Objective: to assess the effect of public-access defibrillation (PAD) on the outcomes of children with out-of-hospital cardiac arrest (OHCA) that received CPR by a bystander.
Design: retrospective propensity-score-matched cohort study.
Setting: population registry database of the Fire and Disaster Management Agency of Japan of cases of OHCA for 2011 and 2012.
Study sample: cases of OHCA in children aged more than 1 year and less than 18 years that underwent basic cardiopulmonary resuscitation (CPR) selected from the All-Japan Utstein Registry, which includes data for every case of OHCA in all age groups.
Methodology: to control for the selection bias characteristic of observational studies, the researchers used a propensity-matching approach,1 creating two cohorts of 50 cases, one in which PAD was used (intervention group [IG]) and another in which children received only CPR (control group [GC]), both of which were homogeneous with respect to potential confounding variables (sex, age, type of resuscitator, witnessed arrest, aetiology of arrest and year). They also fitted a multivariate logistic regression (MLR) model to the overall cohort and separately analysed certain subgroups based on characteristics known to influence outcomes, such as age, bystander witness or cardiac aetiology.
Outcome measurement: the primary outcome was neurologically favourable survival at one month, defined as a Glasgow–Pittsburgh cerebral performance category score of 1 (good performance) or 2 (moderate disability) over 5.2 The secondary outcomes were overall survival and prehospital return of spontaneous circulation. The data were recorded by trained Medical Emergency Department staff, who performed follow-up surveys to document outcomes one month after the OHCA. The effect size was estimated by means of odds ratios (ORs) with a 95% confidence interval (95 CI).
Main results: the authors collected data for a total of 1193 individuals that met the inclusion criteria, of which 57 had received PAD + CPR and the rest only CPR. In the analysis of the two propensity-matched cohorts, 31 of the 50 patients in the IG (62%) had a neurologically favourable survival at 1 month compared to 17 of the 50 patients in the CG (34%) (OR, 3.17 [95 CI, 1.40 to 7.17]). The IG also had a better overall survival at one month (68% versus 40%; OR: 3.19 [95 CI, 1.40 to 7.24]) and more frequent prehospital return of spontaneous circulation (68% versus 28%, OR, 5.46 [95 CI, 2.32 to 12.87]) compared to the CG. The MLR model for the overall cohort also showed enhanced neurological outcomes in patients in whom PAD was used (59.7% versus 13.6%; OR, 5.10 [95 IC, 2.01 to 13.70]). The only subgroups in which there was no evidence of improved outcomes with defibrillation were the unwitnessed subgroup (30% versus 17.7%; OR, 7.76 [95 CI, 0.75 to 81.90]) and the non-cardiac aetiology subgroup (el 30% versus 13.3%; OR, 6.65 [95 CI, 0.64 to 66.24]).
Conclusion: public-access defibrillation was associated with an increased chance of neurologically favourable survival in children aged 1 to 7 years that underwent out-of-hospital cardiac arrest who received bystander CPR, except in cases of unwitnessed arrest or non-cardiac aetiology.
Conflicts of interest: none disclosed.
Founding source: University of Tokyo.