Endotracheal Intubation Using a Direct Laryngoscope and the Protective Performances of Respirators: A Randomized Trial

Purpose. Emergency physicians are at risk for infection during invasive procedures, and the respirators can reduce this risk. This study aimed to determine whether endotracheal intubation using direct laryngoscopes affected protection performances of respirators. Methods. A randomized crossover study of 24 emergency physicians was performed. We performed quantitative fit tests using respirators (cup type, fold type without a valve, and fold type with a valve) before and during intubation. The primary outcome was respirators' fit factors (FF), and secondary outcomes were acceptable protection (percentage of scores above 100 FF [FF%]). Results. 24 pieces of data were analyzed. Compared to fold-type respirator without a valve, FF and FF% values were lower when participants wore a cup-type respirator (200 FF [200-200] versus 200 FF [102.75-200], 100% [78.61-100] versus 74.16% [36.1-98.9]; all P < 0.05) or fold-type respirator with a valve (200 FF [200-200] versus 142.5 FF [63.50-200], 100% [76.10-100] versus 62.50% [8.13-100]; all P < 0.05). There were no significant differences in intubation time and success rate according to respirator types. Conclusions. Motion during endotracheal intubation using direct laryngoscopes influenced the protective performance of some respirators. Therefore, emergency physicians should identify and wear respirators that provide the best personalized fit for intended tasks.