The influence of emergency medical procedures and event circumstances on the acute effectiveness of resuscitation in out-of-hospital sudden cardiac arrest in adults

Introduction. Sudden cardiac arrest is a serious medical event that may occur unexpectedly. It is a serious medical and social issue. Aim. The aim of the study is an analysis of the relationship between the type of medical rescue actions taken and return of spontaneous circulation (ROSC) in adults. Material and methods. The case-control study was based on the medical documentation of the Rescue Service in Katowice collected in 2017. The results have been presented by means of proportions (sample size and sampling rate), median and IQR. Non-parametric methods (Pearson’s chi-squared test or Mann-Whitney U test) were used to compare the group of ROSC-patients with the group of no-ROSCpatients. The default statistical significance adopted for the purpose of all analyses was 0.05. Results. The analysis covered 1713 out-of-hospital sudden cardiac arrest (SCA) cases. Male patients constituted 63.68% (N = 1091) of the group, whereas female patients constituted only 34.5% (N = 591) of the cases. Women were older than men (69.5 vs. 62.9; p = 0.000). However, defibrillation was more frequently applied in men than in women (p = 0.000). In a majority of cases, SCA occurred in domestic conditions (p = 0.000) during the day (p = 0.000). ROSC was reported in 591 cases (34.51%). The ROSC rate was higher in cases when witnesses provided first aid to patients (35.6 vs. 31.41%; p = 0.08). The rate was also higher in patients with ventricular fibrillation than in patients with asystole (56.27 vs. 24.95%; p = 0.000). Conclusions. ROSC depends on the emergency medical procedures actions performed at the place of incident. The ROSC rate in patients is significantly higher when procedures are performed according to the current medical knowledge.