Overnight stay in the emergency department and mortality in sepsis patients

Background Sepsis management in the emergency department (ED) faces challenges due to overcrowding and prolonged boarding, yet the impact of overnight ED stays on outcomes remains unclear. This study evaluated whether sepsis patients who spend a night in the ED waiting for admission to a ward/intensive care unit (ICU) are at increased risk of in-hospital mortality or morbidity. Methods This was a retrospective cohort study of sepsis patients who visited the ED and were admitted to the hospital between January 2021 and August 2024 across the ED of a large general hospital in China. Patients were stratified into an overnight ED stay (midnight–8:00 AM) and a non-overnight (admitted to a ward/ICUs before midnight) group. The primary outcome was in-hospital mortality; secondary outcomes included septic shock, ICU admission, invasive mechanical ventilation (IMV) and length of stay (LOS). Multivariable logistic regression and sensitivity analyses were used to compare end points between groups. Results A total of 1,208 sepsis patients were enrolled in the study, including 503 (42%) female and 705 (58%) male, with 624 (51.7%) in the overnight ED stay group and 584 (48.3%) in the non-overnight ED stay group. Baseline characteristics were balanced between groups. Unadjusted in-hospital mortality was similar (21.2% vs . 21.7%; risk difference (RD) 0.59 [−4.04 to 5.23]). Adjusted logistic regression analyses confirmed no mortality association (adjusted odds ratio (aOR) (95% confidence interval (CI)), 1.090 [0.805–1.477]; P = 0.579). No higher risk was observed for secondary outcomes: septic shock (aOR (95% CI), 1.020 [0.747–1.393]; P = 0.903), ICU admission (aOR 1.362 [0.983–1.895]; P = 0.064), or IMV (aOR (95% CI), 1.048 [0.710–1.549]; P = 0.813). Compliance with the Surviving Sepsis Campaign (SSC) guidelines was comparable between groups(31.6% vs . 29.1%; RD, −2.46 [−7.63 to 2.73]). These findings were consistent across subgroups and sensitivity analyses. Conclusions In this retrospective cohort study, overnight ED boarding was not associated with increased in-hospital mortality or morbidity among sepsis patients when care adhered to SSC guidelines. These results suggest that high compliance with the SSC 1-h bundle may help mitigate potential risks associated with overnight ED boarding.