Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2015
Spontaneous Pain-Like Behaviors Are More Sensitive to Morphine and Buprenorphine Than Mechanically Evoked Behaviors in a Rat Model of Acute Postoperative Pain.
Nonevoked spontaneous pain is most problematic for postoperative patients. Physicians assess this form of pain using the human visual analog scale or verbal numeric rating scale. Recent studies have proposed that spontaneous foot-lifting (SFL) behaviors are an expression of spontaneous pain in animals after spinal nerve injury or adjuvant-induced inflammation. In the current study, we characterize SFL behaviors in a rat model of acute postoperative pain, which includes comparisons with evoked behaviors to analgesic treatments. ⋯ The present study demonstrates that a hindpaw plantar incision induces SFL behaviors in rats and that these behaviors have higher bioassay sensitivity to analgesic interventions with morphine and buprenorphine compared with mechanically evoked behaviors.
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Anesthesia and analgesia · Feb 2015
Review Meta Analysis Comparative StudyCrystalloids Versus Colloids: Exploring Differences in Fluid Requirements by Systematic Review and Meta-Regression.
Positive fluid balance has been associated with worse outcomes, and knowledge of differences in the amounts of different types of fluid needed to achieve the same end points may have important clinical implications. Large molecules persist longer in the blood vessels than smaller molecules, such that less IV colloid may be needed to achieve similar hemodynamic end points compared with crystalloid. Recent clinical data have, however, challenged this physiological concept, with investigators reporting lower-than-expected crystalloid/colloid ratios in various populations. ⋯ Greater fluid volumes are required to meet the same targets with crystalloids than with colloids, with an estimated ratio of 1.5 (1.36-1.65), but there is marked heterogeneity among studies. The crystalloid/colloid ratio seems to have decreased over the years, and differences in ratios are correlated with the concentration of albumin solutions; however, the main reasons behind the high heterogeneity among studies remain unclear.
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Anesthesia and analgesia · Feb 2015
The Effects of Anesthesia, Muscle Paralysis, and Ventilation on the Lung Evaluated by Lung Diffusion for Carbon Monoxide and Pulmonary Surfactant Protein B.
An increased alveolar-arterial oxygen tension difference is frequent in anesthetized patients. In this study, we evaluated the effect on the lung of anesthesia, muscle paralysis, and a brief course of mechanical ventilation. ⋯ A brief course of anesthesia and controlled ventilation leads to: (1) alveolar damage, which is correlated with lung strain and perfusion, and (2) impaired gas exchange mainly due to volume loss but also to reduced aerated lung perfusion.
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Anesthesia and analgesia · Feb 2015
The Incidence and Risk Factors for Perioperative Cardiac Arrest Observed in the National Anesthesia Clinical Outcomes Registry.
Cardiac arrest is a rare but important event in the operating room and postanesthesia care unit, when surgical patients are most intensively monitored. Several recent publications have reported the rate of cardiac arrest in surgical patients during the subsequent hospital stay but have not uniquely identified the immediate perioperative period. We hypothesized that cardiac arrest during this time (intraprocedure and postanesthesia care) would occur at a lower frequency than that described for inpatient hospital care in the available literature. ⋯ The National Anesthesia Clinical Outcomes Registry is an emerging resource for examination of perioperative and anesthesia-related outcomes. Cardiac arrest is less frequent in the periprocedural setting than later in the hospital course, with most arrests predictably occurring in patients with ASA physical status III-V. The finding of increased risk of mortality in male patients cannot be readily explained and should prompt future research attention.