Anesthesiology
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Meta Analysis Comparative Study
Variations in pharmacology of beta-blockers may contribute to heterogeneous results in trials of perioperative beta-blockade.
Randomized controlled trials and meta-analyses provide conflicting guidance on the role of beta-adrenergic receptor blockers (beta-blockers) in reducing perioperative complications. We hypothesize that variability in trial results may be due in part to heterogeneous properties of beta-blockers. First, we propose that the extent of beta-blocker metabolism by cytochrome P-450 and the time available to titrate the dosage before surgery (titration time) may interact; dependence on P-450 may be most harmful when titration time is short. Second, beta-blockers vary in their selectivity for the beta-1 receptor and reduced selectivity may contribute to cerebral ischemia. ⋯ Pharmacological properties of beta-blockers may contribute to heterogeneous trial results. Many trials have used metoprolol, which is extensively metabolized by cytochrome P450 and is less selective for the beta-1 receptor. For these two reasons, the efficacy of metoprolol to prevent perioperative cardiac complications should be compared with the efficacy of other beta-blockers.
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Comparative Study
Quality of postoperative care after major orthopedic surgery is correlated with both long-term cardiovascular outcome and troponin Ic elevation.
The aim of this study performed in patients undergoing major orthopedic surgery was to assess the impact of changes in practice on both the incidence of postoperative myocardial ischemia (PMI) detected by serial measurements of troponin Ic and long-term cardiac outcome. ⋯ Our postoperative care policy after major orthopedic surgery strongly correlated with both short-term cardiac outcome (i.e., PMI with troponin Ic release) and long-term cardiac outcome. Thus, in a given surgical population, variation of incidence of troponin Ic elevations could be used as a result indicator for postoperative care policy.
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Comparative Study
Clinical teaching improves with resident evaluation and feedback.
The literature is mixed on whether evaluation and feedback to clinical teachers improves clinical teaching. This study sought to determine whether resident-provided numerical evaluation and written feedback to clinical teachers improved clinical teaching scores. ⋯ A combination of evaluation and feedback, including comments on areas for improvement, was related to a substantial improvement in teaching scores. Clinical teachers are able to improve by using feedback from residents.
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Comparative Study
In vivo fluorescence-mediated tomography for quantification of urokinase receptor-dependent leukocyte trafficking in inflammation.
Inflammation is characterized by leukocyte recruitment. Macrophages and neutrophils contribute to tissue damage and organ dysfunction. Modulating leukocyte invasion can protect from these adverse effects. Leukocyte recruitment critically depends on the urokinase-type plasminogen activator receptor (u-PAR). We here use a novel technique to longitudinally quantify cell trafficking in inflammatory models in live animals. ⋯ Using noninvasive in vivo fluorescence-mediated tomography to image leukocyte recruitment in inflammatory mouse models, we describe a novel macrophage recruitment defect in u-PAR-/- mice. Targeting u-PAR for modulation of leukocyte recruitment is a promising therapeutic strategy to ameliorate leukocyte induced tissue damage.
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Comparative Study
Influence of tidal volume on pulse pressure variations in hypovolemic ventilated pigs with acute respiratory distress-like syndrome.
Sensitivity and specificity of respiratory change in pulse pressure (DeltaPP) to predict preload dependency has been questioned at small tidal volumes (VT) in critically ill patients suffering from acute respiratory distress syndrome (ARDS). We studied DeltaPP in pigs with ARDS-like syndrome during reversible hemorrhagic shock. ⋯ The present study suggests that DeltaPP is a reliable indicator of severe hypovolemia in pigs with healthy lungs regardless of VT or RR. In contrast, in pigs with ARDS-like syndrome ventilated with small VT, DeltaPP is not a good indicator of severe hemorrhage. However, in this setting, indexing DeltaPP to respiratory changes in transpulmonary pressure allows this marker to significantly indicate the occurrence of hypovolemia.