Objective: The cuff-leak test has been proposed as a simple tool to clinically predict stridor or respiratory distress secondary to laryngeal edema following extubation. However, the true incidence of laryngeal edema in patients on long-term mechanical ventilation is uncertain. The relationship between upper airway obstruction (detected by video bronchoscopy) and the cuff-leak test value for patients with prolonged translaryngeal intubation during percutaneous dilatational tracheostomy (PDT) was investigated.
Design: Prospective, clinical investigation.
Setting: Intensive care unit of a university hospital.
Patients: Ninety-five patients with prolonged translaryngeal intubation requiring PDT were enrolled during a 12-month period.
Interventions: Cuff-leak test, PDT, video bronchoscopy.
Measurements and main results: The average duration of translaryngeal intubation was 28.1 +/- 17.6 days. The incidence of severe laryngeal edema was 36.8% (35/95). We chose 140 mL as the threshold cuff-leak volume below which edema is indicated. The rate of cuff-leak test positivity was 38.9% (37/95). The sensitivity and the specificity of the test were 88.6% and 90.0%, respectively. The positive and negative predictive values were 83.8% and 93.1%, respectively. Patients who developed severe laryngeal edema had a smaller leak volume than those who did not, expressed in absolute values (53.9 +/- 56.2 vs. 287.9 +/- 120.0 mL; p < .001) or in relative values (10.1 +/- 10.2 vs. 55.3 +/- 22.7%, p < .001). The occurrence of severe laryngeal edema was not associated with age, gender, body weight, respiratory failure due to pneumonia, duration of translaryngeal intubation, endotracheal tube diameter, Acute Physiology and Chronic Health Evaluation II score, or history of self-extubation.
Conclusions: A reduced cuff-leak volume measured before PDT may signal the presence of severe laryngeal edema in patients on long-term mechanical ventilation.