Bystanders who witness a cardiac arrest often do not perform CPR because of fears of contamination and contagion.
Animal studies suggest that there is adequate oxygenated blood after primary cardiac arrest.
Population studied The study was performed in the Seattle, Washington area with a fire department-based emergency medical care system. Patients were enrolled if they had a cardiac arrest diagnosed over the telephone by the dispatcher and there was a bystander willing to be instructed. A total of 1296 patients were included in the trial. After receiving a 911 call, the EMS dispatcher would determine if the patient was eligible for this study. Based on computer randomization, the dispatcher provided instructions for traditional CPR or chest compressions alone.