Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2009
ReviewPerioperative hemodynamic monitoring with transesophageal Doppler technology.
Invasive cardiac output (CO) monitoring, traditionally performed with transpulmonary thermodilution techniques, is usually reserved for high-risk patients because of the inherent risks of these methods. In contrast, transesophageal Doppler (TED) technology offers a safe, quick, and less invasive method for routine measurements of CO. After esophageal insertion and focusing of the probe, the Doppler beam interrogates the descending aortic blood flow. ⋯ TED can be used to guide perioperative intravascular volume substitution and therapy, with vasoactive or inotropic drugs. Various studies have demonstrated a reduced postoperative morbidity and shorter length of hospital stay in patients managed with TED compared with conventional clinical management, suggesting that it may be a valuable supplement to standard perioperative monitoring. We review not only the technical basis of this method and its clinical application but also its limitations, risks, and contraindications.
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The introduction of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, i.e., statins, constitutes a milestone in the prevention of cardio- and cerebrovascular disease. The effects of statins extend far beyond their effects on cholesterol levels: pleiotropic effects include vasoprotective mechanisms, comprising improved endothelial function, increased bioavailability of nitric oxide, immunomodulatory and antiinflammatory properties, stabilization of atherosclerotic plaques, as well as antioxidant and stem cell-regulating capacities. Large clinical trials have clearly demonstrated that statins reduce the risk of myocardial infarction and stroke. ⋯ Until now, statins were only available as oral drugs. An IV formulation may be warranted for acute treatment of severely ill patients, for example, those who are unable to swallow or scheduled for surgery. Hydrophilic statins would be suitable for an IV formulation and have been safely tested in healthy volunteers.
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Anesthesia and analgesia · Aug 2009
ReviewContinuous electroencephalogram monitoring in the intensive care unit.
Because of recent technical advances, it is now possible to record and monitor the continuous digital electroencephalogram (EEG) of many critically ill patients simultaneously. Continuous EEG monitoring (cEEG) provides dynamic information about brain function that permits early detection of changes in neurologic status, which is especially useful when the clinical examination is limited. Nonconvulsive seizures are common in comatose critically ill patients and can have multiple negative effects on the injured brain. ⋯ Intracranial EEG recording is being performed in a few centers to better detect seizures, ischemia, and peri-injury depolarizations, all of which may contribute to secondary injury. When cEEG is combined with individualized, physiologically driven decision making via multimodality brain monitoring, intensivists can identify when the brain is at risk for injury or when neuronal injury is already occurring and intervene before there is permanent damage. The exact role and cost-effectiveness of cEEG at the current time remains unclear, but we believe it has significant potential to improve neurologic outcomes in a variety of settings.
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Anesthesia and analgesia · Aug 2009
Review Meta AnalysisThe efficacy of an intraoperative cell saver during cardiac surgery: a meta-analysis of randomized trials.
Cell salvage may be used during cardiac surgery to avoid allogeneic blood transfusion. It has also been claimed to improve patient outcomes by removing debris from shed blood, which may increase the risk of stroke or neurocognitive dysfunction. In this study, we sought to determine the overall safety and efficacy of cell salvage in cardiac surgery by performing a systematic review and meta-analysis of published randomized controlled trials. ⋯ Current evidence suggests that the use of a cell saver reduces exposure to allogeneic blood products or red blood cell transfusion for patients undergoing cardiac surgery. Subanalyses suggest that a cell saver may be beneficial only when it is used for shed blood and/or residual blood or during the entire operative period. Processing cardiotomy suction blood with a cell saver only during cardiopulmonary bypass has no significant effect on blood conservation and increases fresh frozen plasma transfusion.
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Anesthesia and analgesia · Aug 2009
Review Meta AnalysisNeuraxial techniques in obstetric and non-obstetric patients with common bleeding diatheses.
There are few data in the literature regarding the safety of neuraxial techniques in patients with the most common bleeding diatheses, including hemophilia, von Willebrand's disease (vWD), and idiopathic thrombocytopenic purpura (ITP). Neuraxial techniques are not widely used in these populations because of concerns of potential hemorrhagic and/or subsequent neurologic complications. In this article, we review the available literature describing neuraxial techniques in patients with hemophilia, vWD, or ITP with the aim to assist anesthesiologists considering neuraxial techniques in these populations. ⋯ There is a paucity of published data regarding the provision and safety of neuraxial techniques in patients with common bleeding diatheses. The minimum "safe" factor levels and platelet count for neuraxial techniques remain undefined in both the obstetric and general populations, and evidence-based recommendations in the setting of hemophilia, vWD, or ITP cannot be offered.