Resuscitation
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A combined hypercarbic and metabolic acidosis develops during the low flow state of cardiac arrest treated with cardiopulmonary resuscitation. Several negative consequences of the acidosis have been demonstrated, two of the most important being reduced contractility of the ischaemic but still beating myocardium and impaired resuscitability of the arrested heart. Even though interventions to re-establish a spontaneous circulation should be the number one priority during cardiopulmonary resuscitation, attempts to treat the acidosis are often carried out in order to avoid the reported negative inotropic effect. ⋯ A mixture of THAM, acetate, sodium bicarbonate and phosphate registered as Tribonat has been suggested as a suitable alternative to conventional buffer substances. The problems preceding the designation of Tribonat as well as studies evaluating its effects are reviewed in this article. Tribonat seems to offer a more well-balanced buffering without any major disadvantages compared with previously used alkaline buffers, even though improved survival has not been reported.
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The purpose of this investigation was to compare the efficacy of three different cardiopulmonary resuscitation techniques: (a) standard cardiopulmonary resuscitation (CPR), (b) active compression-decompression cardiopulmonary resuscitation (ACD-CPR) with the rescuer standing beside the patient (ACD-B), and (c) ACD-CPR with the rescuer in a standing position over the patient (ACD-S). The physiological responses of the rescuers when performing these techniques were also evaluated. ⋯ Parameters indicative of both CPR performance (time to exhaustion, compression depth and efficacy), and rescuers' physiological responses (blood lactate; minute ventilation (VE); heart rate (HR); oxygen uptake VO2; respiratory exchange rate (RER); and percentage of VO2max) were monitored during the trials. The main findings of this investigation were: (a) the evidence of a greater physiological load for the rescuers during the ACD-CPR techniques compared to CPR, which caused a longer performance time with CPR as compared to ACD-CPR; (b) the overall absence of physiological differences between ACD-B and ACD-S; and (c) a modest decrease in mechanical efficacy for ACD-S when compared to ACD-B.
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Comparative Study Clinical Trial
Transthoracic defibrillation: does electrode adhesive pad position alter transthoracic impedance?
Successful termination of ventricular fibrillation by transthoracic shocks is dependent on achieving adequate current flow, which in turn is governed by transthoracic impedance (TTI). The American Heart Association (AHA) Advanced Cardiac Life Support textbook recommends three electrode positions for defibrillation: (1) anterior-apex, (2) apex-posterior and (3) anterior-posterior. However, there are few data available comparing TTI of these positions. ⋯ Thus, the three AHA-recommended electrode positions for transthoracic defibrillation have equivalent and acceptable TTIs; current flow should be similar using any of these positions. Furthermore, the posterior electrode may be placed in either the right or the left infrascapular position without affecting TTI. TTI is related to BSA in any of the three recommended positions; patients with high BSA and TTI may require higher energy selection to achieve defibrillation.
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The aim of this study was to evaluate the influence of rescuer fatigue on the quality of chest compressions and the influence of the rescuer's gender, age, weight, height or professional status on the reduction of quality of chest compressions caused by fatigue. ⋯ A decrease of compressions quality after the first minute of CPR is produced. This effect does not depend on gender, age, weight, height or rescuer's profession and it is not adequately perceived by the person who performs the chest compressions.