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Cardiac Arrest
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EMS medical care provided to cardiac arrest patients has changed dramatically over time. Ambulances initially functioned merely as transport vehicles, while today EMS is an integrated part of the health care system with the ability to provide advanced life support while en route to a hospital. Regional dispatch centers now decide which resources should respond to an emergency call. Dispatchers, trained in emergency medical dispatch (EMD) techniques, have specific protocols to follow to determine whether basic life support (BLS) or advanced life support (ALS) EMS response is required. Prearrival instructions to bystanders can help expedite initial first aid or CPR.1–4 Recently protocols have expanded the role of EMS providers in treating out-of-hospital cardiac arrest (OCHA) patients ranging from beginning therapeutic hypothermia in the field to bypassing hospitals in favor of a specialized receiving facility.
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Historically, much of EMS medical care grew out of traditional practice with little scientific basis. Today EMS practice is influenced by evidence-based medicine concepts as more rigorous studies are completed and systems demand proven benefit prior to the introduction of new procedures, drugs, and adjuncts in prehospital patient care. This is particularly true with OHCA patients where ongoing research is continually investigating the best treatment options. The American Heart Association (AHA) periodically scientifically reviews recent literature and makes recommendations for treatment changes based on the strength and results of these studies. Prehospital resuscitations guidelines often follow the AHA recommendations closely due to the rigorous scientific process utilized in their updates. The most recent AHA update occurred in 2010, and many of the studies and papers reviewed for the most recent guidelines are discussed in this chapter.
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Review the demographics and presentations of out-of-hospital cardiac arrest (OHCA) patients.
Discuss system access, response types, and processes.
Discuss current prehospital management of OHCA.
Review prehospital OHCA outcomes.
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The Framingham Heart Study reports that from 1950 to 1999, 48% of sudden cardiac deaths (SCD) and 20% of nonsudden coronary heart disease deaths occurred in patients without previously known coronary artery disease.5 Rea et al reported that from 1986 to 1994, the overall incidence of cardiac arrest was 1.89 per 1000 subject years, further breaking this down to an incidence of 0.7, 1.91, and 4.1 per 1000 subject years for the age ranges of 50 to 59, 60 to 69, and 70 to 79, respectively. The incidence of cardiac arrest in males was 2.89 compared to 1.04 for females. Compared to other risk factors, a diagnosis of congestive heart failure carried a cardiac arrest incidence of 21.87 per 1000 subject years, while a history of diabetes mellitus, previous MI, smoking, and hypertension produced incidences of 13.8, 13.69, 9.18, and 7.54, respectively.6 Cardiac arrests, along with myocardial infarction and unstable angina complaints, appear to have a circadian variation with a morning peak shortly after ...