The evaluation of the degree of laryngeal obstruction to indicate a tracheostomy has always been a subjective decision. The authors correlated the visual laryngeal obstruction by flexible nasolaryngoscopy and the peak inspiratory flow using a pocket peak inspiratory flowmeter. Twenty-two patients were evaluated (21 with upper aero-digestive tract malignancies and one with bilateral vocal fold paralysis).
The mean value of the PIF was 53.13 L/min and this was the cutoff value for the decision for tracheostomy (18.3% of the theoretical expected value). This value is close to the previously reported minimal value of 60 L/min as a predictor of decannulation in tracheostomised patients.
This study is interesting but has some limitations due to the acute nature of the obstruction, the lack of controls and the wide range of error of the apparatus (+/- 10%). However, this remains a simple reproducible and easily mastered technique for the objective assessment of patients with acute upper respiratory tract obstruction for decision making.
