The role of laryngeal ultrasound in predicting postextubation laryngeal edema

Purpose The purpose of this study is to determine the accuracy of portable bedside ultrasound (US) in the ICU in predicting postextubation stridor (PES). Patients and methods This prospective observational cohort study enrolled 80 patients who were admitted to Alexandria Main University Hospital, who were planned for extubation. The air-column width difference (ACWD) was measured before planned extubation using a portable US. The primary goal was to assess the diagnostic accuracy of ACWD to predict the presence of significant laryngeal edema (LE), enough to cause PES. Bronchoscopy was done to confirm the presence of PES, whenever possible. Results The prevalence of LE was 25%. The data collected from patients, with and without PES showed no definite risk factors for PES. A cutoff point of 0.9 mm change in ACWD (ACWD at vocal cords) was identified (P<0.001), below which a high probability of developing PES was noticed. The sensitivity and specificity of ACWD below or equal to 0.9 mm were 80% and 90% in predicting PES, respectively, with a negative predictive value of 0.931 and a positive predictive value of 0.727. In selected cases, postextubation bronchoscopy showed good correlation with ACWD by confirming significant LE in six cases out of seven with PES, five of which had an ACWD of below 0.9 mm. Conclusion Portable ICU US measuring ACWD between predeflation and postdeflation of endotracheal tube cuff balloon is a tool of a very good prospective in predicting PES.