Annals of emergency medicine
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Several clinical studies have yielded conflicting results in examining the effectiveness of bystander CPR (BCPR). The purpose of this pilot study was to determine the effectiveness of BCPR in an animal model of cardiac arrest and resuscitation. Ten swine were instrumented for hemodynamic and regional blood flow measurements with tracer microspheres. ⋯ Cortical cerebral blood flow was initially 2.0 +/- 2.8 and fell to 0.6 +/- 0.8 mL/min/100 g during the last two and one-half minutes of BCPR. There were no statistical differences in myocardial blood flow and cerebral blood flow between the initial or late stages of BCPR (P greater than .14). There were no statistical differences in myocardial blood flow and cerebral blood flow between BCPR and NBCPR groups after epinephrine administration (P greater than .09).(ABSTRACT TRUNCATED AT 250 WORDS)
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Cardiopulmonary bypass (CPB) reperfusion has demonstrated improved resuscitation rates in ventricular fibrillation cardiac arrest models. To investigate the effectiveness of CPB reperfusion in an ischemic cardiac arrest setting, simulating the clinical scenario of myocardial ischemia preceding sudden cardiac death, we developed a canine model of acute myocardial infarction followed by ventricular fibrillation. Sixteen dogs were randomly assigned to two groups. ⋯ Myocardial ischemic and necrotic areas were determined in four-hour survivors by dual histochemical staining. All animals were resuscitated; all eight group 1 and six of eight group 2 animals survived to four hours. With the onset of CPB, coronary perfusion pressures increased significantly by 68.6 +/- 31.8 (SD) mm Hg in group 1 and 56.2 +/- 34.6 mm Hg in group 2 over those obtained with CPR (P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)