Timing of Admission to the Surgical Intensive Care Unit is Associated with in-Hospital Mortality

Background: Knowledge about the relationship between timing of admission to the intensive care unit (ICU) and mortality among surgical patients admitted for acute care is limited.Objective: We aimed to investigate whether admission to the surgical intensive care unit (SICU) during after-hours (all the times when intensivists were not staffed in the ICU) was associated with in-hospital mortality.Methods: This retrospective cohort study was conducted at a tertiary academic hospital, in which we analyzed data of 571 patients admitted to the SICU whose complete medical records were available. The work-hours were defined as 07:00-19:00 from Monday to Friday during which intensivists were staffed in the ICU. The after-hours were defined as all other times during which intensivists were not staffed in the SICU. The primary outcome measurement was in-hospital mortality according to the time of SICU admission.Results: In all, 333 and 238 patients were admitted to the SICU during work-hours and after-hours, respectively. Unplanned admissions (33.3% vs. 47.1%, p<0.001), Acute Physiology and Chronic Health Evaluation II score ≥25 (11.1% vs. 23.9%, p<0.001), ventilator support (17.4% vs. 34.0%, p<0.001), and use of inotropics (33.3% vs. 50.0%, p<0.001) were significantly higher in the after-hours group than in the work-hours group. In the multivariate analyses of the association between the time of SICU admission and in-hospital mortality, the timing of SICU admission was an independent factor for in-hospital mortality (OR=2.526; 95% CI=1.010-6.320, p=0.048). Conclusions: In this study, we found that admission to the SICU during after-hours was associated with increased in-hospital mortality.