The effectiveness of dispatcher-assisted cardio-pulmonary resuscitation on survival of out-of-hospital cardiac arrest: a literature review

Background According to data from Department of Health, in 2011 heart diseases was the second commonest leading cause of death in Hong Kong [13]. Shortening the time from cardiac arrest to Cardio-pulmonary Resuscitation (CPR) could increase the chance of survival. If the brain of the patient who suffers from cardiac arrest does not receive oxygen within 4 minutes, severe brain damage might occur [14]. In some countries like US and Finland, dispatcher will give CPR instruction to caller when cardiac arrest is recognized. Therefore, the patient could receive early CPR before the arrival of paramedics. If dispatcher-assisted CPR is implemented in Hong Kong, the chance of survival of out-of-hospital cardiac arrest (OHCA) patient could be increased. Objective 1. To evaluate whether it is evident that dispatcher-assisted CPR and dispatcher instruction [22] would improve survival of OHCA. 2. To evaluate whether these measures could be implemented in Hong Kong. Data Source PubMed was searched for articles in English language with no limit set for time of the study. The keywords were dispatcher-assisted CPR and out of hospital. No inclusion criteria were set on the publication type and other details. Results Initial PubMed search resulted in 24 articles. After reviewing the abstracts, 10 articles were selected for full-text assessment. Finally, four relevant articles were selected for the literature review. Of the four papers, two were retrospective cohort studies; one was before-after comparison study while the remaining one was randomized control trial. Three papers (Rea et al, Eisenberg et al, and Kuisma et al.) used the survival to hospital discharge as the effect measure for the primary outcome to evaluate the effectiveness of dispatcher-assisted CPR. The remaining paper (Hallstrom et al.) mainly studied the potential benefit and harm from dispatcher-assisted CPR. Using no bystander CPR as the reference group, the multivariate adjusted odds ratio of survival was 1.45 (95% CI, 1.21, 1.73) for dispatcher-assisted bystander CPR and 1.69 (95% CI, 1.42, 2.01) for bystander CPR without dispatcher assistance [2]. The percentage of total bystander-initiated CPR increased from 45% to 56% after the programme (difference: 11.1%, 95% CI, ±9.3%). Besides, the percentage discharged for dispatcher-assisted CPR group after the programme was 15% higher than that before the programme [6]. The most important findings are related to the number of cardiac arrest calls in that when the dispatcher handled on less than 4 Ventricular Fibrillation (VF) calls during the study period, the survival to hospital discharge was 22.1% compared to 38.2% and 39.4% when the dispatcher handled 4 to 9 calls or more than 9 calls (p = 0.0227 for the three groups) [8]. With telephone guided CPR, the survival to hospital discharge was 43.1% compared with 31.7% when CPR instructions were not provided (p = 0.0453) [8]. In patients (n = 3,320) receiving advanced cardiac life support (ACLS) a total of 993 (29.9%) was found to be benefited from dispatcher-assisted CPR [7]. Conclusion Instructions by dispatcher can improve bystander CPR rates, which in turn increases the chance of survival [26]. Dispatcher-assisted CPR is worth considering to be recommended to all callers reporting a patient in cardiac arrest in Hong Kong.published_or_final_versionPublic HealthMasterMaster of Public Healt