EMS services provide high-impact acute care for illness and injury throughout the United States. According to the AAA, there were 840,699 EMS personnel in the US in 2007. The patients these providers care for can present with high-impact conditions, such as cardiac arrest and trauma; conditions for which the EMS system was originally developed. In recent years, much new evidence has accumulated to inform and guide the care and treatment for SCA victims. Some notable examples are below.
Resuscitation From Sudden Cardiac Arrest
Sudden cardiac arrest is one of the two conditions for which EMS systems were originally designed. Successful resuscitation for patients in cardiac arrest requires a systems approach. Because of its extreme emergent onset and limited window for intervention, successful systems must develop an integrated, community-wide system of care, beginning with bystander care and continuing through coordinated care in the hospital.
Bystander CPR and AED Use
Bystander CPR can triple a victim’s chance of survival, and is crucial to the patient’s viability while EMS is en route.
Dispatcher Assisted CPR Instructions
Dispatch systems should provide effective just-in-time compression only CPR instruction over the phone to bystanders who access the 911 system.
EMS system personnel must work together using the most evidence-based approach to provide circulation and perfusion during the EMS encounter. Current literature supports the strict limitation of pauses in chest compressions and the use of a system to ensure that rescuers provide high-quality CPR (Pit Crew Resuscitation strategies).
Currently, there is no evidence to support the use of drugs for resuscitation, but some medications may be necessary to stabilize patients following return of spontaneous circulation and in the light of the current emphasis on circulation and perfusion, use of the standard resuscitation drugs should be re-evaluated.
Use of the Cardiac Monitor/Defibrillator
The cardiac monitor/defibrillator is essential to monitor cardiac rhythm, and to provide defibrillation therapy which can be successful for up to 52% of patients with an initial rhythm of VF. Following ROSC patients may be continuously monitored to watch for rearrest, and also to detect any myocardial infarction that may develop.
To date, real-time feedback devices have not been demonstrated to improve survival and may distract crews from attending to the patient.
Endotracheal intubation has taken a secondary role to compressions, what was previously termed the ABCs (Airway, Breathing, Circulation) has been re-emphasized as CAB (Circulation, Airway, Breathing). Intubation is a difficult clinical skill, one for which EMS personnel do not generally receive enough practice, and so, it must be performed carefully.
Use of end-tidal CO2 waveform technology, provided by current monitor/defibrillators must be used to ensure that intubation is successful and that the airway remains intact. End tidal CO2 is also useful for gauging the need for ventilation, and in some cases, when chest compression has optimal and the ET tube placement is confirmed, the lack of end tidal CO2 may confirm that the patient is metabolically beyond resuscitation efforts.
There is no current evidence to suggest that initiating therapeutic hypothermia in the field, or intra-arrest, affects survival or neurological outcome. However, once ROSC is established, therapeutic hypothermia care provided well in the hospital setting has been shown to significantly affect positive neurologic outcome for patients.
Cardiac Arrest Center of Excellence
Patients should be taken to a hospital that is either a Cardiac Care Center of Excellence or a hospital that offers the range of services required by these patients. This likely includes a high volume of cardiac arrest patients, 24/7 access to a cath lab, electrophysiology services, critical care professionals with experience in providing therapeutic hypothermia and neuro critical care. Often genetic counseling may be necessary for these patients and their families, and support of survivors and their families in the form of access to psychological services and survivor groups is indicated.
Hospitals and EMS agencies must work together to share outcome data which will inform best practices and provide powerful quality improvement initiatives for both hospital and EMS providers. Use of CPR analytic software to evaluate cases is encouraged.
Sudden cardiac arrest is a condition for which there will likely be development of new technology in the near future. New technologies should be well studied in appropriate clinical settings before being adopted by EMS.