Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2009
Randomized Controlled Trial Comparative StudyRenal integrity in sevoflurane sedation in the intensive care unit with the anesthetic-conserving device: a comparison with intravenous propofol sedation.
Increased inorganic fluoride levels after methoxyflurane exposure in the 1970s and prolonged intraoperative sevoflurane use have been suggested to be potentially nephrotoxic. In the intensive care unit we evaluated the effect on renal integrity of short-term inhaled postoperative sedation with sevoflurane using the Anesthetic Conserving Device (ACD) compared with propofol. ⋯ Short-term sedation with either sevoflurane using ACD or propofol did not negatively affect renal function postoperatively. Although inorganic fluoride levels were elevated after sevoflurane exposure, glomerular and tubular renal integrity were preserved throughout the hospital stay.
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Anesthesia and analgesia · Jun 2009
Comparative StudySame-patient reproducibility of state entropy: a comparison of simultaneous bilateral measurements during general anesthesia.
State Entropy (SE) is an index of anesthetic depth similar to Bispectral Index (BIS). Both indices use a single-channel electroencephalogram, recorded from a unilaterally applied electrode on the forehead, as their input. Intrapatient reproducibility of BIS was questioned in a recent study in which simultaneous measurements from two electrodes applied to the same patient showed conflicting anesthetic depths. Our purpose was to determine whether SE results are similarly reproducible, even though their computation uses a different algorithm than BIS. In this study, we investigated the reproducibility of SE measurements simultaneously obtained from bilaterally applied electrodes in the same patient. ⋯ SE showed a clinically significant degree of disagreement when probes were applied on both sides of the forehead in the same patient. Bland-Altman statistics showed better same-patient reproducibility in SE than did a similar study on BIS. Nevertheless, 4% of the simultaneously measured pairs of SE suggested different anesthetic depths and differed by more than 10 points. Caution is advised when using SE as a clinical index of anesthetic depth.
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The management of massively transfused trauma patients has improved with a better understanding of trauma-induced coagulopathy, the limitations of crystalloid infusion, and the implementation of massive transfusion protocols (MTPs), which encompass transfusion management and other patient care needs to mitigate the "lethal triad" of acidosis, hypothermia, and coagulopathy. MTPs are currently changing in the United States and worldwide because of recent data showing that earlier and more aggressive transfusion intervention and resuscitation with blood components that approximate whole blood significantly decrease mortality. ⋯ The ideal amounts of plasma, platelet, cryoprecipitate and other coagulation factors given in MTPs in relationship to the red blood cell transfusion volume are not known precisely, but until prospective, randomized, clinical trials are performed and more clinical data are obtained, current data support a target ratio of plasma:red blood cell:platelet transfusions of 1:1:1. Future prospective clinical trials will allow continued improvement in MTPs and thus in the overall management of patients with trauma.
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Anesthesia and analgesia · Jun 2009
ReviewPeripherally acting mu-opioid receptor antagonists and postoperative ileus: mechanisms of action and clinical applicability.
Postoperative ileus (POI), a transient cessation of coordinated bowel function after surgery, is an important health care problem. The etiology of POI is multifactorial and related to both the surgical and anesthetic pathways chosen. Opioids used to manage surgical pain can exacerbate POI, delaying gastrointestinal (GI) recovery. ⋯ This new class is investigational for POI management with the goal of accelerating the recovery of upper and lower GI tract function after bowel resection. In this review, we summarize the mechanisms by which POI occurs and the role of opioids and opioid receptors in the enteric nervous system, discuss the mechanism of action of PAM-OR antagonists, and review clinical pharmacology and Phase II/III POI trial results of methylnaltrexone and alvimopan. Finally, the role of anesthesiologists in managing POI in the context of a multimodal approach is discussed.
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Anesthesia and analgesia · Jun 2009
Sevoflurane formulation water content influences degradation by Lewis acids in vaporizers.
Sevoflurane is produced by several manufacturers. Currently marketed sevoflurane formulations differ in their method of synthesis, impurities, containers in which they are sold, and water content. Of the various types of chemical degradation to which sevoflurane is susceptible, the most pertinent is degradation by Lewis acids (such as metal oxides and metal halides) to hydrofluoric acid and other toxic compounds. Water inhibits such degradation. This observational study determined the degradation profile of three formulations of sevoflurane (two lower-water and one higher-water formulation) when stored in three types of vaporizers. ⋯ Lower-water sevoflurane underwent substantial degradation to hydrofluoric acid and other degradants during storage in the Penlon Sigma Delta vaporizer. Differences in water content of sevoflurane formulations and potential for degradation present a potential patient safety issue.