Resuscitation
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Comparative Study
A comparison of alpha-methylnorepinephrine, vasopressin and epinephrine for cardiac resuscitation.
The objective of this research was to compare the effects of an alpha- and beta-adrenergic agonist, epinephrine, a selective alpha(2)-adrenergic agonist, alpha-methylnorepinephrine (alpha-MNE), and a non-adrenergic vasopressin on post-resuscitation myocardial function and duration of survival. Epinephrine continues to be the primary adrenergic agent for advanced cardiac life support. However, its major inotropic actions and especially its beta-adrenergic and, to a lesser extent, its alpha(1)-actions increase the severity of global ischemia during cardiac arrest and adversely affect post-resuscitation myocardial function and survival. ⋯ All animals were successfully resuscitated. Post-resuscitation myocardial function and survival were significantly better in animals treated with alpha-MNE. Both post-resuscitation myocardial function and survival were most improved after administration of the selective alpha(2)-adrenergic agonist, intermediate after vasopressin and least after epinephrine and saline placebo.
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Comparative Study
The nitric oxide synthase inhibitor N(G)-nitro-L-arginine decreases defibrillation-induced free radical generation.
To demonstrate that nitric oxide (NO) contributes to free radical generation after epicardial shocks and to determine the effect of a nitric oxide synthase (NOS) inhibitor, N(G)-nitro-L-arginine (L-NNA), on free radical generation. ⋯ NO contributes to free radical generation and nitrosative injury after epicardial shocks; NOS inhibitors decrease radical generation by inhibiting the production of O=NOO(-).
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Comparative Study
Comparison of six clinically used external defibrillators in swine.
External defibrillation has long been practiced with two types of monophasic waveforms, and now four biphasic waveforms are also widely available. Although waveforms and clinical dosing protocols differ among defibrillators, no studies have adequately compared performance of the monophasic or the biphasic waveforms. This is the first study to compare defibrillation efficacy among biphasic external defibrillators, and does so as part of a study comparing all commonly available waveforms using their respective manufacturer-provided and clinically used doses. ⋯ Commonly used MDS and MTE waveforms provide markedly dissimilar efficacies. Despite impedance-compensation schemes in biphasic defibrillators, impedance has an impact on their efficacy. At high-impedance, modest efficacy differences exist among clinically available biphasic defibrillators, reflecting differences in both waveforms and manufacturer-provided doses.
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To evaluate the effects of hypertonic saline (HS) and/or hydroxy ethyl starch (HES) on myocardial perfusion pressure (MPP) and blood flow (MBF), and cardiac index (CI) during and after cardiopulmonary resuscitation (CPR). ⋯ Hypertonic solutions (HS and HHS) applied during internal cardiac massage enhanced MBF and significantly increased resuscitation success and survival rate. Addition of HES to HS did not further improve the positive haemodynamic effects of HS alone.