browne R, O’Malley ME. CT of pheochromocytoma and paraganglioma: risk of adverse events with IV administration of nonionic contrast material. AJR 2007; 188:970–974 13. Bailey CJ, Turner RC. Metformin. N Engl J Med 1996; 334:574–579 14. Frank JH, Cooper GW, Black WC, Phillips LH 2nd. Iodinated contrast agents in myasthenia gravis. Neurology 1987; 37:1400–1402
15. Sanelli PC, Deshmukh M, Ougorets I, Caiati R, Heier LA. Safety and feasibility of using a central venous catheter for rapid contrast injection rates. AJR 2004; 183:1829–1834 16. Rigsby CK, Gasber E, Seshadri R, Sullivan C, Wyers M, Ben-Ami T. Safety and efficacy of pressure-limited power injection of iodinated contrast medium through central lines in children. AJR 2007; 188:726–732 17. Donnelly LF, Dickerson J, Racadio JM. Is hand injection of central venous catheters for contrastenhanced CT safe in children? AJR 2007; 189:1530–1532 18. Kaste SC, Young CW. Safe use of power injectors with central and peripheral venous access devices for pediatric CT. Pediatr Radiol 1996; 26:499–501 19. Plumb AA, Murphy G. The use of central venous catheters for intravenous contrast injection for CT examinations. Br J Radiol 2011; 84:197–203 20. Smith LH. Implanted ports, computed tomography, power injectors, and catheter rupture. Clin J Oncol Nurs 2008; 12:809–812 21. Amaral JG, Traubici J, BenDavid G, Reintamm G, Daneman A. Safety of power injector use in children as measured by incidence of extravasation. AJR 2006; 187:580–583 22. Bae KT. Intravenous contrast medium administration and scan timing at CT: considerations and approaches. Radiology 2010; 256:32–61 23. Hollingsworth C, Frush DP, Cross M, Lucaya J. Helical CT of the body: a survey of techniques used for pediatric patients. AJR 2003; 180:401–406
F O R YO U R I N F O R M AT I O N
A data supplement for this article can be viewed in the online version of the article at: www.ajronline.org.
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Pediatric Imaging Original Research
Practice Patterns for the Use of Iodinated IV Contrast Media for Pediatric CT Studies: A Survey of the Society for Pediatric Radiology Michael J. Callahan1 Sabah Servaes 2 Edward Y. Lee 3 Alexander J. Towbin 4 Sjirk J. Westra5 Donald P. Frush 6 Callahan MJ, Servaes S, Lee EY, Towbin AJ, Westra SJ, Frush DP
Keywords: children, CT, IV contrast media DOI:10.2214/AJR.13.11106 Received April 12, 2013; accepted after revision August 4, 2013. A. J. Towbin is an author for Amisys and is a shareholder in Merge Healthcare. 1 Department of Radiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115. Address correspondence to M. J. Callahan ([email protected]). 2 Department of Radiology, Children’s Hospital of Philadelphia, Philadelphia, PA. 3
Department of Radiology and Medicine, Pulmonary Division, Boston Children’s Hospital, Boston, MA. 4
Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. 5
Department Radiology, Massachusetts General Hospital, Boston, MA.
6 Division of Pediatric Radiology, Duke University Medical Center, McGovern-Davison Children’s Health Center, Durham, NC.
Supplemental Data Available online at www.ajronline.org. AJR 2014; 202:872–879 0361–803X/14/2024–872 © American Roentgen Ray Society
872
OBJECTIVE. There are limited data available on the use of IV contrast media for CT studies in the pediatric population. The purpose of this study is to determine the practice patterns of IV contrast media usage for pediatric CT by members of the Society for Pediatric Radiology (SPR). MATERIALS AND METHODS. SPR members were surveyed regarding the use of IV contrast media for pediatric CT studies. Questions pertained to information required before administering IV contrast media, types of central catheters for injecting IV contrast media, injection rates based on angiocatheter size and study type, and management of IV contrast media extravasation. RESULTS. The response rate of 6% (88/1545) represented practice patterns of 26% (401/1545) of the SPR membership. Most respondents thought the following clinical information was mandatory before IV contrast media administration: allergy to IV contrast media (97%), renal insufficiency (97%), current metformin use (72%), significant allergies (61%), diabetes (54%), and asthma (52%). Most administered IV contrast media through nonimplanted central venous catheters (78%), implanted venous ports (78%), and peripherally inserted central catheters (72%). The most common maximum IV contrast media injection rates were 5.0 mL/s or greater for a 16-gauge angiocatheter, 4.0 mL/s for an 18-gauge angiocatheter, 3.0 mL/s for a 20-gauge angiocatheter, and 2.0 mL/s for a 22-gauge angiocatheter. For soft-tissue extravasation of IV contrast media, 95% elevate the affected extremity, 76% use ice, and 45% use heat. CONCLUSION. The results of this survey illustrate the collective opinion of a subset of SPR members relating to the use of IV contrast media in pediatric CT, providing guidelines for clinical histories needed before IV contrast media, maximum IV contrast injection rates for standard angiocatheters, contrast media injection rates for specific CT studies, and management of IV contrast media soft-tissue extravasation.
I
odinated IV contrast media is commonly used for pediatric CT studies, but there are relatively few published guidelines on the appropriate administration of iodinated IV contrast media for CT in the pediatric population [1, 2]. The American College of Radiology (ACR) publishes and updates a webbased document, ACR Manual on Contrast Media, which is currently in the ninth edition [1]. This manual was developed by the ACR as a guide for radiologists to promote the safe and effective use of IV contrast media. The manual has a section dedicated to the use of IV contrast media in children, which primarily focuses only on the incidence and treatment of allergic-like reactions and contrastinduced nephropathy.
An anonymous web-based survey was created to determine the broader practice patterns of Society for Pediatric Radiology (SPR) members regarding their use of iodinated IV contrast media for pediatric CT. The survey was performed to identify areas of consensus opinion in the administration of iodinated IV contrast media for pediatric patients. This information can serve as a point of reference for practice development or modification on the use of iodinated IV contrast media in children. Materials and Methods Study approval was granted by the institutional review board of Boston Children’s Hospital. Because the survey was anonymous, institutional review board approval was not required at the other participating institutions.
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Survey of Use of Iodinated IV Contrast Media in Pediatric CT A 15-question survey (Appendix S1, which can be seen in the AJR electronic supplement to this article, available at www.ajronline.org) was created by members of the CT committee of the SPR utilizing an online surveying website (SurveyMonkey.com). The survey questions encompassed a number of topics related to the use of iodinated IV contrast media for pediatric CT, including prescreening questions for administering IV contrast media, the use of central venous catheters, implanted venous ports, and peripherally inserted central catheters (PICCs) for CT studies; preferred routine injection rates of IV contrast media for contrast-enhanced pediatric CT studies (head, chest, abdomen/pelvis, extremities, peripheral CT angiography [CTA], and neurology CTA studies) based on angiocatheter size and study type; and the management of IV contrast media extravasation in children. In addition, questions regarding practice demographics were also included. The majority of survey responses were a multiple-choice or yes-or-no format. In general, respondents were asked to select the single best answer for a given question. For question 3, which related to prescreening questions for IV contrast media, the respondents were asked to respond with one of three choices: “mandatory,” “clinically useful but not mandatory,” or “not necessary.” The survey was distributed electronically via an e-mail. All recipients were informed of the purpose of the study before participation. Those electing to participate in the survey could do so by following a link embedded in the e-mail. All results were anonymous. No incentive was provided to participants, and there was no penalty for not participating. The survey was open for participation between November 2010 and January 2011. Individuals were asked to respond on behalf of their colleagues if applicable, and if they were responding on behalf of multiple colleagues, they were asked to list the number of SPR members in their practice whom the response data represented. All data from the survey were collected via the online survey website, and the data were provided for tabulation of the results. Data were then exported, and descriptive statistics were evaluated in Microsoft Excel. Percentages reported in this article were rounded to the nearest whole number. As a result, not all percentages for a given question may add up to exactly 100%. Not all questions were answered by the survey participants, and, as a result, the denominator will not always be constant for a given question or portion of a question. On the basis of the collective experiences of the authors, an additional review of the data was performed, and additional comments and interpretation of the data are also provided.
Results The survey was sent anonymously to 1545 SPR members. The actual number of recipients was unknown. There were a total of 88 responders (6%). However, 41 of 88 (47%) responded on behalf of a group of colleagues at their institution, which represented the practices of 401 individuals, equaling 26% (401/1545) of the SPR membership. All of those who responded interpret CT studies in children. Of the 88 respondents, 40% (n = 35) practice in a freestanding children’s hospital, 39% (n = 34) practice in a pediatric radiology division of a larger academic medical center, 15% (n = 13) practice at a primarily adult academic hospital without a pediatric division, and 10% (n = 9) practice in a primarily adult private practice hospital. Two respondents practice exclusively in a nonhospital outpatient community-based practice.
Clinical Questions Before Contrast Media Administration Those surveyed were asked to describe the relative importance of certain clinical questions before the administration of iodinated IV contrast media in children. Most responders thought that one or more of the following questions contained mandatory information needed before the administration of IV contrast media: history of allergy to iodinated IV contrast media, 97% (85/88); renal insufficiency or renal disease, 97% (85/88); current use of drugs containing metformin, 72% (62/86); significant allergies (excluding seafood), 61% (54/88); history of diabetes, 54% (46/85); and history of asthma or asthma inhaler use, 52% (46/88). Many responders thought the following questions contained clinically useful, but not mandatory, information: history of liver disease,
TABLE 1: Responses to Survey Question, “Which of the Following Do You Think Are Mandatory Questions Regarding Patient Histories That Must Be Answered Before the Administration of Iodinated IV Contrast Media in Pediatric Patients?” Answer Options
Question Allergy to IV contrast media?
Clinically Useful but Not Not Mandatory Mandatory Necessary
Response Count
85
2
1
88
Significant allergies to other allergens?
54
30
5
88
Asthma or asthma inhaler use?
46
37
5
88
Shellfish allergy?
20
29
36
85
Renal insufficiency or renal disease?
85
3
0
88
Liver disease?
21
47
16
84
Sickle cell disease?
37
35
14
86
Sickle cell crisis?
41
31
14
86
Pheochromocytoma?
30
40
15
85
Myasthenia gravis?
17
46
22
85
Aspiration pneumonia?
5
35
44
84
Diabetes?
46
22
17
85
Hypertension?
16
37
32
85
Thyroid cancer?
15
36
34
85
Hyperthyroidism?
13
37
33
83
Paraproteinemia (e.g., multiple myeloma)?
22
28
35
83
Cardiac dysfunction (acute congestive heart failure, dysrhythmia, unstable angina pectoris, severe aortic stenosis, cardiomyopathy, or pulmonary hypertension)?
33
35
17
85
Metformin use?
62
16
8
86
Aminoglycoside use?
16
40
26
82
Amphotericin B use?
9
42
30
81
Note—Data are no. of responses.
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Callahan et al. 56% (47/84); and history of myasthenia gravis, 54% (46/85). Forty-two percent (36/85) of responders thought a history of shellfish allergy was not clinically relevant in the setting of IV contrast agent administration. Notably, 24% of responders thought a history of shellfish allergy was mandatory before administration of IV contrast media; 34% thought this information was clinically useful, but not mandatory. A relative minority of responders thought that one or more of the following clinical histories was mandatory before administration of iodinated IV contrast media in children: paraproteinemia, 27% (22/83); liver disease, 25% (21/84); myasthenia gravis, 20% (17/85); aminoglycoside use, 20% (16/82); hypertension, 19% (16/85); thyroid cancer, 18% (15/85); hyperthyroidism, 16% (13/83); amphotericin B use, 11% (9/81); and aspiration pneumonia, 6% (5/84). The complete responses to the question regarding what clinical information is needed before administering IV contrast are included in Table 1. Catheter Use The majority of responders (69/88; 78%) administer IV contrast media through nonimplanted central venous catheters (i.e., Broviac and Hickman catheters, Bard Medical) for diagnostic CT studies. Of those who use nonimplanted central venous catheters, 54% (38/71) perform hand injections, 13% (9/71) exclusively use the power injector, and 35% (25/71) perform both hand injections and power injection of IV contrast media. Seventy-eight percent (66/85) of responders use implanted venous ports for IV contrast media injection, and 72% (63/87) of responders are willing to use a PICC. Of those responders who are willing to use PICCs, 74% (57/77) use PICCs specifically designed for CT power injectors, whereas 26% (20/77) report the use of non–power injectable PICCs for diagnostic CT examinations. Seventy-six percent of responders (66/87) routinely use a saline bolus to follow the IV contrast media bolus. Responders were then asked to report the smallest peripheral IV catheter they routinely used with a power injector. Forty-nine percent (40/81) of responders reported a 22 gauge as their smallest-gauge angiocatheter for routine IV contrast media administration via power injector. Thirty-three percent (27/81) answered 24 gauge, 15% (12/81) answered 20 gauge, and 4% (3/81) reported the smallest-gauge angiocatheter they use for power injection is 18 gauge.
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Contrast Media Injection Rates The most common maximum IV contrast injection rates were 5.0 mL/s or greater for a 16-gauge angiocatheter, 4.0 mL/s for 18 gauge, 3.0 mL/s for 20 gauge, and 2.0 mL/s for a 22-gauge angiocatheter (Table 2). Fifty percent (32/64) of responders hand-inject a 24-gauge angiocatheter, but 38% (24/64) use 1.0 mL/s through a power injector as the maximum injection rate for this size of catheter. Most responders routinely administer IV contrast media at a rate of 2.0 mL/s for contrast-enhanced studies of the neck (52%; 35/68), chest (52%; 35/68), and abdomen/ pelvis (49%; 33/68). Eighty-five percent (58/68) of responders use an injection rate of 1.0–2.0 mL/s for neck CT studies, 82% (56/68) of responders use an injection rate of 1.0–2.0 mL/s for chest CT studies, and 79% (54/68) use an injection rate of 1.0– 2.0 mL/s for abdominal/pelvic CT studies (Table 3).
In contrast to body imaging, which often requires a more-rapid bolus, 69% (47/68) of contrast-enhanced head CT studies are performed at an injection rate of 1.0–2.0 mL/s. Twenty-nine percent of responders (20/68) reported a routine injection rate of 2.0 mL/s for contrast-enhanced head CT examinations in children (Table 3), but 22% (15/68) routinely use 1.5 mL/s, and 18% (12/68) perform these studies at 1.0 mL/s. A relatively large percentage of responders (27%; 18/68) hand inject IV contrast media for head CT studies, and in these cases, the exact IV contrast media injection rate is unknown. The majority of responders use 3.0 mL/s for peripheral CTA studies (37%; 25/68), and greater than 3 mL/s for pulmonary CTA studies (44%; 30/68) and head/neck CTA studies (41%; 28/68). However, it should be noted that 70% (48/68) use rates of 2.0–3.0 mL/s, and 35% (24/68) use rates greater than 3.0 mL/s for peripheral CTA studies. For
TABLE 2: Responses to Survey Question, “Please List Your Department’s Maximum Power Injection Rate for Each Size of Peripheral Angiocatheter (IV) in the List Below” Answer Options Not Applicable Angiocatheter (Manual Gauge Injection)
1.0 mL/s
2.0 mL/s
3.0 mL/s
4.0 mL/s
≥ 5.0 mL/s
Response Count
16
3
0
5
10
16
35
68
18
1
1
9
16
25
22
73
20
3
2
21
28
13
7
72
22
4
13
37
14
4
0
70
24
32
24
9
2
0
0
64
Note—Data are no. of responses.
TABLE 3: Responses to Survey Question, “Please List Your Typical IV Contrast Injection Rates for Each of the Following Routine Diagnostic CT Studies if IV Contrast Is Used (If Your Injection Rate Is Different From the Rates Listed Below, Please Give Your Best Estimate)” Answer Options
Type of Study
Not Applicable (Manual Response Injection) 1.0 mL/s 1.5 mL/s 2.0 mL/s 2.5 mL/s 3.0 mL/s > 3.0 mL/s Count
Head CT
18
12
15
20
3
7
1
68
Neck CT
6
10
13
35
5
7
2
68
Chest CT
3
9
12
35
7
8
2
68
Abdomen/pelvis CT
3
9
12
33
8
9
2
68
Peripheral CTA
4
2
3
7
16
25
24
68
Pulmonary CTA
4
2
2
8
12
22
30
68
Head/neck CTA
4
3
3
7
15
19
28
68
Note—Data are no. of responses. CTA = CT angiography.
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pulmonary CTA studies, 62% (42/68) of responders use injection rates of 2.0–3.0 mL/s, and for head/neck CT studies, 60% (41/68) of those surveyed most commonly use injection rates of 2.0–3.0 mL/s. Soft-Tissue Extravasation The majority of responders (81%; 70/87) report that soft-tissue extravasation of iodinated IV contrast media occurs in less than 1% of contrast-enhanced CT examinations. Management of soft-tissue extravasation of IV contrast media is somewhat variable among the SPR membership (Fig. 1); 95% of responders (81/85) elevate the affected extremity after soft-tissue extravasation. All responders (100%; 88/88) monitor these patients with close clinical observation. Different levels of clinical observation were not defined for this survey. Seventy-six percent report using an ice pack (62/82), and 45% report using heat (28/62). Fifty-three percent reported requesting a plastic surgery consultation (42/79). The survey did not specify which type of extravasation would necessitate a plastic surgery consultation. Discussion In this study, we describe the current practice patterns of the SPR membership for the routine use of iodinated IV contrast media for pediatric CT. The purpose of this survey was to provide both pediatric and adult radiologists with a general knowledge of the current SPR membership’s use of iodinated IV contrast media in pediatric patients. This information can serve as a guide for the safe and effective use of IV contrast media for pediatric CT studies in a wide variety of radiology practices. Clinical Questions Before Contrast Media Administration Fortunately, the incidence of allergiclike reactions associated with the administration of iodinated IV contrast media in the pediatric population is very low, with a recently reported incidence between 0.18% and 0.46% [2, 3]. Despite a low overall incidence, a direct relationship between patient age and incidence of contrast agent reactions has been described [3]. In pediatric patients, the incidence of contrast media reactions peaks at 16–18 years of age. Adverse events related to IV contrast media administration are exceedingly uncommon in children younger than 3 years [3]. The ACR lists certain risk factors that increase an individual’s risk of an adverse
No. of Survey Respondents
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Survey of Use of Iodinated IV Contrast Media in Pediatric CT 100 90 80 70 60 50 40 30 20 10 0
No Yes
Elevation of Affected Extremity
Ice Pack
Heat
Close Clinical Observation
Plastic Surgery Consultation
Fig. 1—Responses to survey question, “How do you manage soft-tissue extravasation of IV contrast in pediatric patients? (Please check all that apply).”
event [1]. A history of an allergic reaction to IV contrast media is associated with up to a fivefold increased likelihood of a subsequent reaction. Additional risk factors include history of atopy, especially in patients with a history of anaphylactic responses to one or more allergens [4]. Prior studies have shown that there are no specific allergens, besides iodine and iodinated IV contrast media, that predict a future allergic reaction to the current nonionic iodinated contrast materials [4, 5]. These data generally reflect the practice of the responders to our survey, even though nearly 23% of our survey responders still thought allergy to shellfish was mandatory information before IV contrast media administration. Although a history of asthma may indicate an increased likelihood of a contrast media reaction, the risk is minimal [6], and, in general, a history of allergies or asthma in itself does not require premedication. In a study of greater than 12,000 pediatric patients at a large pediatric tertiary medical center, only 5% (3/57) of patients with documented allergic-like reactions to IV contrast media had a history of asthma in their medical record. However, the total number of patients with a history of asthma in that study population was unknown. Other studies indicate an increased likelihood of contrast agent reaction in asthmatic patients [7, 8]. Trout et al. [9] surveyed the Society of Chairs of Radiology in Children’s Hospitals and found that 2% of respondents premedicated children with a history of mild asthma, 26% premedicated patients with moderate-to-severe asthma, and 41% would premedicate patients with a recent asthma attack. In that same study, 60% of respondents stated that they would either premedicate or avoid IV contrast media administration in patients with a history of life-threatening reaction to other allergens [9].
As expected, the vast majority of respondents (97%; 85/88) thought knowledge of renal insufficiency or renal disease was mandatory before the administration of IV contrast media. Contrast-induced nephropathy is defined as a sudden deterioration in renal function after the recent administration of IV contrast media and is rare in children [2]. Laboratory tests, such as serum creatinine level and glomerular filtration rate, have been used as screening tools for the injection of IV contrast media, but there is no universally accepted threshold of serum creatinine elevation beyond which iodinated IV contrast media should not be given. Fortunately, the risk of clinically relevant renal dysfunction is very low in most situations. However, patients with acute kidney injury, severe chronic renal disease, or patients who receive multiple doses of iodinated IV contrast media over a short period of time are at a higher risk of contrast-induced nephropathy related to the administration of iodinated IV contrast media [2]. Adequate hydration is a major preventive action against contrast-induced nephropathy, because renal blood flow and glomerular filtration rate are diminished in the setting of dehydration. The administration of IV contrast media in patients with sickle cell disease and acute or subacute sickle cell crisis currently remains somewhat controversial. Some authors report no increased risk of adverse events when compared with the general population [10, 11]; however, the results of this survey indicate some variability in opinion throughout the SPR. Forty-eight percent (41/86) of responders think that a current history of sickle cell crisis denotes mandatory clinical information, and 43% (37/86) think that a history of sickle cell disease without history of acute crisis represents mandatory clinical information before administration of IV con-
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Callahan et al. trast media. Only 16% (14/86) of responders think that knowledge of sickle cell disease or sickle cell crisis was not necessary for IV contrast media administration. Almost half of respondents (40/85; 47%) think that knowledge of a history of pheochromocytoma was clinically useful information, and 35% (30/85) thought this information was mandatory. Bessell-Browne and O’Malley [12] reported that nonionic IV contrast material could be safely administered to patients with suspected or known pheochromocytoma or related tumors, and α-blockade is not specifically required for contrast agent administration in this patient population. However, it should be noted that our survey did not specifically address whether the respondents would inject IV contrast media to a patient with known pheochromocytoma, only whether the information is useful before injecting contrast media. Metformin-containing medications are used for diabetes mellitus and polycystic ovary disease. Patients who take metformincontaining medications have an increased risk of developing lactic acidosis if their blood levels of metformin are high. Because nephrotoxicity is associated with the use of iodinated IV contrast agents, it was initially thought that the concomitant use of metformin could lead to an increased risk of lactic acidosis. This has since been disproved empirically. In an effort to be cautious, the package insert for metformin-containing medications states that the drug should be stopped at the time iodinated IV contrast media is administered, and the use of metformin should be held for 48 hours before resuming normal use. In general, metformin is contraindicated in patients with compromised renal function. If a contrast-enhanced CT study is requested in a patient with elevated serum creatinine levels and coexisting metformin use, at the very least the study should be deferred until the referring physician is notified [6, 13]. As expected, the majority (62/86; 72%) of respondents considered a history of current metformin use a mandatory question before iodinated IV contrast media administration. Respondents’ opinions were somewhat mixed on a history of cardiac dysfunction in children. Thirty-nine percent (33/85) thought knowledge of this history was mandatory, 41% (35/85) thought it was clinically useful but not mandatory, and 20% (17/85) thought a history of cardiac dysfunction or disease was unnecessary for IV contrast media administration. ACR guidelines suggest
876
that patients with significant cardiac disease (e.g., congestive heart failure, aortic stenosis, pulmonary hypertension, and severe cardiomyopathy) have an increased risk for adverse reactions related to IV contrast media [1]. A history of cardiac disease in itself is not a contraindication for IV contrast media; however, if a pediatric cardiac patient is fluid restricted, care should be taken to minimize IV contrast media and saline bolus volumes. There are scant data on the risks of iodinated IV contrast media administration in patients with myasthenia gravis, but administration has been reported to cause increased weakness in this patient population. Frank et al. [14] reviewed the records of 136 patients with myasthenia gravis who received iodinated IV contrast media and found that five (3.7%) patients had subjective or objective increases in weakness. The authors of that study concluded that IV contrast media is not contraindicated in myasthenia gravis, but extra care should be taken when administered [14]. A majority of responders to our survey (54%; 46/85) thought a history of myasthenia gravis was clinically useful, but not mandatory for IV contrast media administration. Certain patients with hyperthyroidism or thyroid disease can develop iodine-provoked hyperthyroidism 4–6 weeks after IV contrast media administration. This is typically self-limited. Patients with a history of thyroid carcinoma require special consideration when iodinated IV contrast media is being administered. Uptake of 131I in the thyroid gland decreases about 1 week after administration of iodinated IV contrast media but normalizes after a few weeks. A majority of responders to our survey thought a history of hyperthyroidism (45%; 37/83) or thyroid carcinoma (42%; 36/85) was clinically useful but not mandatory for iodinated IV contrast media administration. Catheter Use The majority of respondents, at least 72% depending on type, are willing to administer contrast media through central venous catheters. Of those responders who are willing to use nonimplanted central catheters, a majority prefer to use hand injection (54%; 38/71) or a combination of hand injection and power injection (35%; 25/71). Only 13% (9/71) exclusively use a power injector for nonimplanted central catheters. Although studies exist documenting the safety of injecting contrast agents through certain central catheters, there is a theoretic risk of damaging
central lines during the rapid administration of IV contrast media [15–19], particularly during hand injection [17]. According to ACR guidelines [1], power injection of contrast media through nonimplanted central venous catheters can be performed safely, provided the CT scout scan or a recent chest radiograph confirms a central and intravascular location of the catheter tip, and the catheter tip position is tested for venous backflow. If saline can be injected without abnormal resistance, contrast media can be administered through the central catheter safely. Large-bore (9.5 to 10 French) central venous catheters can be injected using flow rates of up to 2.5 mL/s, which have been shown to generate pressures below the manufacturers’ specified limits. For power injection of contrast media through central venous catheters, the radiologist should consult individual manufacturers’ recommendations. As expected, a majority of those who are willing to use implanted ports or PICCs specifically designed for power injectors use a power injector for administration of IV contrast media for CT studies (74%; 57/77). However, there are many pediatric patients with chronic diseases who have an implanted port or PICC that is not specifically designed for use with a power injector. This presents a dilemma for radiologists because many of these patients have relatively poor peripheral IV access. In addition, because of repeated blood draws and needle sticks, it is the authors’ experience that many of these patients with chronic diseases are “needle phobic,” often to a greater extent than the general pediatric population. As a result, it can be challenging for the radiologist to explain to parents, patients, and referring physicians why placement of a peripheral IV catheter may be required for contrast-enhanced CT studies in children with a preexisting implanted port [20] or PICC. There is variability in the size of the smallest-gauge catheter used for power injection. Forty-nine percent (40/81) report a 22-gauge angiocatheter is the smallest catheter used with a power injector, although up to 33% (27/81) of responders use a power injector for 24-gauge angiocatheters, and this practice is supported in the literature [21]. There was variability in the maximum rate of injection used for different-sized angiocatheters. Twenty-two–gauge catheters can reportedly tolerate flow rates up to 5 mL/s, but a 20-gauge or larger catheter is preferred for flow rates greater than 3 mL/s. Amaral et al.
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Survey of Use of Iodinated IV Contrast Media in Pediatric CT [21] reported maximum power injector rates of 5 mL/s for 18- to 20-gauge angiocatheters, 3 mL/s for a 22-gauge catheter, and 1.5 mL for a 24-gauge angiocatheter. Our results were similar to those reported by Amaral et al. Maximum power injection rates varied by catheter size, and the majority of maximum injection rates ranged from 2.0 to 5.0 mL/s. However, it should be noted that the preferred maximum contrast media injection rates varied substantially for 18-, 20-, and 24-gauge angiocatheters, but were relatively more uniform for 16- and 22-gauge angiocathers (Table 2). It is not clear to the authors why there is relative uniformity in the preferred injection rates for certain catheter sizes and relative heterogeneity for other catheter sizes. Contrast Media Injection Rates Roughly half of responders routinely administer IV contrast agents at 2.0 mL/s for contrast-enhanced studies of the neck, chest, and abdomen/pelvis (Table 3). Although most responders use 2.0 mL/s for routine contrast-enhanced head CT studies, this examination had the most variability of IV contrast media injection rates (Table 3). Contrast media injection rates for CT angiography studies are generally higher than those used for conventional contrast-enhanced CT (Table 3). The details of IV contrast media administration for various imaging studies have been described, and a wide variety of contrast injection rates have been suggested elsewhere [22] and are dependent on the clinical indication. Soft-Tissue Contrast Media Extravasation Extravasation of contrast media into soft tissues is uncommon and is reported to occur in 0.1–0.9% of injections, which was consistent with the reported frequency in our survey. Extravasated iodinated contrast material can be harmful to the surrounding tissues, and some of these patients require close clinical follow-up. Despite the relative risks, most patients who experience soft-tissue extravasation of IV contrast media recover without long-term complications. Treatment depends on the agent administered, the volume extravasated, and the presence or absence of mechanical compression [21]. The most commonly reported severe injury is compartment syndrome. Less-common side effects include tissue ulceration, necrosis, and neurovascular injury. The ACR guidelines state that there is no consensus regarding treatment of contrast
medium extravasation [1]. Ninety-five percent (81/85) of our responders elevate the affected extremity after soft-tissue extravasation (Fig. 1), which decreases capillary hydrostatic pressure and promotes resorption. There is no clear evidence to favor the use of ice or heat compresses. Not unexpectedly, the decision to use ice or heat on the affected extremity resulted in a mixed response in our survey: 76% (62/82) report using an ice pack, and 45% (28/62) report using heat. Given the results, several responders chose both ice and heat in their responses. Those who use cold compresses report that patients have pain relief at the site of extravasation, whereas those who use warm compresses think that it facilitates absorption and improves distal blood flow. Fifty-three percent (42/79) of survey respondents reported requesting a plastic surgery consultation after soft-tissue extravasation of iodinated IV contrast media. The severity of extravasation was not specified in our survey, but surgical consultation is generally recommended in the setting of blistering, altered tissue perfusion, or clinical signs of compartment syndrome. Recommendations We have presented a few practical guidelines for the use of iodinated IV contrast media for CT in children. Many of our suggestions are supported by the literature presented, some are supported by the results of the survey, but most are based on the collective experiences of the authors, all of whom are current members or have been members of the SPR CT committee in the past and have expertise in pediatric CT. At a minimum, we suggest that the following clinical information should be obtained before the administration of iodinated IV contrast media in children: history of allergy to iodinated IV contrast media, history of severe allergies or atopy to other allergens, history of renal insufficiency, and current use of metformin-containing medication. Other clinical information could be obtained at the discretion of the individual practice or institution. A history of, or a potential for, sick-
le cell disease or sickle cell crisis, pheochromocytoma, myasthenia gravis, diabetes mellitus, or medical history of asthma might be clinically useful in certain patients, but a history of one of these disease processes should not affect a radiologist’s decision to administer iodinated IV contrast media for a clinically indicated CT study. The authors’ suggested maximum IV contrast media injection rates for pediatric patients are as follows: 5.0 mL/s for 16- to 18-gauge angiocatheters, 4.0 mL/s for 20-gauge, 2.5 mL/s for 22-gauge, and 1.0 mL/s for 24-gauge angiocatheters (Table 4). It should be noted that the recommendations of the respondents were slightly more conservative than the recommendations of the authors, but the maximum IV contrast media injection rates from our survey (Table 2) would suffice for most clinical applications, particularly routine nonCTA contrast-enhanced CT studies. When peripheral IV access is not possible, central venous catheters are often used for injection of IV contrast media in CT studies. Risk of adverse events has been reported between 0.3% and 1% [17–19]. We endorse the use of implanted ports and PICCs specifically designed for use with power injectors, provided the manufacturers’ rate limits are followed. We also support power injection of nonimplanted central venous catheters, provided certain pressure limits are observed [18]. Particular caution must be exercised when hand injecting central venous catheters [17], because substantial pressure can be generated with a syringe, resulting in a higher risk of subsequent catheter damage. Although there are a range of acceptable IV contrast media injection rates for routine (non-CTA) contrast-enhanced CT studies, the authors suggest 1.0–2.0 mL/s for contrastenhanced head CT studies and 1.0–2.0 mL/s for routine contrast-enhanced neck, chest, extremity, or abdomen/pelvis CT studies (Table 5). Two milliliters per second would be preferable for body CT studies, particularly in older children and adolescents. CTA studies at adult-based practices are often performed with angiocatheters sized
TABLE 4: Maximum Suggested Injection Rates for Pediatric CT Studies Maximum Injection Rate
Catheter Size
5.0 mL/s
16–18 gauge
4.0 mL/s
20 gauge
2.5 mL/s
22 gauge
1.0 mL/s
24 gauge
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Callahan et al. TABLE 5: Suggested IV Contrast Media Injection Rates for Routine (Non–CT Angiography) Contrast-Enhanced CT Studies in Pediatric Patients
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Injection Rate
Study
1.0–2.0 mL/s
Head CT
1.0–2.0 mL/s
Neck, chest, extremity, or abdomen/pelvis CT
Note—Injection rates of less than 1.0 mL/s may be acceptable for certain indications, and some implanted ports, peripherally inserted central catheters, or small-gauge (24-gauge) angiocatheters may necessitate a rate of 1.0 mL/s or less.
20 gauge and larger. It has been the authors’ experience that many pediatric CT angiography studies can be successfully performed in infants and children using a power injector with a 22-gauge angiocatheter at an injection rate of 2.0–2.5 mL/s or with a 24-gauge angiocatheter at an injection rate of 1.0–1.5 mL/s. As such, it is not practical, or even possible, to insert a 20-gauge angiocatheter (or larger) in many pediatric patients. Contrast media injection rates for CTA studies are influenced by the clinical indication, the size of the patient, the volume of contrast agent, the size and stability of the angiocatheter or central catheter, and CT protocol parameters. In general, most pediatric CT angiography studies can be successfully performed at contrast media injection rates of 2.0–4.0 mL/s (Table 6). A rate of 1.0 mL/s is acceptable for very small patients (< 15 kg) using a 24-gauge angiocatheter, often by hand injection. Timing of IV contrast-enhanced CT studies with respect to scan initiation is a complicated topic and is beyond the scope of this article. If soft-tissue extravasation of IV contrast media occurs, the authors suggest an initial clinical evaluation and examination by a radiologist. It is important to estimate how much IV contrast media was extravasated, if possible. If the amount of extravasated contrast media is thought to be clinically significant, the authors suggest elevating the affected extremity and subsequent application of an ice pack. If there is delayed capillary refill or other signs of abnormal tissue perfusion, significant pain, neurologic symptoms, or other signs of compartment syndrome, a plastic surgery consultation is indicated. Surgical consultation is not required for all IV contrast media extravasations, and radiographs are not needed to quantify the volume of IV contrast media extravasation. Our study has limitations. The answers to most of the survey questions are subjective, and the responses would benefit from further discussion or qualification. For instance, it is not practical to provide a list of all relevant
878
questions that are necessary before the administration of IV contrast media, and not all responses are straightforward. The circumstances surrounding the decision to inject iodinated IV contrast media are multifactorial and can vary from patient to patient. The survey was sent to 1585 e-mail addresses, but the exact number of recipients was unknown. The responses to this survey represent the collective opinion of our 88 individual respondents; however, 41 respondents answered the survey on behalf of 401 SPR colleagues. The authors acknowledge that more than one member of the same institution may have answered the survey, which could introduce institution bias to a small extent. Nevertheless, the practice patterns of certain individuals within a single institution can vary among the individual radiologists, and it is unlikely that two individuals would fill out the survey exactly the same, even if they are at the same institution. Also, a certain percentage of those responding on behalf of others may be biased by those individuals who are most familiar with the standard techniques. Those who chose not to respond may not know what is used, and these data could affect the numbers recorded. We did not specifically ask the survey participants to list the types of iodinated IV contrast media used in their practice, and we did not address premedication for IV contrast media. Most pediatric practices have used low-osmolar iodinated IV contrast media for years [23]. IV contrast media doses, concentration of iodinated IV contrast media used
for pediatric CT studies, and the use of premedication were not specifically addressed by this study but have been reported in the recent literature [9]. The results of our survey and our suggestions may generate discussion and debate on the appropriate use of IV contrast media for CT studies in children. We hope that this article will stimulate further research on this important topic. Potential areas of future work include determining optimal IV contrast media iodine concentrations for specific pediatric CT studies and creating more-specific guidelines for optimal volumes, timing, and injection rates of IV contrast media required for contrast-enhanced pediatric CT studies and CTA studies. Although premedication for IV contrast media was not specifically addressed in this article, further work on pediatric premedication appropriateness criteria is another potential area of future research that could supplement previous work on this topic [9]. Conclusion The purpose of this survey was to determine the current practice patterns for the administration of iodinated IV contrast media for pediatric CT studies among SPR members and to provide suggestions for the use of IV contrast media on the basis of a combination of the survey results and the authors’ suggestions. The results of this survey show the current opinions of pediatric radiologists relating to information required before administering IV contrast media, methods of administering IV contrast media to children, and methods to treat soft-tissue extravasation of IV contrast media in the pediatric population. Because most pediatric patients are imaged at adult-based radiology practices, we hope that this article will serve as a general guideline for those adult radiologists who occasionally image children and will provide some direction for the effective use of iodinated IV contrast media and management of
TABLE 6: Suggested IV Contrast Media Injection Rates for CT Angiography (CTA) Studies in Pediatric Patients Injection Rate
Study
2.0–4.0 mL/s
Conventional chest, abdomen/pelvis, or extremity CTA (arterial phase)
2.5–4.0 mL/s
Pulmonary CTA
2.0–4.0 mL/s
Head/neck CTA
Note—Many CTA studies can be successfully performed in small children with a 22-gauge angiocatheter at a rate of 2.0 mL/s or less. CTA studies in infants can be performed with a hand injection of a 24-gauge angiocatheter at rates as low as 1 mL/s.
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Survey of Use of Iodinated IV Contrast Media in Pediatric CT
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IV contrast media extravasation for CT studies in children. Acknowledgment We thank Richard Cappock (Children’s Hospital Boston) for his assistance. References 1. American College of Radiology. ACR manual on contrast media, version 9. American College of Radiology website. www.acr.org/~/media/ACR/ Documents/PDF/QualitySafety/Resources/Contrast%20Manual/2013_Contrast_Media.pdf. Published 2013. Accessed December 9, 2013 2. Dillman JR, Strouse PJ, Ellis JH, Cohan RH, Jan SC. Incidence and severity of acute allergic-like reactions to IV nonionic iodinated contrast material in children. AJR 2007; 188:1643–1647 3. Callahan MJ, Poznauskis L, Zurakowski D, Taylor GA. Nonionic iodinated intravenous contrast material-related reactions: incidence in large urban children’s hospital—retrospective analysis of data in 12,494 patients. Radiology 2009; 250:674–681 4. Coakley FV, Panicek DM. Iodine allergy: an oyster without a pearl? AJR 1997; 169:951–952 5. Lieberman PL, Seigle RL. Reactions to radiocontrast material: anaphylactoid events in radiology. Clin Rev Allergy Immunol 1999; 17:469–496 6. Bettmann MA. Frequently asked questions: iodinated contrast agents. RadioGraphics 2004; 24(suppl 1):S3–S10
7. Shehadi WH. Adverse reactions to intravascularly administered contrast media: a comprehensive study based on a prospective survey. Am J Roentgenol Radium Ther Nucl Med 1975; 124:145–152 8. Katayama H, Yamaguchi K, Kozuka T, Takashima T, Seez P, Matsuura K. Adverse reactions to ionic and nonionic contrast media: a report from the Japanese Committee on the Safety of Contrast Media. Radiology 1990; 175:621–628 9. Trout AT, Dillman JR, Ellis JH, Cohan RH, Strouse PJ. Patterns of intravenous contrast material use and corticosteroid premedication in children: a survey of Society of Chairs of Radiology in Children’s Hospitals (SCORCH) member institutions. Pediatr Radiol 2011; 41:1272–1283 10. Rao VM, Rao AK, Steiner RM, Burka ER, Grainger RG, Ballas SK. The effect of ionic and nonionic contrast media on the sickling phenomenon. Radiology 1982; 144:291–293 11. Campbell KL, Hud LM, Adams S, et al. Safety of iodinated intravenous contrast medium administration in sickle cell disease. Am J Med 2012; 125:100.e111–100.e116 12. Bessell-Browne R, O’Malley ME. CT of pheochromocytoma and paraganglioma: risk of adverse events with IV administration of nonionic contrast material. AJR 2007; 188:970–974 13. Bailey CJ, Turner RC. Metformin. N Engl J Med 1996; 334:574–579 14. Frank JH, Cooper GW, Black WC, Phillips LH 2nd. Iodinated contrast agents in myasthenia gravis. Neurology 1987; 37:1400–1402
15. Sanelli PC, Deshmukh M, Ougorets I, Caiati R, Heier LA. Safety and feasibility of using a central venous catheter for rapid contrast injection rates. AJR 2004; 183:1829–1834 16. Rigsby CK, Gasber E, Seshadri R, Sullivan C, Wyers M, Ben-Ami T. Safety and efficacy of pressure-limited power injection of iodinated contrast medium through central lines in children. AJR 2007; 188:726–732 17. Donnelly LF, Dickerson J, Racadio JM. Is hand injection of central venous catheters for contrastenhanced CT safe in children? AJR 2007; 189:1530–1532 18. Kaste SC, Young CW. Safe use of power injectors with central and peripheral venous access devices for pediatric CT. Pediatr Radiol 1996; 26:499–501 19. Plumb AA, Murphy G. The use of central venous catheters for intravenous contrast injection for CT examinations. Br J Radiol 2011; 84:197–203 20. Smith LH. Implanted ports, computed tomography, power injectors, and catheter rupture. Clin J Oncol Nurs 2008; 12:809–812 21. Amaral JG, Traubici J, BenDavid G, Reintamm G, Daneman A. Safety of power injector use in children as measured by incidence of extravasation. AJR 2006; 187:580–583 22. Bae KT. Intravenous contrast medium administration and scan timing at CT: considerations and approaches. Radiology 2010; 256:32–61 23. Hollingsworth C, Frush DP, Cross M, Lucaya J. Helical CT of the body: a survey of techniques used for pediatric patients. AJR 2003; 180:401–406
F O R YO U R I N F O R M AT I O N
A data supplement for this article can be viewed in the online version of the article at: www.ajronline.org.
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