Comparison between Cuff Leak Test and Ultra Sound Assessment of Laryngeal Edema in Predicting Successful Extubation in Mechanically Ventilated Patients

Objects: Endotracheal intubation commonly leads to local complications, including mechanical lesions, such as friction and compressions between the tube and the anatomic structures of the larynx leading to laryngeal edemamanifested as ‘‘stridor’’ after extubation. There is no standard method to predict patients at risk of post-extubation stridor. This study was conducted to compare between cuff leak test and ultra sound in predicting successful extubation in mechanically ventilated patients.

Patients and Methods: We included a total of 83 mechanically ventilated patients with endotracheal intubation > 24 hours. They were divided according to the outcome after extubation into 72 patients who didn’t develop laryngeal edema and 11 patients who developed laryngeal edema. The patients were extubated when they fulfilled the criteria of extubation and become negative to cuff leak test. All patients underwent both cuff leak test (CLT) and ultra-sound to assess air column width difference (ACWD) after intubation and before extubation.

Results: All patients were matched as regard demographic data. There was a significant increase in the duration of mechanical ventilation in the LE group. No significant difference was detected between the two groups regarding CLT and ACWD after intubation. However, cases with laryngeal edema had significantly lower CLT and ACWD before extubation. Using a cut off value of 1.52 mm, ACWD had sensitivity and specificity of 90.9 and 91.7% respectively to predict laryngeal edema after extubation.

Conclusions: Laryngeal Ultrasonography could be a useful, reliable, non-invasive method in the evaluation of vocal cords, laryngeal morphology and airflow passing through the vocal cords or subglottic area in intubated patients in comparison with cuff leak test.