Association between the timing of ICU admission and mortality in patients with hospital-onset sepsis: a nationwide prospective cohort study

Background: Based on sparse evidence, the current Surviving Sepsis Campaign guideline suggests that critically ill patients with sepsis be admitted to the intensive care unit (ICU) within 6 h. However, limited ICU bed availability often makes immediate transfer difficult, and it is unclear whether all patients will benefit from early admission to the ICU. Therefore, the purpose of this study was to determine the association between the timing of ICU admission and mortality in patients with hospital-onset sepsis. Methods: This nationwide prospective cohort study analyzed patients with hospital-onset sepsis admitted to the ICUs of 19 tertiary hospitals between September 2019 and December 2020. ICU admission was classified as either early (within 6 h) or delayed (beyond 6 h). The primary outcome of in-hospital mortality was compared using logistic regression adjusted for key prognostic factors in the unmatched and 1:1 propensity-score-matched cohorts. Subgroup and interaction analyses assessed whether in-hospital mortality varied according to baseline characteristics. Results: A total of 470 and 286 patients were included in the early and delayed admission groups, respectively. Early admission to the ICU did not significantly result in lower in-hospital mortality in both the unmatched (adjusted odds ratio [aOR], 1.35; 95% confidence interval [CI], 0.99–1.85) and matched cohorts (aOR, 1.38; 95% CI, 0.94–2.02). Subgroup analyses showed that patients with increasing lactate levels (aOR, 2.10; 95% CI, 1.37–3.23; P for interaction = 0.003), septic shock (aOR, 2.06; 95% CI, 1.31–3.22; P for interaction = 0.019), and those who needed mechanical ventilation (aOR, 1.92; 95% CI, 1.24–2.96; P for interaction = 0.027) or vasopressor support (aOR, 1.69; 95% CI, 1.17–2.44; P for interaction = 0.042) on the day of ICU admission had a higher risk of mortality with delayed admission. Conclusions: Among patients with hospital-onset sepsis, in-hospital mortality did not differ significantly between those with early and delayed ICU admission. However, as early intensive care may benefit those with increasing lactate levels, septic shock, and those who require vasopressors or ventilatory support, admission to the ICU within 6 h should be considered for these subsets of patients.