Epidemiology and outcomes of poisoning-induced out-of-hospital cardiac arrest

Objectives: We aimed to describe and compare the epidemiologic features and outcomes among patients with poisoning-induced out-of-hospital cardiac arrests (POHCAs) according to causative agent groups.

Methods: We identified emergency medical service (EMS)-treated POHCA patients from a nationwide OHCA registry between 2006 and 2008, which was derived from EMS run sheets and followed by hospital record review. Utstein elements were collected and hospital outcomes (survival to admission and to discharge) were measured. We compared risk factors and outcomes according to the main poisons. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated from a multivariate logistic regression model for hospital outcomes.

Results: The total number of non-cardiac aetiology OHCAs was 20,536. Of these, the number of EMS-assessed and EMS-treated POHCAs was 900 (4.4%). For EMS-treated POHCAs, insecticides (n=111, 15.5%) including organophosphate and carbamates; herbicides (n=94, 13.2%); unknown pesticides (n=142, 19.9%); non-pesticide drugs (n=120, 16.8%); and unknown poisons (n=247, 6%) were identified. The survival to admission rate was 22.5% for insecticides, 3.2% for herbicides, 16.2% for unknown pesticides, 16.7% for non-pesticides and 11.3% for the unknown group. The survival to discharge rates were 9.9% for insecticides, 0.0% for herbicides, 2.1% for unknown pesticides, 3.3% for non-pesticides and 3.2% for the unknown group. The adjusted OR for each group for survival to admission was significantly lower when compared with insecticides: herbicides (OR=0.11, 95% CI=0.03-0.44), non-pesticide drugs (OR=0.28, 95% CI=0.13-0.61) and unknown group (OR=0.40, 95% CI=0.21-0.76). The adjusted OR for each group for survival to discharge was significantly lower when compared with insecticides: herbicides (OR<0.01, 95% CI<0.01 or >99.9), unknown pesticides (OR=0.23, 95% CI=0.0.06-0.87), non-pesticide drugs (OR=0.14, 95% CI=0.04-0.54) and unknown group (OR=0.30, 95% CI=0.11-0.83).

Conclusion: Using a nationwide OHCA registry, we found that poisonings were responsible for 4.4% of OHCAs of a non-cardiac aetiology. Ingestion of insecticides including organophosphate and carbamate was associated with more favourable outcomes.