Critical care medicine
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Critical care medicine · Nov 2008
ReviewUrgent coronary angiography and percutaneous coronary intervention as a part of postresuscitation management.
Because an acute coronary thrombotic event may be viewed as the main trigger of sudden cardiac arrest, urgent coronary angiography followed by percutaneous coronary intervention appeared as a promising tool in the early postresuscitation phase. Unfortunately, large randomized trials, which have unequivocally demonstrated benefits of urgent percutaneous coronary intervention in patients with acute coronary syndromes, systematically excluded patients with preceding cardiac arrest followed by successful reestablishment of spontaneous circulation. There are several nonrandomized trials in patients with electrocardiographic signs of acute ST-elevation myocardial infarction after reestablishment of spontaneous circulation which together accumulated 478 patients. ⋯ Success of primary percutaneous coronary intervention and hospital survival in patients regaining consciousness soon after reestablishment of spontaneous circulation appeared to be comparable with ST-elevation myocardial infarction population without preceding cardiac arrest. This is in contrast with comatose survivors of cardiac arrest in whom survival to hospital discharge was, despite somewhat smaller patency of infarct-related artery after percutaneous coronary intervention (94% vs. 82%; p = .12), disproportionably decreased to 57% with good neurologic outcome in only 38%. There is evidence that in these patients, urgent coronary angiography and percutaneous coronary intervention can be safely combined with mild induced hypothermia to facilitate neurologic recovery.
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Critical care medicine · Nov 2008
Excessive tidal volume from breath stacking during lung-protective ventilation for acute lung injury.
Low tidal volume ventilation strategies for patients with respiratory failure from acute lung injury may lead to breath stacking and higher volumes than intended. ⋯ Stacked breaths occur frequently in low tidal volume ventilation despite deep sedation and result in volumes substantially above the set tidal volume. Set tidal volume has a strong influence on frequency of stacked breaths.
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Critical care medicine · Nov 2008
ReviewTargeting mitochondria for resuscitation from cardiac arrest.
Reversal of cardiac arrest requires reestablishment of aerobic metabolism by reperfusion with oxygenated blood of tissues that have been ischemic for variable periods of time. However, reperfusion concomitantly activates a myriad of pathogenic mechanisms causing what is known as reperfusion injury. At the center of reperfusion injury are mitochondria, playing a critical role as effectors and targets of injury. ⋯ Additional studies in similar animal models of ventricular fibrillation have shown that mitochondrial injury leads to activation of the mitochondrial apoptotic pathway, characterized by the release of cytochrome c to the cytosol, reduction of caspase-9 levels, and activation of caspase-3 coincident with marked reduction in left ventricular function. Cytochrome c also "leaks" into the bloodstream attaining levels that are inversely proportional to survival. These data indicate that mitochondria play a key role during cardiac resuscitation by modulating energy metabolism and signaling apoptotic cascades and that targeting mitochondria could represent a promising strategy for cardiac resuscitation.
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Critical care medicine · Nov 2008
Impaired baroreflex sensitivity predicts outcome of acute intracerebral hemorrhage.
Impaired blood pressure regulation in the acute phase of stroke has been associated with less favorable outcome. Mechanisms and effects of blood pressure dysregulation in stroke are not well understood; however, central autonomic impairment with sympathetic overactivity and baroreflex involvement are discussed. Baroreflex sensitivity (BRS) in spontaneous intracerebral hemorrhage has not been investigated. We sought to examine BRS in patients with intracerebral hemorrhage and evaluate the relationship between BRS and short-term outcome measures. ⋯ We found that BRS was decreased in patients with acute intracerebral hemorrhage and correlated with increased beat-to-beat blood pressure variability. BRS independently predicted outcome at 10 days. Modulation of baroreceptor reflex sensitivity may represent a new therapeutic target in acute stroke and warrants future studies.
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Critical care medicine · Nov 2008
B-type natriuretic peptide as a marker for sepsis-induced myocardial depression in intensive care patients.
In early stages of septic shock, impaired myocardial function plays an important prognostic role. In this context, B-type natriuretic peptide (BNP) has been shown to be a neurohumoral marker for left ventricular dysfunction, because myocardial strain and ischemia both increase BNP concentration. The present study was designed to test if BNP allows for identification of patients at risk for developing sepsis-induced myocardial depression and if an increased concentration of BNP is associated with an adverse outcome in patients with septic shock. ⋯ These results indicate that plasma BNP concentration represents a reliable marker for identification of patients developing sepsis-induced myocardial depression. In addition, BNP concentration on day 5 may be used as a prognostic marker to identify patients with an elevated risk for an adverse outcome.