Clinical characteristics, management, and outcomes of adults admitted to participating Japanese intensive care units with registry-identified anaphylactic shock: a multicenter retrospective descriptive study

Background Anaphylactic shock is an uncommon reason for admission to an intensive care unit (ICU). Existing multicenter Japanese data have focused on perioperative anaphylaxis, and the cross-setting Japanese ICU population has not been described. We aimed to describe such admissions, including those arriving from wards and the emergency department, in a voluntary multicenter Japanese registry. Methods This retrospective study used the Japanese Intensive Care Patient Database (JIPAD), a voluntary registry of participating Japanese ICUs; the unit of analysis was the ICU admission. Eligible records were admissions of patients aged 18 years or older between 1 April 2015 and 31 March 2024 (fiscal years 2015–2023) whose mandatory clinician-entered diagnosis text contained the Japanese stems for both “anaphylaxis” and “shock”; ICU readmissions were excluded. The descriptive cohort comprised 643 admissions; 632 admitted from the operating room, ward, or emergency department formed a route-stratified subset. Results Among 643 admissions, 62 (9.6%) followed cardiac arrest, and a continuous vasoactive infusion was recorded in 234 of the 558 admissions with the relevant fields available (41.9%). All-cause ICU mortality was 1.6% (10/643; 95% confidence interval [CI] 0.8–2.8) and all-cause index-hospital mortality 3.3% (21/643; 95% CI 2.1–4.9); 11 of these 21 deaths occurred after discharge alive from the ICU. Sixty-five admissions (10.1%) ended in transfer alive, with later outcomes unavailable. Conclusions Among ICU admissions with a registry diagnosis of anaphylactic shock at participating Japanese facilities, all-cause ICU mortality was lower than all-cause index-hospital mortality, and more than half of the index-hospital deaths occurred after ICU discharge. Causes of death were unavailable, so these deaths could not be attributed specifically to anaphylaxis.