The cuff leak test is not predictive of successful extubation

Liberation from mechanical ventilation in critically ill patients: Korean Society of Critical Care Medicine Clinical Practice Guidelines

BACKGROUND

Successful liberation from mechanical ventilation is one of the most crucial processes in critical care because it is the first step by which a respiratory failure patient begins to transition out of the intensive care unit and return to their own life. Therefore, when devising appropriate strategies for removing mechanical ventilation, it is essential to consider not only the individual experiences of healthcare professionals, but also scientific and systematic approaches. Recently, numerous studies have investigated methods and tools for identifying when mechanically ventilated patients are ready to breathe on their own. The Korean Society of Critical Care Medicine therefore provides these recommendations to clinicians about liberation from the ventilator.

METHODS

Meta-analyses and comprehensive syntheses were used to thoroughly review, compile, and summarize the complete body of relevant evidence. All studies were meticulously assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method, and the outcomes were presented succinctly as evidence profiles. Those evidence syntheses were discussed by a multidisciplinary committee of experts in mechanical ventilation, who then developed and approved recommendations.

RESULTS

Recommendations for nine PICO (population, intervention, comparator, and outcome) questions about ventilator liberation are presented in this document. This guideline includes seven conditional recommendations, one expert consensus recommendation, and one conditional deferred recommendation.

CONCLUSIONS

We developed these clinical guidelines for mechanical ventilation liberation to provide meaningful recommendations. These guidelines reflect the best treatment for patients seeking liberation from mechanical ventilation.

Role of Submandibular Ultrasound in Airway Management of a Patient With Angioedema

Angioedema is one of several life-threatening clinical scenarios that lacks clarity on when a patient requires intubation. We present a case of angiotensin-converting enzyme-inhibitor-induced angioedema with peri-oral swelling and normal airway measurements on ultrasound, who was intubated with an abundance of caution and extubated successfully. Current tests for intubation and extubation, such as traditional bedside assessments and the cuff leak test, vary in reliability for angioedema and similar urgent situations. Submandibular ultrasound is a quick, low-cost, non-invasive method for determining quantitative criteria for and assessing when intubation and extubation is indicated, which may lead to improved quality of care and patient safety.

Predictors of post-extubation stridor in patients on mechanical ventilation: a prospective observational study

The cuff leak test (CLT) has been widely accepted as a simple and noninvasive method for predicting post-extubation stridor (PES). However, its accuracy and clinical impact remain uncertain. We aimed to evaluate the reliability of CLT and to assess the impact of pre-extubation variables on the incidence of PES. A prospective observational study was performed on adult critically ill patients who required mechanical ventilation for more than 24 h. Patients were extubated after the successful spontaneous breathing trial, and CLT was conducted before extubation. Of the 191 patients studied, 26 (13.6%) were deemed positive through CLT. PES developed in 19 patients (9.9%) and resulted in a higher reintubation rate (8.1% vs. 52.6%, p < 0.001) and longer intensive care unit stay (8 [4.5-14] vs. 12 [8-30.5] days, p = 0.01) than patients without PES. The incidence of PES and post-extubation outcomes were similar in patients with both positive and negative CLT results. Compared with patients without PES, patients with PES had longer durations of endotracheal intubation and required endotracheal suctioning more frequently during the 24-h period prior to extubation. After adjusting for confounding factors, frequent endotracheal suctioning more than 15 times per day was associated with an adjusted odds ratio of 2.97 (95% confidence interval, 1.01-8.77) for PES. In conclusion, frequent endotracheal suctioning before extubation was a significant PES predictor in critically ill patients. Further investigations of its impact on the incidence of PES and patient outcomes are warranted.

Performance of the cuff leak test in adults in predicting post-extubation airway complications: a systematic review and meta-analysis

Background

Clinical practice guidelines recommend performing a cuff leak test in mechanically ventilated adults who meet extubation criteria to screen those at high risk for post-extubation stridor. Previous systematic reviews demonstrated excellent specificity of the cuff leak test but disagreed with respect to sensitivity. We conducted a systematic review and meta-analysis to assess the diagnostic accuracy of the cuff leak test for predicting post-extubation airway complications in intubated adult patients in critical care settings.

Methods

We searched Medline, EMBASE, Scopus, ISI Web of Science, the Cochrane Library for eligible studies from inception to March 16, 2020, without language restrictions. We included studies that examined the diagnostic accuracy of cuff leak test if post-extubation airway obstruction after extubation or reintubation was explicitly reported as the reference standard. Two authors in duplicate and independently assessed the risk of bias using the Quality Assessment for Diagnostic Accuracy Studies-2 tool. We pooled sensitivities and specificities using generalized linear mixed model approach to bivariate random-effects meta-analysis. Our primary outcomes were post-extubation airway obstruction and reintubation.

Results

We included 28 studies involving 4493 extubations. Three studies were at low risk for all QUADAS-2 risk of bias domains. The pooled sensitivity and specificity of cuff leak test for post-extubation airway obstruction were 0.62 (95% CI 0.49–0.73; I² = 81.6%) and 0.87 (95% CI 0.82–0.90; I² = 97.8%), respectively. The pooled sensitivity and specificity of the cuff leak test for reintubation were 0.66 (95% CI 0.46–0.81; I² = 48.9%) and 0.88 (95% CI 0.83–0.92; I² = 87.4%), respectively. Subgroup analyses suggested that the type of cuff leak test and length of intubation might be the cause of statistical heterogeneity of sensitivity and specificity, respectively, for post-extubation airway obstruction.

Conclusions

The cuff leak test has excellent specificity but moderate sensitivity for post-extubation airway obstruction. The high specificity suggests that clinicians should consider intervening in patients with a positive test, but the low sensitivity suggests that patients still need to be closely monitored post-extubation.

Cuff Leak Test for the Diagnosis of Post-Extubation Stridor: A Multicenter Evaluation Study

BACKGROUND:

Cuff leak test was developed to predict the occurrence of post-extubation stridor (PES). This study evaluated the diagnostic performance of this test in unselected critically ill patients.

METHODS:

Multicenter prospective study including unselected ventilated patients at the time of their first planned extubation. The diagnostic performance of 4 different cuff leak tests was assessed.

RESULTS:

Post-extubation stridor occurred in 34 (9.4%) of 362 included patients. Compared to patients without PES, patients with PES required more frequently reintubation (6 [17.6%] vs 26 [7.9%], P = .041), prolonged duration of ventilation (6 [3-13] vs 5 [2-9] days, P = .029), and longer intensive care unit (ICU) stay (12 [6-17.5] vs 7.5 [4-13] days, P = .018). However, ICU mortality was similar in both groups (1 [2.9%] vs 23 [7.0%], P = .61). The 4 cuff leak tests display poor diagnostic accuracy: sensitivities ranging from 27% to 46%, specificities from 70% to 88%, positive predictive values from 14% to 19%, and negative predictive values from 92% to 93%.

CONCLUSION:

Post-extubation stridor occurs in less than 10% of unselected critically ill patients. The several cuff leak tests display limited diagnostic performance for the detection of PES. Given the high rate of false positives, routine cuff leak test may expose to undue prolonged mechanical ventilation.

Risk factors associated with post-extubation stridor in the trauma intensive care unit

BACKGROUND

Post-extubation stridor is an uncommon complication in medical intensive care units (ICUs) but has not been well studied in trauma patients. We sought to determine the incidence of reintubation due to stridor in trauma patients and describe associated risk factors.

METHODS

A retrospective review of all intubated trauma patients was performed. Data collected included presence of stridor, demographic data, and details of intubation and extubation.

RESULTS

Of all trauma patients reintubated, 31% were for stridor. Although female gender, age less than 18, blunt mechanism, and duration of intubation 5 days or more were associated with reintubation for stridor, endotracheal tube diameter was not. Mortality was not increased with reintubation.

CONCLUSIONS

Trauma ICU patients are reintubated for stridor at a higher rate than medical ICU patients. Age, gender, blunt mechanism, and duration of intubation are risk factors for this complication.

Cuff leak test and laryngeal survey for predicting post-extubation stridor

Background and Aims:

Evidence for the predictive value of the cuff leak test (CLT) for post-extubation stridor (PES) is conflicting. We evaluated the association and accuracy of CLT alone or combined with other laryngeal parameters with PES.

Methods:

Fifty-one mechanically ventilated adult patients in a medical-surgical intensive care unit were tested prior to extubation using; CLT, laryngeal ultrasound and indirect laryngoscopy. Biometric, laryngeal and endotracheal tube (ETT) parameters were recorded.

Results:

PES incidence was 4%. CLT demonstrated ‘no leak’ in 20% of patients. Laryngeal oedema was present in 10% of the patients on indirect laryngoscopy, and 71% of the patients had a Grades 1-3 indirect laryngoscopic view. Mean air column width on laryngeal ultrasound was 0.66 ± 0.15 cm (cuff deflated), mean ratio of ETT to laryngeal diameter was 0.48 ± 0.07, and the calculated CLT and laryngeal survey composite was 0.86 ± 1.25 (range 0-5). CLT and the CLT and Laryngeal survey composite measure were not associated with or predict PES. Age, sex, peri-extubation steroid use, intubation duration and body mass index were not associated with PES.

Conclusion:

Even including ultrasonographic and indirect laryngoscopic examination of the airway, no single aspect of the CLT or combination with laryngeal parameters accurately predicts PES.

Prognosis and Patterns of Failure for the Extubation of Patients Who Remain Intubated After Head and Neck Surgery

Objective:

This study aimed to analyze the rate of failure, patterns of failure, and prognostic factors for patients who remain intubated after head and neck surgery and then undergo delayed extubation.

Methods:

Retrospective chart review of all otolaryngology patients who remained intubated after head and neck surgery and then underwent delayed extubation between 2006 and 2013. The incidence and patterns of extubation failure were analyzed. Univariable logistic regression analysis was performed to identify risk factors for postextubation failure.

Results:

Fifteen of the 129 patients (12%) who remained intubated after head and neck surgery and underwent delayed extubation subsequently failed and required either repeat intubation or an emergency surgical airway. The most common reasons for failure were hemorrhage (47%) and upper airway edema (33%). Failure typically occurred within 6 hours of extubation. Twenty-seven percent of the patients who failed extubation (4/15) required an emergency surgical airway. On univariable logistic regression analysis, ligation of a major neck vessel predicted extubation failure (odds ratio = 5.20; 95% confidence interval, 1.48-18.23).

Conclusion:

Postextubation failure in carefully selected patients undergoing delayed extubation after head and neck surgery is infrequent and most commonly due to postoperative bleeding. Prospective data are required to facilitate safe and quality care for these patients.

Difficult Airway Society Guidelines for the management of tracheal extubation

Tracheal extubation is a high-risk phase of anaesthesia. The majority of problems that occur during extubation and emergence are of a minor nature, but a small and significant number may result in injury or death. The need for a strategy incorporating extubation is mentioned in several international airway management guidelines, but the subject is not discussed in detail, and the emphasis has been on extubation of the patient with a difficult airway. The Difficult Airway Society has developed guidelines for the safe management of tracheal extubation in adult peri-operative practice. The guidelines discuss the problems arising during extubation and recovery and promote a strategic, stepwise approach to extubation. They emphasise the importance of planning and preparation, and include practical techniques for use in clinical practice and recommendations for post-extubation care.

Cuff-leak test for predicting postextubation airway complications: a systematic review

BACKGROUND AND OBJECTIVE

Postextubation problems such as laryngeal edema and reintubation are common complications after tracheal intubation. The cuff-leak test has been proposed as a method of identifying those patients at high risk in clinical practice, but its efficacy remains controversial.

METHODS

We searched electronic databases including PubMed, the Cochrane Controlled Trials Register, Web of Science, Ovid, and Embase. Studies were included if they were concerned with accuracy of the cuff-leak test and the effect of cuff-leak test screening on patient-important outcomes. Two reviewers independently assessed study quality with the QUADAS tool and extracted data. We compiled diagnostic two by two tables and pooled estimates of sensitivity and specificity, but refrained from pooling when there was considerable clinical or statistical heterogeneity.

RESULTS

Sixteen diagnostic tests with 3172 participants and six clinical trials with 2500 patients were identified. The median diagnostic odds ratios for predicting postextubation laryngeal edema and reintubation were 18.16 (range, 3.54 to 356.00) and 10.80 (2.74 to 1665.00), respectively. The accuracy of the cuff-leak test varied with different methods, duration of intubation, and study population. An indirect comparison found significant differences in post-extubation incidence of laryngeal edema (OR = 2.09, 95% CI, 1.28 to 2.89) but not reintubation (OR = 0.94, 95% CI, 0.32 to 1.57) if using cuff-leak test screening.

CONCLUSIONS

Our results suggest the cuff-leak test accurately predicts which adult patients are at high risk of postextubation airway complications, but randomized controlled trials are needed to further assess this diagnostic strategy.