An epidemiological assessment of choking-induced out-of-hospital cardiac arrest: A post hoc analysis of the SOS-KANTO 2012 study

The aim of this study was to reveal the neurological outcomes of choking-induced out-of-hospital cardiac arrest (OHCA) and evaluate the presence of witnesses, cardiopulmonary resuscitation (CPR) performed by a witness (bystander-witnessed CPR), and the proportion of patients with favourable neurological outcomes by the time from CPR by emergency medical services (EMS) to the return of spontaneous circulation (ROSC) (CPR-ROSC time).We retrospectively analysed the SOS-KANTO 2012 database, which included data of 16,452 OHCAs in Japan. We selected choking-induced OHCA patients aged ≥ 20 years. We evaluated the neurological outcomes at 1 month with the Cerebral Performance Category (CPC). We defined favourable neurological outcomes (CPCs: 1-2) and present the outcomes with descriptive statistics.Of 1,045 choking-induced OHCA patients, 18 (1.7%) had a favourable neurological outcome. Of 1,045 OHCAs, 757 (72.6%) were witnessed, and 375 (36.0%) underwent bystander-witnessed CPR. Of the 18 OHCAs with favourable outcomes, 17 (94.4%) were witnessed, and 11 (61.1%) underwent bystander-witnessed CPR. With a CPR-ROSC time of 0-5 minutes, the proportion of patients with favourable neurological outcomes was 29.7%, ranging from 0% to 6% in the following time groups.The neurological outcome of choking-induced OHCA was poor. The neurological outcomes deteriorated rapidly from 5 minutes after the initiation of CPR by EMS. The presence of witnesses and bystander-witnessed CPR may be factors that contribute to improved outcomes, but the effects were not remarkable. As another approach to reduce deaths due to choking, citizen education for the prevention of choking may be effective.