Association between timing of intubation and outcome in critically ill patients: A secondary analysis of the ICON audit

Purpose The optimal timing of endotracheal intubation in critically ill patients requiring invasive mechanical ventilation remains undefined. Material and methods In a secondary analysis of the large, prospective ICON database, we used a piecewise proportional hazards model to compare outcomes in patients who underwent intubation early (within two days after intensive care unit [ICU] admission) or later. Results After excluding 5340 patients already intubated on admission or with therapeutic limitation, 4729 patients were analyzed, of whom 4074 never underwent intubation. Of the remaining 655 patients, 449 underwent intubation early and 206 later. Despite similar severity scores on ICU admission, unadjusted ICU (27.6 vs. 18.2%) and hospital (33.3 vs. 23.4%) mortality rates were higher in patients intubated later than in those intubated earlier, as were ICU (9 [5–16] vs. 4 [2–9] days) and hospital (24 [9–35] vs. 13 [7–24] days) lengths-of-stay (all p < 0.001). After adjustment, the hazard for ICU and hospital death was significantly greater > 10 days after ICU admission for patients intubated late. Conclusions In this large cohort of critically ill patients requiring intubation, intubation > 2 days after admission was associated with increased mortality later in the hospital course.