ORIGINAL CONTRIBUTION ketamine

Ketamine Sedation for Pediatric Procedures: Part 1, A Prospective Series Emergency physicians f r e q u e n t l y perform painful but necessary procedures on frightened children. We conducted a prospective, uncontrolled clinical trial of ketamine sedation (4 mg/kg IM) to facilitate a variety of procedures in 108 children aged 14 months to 13 years. Acceptable conditions were achieved with a single injection in 97% of the patients, and adjunctive restraint or local anesthesia was not required in 86%. Full sedation was produced within five minutes in 83%. Mean duration from injection to dischargeable recovery was 82 minutes (range, 30 to 175 minutes). One 18-month-old child vomited shortly after injection and experienced transient laryngospasm with cyanosis; intubation was not required, and there were no adverse sequelae. Airway patency and independent respirations were fully maintained in all other patients; no hemodynamic instability occurred at any time. There were no other clinically significant complications. Emesis well into the recovery phase was noted in 6% of the patients. Nightmares were not observed. Response from parents and physicians was strongly positive. Ketamine can be effectively used by emergency physicians to facilitate procedural sedation, yet equipment and expertise for advanced airway management are mandatory due to the rare occurrence of laryngospasm. [Green SM, Nakamura R, Johnson NE: Ketamine sedation for pediatric procedures: Part 1, a prospective series. Ann Emerg Med September 1990;19:1024-1032.]

INTRODUCTION Frightened children frequently present to the emergency department requiring painful but necessary procedures. Local anesthesia and a cahn, reassuring bedside manner often attenuate their fears, but unfortunately, there is an appreciable subset of children in whom these techniques alone do not suffice. Children with complex facial lacerations are typical examples; the continuous thrashing of a terrified child frequently precludes the degree of immobilization needed for optimal repair. Sedation in some form is highly desirable in this subset of patients. The "ideal" drug to facilitate ED performance of short painful procedures should provide ease of administration, rapid onset, effective analgesia, adequate immobilization, minimal cardiac and respiratory effects, stable airway maintenance, a broad margin of safety, and a rapid smooth recovery. Ketamine satisfies most of these characteristics. Alternative agents used include narcotics, benzodiazepines, chloral hydrate, and nitrous oxide. The IM combination of meperidine, promethazine, and chlorpromazine (referred to variously as DPT, Demerol ® compound, lytic cocktail, or Toronto mixture) has been used frequently in EDs since its original description for pediatric cardiac catheterization in 1958.1 Recommendations for its use are frequently seen with varying doses. 2-~ The safety and efficacy of DPT remain poorly substantiated. The original series of 670 children details two cases of apnea, six cases of "serious" respiratory depression, and three apparent respiratory deaths.~ A recent retrospective series of 486 cases noted two patients who required assisted ventilation and naloxone. 9 A third DPT series of 95 patients noted three episodes of respiratory depression and one respiratory arrest; two thirds of these patients were asleep for seven or more hours after injectionJ ° Inadequate sedation occurs frequently; in a fourth series, more than one half of

19:9 September 1990

Annals of Emergency Medicine

Steven M Green, MD* Riverside, and Oakland, California Robert Nakamura, MD, FACEP1N Eric Johnson, MD, MPH, FACEP Loma Linda, California From the Department of Emergency Medicine, Riverside General Hospital, Riverside, California;* California Emergency Physicians Medical Group, Oakland, California;* and the Department of Emergency Medicine, Loma Linda University Medical Center, Loma Linda, California.t Received for publication May 1, 1989. Revision received September 7, 1989. Accepted for publication November 14, 1989. Presented at the Society for Academic Emergency Medicine Annual Meeting in San Diego, May 1989. Address for reprints: Steven M Green, MD, Department of Emergency Medicine, Riverside General Hospital, 9851 Magnolia Avenue, Riverside, California 92503.

1024/119

KETAMINE Green, Nakamura & Johnson

FIGURE 1. S t u d y inclusion and exclusion criteria.

Inclusion Criteria

Age 3 months to 15 years and weight 5 kg or more FIGURE 2. K e t a m i n e sedation protocol. the children resisted or cried during the procedure, l~ DPT possesses more sedating properties than analgesic usefulness and demonstrates wide variability in onset and recovery time.~,¢,lo, l~, 13 Other authors have also criticized this drug combination.7,~4As Oral chloral hydrate is frequently used for pediatric sedation in doses ranging from 25 to 75 mg/kg; however, its analgesic efficacy is minimal, and a prolonged recovery time is common. 2 This agent appears better suited for c o m p u t e d t o m o g r a p h y (CT) scan sedation than for painful procedures such as laceration repair.6,8,16-1s Pentobarbital 4 to 6 mg/ kg IM or 2.5 mg IV also has been reported as effective sedation for CT scanning. ~8,~9 Adequate conditions for pediatric procedures have been achieved using the short-acting narcotic fentanyl in slow IV doses of 2 to 3 ixg/kg.20,2~ Only three cases of respiratory depression requiring naloxone occurred in a series of 2,000 patients. 2o Fentanyl lollipops have been used successfully for anesthesia premedication and might be useful in the ED. 22 Nitrous oxide also has been used for painful pediatric ED procedures; success was most apparent in children more than 8 years old. This technique appears to be limited in younger children by the necessity of having a second physician present to titrate the inhalation. 23 Ketamine has been used extensively for pediatric procedures inside and outside of the operating suite; this experience is reviewed in detail in a concurrent report. ~4 Four limited descriptions of ketamine use in the ED cite successful results with no significant complications. 2s-2s Ketamine produces pronounced sedation and analgesia w i t h o u t the cardiorespiratory depression typically seen w i t h b e n z o d i a z e p i n e s and narcotics.Z9-31 We conducted a study to determine whether the combination of low-dose IM racemic ketamine (4 mg/kg) and atropine (0.01 mg/kg) is a safe, effective, and economical method of analgesia and sedation for pediatric pro120/1025

Necessary procedure either requiring complete immobilization or judged likely to produce excessive emotional disturbance Exclusion Criteria

Pulmonary infection or disease (acute or chronic), including asthma Full meal within three hours of presentation Cardiovascular disease, including hypertension Head injury associated with loss of consciousness, altered mental status, or emesis CNS mass lesions, hydrocephalus, or other conditions associated with intracranial hypertension Glaucoma or acute globe injury Prior adverse reaction to ketamine Psychosis Thyroid disorder or medication Porphyria

Ketamine hydrochloride 4 mg/kg and atropine 0.01 mg/kg (maximum, 0.3 mg) drawn up in the same syringe and administered IM Repeat ketamine dose (2 to 4 mg/kg IM without additional atropine) if sedation inadequate after 10 minutes Adjunctive local anesthetic if needed for incomplete analgesia Adjunctive physical restraint if needed to control random motion Physician proficient in pediatric intubation readily available Equipment available in room: Cardiac monitor Suction, oxygen, and airway equipment Pediatric resuscitation cart with drugs, including succinylcholine Parents allowed at bedside if desired Continuous clinical one-on-one monitoring by bedside physician or nurse until recovery well established Discharge criteria: Return to pretreatment level of verbalization or awareness Parental recognition Purposeful neuromuscular activity Discharge instructions: Nothing by mouth for two hours Careful parental observation and no independent ambulation for two hours Data form completed by treating physician at patient discharge Follow-up telephone call to parents by author 2

cedures in the ED setting. The IM route was believed to be the most desirable because of its simplicity, economy, and minimal upset to the child. Prior studies have demonstrated rapid onset and a s m o o t h course with IM ketamine. 29,32,33 A dose of 4 mg/kg IM was chosen for prospective analysis based on reports Annals of Emergency Medicine

in the literatureS9, 34 36 and the authors' prior experience. This amount was estimated to represent the lowest dose at which acceptable sedation and analgesia can be produced by the IM route.

MATERIALS AND METHODS Ketamine sedation was considered 19:9 September 1990

TABLE 1. Distribution of procedures facilitated with ketamil~e among

I08 patients Procedures Head and Facial Lacerations Scalp Forehead Eyelid Nose Cheek Ear Lip Tongue Palate Chin Multiple sites

Trunk Lacerations Buttocks Scrotum

Extremity Lacerations Arm Hand Leg Foot

Orthopedic Procedures Fracture reduction Hip relocation Knee aspiration

Diagnostic Evaluations CT scanning Eye examination Pelvic examination

Miscellaneous Procedures Abscess incision and drainage Cactus spine removal Foreign body removal Lumbar puncture Nasal packing Suture removal Tooth removal Wound exploration

in any patient between the ages of 3 months and 15 years who required a painful and/or disturbing procedure in the ED. Use of ketamine generally was reserved for cases in which imm o b i l i z a t i o n was critical for procedural success, the child's emotional disturbance was excessive, or severe pain was anticipated. Other cases were managed with local anest h e s i a and a r e s t r a i n t b o a r d as needed. Physicians participating in the study used ketamine in consecutive appropriate cases; however, other physicians used DPT or other 19:9 September 1990

No. of Patients (%) 57 (52.8) 6 11 3 5 5 1 9 6 1 6 4

2 (1.9) 1 1

24 (22.2) 2 15 4 3

10 (9.3) 7 1 2 4 (3.7) 1 2 1

11 (10.2) 2 1 1 3 1 1 1 1

sedatives at their discretion during the study period. Inclusion and exclusion criteria used are shown (Figure 1); the protocol is described (Figure 2). Eligible patients were moved to an area with precautionary suction, cardiac monitor, and equipment for advanced airway management. A physician skilled in pediatric intubation was present at all times. Ketamine 4 mg/kg was combined with atropine 0.01 mg/kg (up to 0.3 mg) in a single IM i n j e c t i o n to m i n i m i z e hypersalivation. An estimate was made of Annals of Emergency Medicine

the duration from injection until onset of sedation. A repeat ketamine dose of 2 to 4 mg/kg (no additional atropine) was given if sedation was insufficient after ten minutes; the exact repeat dose was left to individual physician discretion. Parents were present during the procedure and recovery if they desired. Each patient was closely observed by a physician, nurse, or both from the time of injection until recovery was well established. Heart and respiratory rates were measured at the time of admission, during the procedure, and at discharge. No further monitoring requirements were stipulated in our protocol, as the literature is replete with uncomplicated ketamine series managed with observation alone. 24 A majority of physicians chose to use continuous cardiac monitoring for their patients; however, no criteria for its use were imposed. A p p r o x i m a t e l y h a l f w a y through the study a pulse oximeter became available to our department and was used for most subsequent cases, again at the treating physician's discretion. IV lines were not placed unless indicated for an unrelated reason. Audiovisual stimuli were minimized during the recovery period; lights were dimmed, and the area was kept as quiet as possible. Criteria for safe discharge included return to presedation level of consciousness with appropriate verbalization for age, ability to recognize parents, and return of purposeful neuromuscular activity. Parents were warned of the possibility of unsteady gait and vomiting for several hours after discharge. A data form was completed immediately after each administration by the treating physician and detailed vital signs, efficacy and duration of sedation, side effects, recovery phase, and parental reactions. Follow-up telephone calls were made by one of the authors to parents approximately three weeks after the procedure to obtain information on parental satisfaction, side effects after discharge, nightmares, or delayed phenomena. The study was approved by the Loma Linda University Medical Center Institution Review Board. The paired t test was used to compare pulse and respiratory rates. RESULTS One hundred twelve pediatric pa1026/121

KETAMINE Green, Nakamura & Johnson

tients were given ketamine during an eight-month period in our university ED (98) and c o m m u n i t y EDs (14). The series was arbitrarily terminated at a predetermined date; 110 patients had been studied at this point. Our department then continued to use k e t a m i n e under conditions of the protocol, however, and two cases later, a child experienced laryngospasm. It was deemed appropriate to extend the data collection to include this complication, making a total of 112 cases. Four cases were removed from the series because these patients were given doses of ketamine below those specified by the study protocol, leaving 108 cases for analysis. There were no significant complications in the excluded cases. Clinical response to ketamine was fairly uniform. Each child typically cried after injection, but within minutes all whimpering subsided and a wide-eyed glassy stare with nystagmus appeared. Withdrawal to pain diminished or disappeared and was replaced by occasional, random, purposeless movements of the arms or legs. The gaze wandered, unfixed. Muscle tone often was somewhat increased. Age distribution of patients ranged from 14 months to 13 years with a mean and standard deviation of 54 and 34 months, respectively. The most frequent indication was repair of facial lacerations, although ketamine proved useful for a wide variety of applications (Table 1). Tongue lacerations, a r e c u r r e n t problem, were readily repaired with ketamine. A 10-year-old boy fell onto a cactus bush and presented with scores of imbedded spines; k e t a m i n e facilitated painless and thorough removal {patient 10). An abdominal laceration p o t e n t i a l l y p e n e t r a t i n g the peritoneum was sustained in a hysterical 5-year-old struck by a large branch; ketamine allowed careful wound exploration confirming the suspicion and leading to subsequent abdominal exploration in the operating suite (patient 75). A meticulous pelvic examination in an 8-year-old sexual assault victim was readily performed with complete procedural amnesia {patient 89). A 4-year-old girl whose deltoid abscess had been incised with major discomfort under local anesthesia returncd the next day with persistent symptoms; ketamine sedation allowed dist22/1027

TABLE 2. Time from ketamine injection until onset of acceptable conditions in 105 patients responding to one dose Onset (min) 0

No. of Patients (%)

2

17 (16.2)

2 - 5

70 (66.7)

5 -- 10

16 (15.2)

> 10

2 (1,9)

TABLE 3. Wtol sign changes during ketamine sedation in 85 patients*

Mean

Pulse SD

pt

Respirations Mean SD pt

Arrival in ED

110

20

--

24

6

--

During procedure

127

18

.001

25

6

NS

Time of discharge

125

17

.001

25

5

NS

*Vital sign records of the 23 other cases were incomplete and were excluded for the purposes of statistical comparison. tSignificance compared with baseline arrival vaMe; NS denotes a lack of significance (ie, P > .05).

TABLE 4. Efficacy of ketamine sedation in I08 patients No. of Patients (%) Fully a d e q u a t e conditions with a single ketamine dose

93 (86.1)

Sedation adequate but local anesthesia a d d e d due to insufficient analgesia

8 (7.4)

Sedation adequate but physical restraint necessary due to random movement

4 (3.7)

Inadequate sedation necessitating a repeat dose*

3 (2.8)

*Arl conditions in all three cases were acceptable after the repeat dose.

covery of a deeper abscess tract and effective drainage {patient 86). Onset of action was quite rapid; p r o c e d u r e s c o u l d be p e r f o r m e d within five m i n u t e s in 87 of the cases {82.9%) responding to a single dose {Table 2). Serial vital sign measurements demonstrated a mild but statistically significant increase in pulse continuing from the procedure until time of discharge; the respiratory rate was not significantly altered {Table 3). Blood pressure measurement was not required in the protocol; on the rare cases where it was performed, there was no appreciable alteration from that at ED arrival. Cardiac monitoring, when used, Annals of Emergency Medicine

was unremarkable in all cases except one healthy 3-year-old boy who was noted to have rare unifocal premature ventricular contractions; this was of no clinical consequence {patient 45). Pulse oximetry, when used, uniformly displayed stable oxygen saturations at the patient's baseline level. The effectiveness of ketamine is summarized {Table 4). Fully adequate sedation, analgesia, and immobilization were produced by a single ketamine dose alone in 93 cases (86.1%). Despite effective sedation, a withdrawal response to pain persisted in eight cases (7.4%), and adjunctive local anesthesia was administered with 19:9 September 1990

FIGURE 3. Recovery time after ket-

aznil~e sedatio¢l m 92 patients. 15 14 13 12 ~9 *d 11 10 9 ~b 8 7 C) z 6

I II Ii,.,.

20 30 40 50 60 70 80 90 100110120130140150160170180 + Minutes Excluded from this figure are patients who received multiple doses for either insufficient effect (three) or prolonged procedures (seven) and patients in whom recovery time was not documented (six). 3

TABLE 5. Side effects noted dtlrit~g ketanline sedcltion izl 108 pdtier~ts

Mild, Not Requiring Requiring Intervention (%) Intervention (%)

Reaction Hypersalivation Muscular hypertonicity Transient clonus Transient stridor or laryngospasm Emesis while sedated IEmesis well into recovery Transient rash Unpleasant agitation

14 52 2 2 0 6 19 1

(13.0) (48.1) (1.9) (1.9) (5.6) (17.6) (0.9)

0 0 0 1 (0.9)* 1 (0.9)* 0 0 0

Nightmares 0 0 *Intervention for patient safety was required just once; suctioning and supplemental oxygen were used in one patient, as described in the text.

TABLE 6. Recovery period descriptiozl

Recovery Period Description Quiet and uneventful Mild agitation Moderate agitation Pronounced agitation

19:9 September 1990

As Judged by Treating Physician (N = 108) (%)

As Recalled by Parent at Telephone Follow-up (N - 77) (%)

86 (79.6) 18 (16.7)

66 (85.7) 10 (13.0) I (1.3)

3 (2.8) 1 (0.9)

0 (0) Annals of Emergency Medicine

effective results. Four other children (3.7%) required physical restraint despite a d e q u a t e sedation and an abs e n t w i t h d r a w a l r e s p o n s e to p a i n ; these patients had greater than average m u s c l e tone and r a n d o m extremity motion. Repeat doses were necessary due to i n a d e q u a t e s e d a t i o n in t h r e e c a s e s (2.8%). O n e of t h e s e c h i l d r e n rec e i v e d an e x t r a 4 m g / k g and t h e o t h e r s r e c e i v e d an e x t r a 2 m g / k g (doses at physician discretion}; in all three, acceptable sedation and i m m o bilization were achieved. Procedures of extended duration necessitated repeat doses of k e t a m i n e in seven cases (6.5%}; g e n e r a l l y , e a c h i n j e c t i o n w o u l d provide a p p r o x i m a t e l y 15 to 20 m i n u t e s of sedation and analgesia. The m e a n t i m e from injection until recovery criteria for discharge in patients receiving a single dose was 82 m i n u t e s (standard deviation, 33 m i n u t e s ) w i t h a range of 30 to 175 m i n u t e s (Figure 3). Ten p a t i e n t s rec e i v e d t w o or m o r e d o s e s w i t h a m e a n r e c o v e r y t i m e of 121 m i n u t e s (standard deviation, 48 minutes). D e s p i t e f r e q u e n t l y observed m u s cular h y p e r t o n i c i t y (48.1%) and occasional r a n d o m m o v e m e n t s , the patients generally r e m a i n e d quite still d u r i n g t h e p r o c e d u r e s ( T a b l e 5). N y s t a g m u s and b l a n k staring were almost uniformly present. A fleeting p a t c h y h y p e r e m i c rash of no apparent c o n s e q u e n c e was recognized in 19 cases (17.6%); no urticaria or other allergic r e a c t i o n s were noted. Occas i o n a l h y p e r s a l i v a t i o n (13.0%} was never a significant problem. A i r w a y p a t e n c y was f u l l y m a i n tained in all cases except one. An 18m o n t h - o l d g i r l in a p p a r e n t g o o d h e a l t h was given k e t a m i n e to facilitate forehead l a c e r a t i o n repair. App r o x i m a t e l y 15 m i n u t e s after the injection, she v o m i t e d a small a m o u n t of clear fluid. Stertorous respirations, repetitive vomiting, and laryngospasm ensued; suctioning was i m m e d i a t e l y p e r f o r m e d , a n d an o x y g e n m a s k placed. Bag-valve-mask ventilation was a t t e m p t e d w h e n c y a n o s i s developed; however, repetitive e m e s i s m a d e this i n e f f e c t i v e . T h e ] a r y n g o s p a s m and c y a n o s i s s p o n t a n e o u s l y cleared w i t h i n five minutes, and i n t u b a t i o n was n o t required. A pulse o x i m e t e r was not used in this

1028/123

KETAMINE Green, Nakamura & Johnson

particular case; however, continuous cardiac monitoring showed no bradycardia or d y s r h y t h m i a . The procedure was completed without incident, and recovery was uneventful. Auscultation and a chest radiograph showed no evidence of aspiration, and at discharge, the child was alert and playful. On re-evaluation 24 hours later, the p a t i e n t appeared c o m p l e t e l y h e a l t h y ; again, a u s c u l t a t i o n and chest radiograph were clear. Two weeks later on telephone follow-up, the mother reported normal behavior with no apparent physical or emotional sequelae; this child had experienced easily provoked emesis in the past and had a history of recently inactive asthma (patient 108). Vomiting well into the recovery phase was observed in six other patients (5.6%}, who at this point were awake but ataxic; none required assistance in clearing the vomitus. One 6-year-old boy experienced five to ten episodes of emesis during his recovery but had no further vomiting after discharge (patient 83). Soft stridorous sounds were transiently heard in two patients (36 and 44); neither required any intervention. One of these children had incidental croup, a relative contraindication to ketamine not appreciated by the treating physician. Motor activity generally increased as recovery progressed, and children often gazed about with a look of apparent "wonder." Occasional verbalizations during this phase were often amusing to parents; children "acted silly" or sang songs, but these episodes were never unpleasant. One &year-old boy described spiders and bugs as he awoke but was completely unafraid (patient 64). Agitation during recovery was generally mild if present at all (Table 6), and amnesia to the procedure was consistently noted. A 2-year-old girl cried for 15 minutes during recovery in a noisy area with bright lights; however, she was cheerful and happy by the time of discharge and had no further problems at telephone follow-up (patient 87). Follow-up telephone contact with parents was achieved successfully in 77 cases (71.3%) an average of three weeks after each procedure. Followup failures were due to lack of a home telephone, an incorrect number, or a disconnected number. Age, 124/1029

TABLE 7. Information and opinions obtained from parents on 77 telephone follow-ups No. Responding "Yes" (%)

Vomiting after ED discharge? Ataxia or impaired coordination after ED discharge? Satisfied with results of specific procedure in ED? Pleased with the concept of procedural sedation? Would parents desire use of ketamine in repeat situation?

5 24 74 77 73

(6.5) (31.2) (96.1) (100.0) (94.8)

TABLE 8. Parental reaction to ketamine sedation as noted by physician

Parental Reaction to Ketamine Sedation

Day of Procedure (N = 108) (%)

Verbalized positive response No apparent dissatisfaction Mild anxiety Verbalized negative response

observed effects, and recovery time were comparable between the contacted group and the noncontacted group. Parental opinions and reported side effects are shown (Table 7). Most parents put their children directly to bed when they return home, and sound, undisturbed sleep for several hours was typical. Postdischarge vomiting was noted in five patients (6.5%), only one of whom had experienced emesis in the ED. Appetite was generally unimpaired; one child ate a voluminous Thanksgiving dinner within hours of arriving home. Persistent disequilibrium was reported in 24 c h i l d r e n (31.2%) after discharge, emphasizing the importance of careful parental observation during this period. This impaired coordination did not persist for more than six hours, and no injuries resulted. No personality changes or nightmares were apparent as a result of k e t a m i n e a d m i n i s t r a t i o n . One mother reported that her 3-year-old cried out at night three or four times in the five weeks after the procedure; however, he always went back to sleep quickly, and no other unusual behavior was noted (patient 18). An 8-year-old girl was withdrawn and tearful for several days after a ketAnnals of Emergency Medicine

68 32 8 0

(63.0) (29.6) (7.4) (0)

Telephone Follow-up (N = 77) (%)

71 3 2 1

(92.2) (3.9) (2.6) (1.3)

amine-assisted pelvic examination for sexual assault evaluation; her parents believed this behavior to be a consequence of the assault itself (patient 89). A 3-year-old boy woke up crying twice a night for three days after facial laceration repair with ketamine; however, he was easily consoled, and these episodes did not continue (patient 107). Overall parental reaction to the use of ketamine sedation was strongly positive, especially at the time of telephone follow-up (Table 8). Occasional anxiety invariably centered on the ketamine "blank stare," emphasizing the importance of adequate parental education before sedation. Four parents (5.2%) felt that they would rather not have ketamine used in a repeat circumstance. Two of these parents were dissatisfied with several aspects of the ED visit, including long pretreatment waits and poor wound healing; a third was upset that his l l - y e a r - o l d son used "dirty words" during recovery and vomited in the family car on the ride home. The only negative statement regarding the effects of the drug itself came from the mother of the child who experienced emesis and laryngospasm. However, she was pleased that a form of sedation had been used

19:9 September 1990

TABLE 9. Comparison of ketamine with DPT for pediatric procedural sedation Ketamine (Present Report)

Terndrup 9

No. in series

108

486

95

45

Prospective study

Yes

No

Yes

Yes

4

2/1/1

2.5/0.65/0.65

2/0.5/0.5

86.1 1.4

? 3.3

? 7t

48.9 ?

Respiratory depression (%)

0

0.4

3.2

0

Respiratory arrest (%)

0

0.2

1.1

0

0.9

0

0

0

Compared Items

Dose (mg/kg)* Full sedation and immobilization (%) Average recovery (hr)

Laryngospasm (%)

DPT Combination Nahata lo

Myers 11

*Doses separated by slashes are for meperidine, promethazine, and chlorpromazine, respectively. tAverage unstated; however, report mentions that two thirds were "asleep for seven or more hours."

and only wished that a "different medicine" be used in a repeat circumstance to achieve the same effect.

DISCUSSION The unique characteristics of ketamine present several advantages for pediatric sedation in the ED. Ease of administration, rapid onset, effective analgesia, adequate immobilization, relatively low cost, and a smooth, relatively rapid recovery have been demonstrated. Physician acceptance of ketamine was excellent. Plastic surgery and orthopedic consultants frequently requested that we enlist their patients in our study. The n u r s i n g staff readily accepted ketamine and became indispensable in parental education, although the necessity of constant observation during the recovery phase was considered a disadvantage during busy hours. This investigation initially provoked a skeptical reaction from the anesthesia departments in all three hospitals; however, after careful review of the study protocol support was obtained. It is r e c o m m e n d e d that emergency physicians contemplating use of ketamine first discuss this issue with their anesthesia department to prevent unfortunate adversarial responses. The use of ketamine sedation generated excellent public relations for our ED. Parents seemed genuinely impressed that the comfort and psychological well-being of their child was addressed, and repeated appreciation was expressed frequently. Sev19:9 September 1990

eral parents mentioned other children who were "deathly afraid" of physicians after use of unsedated forcible restraint. One mother stated that her child had experienced recurrent nightmares after an unsedated laceration repair and wished that ketamine had been used in that circumstance. More than one parent repeated that they would bring their children back to our hospital for ketamine sedation if a similar procedure was necessary. The emesis and laryngospasm experienced by one child are unexplained. No upper respiratory infection or other established contraind i c a t i o n was r e c o g n i z e d to be present. The child's last meal of chicken and rice was four hours before injection; however, multiple studies have demonstrated the safety of ketamine with partially full stomachs, 12,25-28,37-45 and it is unlikely that this was the precipitant. 24 Approximately three months after termination of data collection for this series, a second case of emesis-associated laryngospasm occurred in our ED. Again, there was no known precipitating factor and no sequelae. Both patients had histories of "easy gagging" and inactive asthma, although a relation between these factors and laryngospasm is at best uncertain. The rare occurrence of ketaminerelated laryngospasm is reviewed extensively in an a c c o m p a n y i n g report; 24 in most cases, it is associated with respiratory infections 36,46,47 as is laryngospasm with general anesthetics. 48 Laryngospasm requiring Annals of Emergency Medicine

intubation in healthy children is extremely unusual; pooled data compilation of 77 separate ketamine series reveals an incidence of 0.017% (two of 11,589).24 Despite the low apparent likelihood of encountering laryngospasm in any given healthy patient, we strongly recommend ready access to airway equipment and succinylcholine. Due to the similarities in the histories of the two patients with laryngospasm, we subsequently have used special precautions (IV access and pulse oximetry) in patients with histories of asthma or "easy gagging." No physician elected to use keta m i n e in any child less than 14 months old despite protocol specification of a three-month minimum. A probable explanation is that infants are less likely than toddlers to fall and sustain lacerations or other injuries. Subsequent to the case of a child with laryngospasm reported above, we have requested a minimum age of 12 months for further ketamine administrations in our ED; this is a conservative response to literature suggesting a higher incidence of airway c o m p l i c a t i o n s in y o u n g infants.3 t,32,48 51 The minimum dose at which consistent procedural sedation is produced appears to be 4 mg/kg IM. On four occasions, the treating physician purposefully administered doses of 2 to 3 mg/kg; three of these children required a repeat dose for adequate effect. These cases were excluded from the series due to protocol deviation. Use of ketamine for CT scanning 1030/125

KETAMINE Green, Nakamura & Johnson

was believed to be less than optimal; despite full sedation, the child exhibited random m o v e m e n t , which made the s c a n n i n g process difficult. Pure sedating agents such as chloral hydrate or p e n t o b a r b i t a l are probably b e t t e r s u i t e d for t h i s i n d i c a tion.2,6,sAs, 19 K e t a m i n e proved fully adequate for ophthalmological examinations despite nystagmus. The most frequently used "alternat i v e " to k e t a m i n e is DPT. Because this study did n o t directly compare k e t a m i n e w i t h DPT, f i r m c o n c l u s i o n s on t h e s u p e r i o r i t y of e i t h e r agent cannot be made. Ketamine data f r o m t h e c u r r e n t r e p o r t are contrasted w i t h those from three published DPT series (Table 9). Comparison suggests that k e t a m i n e is more c o n s i s t e n t l y efficacious, allows a faster recovery, and possesses a safety profile roughly equivalent to that of DPT. We have taken careful precautions for all p a t i e n t s in this series. Proc e d u r e s w e r e p e r f o r m e d i n areas e q u i p p e d w i t h s u c t i o n and airway e q u i p m e n t ; s u c c i n y l c h o l i n e and a physician skilled in pediatric intubation were always readily available. C o n t i n u o u s cardiac m o n i t o r i n g and pulse o x i m e t r y were used i n m a n y cases at physician discretion. Conservative exclusion criteria were maintained. Despite the broad margin of safety demonstrated in this series, we believe that k e t a m i n e sedation is inappropriate in any setting lacking the above p r e c a u t i o n a r y e q u i p m e n t and expertise. T h i s agent should clearly be used only by physicians capable of effectively dealing with potential airway complications. Children are more susceptible than adults to psychological scarring from p a i n f u l events. To the fearful child, an ED p r o c e d u r e can h a r d l y prove a n y t h i n g but terrifying and emot i o n a l l y t r a u m a t i c . P a n i c is i n t e n sified by forcible physical restraint from strangers and a tearful, anxious parent. T r a d i t i o n a l practice is to forcibly r e s t r a i n the f r i g h t e n e d child, grit one's teeth, and quickly attend to the procedure at hand. This is clearly a l e s s - t h a n - p l e a s a n t experience for all parties i n v o l v e d , as n u m e r o u s ED nurses will vociferously attest. Although easily discounted, it is difficult to assess the emotional upheaval c h i l d r e n s u s t a i n from s u c h t u m u l tuous events. Certainly every emer126/1031

gency physician has encountered the inexperienced, horror-stricken parent who expected something more civilized than the outward appearance of torture. Further, let us not ignore the patient with migraine or depression in the next bed who is forced to endure ten m i n u t e s of screaming while speculating with raised eyebrows as to its m e a n i n g and necessity. T h e s o p h i s t i c a t i o n of e m e r g e n c y medical care is increasing, and pat i e n t s w i l l c o n t i n u e to expect imp r o v e m e n t s in therapy and comfort from their local EDs. The cosmetic results of each laceration repair will be viewed by both parents and future teenagers w i t h i n c r e a s i n g s c r u t i n y , and it behooves emergency care specialists to do everything possible to ensure the best p a t i e n t satisfaction. Effective sedation and analgesia in a terrified c h i l d m a y seem i n c o n s e q u e n t i a l to some, b u t these techniques demonstrate long-overdue compassion for the physical discomfort and precarious e m o t i o n a l state u n i q u e to the acutely injured child.

CONCLUSION A prospective series of 108 pedb atric cases is described wherein painf u l or t e c h n i c a l l y c o m p l e x procedures i n the ED were f a c i l i t a t e d w i t h k e t a m i n e sedation. Acceptable c o n d i t i o n s were r e l i a b l y achieved, and p a r e n t a l r e a c t i o n was s t r o n g l y positive. The only significant complication was a patient with emesisrelated laryngospasm that spontan e o u s l y cleared w i t h o u t morbidity. We s u g g e s t t h a t k e t a m i n e can be used effectively by emergency physicians to facilitate procedural sedation in c h i l d r e n aged 12 m o n t h s to 15 years, yet emphasize that e q u i p m e n t a n d expertise for a d v a n c e d a i r w a y m a n a g e m e n t are m a n d a t o r y due to the rare occurrence of laryngospasm. The authors thank Paul M Paris, MD; David C Seaberg, MD; Ronald D Stewart, MD; Grenith Zimmerman, PhD; Lyslc Williams, MD; Michael Kirby, PhD; Agnes Kutzner, and Stevcn Rothrock, MD, for their many helpful ideas. Thanks also go to James Fisgus, MD; Cathey Putnam, MD; Edward Hackie, MD; Donald Minesinger, MD; Bruce Heischober, MD; David Joss, MD; Debbie Marks, MD; Karin Covi, MD; Henk Goorhuis, MD; Ronald Howard, MD; Gall Pignatiello, MD; Steven Rothrock, MD; and Linda Sturges, MD, for their study participation. Additional thanks go to the nurses of Annals of Emergency Medicine

Loma Linda University Medical Center and Victor Valley Community Hospital for their support.

REFERENCES

1. Smith C, Rowe RD, Vlad P: Sedationof children for cardiac catheterization with an ataractic mixture. Can Anaesth Soc J 1958;5:35-43. 2. Amberg HL, Gordon G: Low-dose intramuscular ketamine for pediatric radiotherapy: A case report. Anesth Analg 1976;55:92-94. 3. Callahanr ML: Current Therapy in Emergency Medicine. Toronto, BC Decker, 1987, p 826. 4. Cole CH: The Harriet Lane Handbook. Chicago, Year Book Medical Publishers, 1984. 5. Mayer TA: Emergency Management of Pedi attic Trauma. Philadelphia, WB Saunders Co, t985, p 530, 533. 6. Mitchell AA, Louik C, Lacouture P, et al: Risks to children from computed tomographic scan premeditation, lAMA 1982;247:2385-2388. 7. Topkins MI: Anesthetic managementof cardiac catheterization. Int Anesthes Clin 1980;18: 59-69. 8. Weir MR, Segapeli JH, Tremper LJ: Sedation for pediatric procedures. M i l i t M e d 1986;151: 181d84. 9. Terndrup TE, Cantor RM, Madden CM: Intramuscular meperidine, promethazine, and chlorpromazme: Analysis of use and complications in 487 pediatric emergency deparmrent patients. A n n Emerg Med 1989;18:528-533. 10. Nahata MC, Clotz MA, KroggEA: Adverse effects of meperidine, promethazine, and chlorpromazine for sedation in pediatric patients. (tim Pediatr 1985;24:558-560. 1l. Myers DR, Shoal HK: The intramuscular use of a combination of meperidine, promethazinc, and chlorpromazine for sedation of the child dental patient. ASDC / Dent Child 1977; 44:453-456. 12. Elliott ti, Hanid TK, Arthur LJ, et ah Ketamine anaesthesia for medical procedures in children. Arch Dis Child 1976;51:56-59. 13. Maltby JR, Watkins DM: Repeat ketamine anaesthesia of a child for radiotherapy in the prone position. Can A n a e s t h Soc ] 1983;30: 526-530. 14. BenusisKP, KapaunD, Fmnam LJ: Respzratory depression in a child followiug meperidine, promethazine, and chlorpromazine prenredication: Report of a case. A S D C [ Dent Child 1979; 46:50-53, 15. Stambaugh JE: Drug interaction Meperidine and chlorpromazinc, a toxic combi nation. J Clin Pharmacol 1981;21:140-146. 16. Gomez MR, Reese DF: Computed tomography of the head in infants and children. Pediatr Clin North A m 1976;23:473-498. 17. McCulloughDC, Kufta C, AxelbamrrSP, et ah Computerized axial tomography in clinical pediatrics. Pediatrics 1977;59:173-181. 18. Sander JE, Lo W: Computed tonrographic premeditation in children, l A M A 1983;249: 2639. 19. Strain JD: IV nembutal: Safe sedation for children undergoingCT. A m J Neurorad 1988; 9:955. 19:9 September 1990

20. Billmire DA, Neale HW, Gregory RO: Use of IV fentanyl in tire outpatient treatment of ped i a t r i c f a c i a l t r a u m a . ] Trauma 1985;25: 1079-1080. 21. M a u n u k s e l a L, Rajantie J, Siimes MA: £1unitrazepam-fentanyl induced sedation and analgesia for bone marrow aspiration and needle biopsy in children. Acta Anaesthesio] S t a n d 1986;30:409-411. 22. Nelson PS, Streisand JB, Muhler SM, et ah Comparison of oral transmucosal fentanyl ci tratc and an oral solution of meperidine, diazepam, and atropine for premedication in children. Anesthesiology 1989;70:616-621. 23. Gamis AS, Knapp JF, Glenski JA: Nitrous oxide analgesia in a pediatric emergency department. A n n Emerg Med 1989;18:177-181. 24. Green SM, Johnson NE: Ketamine sedation for pediatric procedures: Part 2, review and im plications. Ann Emerg Med 1990;19:1033-1046. 25. Caro DB: Trial of ketamine in an accident and emergency department. An~lesthesia 1974; 29:227-229. 26. Dailey RH, Stone R, Repert W: Ketamine dissociative anesthesia - Emergency department use in children. JACEP 1979;8:57-58. 27. Hirlinger WK, Dick W: Untersuchungcn zur i n t r a m u s k u l a r e n k e t a m i n a n a l g e s i e bei notfallpatienten. Anaesthe~ist 1984;33:272-275. 28. Hirlinger WK, Pfenninger E: lntravenose an~ algesie mit ketamin bei notfallpatienten. A~ aesthesist 1987;36:140-142. 29. white PF, Way WL, Trevor AJ: Ketamine Its pharmacology and therapeutic uses. Anesthesiology 1982;56:119-136.

19:9 September 1990

30. Reich DL, Silvay G: Ketamine: An update on the first twenty five years of clinical experience. Can J Anaesth 1989;36:186-197. 31. Corssen G, Reves )G, Stanley TH: Intravenous Anesthesia ~md Analgesia. Philadelphia, Lea & Febiger, 1988, p 99-174. 32. Brown TC, Cole WH, Murray GI-t: Ketamine - A new anaesthetic agent. A u s t N Z J Surg 1970;39:305-310. 33. Page P, Morgan M, Lob L: Ketamine an aesthesia in paediatric procedures. Acttl Anaesth Scand 1972;16:155-160. 34. Carrel R: Ketamme A general anesthetic for unmanageable ambulatory patients. ASDC J Dent Child 1973;40:288-292. .35. Demling RH, Ellerbe S, Jarrett F: Ketamine anesthesia for tangential excision of burn eschar A burn unit procedure. J Trauma 1978;/8: 269-270. 36. Matthias ]Q, Knapton PJ: Ketamine for minor procedures in children. Lmrcet 1972;388. 37. Bennett ]A, Bullimore JA: The use of keta m i n e h y d r o c h l o r i d e a n a e s t h e s i a for radiotherapy in young children. Brit J Anaesth 1973; 45:197-201. 38. Birkhan J, Shamash R, G ut ma n D: Ketamine dissociative anesthesia in pediatric oral surgery. J Oral Sucg 197l;29:853-857. 39. Cronin MM, Bousfield JD, Hewett EB, et al: Ketaminc anaesthesia for radiotherapy in small children. Anaesthesia 1972;27:135 142. 4(1. Elavia MH, Shah SC, Savant NS: Ketamine HC1 as sole anaesthetic agent for children undergoing radiotherapy, h?d ] C~lncer 1978;15: 60-64.

Annals of Emergency Medicine

41. Faithfull NS, Haider R: Ketamine for cardiac catheterisation. Arrr*esthesia 1971;26:318-323. 42. K a m m GD, Bewes PC: K e t a m i n e an aesthesia by continuous intravenous drip. Tropical Doctor 1978;8:68-72. 43. Spoerel WE: Ketalar {Cb581) in paediatric dentistry: A field trial in three arctic commu k nitics. Can Anelesth Sot J 1970;17:464-476. 44. Szappanyos GG, Bopp P, Fournet PC: The use and advantage of "Ketalar" (CI 581) as anaesthetic agent in pediatric cardiac catheterisal i o n and a n g i o c a r d i o g r a p h y . A n ~ l e s t h e s J s l 1969;18:365 366. 45. Wilson RD, Nichols RJ, McCoy NR: Dissociative anesthesia with CI-581 in burned chil dren. Anesth Analg 1967;46:719-724. 46. Apivor D: Ketamine in paediatric ophthalm o l o g i c a l surgery. A n a e s t h e s J e i 1973;28: 501-508. 47. Corssen G, Bjarncsen W: Recent advances in intravenous anesthesia. / Arn A Nurse At7 esth 1966;34:416-427. 48. Olsson GL, ttallen B: Laryngospasm during anaesthesia - A computer~aided incidence study in 136,929 patients. Acta Anaesthesiol Scdnd 1984;28:567k575. 49. Coppel DL, Dundee/W: Ketamine anesthesia for cardiac catheterization. Anaesthesi~l 1972;27:25-31. 50. Phillips LA, Seruvatu SG, Rika PN: Anaesthesia for the surgeon-anaesthetist in diffi cult situations. Anaesthesia 1970;25:36-45. 51. Sears BE: Complications of ketamine. Anesthesiology 1971;35:231.

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