Annals of emergency medicine
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Recent animal studies and preliminary clinical observations suggest that the addition of interposed abdominal compressions (IAC) to ventilation and chest compression of standard cardiopulmonary resuscitation (CPR) augments blood flow, blood pressures, and immediate survival. To investigate the physical basis for enhanced circulation during IAC-CPR, we developed an electrical model of the circulation. Heart and blood vessels were modeled as resistive-capacitive networks, pressures as voltages, blood flow as electric current, blood inertia as inductance, and the cardiac and venous valves as diodes. ⋯ During simulation of CPR, IAC improved cranial and myocardial perfusion at all levels of chest compression pressure by amounts linearly related to peak abdominal pressure, suggesting that the abdomen can function as a second, independent blood pump during CPR. Brain and heart flow were improved further during simulated vasoconstriction in kidneys, abdominal viscera, and extremities. Based on the fundamental properties of the cardiovascular system represented in the model, abdominal counterpulsation provides a rational basis for flow augmentation during CPR.
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Epinephrine is the recommended drug for use in resuscitation from all types of cardiac arrest. Experimental evidence has shown that the actions of epinephrine important for the restoration of spontaneous circulation are mediated by the alpha-adrenergic properties. The beta-adrenergic effects do not aid restoration of spontaneous circulation, nor do they aid defibrillation; however, beta-adrenergic stimulation does increase the oxygen consumption of the fibrillating myocardium, a potentially deleterious effect. ⋯ Because phenylephrine and methoxamine do not have significant beta-adrenergic actions, they should be considered as alternatives to epinephrine for aid in restoring spontaneous circulation. Once spontaneous circulation is restored, alpha-and/or beta-adrenergic agonists may be needed for circulatory support. Which drugs will provide the best longterm survival has not been established.
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Two hundred consecutive cases brought to the attention of a malpractice insurer by evidence of expected legal action were reviewed. Of these cases, 132 (66%) were attributed primarily to misdiagnosis, and 87 of these would have satisfied admission criteria. The most common error was grossly deficient examination relating to the chief complaint. Focused attention to physical examination and diagnostic skills, history taking, and minimal use of laboratory studies could have avoided the initiation of the majority of cases.
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We developed a cardiopulmonary resuscitation (CPR) message that can be given via telephone by emergency dispatchers directly to an individual reporting a cardiac arrest. The message was developed and evaluated on the basis of empirical observation of CPR performance of 203 community volunteers during simulated cardiac arrest events. ⋯ We judged the quality of CPR to be comparable to the performance of individuals who have received formal training. The specific words used in the message directly determined adequacy of performance, and resulted in significantly better CPR performance than did impromptu instruction offered by professional dispatchers (P less than or equal to .02).
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A study was done to assess the effect of open-chest massage on resuscitation from cardiac arrest. Ten mongrel dogs weighing 20.3 +/- 3.2 kg were fibrillated electrically. Cardiopulmonary resuscitation (CPR) was initiated and continued for 15 minutes. ⋯ Four of the five dogs that underwent open cardiac massage were resuscitated. Significant differences in aortic pressures and coronary perfusion pressures were noted for the first two minutes of open-chest massage (P less than .05). The results of this study indicate that resuscitation may be improved using open-chest massage when closed-chest massage fails to produce an adequate coronary perfusion pressure.