Laryngeal ultrasound: a useful method in predicting post-extubation stridor. A pilot study.

The cuff-leak test was widely used for the prediction of post-extubation stridor, but controversial results limit its clinical application. The current study used real-time ultrasonography to evaluate the air-leak and hypothesised that the air-column width, measured by ultrasonography, may be correlated to the development of post-extubation stridor. From June 1, 2001 to March 1, 2002, a total of 51 planned extubations in 51 consecutively intubated patients were included. All of the patients received ultrasonographical examinations of their vocal cords and larynx in addition to an air-column width measurement within 24 h prior to extubation. The overall post-extubation stridor rate was 7.8%. The air-leak volume presented as median (interquartile range) were 300 (350) mL and 25 (20) mL, respectively, for the nonstridor and stridor groups. The air-column width during cuff deflation was 6.4 (2) mm and 4.5 (0.8) mm, respectively. They were found to be statistically significant. In conclusion, the authors demonstrated that laryngeal ultrasonography could be a reliable, noninvasive method, in the evaluation of vocal cords, laryngeal morphology and the ease of airflow, which passed through vocal cords or subglottic area due to laryngeal oedema. The air-column width during cuff deflation was a potential predictor of post-extubation stridor.