A retrospective study on epidemiological analysis of pre-hospital emergency care in Hangzhou, China

Abstract

Out-of-hospital cardiac arrest (OHCA) is a leading cause of global mortality, with numerous factors influencing the patient survival rate and prognosis. This study aimed to evaluate the OHCA epidemiology in China and elaborate on the current Hangzhou emergency system status. This retrospective analysis was based on the medical history system of the Hangzhou Emergency Center registered from 2015-2021. We provided a detailed description of OHCA characteristics and investigated the factors affecting the success rate of emergency treatment in terms of epidemiology, causes of onset, bystander rescue, and outcome factors. We included 9585 out-of-hospital cardiac arrest cases, of which 5442 (56.8%) had evidence of resuscitation. Patients with underlying diseases constituted the vast majority (80.1%); trauma and physicochemical factors accounted for 16.5% and 3.4%, respectively. Only 30.4% of patients (about 80.0% of bystanders witnessed) received bystander first aid. The outcome rate of emergency doctors dispatched by emergency centres was significantly higher than doctors dispatched by hospitals. Additionally, physician's first-aid experience, emergency response time, emergency telephone availability, initial heart rhythm, out-of-hospital defibrillation, out-of-hospital intubation, and using of epinephrine significantly can significantly improve the out-of-hospital return of spontaneous circulation in patients. All steps in pre-hospital care are important for patients, especially for bystander first aid and physician's first-aid experience. The popularity of first-aid training and the public emergency medical system are not potent enough. We should take those key factors into consideration when developing a pre-hospital care system for OHCA.

Fig 1. Demographic information of emergency patients with cardiac arrest.

The number of emergency patients with cardiac arrest is indicated yearly (2015–2021) (A). The number of emergency patients with cardiac arrest by sex is indicated yearly (2015–2021) (B). The number of emergency patients by sex among the different causes of cardiac arrest, including disease, physicochemical stimulation, and trauma (C). Age distribution of patients with cardiac arrest due to different causes (disease: Blue, physicochemical: Red, trauma: Green) is indicated yearly (D) (* p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001).

Fig 2. Analysis of onset time in patients with cardiac arrest.

The number of occurrences in emergency patients with cardiac arrest at different times daily (different colored lines represent different years) (A). And the number of occurrences in emergency patients with cardiac arrest at different times attributable to disease (B), physicochemical causes (C), and trauma (D) daily.

Fig 3. Analysis of causes of death in different types of patients with OHCA.

Death proportions in cardiac arrest due to disease (left), physicochemical causes (middle), and trauma (right).

Fig 4. Analysis of on-site treatment of bystanders.

The proportion of bystanders and bystanders who performed first aid during cardiac arrest is indicated for overall (A) and each year (2015–2021) (B). The blue bars represent the percentage of all patients, the red bars represent the percentage of bystanders, and the green bars represent the percentage of treatment. Proportion of different types of people in bystanders (C). The proportion of different types of witnesses in different causes of cardiac arrest and the proportion of treatment taken (D). Proportion of all treatments using OCC (red) and CPR (green) each year (2015–2021) (E). OCC: Open chest cardiac compression. CPR: Cardiopulmonary resuscitation. Correct rate (red) and incorrect rate (green) of rescue by bystanders (F).