Abstract Rationale Among critically ill adults undergoing tracheal intubation, the size (i.e. inner diameter) of an endotracheal tube (ETT) may impact patient outcome, but tube size is often selected arbitrarily. We sought to evaluate the association between ETT size, relative to body height, and hospital mortality. Methods In this retrospective observational study, we analyzed all tracheal intubation procedures performed outside of the operating room for patients 18 years of age at a single center (2010-2024). Intubations missing ETT size or patient height were excluded. The exposure of interest was ETT size, categorized as small, recommended-for-height, or large based on a published nomogram. Tube inner diameter in the small and large ETT groups differed from the recommended-for-height group by 0.5 mm. The primary outcome was in-hospital mortality and the secondary outcome was the duration of mechanical ventilation. We used logistic and quantile regression to model the association between ETT size and the primary and secondary outcomes, respectively. Both models were adjusted for age, sex, year, admitting intensive care unit (medical vs. surgical), and pre-selected co-morbidities. Results Among 12,550 intubations for 10,281 critically ill adults, the median age (interquartile range) was 51 years (35-64), 67% were male, and the most frequent ETT size was 7.5 mm (83% of intubations). Applying the height-based nomogram, the ETT size was categorized as small in 3,066 intubations (24%), recommended-for-height in 7,266 (58%), and large in 2,218 (18%). As compared to the group intubated with a recommended-for-height ETT, the large ETT group experienced similar mortality (adjusted odds ratio aOR 1.05, 95% CI 0.92 to 1.20); however, the small ETT group experienced 12% lower odds of in-hospital mortality (aOR 0.88, 95% CI 0.77 to 0.99). The median duration of mechanical ventilation in the small ETT, recommended-for-height ETT, and large ETT groups was 90.5 hours (28-257), 85 hours (27-240), and 104 hours (32-283), respectively. The adjusted difference in median ventilator duration between the small ETT and recommended-for-height ETT group was +3.5 hours (95% CI -3.7 to 10.8), and between the large ETT and recommended-for-height ETT group was +10.4 hours (95% CI 2.2 to 18.5). Conclusions In this single center study of critically ill adults, 42% of tracheal intubations used an ETT that was smaller or larger than recommended according to a height-based nomogram. The observed independent association between smaller than recommended ETTs and lower mortality warrants further study in a randomized clinical trial. This abstract is funded by: None
Herzig et al. (Fri,) studied this question.