Post-intubation laryngeal injuries and extubation failure: a fiberoptic endoscopic study

Abstract

To describe laryngeal injuries after intubation in an intensive care unit and assess their risk factors and their association with post-extubation stridor (PES) and extubation failure. Prospective study including 136 patients extubated after more than 24 h of mechanical ventilation. Fiberoptic endoscopic examination of the larynx was systemically performed within 6 h after extubation in order to record four types of laryngeal anomalies: edema, ulceration, granulation, and abnormal vocal cord (VC) mobility. Median duration of intubation was 3 days (min 24 h, max 56 days). Laryngeal injuries were frequent (73% of patients) and were associated with duration of intubation [odds ratios (OR) 1.11, 95% confidence interval (CI) 1.02-1.21, P = 0.02] and absence of use of myorelaxant drugs at intubation (OR 0.13, 95% CI 0.01-0.99, P = 0.05). Eighteen patients presented a PES. Lesions associated with PES were edema (67%, P < 0.01) and abnormal VC mobility (67%, P < 0.01). These injuries were associated with duration of intubation (OR 1.05, 95% CI 1.01-1.09, P = 0.04), emergency intubation (OR 2.7, 95% CI 1.2-6.4, P = 0.02), and height/endotracheal tube size ratio (OR 0.97, 95% CI 0.95-0.99, P = 0.01). Seventeen patients were reintubated within 48 h following extubation. Laryngeal examination of these patients more frequently showed granulation (29.4%, P = 0.02) and abnormal VC mobility (58.8%, P < 0.01). This study found a high frequency of laryngeal injuries after extubation in ICU, which were associated with intubation duration and patient's height/ETT size ratio. Edema was not the only injury responsible for PES, and although edema is frequent it is not the only injury associated with reintubation.