Epidemiology and clinical outcomes of poisoning-induced cardiac arrest in Japan: Retrospective analysis of a nationwide registry.

Background: Poisoning is an important cause of out-of-hospital cardiac arrest which can be challenging to manage. Neurological outcomes after poisoning-induced out-of-hospital cardiac arrest (POHCA) are yet to be fully elucidated. This retrospective cohort study sought to describe the characteristics of POHCA, and identify factors associated with favourable neurologic outcomes.

Methods: Cardiac arrests recorded in the "All Japan Utstein Registry" from 1 January 2012 to 31 December 2017 were included. A descriptive analysis of the characteristics of POHCA and non-POHCA patients was performed. Neurological outcomes were compared between the POHCA and non-POHCA groups using logistic regression analysis. Subgroup analysis was performed for patients who underwent prolonged resuscitation.

Results: Compared to non-POHCA patients (n = 665,262), POHCA patients (n = 1,868) were younger (median age, 80 vs 51 years) and had a lower likelihood of having a witness, bystander cardiopulmonary resuscitation, and an initial shockable rhythm. Multivariable logistic regression analysis showed that POHCA was associated with favourable neurologic outcomes (odds ratio 1.54, 95 % confidence interval 1.19-2.01, p = 0.001). Among patients who received > 30 min of resuscitation, neurologic outcomes were similar in those with POHCA and non-POHCA (favourable neurologic outcome, 1.03 % vs 0.98 %, p = 0.87).

Conclusions: POHCA is associated with favourable neurological outcomes and requires aggressive resuscitation. However, in patients who required prolonged resuscitation, the outcomes of POHCA were not different from those of non-POHCA. The decision to perform prolonged resuscitation should be guided on a case-by-case basis based on a range of factors.