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research-article2014

AORXXX10.1177/0003489414528866Annals of Otology, Rhinology & LaryngologySood et al

Article

Preventing Cuff Rupture During Tracheostomy: Importance of Endotracheal Tube Positioning

Annals of Otology, Rhinology & Laryngology 2014, Vol. 123(9) 654­–657 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0003489414528866 aor.sagepub.com

Amit Sood, BA1, M. Reza Taheri, MD, PhD2, and Arjun S. Joshi, MD1

Abstract Objective: The objective of our study is to describe the technique of distal endotracheal tube (ETT) positioning for avoiding cuff rupture and validate the technique in a virtual tracheostomy model. Methods: A prospective nonrandomized case series of 129 patients who had undergone tracheostomy using the senior author’s technique were evaluated. Primary outcome was ETT cuff rupture. One hundred normal patient computed tomography (CT) scans were used to generate a virtual tracheostomy model, and the probability of cuff rupture, among other values, was obtained. Results: One hundred twenty-three of 129 patients underwent tracheostomy without cuff rupture when the distal tip of the ETT was placed just proximal to the carina. After analysis of 100 3-dimensional CT scans, the average distance from the tracheotomy to the superior aspect of the cuff was 54.6 mm in men and 39.87 mm in women when a 6.5-size ETT was used, and 44.8 mm in men and 30.07 mm in women when a 7.5-size ETT was used. Virtual tracheotomy between the second and third tracheal rings resulted in no probability of inadvertent ETT cuff rupture. Conclusion: Distal ETT positioning during tracheostomy should be considered for avoiding inadvertent ETT cuff rupture. Keywords endotracheal tube position, ETT, tracheostomy complications, endotracheal tube, cuff rupture, quality improvement, tracheostomy, resident training

Introduction Tracheostomy is one of the most common procedures performed within the inpatient setting. In fact, in 2006, nearly 114 000 adult tracheostomies were performed in the United States.1 Tracheostomies are generally considered safe procedures but can result in untoward complications. In a recent survey of American Academy of Otolaryngology–Head and Neck Surgery members, it was calculated that 55% of otolaryngologists cared for at least 1 patient who underwent tracheostomy that resulted in a catastrophic complication.2 In particular, the overall incidence of tracheostomy complications has been suggested to be 3% to 15%.1,3 Complications of tracheostomy can be divided into intraoperative, early, and late. Intraoperative complications include hemorrhage; pneumomediastinum, pneumothorax, and recurrent laryngeal nerve injury; and inadvertent endotracheal tube (ETT) cuff rupture. Early complications include hemorrhage, tracheitis, mucous plugging, accidental decannulation, subcutaneous emphysema, and swallowing problems.4 Late complications can include tracheal stenosis from excessive granulation tissue, tracheomalacia,

tracheoesophageal fistula, tracheoinnominate fistula, and recurrent aspiration.5 Premature ETT cuff rupture, which can occasionally occur during tracheostomy, can result in failure of ventilation and poor visualization. This may result in inadvertent tracheal wall lacerations and posterior wall rupture.6 Although tracheostomy cases generally occur without incident, premature cuff rupture can create anxiety in the operating room for all those involved. This is especially true in those patients with poor pulmonary function and pulmonary disease or with low functional residual capacity of the lungs, or in obese patients who are likely to decompensate

1

Division of Otolaryngology–Head and Neck Surgery, George Washington University, Washington, DC, USA 2 Department of Diagnostic Radiology, George Washington University, Washington, DC, USA Corresponding Author: Arjun S. Joshi, MD, Division of Otolaryngology–Head and Neck Surgery, Department of Diagnostic Radiology, George Washington University, 2021 K Street NW, Suite 206, Washington, DC 20006, USA. Email: [email protected]

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Sood et al rapidly when positive pressure ventilation is lost and a surgical airway is not established in a timely fashion. In this study, we describe a simple change to the timehonored surgical technique of tracheostomy in order to reduce intraoperative complication rates. By modifying a usually overlooked variable—endotracheal tube cuff position—we have found in our clinical practice that the outcome of premature ETT cuff rupture can be reduced. We have also created a virtual tracheostomy model to further study the relation between ETT position and cuff rupture.

Methods From July 2008 to January 2012, 129 consecutive tracheostomies were performed using the senior author’s (A.S.J.) technique with informed consent. Demographic data were tabulated and included age, sex, body mass index (BMI), and indication for procedure. Main outcome variables included surgical time (measured from skin incision to insertion of tracheostomy tube), blood loss, inadvertent ETT cuff rupture, and other intraoperative complications. Statistical multivariate analysis was performed using Fisher’s exact test and sensitivity/specificity analyses. Significance was determined with a P value < .05. We then generated a 3-dimensional virtual tracheostomy model using 100 normal patient computed tomography (CT) scans, using DR Dominator software (DR Systems, Inc, San Diego, California, USA). Patients without evidence of upper airway pathology (not the same patients who underwent tracheostomy) were chosen by the attending radiologist as a control group that was age, sex, and BMI matched. Measurements of mean tracheal length and mean distance between the tracheotomy and the superior aspect of the ETT were taken. Primary outcome was the presence or absence of ETT cuff rupture. Institutional review board approval for the study was obtained through the Office of Human Research at George Washington University.

Author’s Modification to Tracheostomy Technique Once the patient was intubated, and after the neck was extended with a shoulder roll, the ETT was distally advanced until it was past the carina. The ETT was then retracted proximally until bilateral lung sounds were auscultated and equal chest rise was seen. Further confirmation of positioning can be performed using a flexible bronchoscope. Although this is not necessary in most cases, a bronchoscope can be useful in patients with large BMI in which chest rise and breath sounds can be difficult to ascertain. Surgical exposure may be performed using any of numerous standard techniques, and hemostasis was obtained as the pretracheal fascia was exposed. A horizontal tracheotomy

Table 1.  Means of Patient and Operative Variables. Variable

Mean (Range)

Age, y Body mass index Surgical time, min Intraoperative bleeding, cc

63.02 (24-87) 26.56 (13.3-41) 21.9 (14-30) 22.9 (10-40)

Table 2.  Multivariate Analysis and Comparison of Patient Demographic and Operative Variables in Patients With and Without Endotracheal Tube Cuff Rupture Using the Author’s Modified Technique. No Cuff Rupture Cuff Rupture Patients, No. (%) Age, y Surgical time, min Body mass index Bleeding, cc

123 (95.4) 63.02 21.86 26.13 22.43

6 (4.6)a 63.00 23.83 35.28 33.33

P Value   .9959 .1487 .0001 .0038

a 4 female, 2 male; 3 of 6 patients (50%) had decreased thyromental distance.

with Bjork flap was performed in the usual fashion, and location can be varied depending on the indication. The tracheostomy was made with a No. 15 scalpel blade until the tracheal mucosa was seen. Mosquito forceps were then used to enlarge the tracheotomy. The rigid ETT was visualized and the cuff was almost always protected in the distal airway. The tracheostomy tube was placed after the ETT cuff was taken down and then withdrawn.

Results Over a 4-year period, 129 patients underwent tracheostomy with the author’s modified technique. Indications for tracheostomy were adjunctive (n = 112, 86.8%), airway (n = 11, 8.5%), trauma-related (n = 4, 3.1%), and ventilation dependence (n = 2, 1.5%). The patients had a mean age of 63.02 years (range, 24-87 years) and BMI of 26.56 (range, 13.3-41). The mean surgical time was 21.9 minutes (range, 14-30 minutes), and mean intraoperative bleeding was 22.9 cc (range, 10-40 cc) (Table 1). One hundred twenty-three of 129 patients (95.4%) did not experience cuff rupture. Six of 129 patients (4.6%) experienced cuff rupture during tracheostomy. Of the 6 patients who experienced cuff rupture during tracheostomy, 4 (66%) were female, 2 (33%) were male, and 3 (50%) had a decreased thyromental distance. Only BMI (P < .0001) and intraoperative bleeding (P < .0038) were found to be statistically significant between the 2 groups (Table 2). Anecdotally, there did not appear to be a difference in cuff rupture, depending on the level of the surgeon, although this variable was not specifically studied. Table 3

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Annals of Otology, Rhinology & Laryngology 123(9)

Table 3.  Endotracheal Cuff Rupture Group. Patient No. 1 2 3 4 5 6

Sex

BMI

F M F F M F

34.4 40.1 34.8 34.4 27.9 40.1

Indication

Complications

Adjunctive Adjunctive Ventilation dependence Adjunctive Airway concern Adjunctive

None None None None None None

Misc. Comments Decreased thyromental distance Decreased thyromental distance NA NA NA Decreased thyromental distance

Abbreviations: BMI, body mass index; NA, not applicable.

Table 4.  Mean Measurements After Computed Tomography 3-Dimensional Reconstruction Stratified by Sex.

Age, mean (range), y Distance from first-second tracheal ring to carina, mm Distance from second-third tracheal ring to carina, mm

Men

Women

59.92 (42-72) 98.87

61.0 (32-92) 84.67

94.90

80.17

summarizes the indication for tracheostomy, intraoperative complications, sex, and other patient-specific variables in those patients with cuff rupture. The 100 patient CT scans were equally divided between men and women (age, sex, and BMI matched); distances of average tracheal length and mean distance between tracheostomy incision site and superior aspect of ETT cuff were measured. The male cohort had an average age of 59.92 years (range, 42-72 years), and the female cohort had an average age of 61.0 years (range, 32-92 years). The average tracheal length was determined to be 98.87 mm in men and 84.67 mm in women (Table 4). The virtual tracheotomy incision was made horizontally between the second and third tracheal rings. In men, the average distance between the tracheostomy site and the superior aspect of the ETT cuff was 54.6 mm and 44.8 mm with 6.5-size and 7.5-size ETTs, respectively. In women, this value was determined to be 39.87 mm and 30.07 mm with 6.5-size and 7.5-size ETTs, respectively (Table 5). From the 3-dimensional CT virtual tracheostomy model, there was a 0 out of 100 (0%) incidence of cuff rupture with distal ETT positioning.

Discussion Premature ETT cuff rupture is common and can cause significant anxiety for all involved, especially in the case of tenuous airways. Risk factors for ETT cuff rupture include hyperinflation and cuff penetration through the tracheostomy incision. Of these 2, cuff penetration has been noted to be more common in our clinical observation and appears to

Table 5.  Mean Distances Between Tracheostomy Incision Site and Superior Aspect of ETT Cuff After Computed Tomography 3-Dimensional Reconstruction Stratified by Sex.

Distance between incision site and superior aspect of cuff with 6.5 ETT, mma Distance between incision site and superior aspect of cuff with 6.5 ETT, mmb Distance between penetration point and superior aspect of cuff with 7.5 ETT, mma Distance between penetration point and superior aspect of cuff with 7.5 ETT, mmb

Men

Women

58.57

44.37

54.6

39.87

48.77

34.57

44.80

30.07

Abbreviation: ETT, endotracheal tube. a Incision site between first and second tracheal rings. b Incision site between second and third tracheal rings.

have a significant association with improper ETT cuff positioning. The current literature does not address proper positioning of the ETT during a tracheostomy. The senior author’s technique was performed on a total of 129 live patients requiring tracheostomy for standard indications. One hundred twenty-three patients (95.4%) did not display evidence of cuff rupture. Premature cuff rupture occurred in 6 of 129 patients (4.6%). Three of 6 patients (50%) were noted to have a decreased thyromental distance. Although specific thyromental distances were not calculated for each patient in our cohort, numerous studies have indicated that shorter thyromental distances are valuable predictors for difficult intubation and challenging surgical airways.7,8 In terms of intraoperative variables, intraoperative bleeding was the only variable found to be statistically significant (P < .0038). Specifically, patients with cuff rupture had 11 cc greater intraoperative bleeding than patients without ETT cuff rupture. As the range of blood loss did not vary significantly across our data set, we can only assume that increased bleeding could have been associated with poor visualization and inadvertent cuff rupture. In terms of demographic characteristics, BMI was found to be statistically significant (P < .0001). Specifically, patients with cuff rupture had an average BMI of 35.28 in

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Sood et al Table 6.  Cut-off Point of Body Mass Index for Predicting Cuff Rupture. Purpose

Cut-off Value

Sensitivity

Optimal

27.9

1.0

Positive Specificity Likelihood Ratio 0.715

3.51

comparison to 26.13 in patients without cuff rupture. Using receiver operating characteristic (ROC) curve analysis, the cut-off point for BMI as a predictor of cuff rupture was determined to be 27.9 with a positive likelihood ratio of 3.51 (Table 6). The increased BMI and its association with incidence of cuff rupture is an interesting finding. Patients with a higher BMI are generally associated with increased weight of the chest wall and often have other comorbidities that may include respiratory-compromised conditions, making ETT positioning during tracheostomy even more important. Furthermore, high BMI values have been found to be a successful predictor of difficult intubation.7 Due to the statistical significance between ETT cuff rupture and higher BMI values, we suggest using a fiberoptic scope in patients with higher BMI to decrease ETT malpositioning. This suggestion is particularly timely, as an increasing number of adjunctive tracheostomies are being performed in patients with poor pulmonary reserve for prolonged intubation and respiratory failure. We suspect that questions may arise regarding the validity of the virtual tracheostomy as it correlates with surgical conditions. The virtual tracheostomy resulted in a 0 out of 100 (0%) incidence of cuff rupture. Although the senior author’s technique was performed with the neck in extension and the 3-dimensional reconstructions of randomly sampled patients were not oriented in the extended position, this discrepancy does not affect the accuracy of the virtual tracheostomy since the length of the trachea is fairly constant and is not significantly altered with neck movement. Neck extension or other postural changes correlate to tracheal variations only as they relate to vertebral level.9 The fact that there was a 0% incidence of ETT cuff rupture in a nonextended virtual neck only underscores the importance of distal positioning, given the fact that extension in theory can only potentially lengthen the patient’s trachea. Another factor that may question the validity of the virtual tracheostomy is the variation of ETT curvature according to neck position, a variable that may influence cuff location indirectly. Although ETT curvature may be affected by postural changes, these variations are extremely minimal and would not have a significant effect on changes in cuff location if the author’s technique is followed. It is

imperative that the anesthesiologist monitor the new position of the tube intraoperatively to minimize variance in cuff position.

Conclusion Premature ETT cuff rupture causes significant anxiety and may result in complications during tracheostomy. This study serves to underscore the importance of ETT positioning during a tracheostomy and provides radiologic evidence for the author’s approach. In addition, this study has implications for resident training, as the technique provides a safe airway for supervising trainees during tracheostomy. We conclude that distal ETT positioning appears to reliably result in decreased ETT cuff rupture during tracheostomy. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.

References 1.  Shah R, Lander L, Barry J, Nussenbaum B, Merati A, Roberson D. Tracheostomy outcomes and complications: a national perspective. Laryngoscope. 2012;122:25-29. 2. Das P, Zhu H, Shah K, Roberson D, Berry J, Skinner M. Tracheotomy-related catastrophic events: results of a national survey. Laryngoscope. 2012;122:30-37. 3.  Bradley PJ. Management of the obstructed airway and tracheostomy. In: Kerr AG, ed. Scott-Brown’s Otolaryngology. 6th ed. London: Butterworth-Heinemann; 1997. 4.  Halum S, Ting J, Plowman E, et al. A multi-institutional analysis of tracheotomy complications. Laryngoscope. 2012;122:3845. 5.  Epstein SK. Late complications of tracheostomy. Respir Care. 2005;50(4):542-549. 6.  Gillies M, Smith J, Langrish C. Positioning the tracheal tube during percutaneous tracheostomy: another use for videolaryngoscopy. Br J Anaesth. 2008;101(1):129. 7.  Kim WH, Ahn HJ, Lee CJ, et al. Neck circumference to thyromental distance ratio: A new predictor of difficult intubation in obese patients. Br J Anaesth. 2011;106(5):743-748. 8. Connor CW, Segal S. Accurate classification of difficult intubation by computerized facial analysis. Anesth Analg. 2011;112:84-93. 9.  Conrardy PA, Goodman LR, Lainge F, Singer MM. Alteration of endotracheal tube position. Flexion and extension of the neck. Crit Care Med. 1976;4(1):7-12.

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Preventing cuff rupture during tracheostomy: importance of endotracheal tube positioning.

The objective of our study is to describe the technique of distal endotracheal tube (ETT) positioning for avoiding cuff rupture and validate the techn...
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