Annals of emergency medicine
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Case Reports
Aortoiliac occlusion secondary to atherosclerotic plaque rupture as the result of blunt trauma.
Abdominal aortic injuries secondary to blunt trauma are uncommon, particularly without associated visceral injury or external signs of localized trauma. Blunt trauma-induced abdominal aortic injuries most frequently result in intimal tearing. ⋯ Atherosclerotic disease may be present in young asymptomatic individuals and may be a predisposing factor for aortic intimal tearing. A high degree of suspicion and periodic reassessment of peripheral circulation in trauma patients are required to ensure early diagnosis of this injury.
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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)
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Comparative Study
End-tidal CO2 measurement in the detection of esophageal intubation during cardiac arrest.
Measurement of end-tidal carbon dioxide (ETCO2) has been used to detect accidental esophageal tube placement in noncardiac arrest situations. The purpose of our study was to determine whether ETCO2 measurement could distinguish tracheal from esophageal tube placement during closed-chest massage (CCM). Twelve large dogs were anesthetized, and endotracheal tubes were placed in both the trachea and the esophagus. ⋯ In group B, ETCO2 ranged from 2 to 11 mm Hg (median, 3 mm Hg). In this experimental model, measurement of ETCO2 reliably distinguished esophageal from tracheal intubation during cardiac arrest and CCM. If confirmed in human beings, this may prove to be a quick, reliable method of detecting esophageal intubation during cardiac arrest.
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Previous studies in dogs have shown resuscitation from prolonged cardiac arrest to conscious survival to be more effective with the use of cardiopulmonary bypass (CPB) than with standard advanced cardiac life support. This study compared cardiovascular resuscitability with CPB only after varying periods of cardiac arrest without artificial circulatory support in a canine model. Group 1 (ten) was subjected to ventricular fibrillation for 15 minutes; group 2 (ten) for 20 minutes; and group 3 (ten) for 30 minutes. ⋯ In groups 1 and 2, CPB reperfusion allowed for successful defibrillation in less than five minutes, weaning from CPB in all dogs at four hours, and stable spontaneous circulation thereafter. In group 3, only five of ten dogs could be weaned from bypass at four hours, and all died early with myocardial necroses. It was concluded that CPB may be of value in the setting of prolonged cardiac arrest when advanced cardiac life support has not been provided or is unable to restore spontaneous heart-beat.