TIME FROM HOSPITAL ADMISSION TO ONSET OF SEPTIC SHOCK IS ASSOCIATED WITH HIGHER IN-HOSPITAL MORTALITY.

Objective: Several studies have shown septic shock developing later during the hospital stay is associated with higher mortality. However, the precise point at which time from hospital admission to the onset of septic shock (admission-shock-onset-time) becomes an independent prognostic marker of mortality remains unknown. This study evaluated the association between admission-shock-onset-time and in-hospital mortality among patients with septic shock and the optimal cutoff period to categorize early- and late-onset septic shock. Method: We conducted a single-center retrospective, observational cohort study at a quaternary academic hospital comprising adult patients with septic shock admitted to a medical intensive care unit (ICU) from January 2011 to December 2020. A multivariable additive logistic regression model was developed to assess if log-transformed admission-shock-onset-time was associated with in-hospital mortality. The thin plate spline function was used to describe the nonlinear relationship between the log-transformed admission-shock-onset-time and in-hospital mortality. The primary outcome was in-hospital mortality, and the secondary outcome was ICU mortality. Results: Two thousand five hundred twenty patients met the inclusion criteria with an overall in-hospital mortality of 37.3%. The log-transformed admission-shock-onset-time was associated with higher in-hospital and ICU mortality even after adjusting for clinical variables. The odds ratio for in-hospital mortality continued to increase throughout the observation period. The adjusted odds ratio exceeded 2 in between 20.1 and 54.6 h, and it surpassed 3 in between 54.6 and 148.4 h of the time from the hospital admission to shock onset. Conclusion: In-hospital mortality continued to rise as admission-shock-onset-time increased in patients with septic shock. No clear dichotomization between early and late septic shock could be ascertained, and this categorization may limit our understanding of the temporal relationship of shock onset to mortality.