Prospective studies evaluating the standard endotracheal tube and a prototype endotracheal tube.

Two prospective studies were designed to evaluate laryngeal injury sustained with the standard endotracheal tube (ETT) and the relative safety of a new prototype ETT. The first study followed patients after prolonged intubation with the standard ETT. Potential patient host factors were recorded and correlated with subjective complaints and objective findings on fiberoptic laryngoscopy. Nearly all patients sustained laryngeal injury after prolonged intubation, although over two thirds experienced resolution. Nasogastric feeding tubes and larger-diameter ETTs were associated with true vocal cord (TVC) granuloma formation. Duration of intubation was associated with delayed TVC immobility. The mechanisms of TVC granulomas and immobility are probably different, as suggested by the different host factor associations and onset times. The second study compared the standard ETT with the prototype ETT in short-term intubations. The prototype ETT was associated with no complications in this setting and is considered relatively safe for further testing in the patient with prolonged intubation.