Improving outcomes from cardiac arrest—the pre-hospital contribution

Despite the overall improvement in cardiovascular disease outcomes in the past decade, the survival of people following an Out of Hospital Cardiac Arrest (OHCA) has remained relatively low, at about 5 to 10% (Sasson et al, 2010). This lack of improvement in OHCA survival is disappointing, however, there are currently several promising interventions emerging that demonstrate the potential to improve these outcomes in the future. The well-established methodological chain of survival that follows as rapidly as possible after an OHCA event, and the two procedures involved therein, can only be said to be as strong or reliable as the weakest link, with the central links depicting the integration of cardiopulmonary resuscitation (CPR) and defibrillation as the fundamental components of early resuscitation in an attempt to restore life (Nolan et al, 2006). This is where recent protocols have been focusing in order to improve patient outcomes by ensuring that the core element of ongoing chest compressions is emphasized. Getting bystanders involved at an early stage is also important, as lay people are the most likely to arrive first at the scene of a cardiac arrest and many of them lack the confidence and training to offer help they are quite capable of providing. Successful strategies that can be employed to increase the level of bystander CPR performance include increasing coverage of CPR training, improving dispatcher assisted CPR, and increased participation of CPR by reassuring people that their efforts can be successful. Furthermore, untrained bystanders who may be dissuaded from performing CPR, as they are unwilling to provide ventilation, should be encouraged to perform compressions only. There is unequivocal evidence demonstrating an inverse relationship between the time taken to perform the first defibrillation on the patient, and survival from Ventricular Fibriliation (VF). A key factor in combating OHCA, therefore, would be an increased number of public access defibrillation units, combined with good quality chest compressions (Nolan et al, 2006). On the other hand however, a 2-tier response system in which Emergency Medical Services (EMS) oversee the activity of lay volunteers and non-medical EMS equipped with automatic external defibrillators (AEDs), have also shown considerable promise.