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

Summary by Elizabeth Scheiderer MD, 6.11.23
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7648377/


Take Home Message:

  • The cuff leak test has excellent specificity but moderate sensitivity for post-extubation airway obstruction

  • Patients should be monitored closely after extubation regardless of a negative cuff leak test

  • Cuff leak test is less specific for patients intubated greater than 6 days

 

Summary:

 

Background: A cuff leak test is recommended to predict the presence of laryngeal edema and post-extubation airway obstruction in patients who meet extubation criteria and are at high risk for post-extubation stridor. A quantitative cuff leak test measures the air leak by comparing the tidal volumes while the cuff is inflated and while the cuff is deflated. A qualitative cuff leak test examines the presence of audible leak around a deflated ETT. Previous systematic reviews have demonstrated that the cuff leak test provides great specificity, but no consensus regarding its sensitivity. This systematic review was conducted to determine the diagnostic accuracy of the cuff leak test for predicting post-extubation airway complications in adult patients.

 

Study Design: systematic review and meta-analysis

 

Methods: Medline, EMBASE, Scopus, ISI Web of Science, and the Cochrane Library were searched for eligible studies from inception to March 16, 2020, without language restrictions. The diagnostic accuracy of the cuff leak test was investigated in adult patients in critical care settings. Studies were included if they explicitly reported post-extubation airway obstruction after extubation or reintubation. The following data were extracted from each study: patient demographics (age, sex), study characteristics (country, study population, duration of mechanical ventilation, mode of ventilation, observation period after extubation), type of cuff leak test (quantitative or qualitative), numbers of true-positive, false-positive, true-negative, and false-negative, and the reference standards (stridor or laryngeal edema including confirmation with bronchoscopy or laryngoscopy). The Quality Assessment for Diagnostic Accuracy Studies-2 tool was used to assess the risk of bias. Data was analyzed using a generalized linear mixed model approach to bivariate random-effects meta-analysis.

 

Inclusion criteria: observational studies (cross-sectional and cohort studies) that examined the diagnostic accuracy of cuff leak test in critical care setting if: (1) the data were extractable into a 2x2 table from the reported data, (2) post-extubation airway obstruction after extubation or reintubation was explicitly reported as the reference standard

 

Exclusion criteria: pediatric population, routine use of prophylactic corticosteroids, other screening modalities, conference proceedings without data, no outcome or cutoff of leak test, perioperative setting

  

Primary outcome: Primary outcomes were post-extubation airway obstruction and reintubation due to post-extubation airway obstruction

 

 

Results: A total of 28 studies were included in the analysis, consisting of 4,493 extubations. The pooled sensitivity and specificity of cuff leak test for post-extubation airway obstruction were 0.62 (95% CI 0.49–0.73) and 0.87 (95% CI 0.82–0.90) respectively. The pooled sensitivity and specificity of the cuff leak test for reintubation were 0.66 (95% CI 0.46–0.81) and 0.88 (95% CI 0.83–0.92 respectively. Subgroup analyses suggested that the type of cuff leak test and length of intubation might be the cause of statistical differences of sensitivity and specificity, respectively, for post-extubation airway obstruction. The specificity of the cuff leak test was worse for patients intubated for more than 6 days. The sensitivity and specificity of the cuff leak test based on a cuttoff point of 110mL were 0.44 (95% CI 0.31-0.59) and 0.91 (95% CI 0.82-0.95), respectively.

 

Discussion/conclusion: The cuff leak test has excellent specificity but moderate sensitivity (62%) for post-extubation airway obstruction. The high specificity suggests that clinicians should strongly consider treating patients with a positive test (administer systemic corticosteroids and keep patient intubated), but the low sensitivity suggests that the test may fail to identify some patients with airway obstruction. Qualitative cuff leak test is subjective and has a sensitivity of 35% in predicting post-extubation airway obstruction. Female sex and reintubation had no effect on accuracy of cuff leak test.