Outcomes and Factors Associated with Occult Septic Shock in Emergency Department Patients with Soft Tissue Infection

INTRODUCTION: Patients who develop occult septic shock (OSS) are associated with worse outcomes than those with early septic shock (ESS). Patients with skin and soft tissue infection (SSTI) may have underlying organ dysfunction due to OSS, yet the prevalence and the outcomes of patients with SSTI and early versus occult shock have not been described. This study compared the clinical characteristics of SSTI patients and the prevalence of having no septic shock (NSS), ESS, or OSS. METHODS: We retrospectively analyzed charts of adult patients who were transferred from any emergency department to our academic center between January 1, 2014, and December 31, 2016. Outcomes of interest were the development of OSS and acute kidney injury (AKI). We performed logistic regressions to measure the association between clinical factors with the outcomes and created probability plots to show the relationship between key clinical variables and outcomes of OSS or AKI. RESULTS: Among 269 patients, 218 (81%) patients had NSS, 16 (6%) patients had ESS, and 35 (13%) patients had OSS. Patients with OSS had higher mean serum lactate concentrations than patients with NSS (3.5 vs. 2.1 mmol/L, P < 0.01). Higher sequential organ failure assessment (SOFA) score was associated with higher likelihood of developing OSS (odds ratio [OR] 1.41, 95% confidence interval [CI] 1.23–1.62, P < 0.001). NSS was associated with very low odds of developing AKI (OR 0.16, 95% CI 0.08–0.33, P < 0.001). CONCLUSIONS: 13% of the patients with SSTI developed OSS. Patients with OSS had elevated serum lactate concentration and higher SOFA score than those with NSS. Increased SOFA score is a predictor for the development of OSS.