Performance of Termination-of-Resuscitation Rules in Foreign Body Airway Obstruction-Related Out-of-Hospital Cardiac...

Termination-of-resuscitation (TOR) rules were derived mainly from cardiac-origin out-of-hospital cardiac arrest (OHCA), but their interpretation in foreign body airway obstruction (FBAO)-related OHCA remains uncertain. This condition is a potentially reversible hypoxic arrest in which standard TOR criteria may perform differently. We evaluated the 2025 American Heart Association basic life support (BLS)-TOR and advanced life support (ALS)-TOR criteria in FBAO-related OHCA.

This secondary analysis of the prospective Multi-center Observational CHoking Investigation (MOCHI) registry included patients with FBAO-related OHCA transported to 25 Japanese hospitals from April 2020 to March 2023. For the primary TOR analysis, we included patients who had not achieved return of spontaneous circulation (ROSC) before emergency medical services (EMS) arrival, because TOR rules are intended for patients who remain in cardiac arrest at the time of EMS assessment. Patients were retrospectively classified according to BLS-TOR and ALS-TOR criteria. Primary measures were the specificity of TOR-positive status for predicting unfavorable neurological outcome, defined as the proportion of patients with favorable neurological outcome (Cerebral Performance Category 1-2) who were classified as TOR-negative, and the proportion of TOR-positive patients who nevertheless achieved favorable neurological outcome.

Of 248 patients with FBAO-related OHCA (median age, 81.5 years; 83.1% witnessed), 49 (19.8%) survived to 30 days and 9 (3.6%) achieved favorable neurological outcome. The BLS-TOR rule classified 150/229 evaluable patients as TOR-positive; 2 achieved favorable neurological outcome (1.3%; 95% CI, 0.4-4.7; specificity, 77.8% [95% CI, 45.3-93.7]), and 20 survived to 30 days (13.3%; 95% CI, 8.8-19.7). The ALS-TOR rule classified 12/242 patients as TOR-positive; none achieved favorable neurological outcome, but 4 survived to 30 days (33.3%; 95% CI, 13.8-60.9).

In FBAO-related OHCA, BLS-TOR would have classified two patients with favorable neurological outcome as TOR-positive. The ALS-TOR rule was restrictive, but small numbers and 30-day survival among TOR-positive patients preclude firm safety conclusions. Termination-of-resuscitation criteria warrant cautious, etiology-aware interpretation when FBAO is suspected.