Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1992
Sevoflurane is biotransformed by guinea pig liver slices but causes minimal cytotoxicity.
Guinea pig liver slices were used to evaluate the biotransformation and hepatotoxic potential of sevoflurane. Precision-cut liver slices (250-300 microns thick) were incubated in sealed roller vials in buffer at 37 degrees C under 95% O2. Sevoflurane was added to produce 0.9 or 2.1 mM medium concentrations. ⋯ Sevoflurane (2.1 mM) and isoflurane (2.3 mM) had no effect on slice K+ content, but both anesthetics depressed protein synthesis. The biotransformation of sevoflurane was maximal at 95% O2, with threefold more F- produced from sevoflurane than isoflurane. Sevoflurane appears to have a minimal effect on the guinea pig liver slices, which is consistent with in vivo studies in which minimal or no hepatotoxicity has been observed.
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Anesthesia and analgesia · Sep 1992
Comparative StudyBlood flow and tissue oxygen pressures of liver and pancreas in rats: effects of volatile anesthetics and of hemorrhage.
The object of this investigation was to compare the effects of volatile anesthetics and of hemorrhage at comparable arterial blood pressures on splanchnic blood flow (radioactive microspheres) and tissue oxygenation of the liver and pancreas (surface PO2 [PSO2] electrodes). In contrast to earlier studies, we did not use identical minimum alveolar anesthetic concentration multiples as a reference to compare volatile anesthetics; rather, we used the splanchnic perfusion pressure. Under general anesthesia (intravenous chloralose) and controlled ventilation, 12 Sprague-Dawley rats underwent laparotomy to allow access to abdominal organs. ⋯ Thus, volatile anesthetics preserved pancreatic but not hepatic blood flow and tissue oxygenation in this rat model. Despite comparable effects on perfusion, the PSO2 of the liver and pancreas was the least during hemorrhagic hypotension compared to that with the anesthetics. Because the volative anesthetic-induced hypotension has such a different effect on splanchnic tissue oxygenation compared with hemorrhagic-induced hypotension, the authors conclude that the method of inducing hypotension may have different effects on oxygenation of various tissues.
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Anesthesia and analgesia · Sep 1992
Randomized Controlled Trial Comparative Study Clinical TrialComparative effects of laryngeal mask airway and endotracheal tube insertion on intraocular pressure in children.
Intraocular pressure (IOP) measurements in children are frequently performed under halothane-nitrous oxide anesthesia; however, anesthesia face masks may limit access to the eyes, and tracheal intubation is associated with transient increases in IOP. Use of the laryngeal mask airway (LMA) permits the maintenance of a patent airway without the need for laryngoscopy and tracheal intubation. In a randomized study of 41 children, we compared the IOP, hemoglobin oxygen saturation, and hemodynamic responses to the insertion of an LMA or tracheal tube during a standardized steady-state anesthetic technique consisting of 1 MAC halothane and 66% nitrous oxide. ⋯ The LMA did not increase IOP, heart rate, or arterial blood pressure above baseline values. In contrast, tracheal intubation was associated with significant increases of IOP, heart rate, and arterial blood pressure. We concluded that the laryngeal mask offers advantages over tracheal intubation and the face mask for airway management in patients undergoing IOP measurements.
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Anesthesia and analgesia · Sep 1992
Randomized Controlled Trial Comparative Study Clinical TrialHeadache after spinal anesthesia for cesarean section: a comparison of the 27-gauge Quincke and 24-gauge Sprotte needles.
A high incidence of postdural puncture headache (PDPH) occurs after spinal anesthesia for cesarean section. To examine this problem, a study was conducted with the recently developed 24-gauge Sprotte and 27-gauge Quincke needles in patients undergoing elective and emergency cesarean section (n = 298). The needle to be used was assigned in a random manner: group I, 27-gauge Quincke (n = 147); group II, 24-gauge Sprotte (n = 151). ⋯ Five headaches were classified as mild, and only one was moderate to severe. All headaches resolved quickly with conservative management and without blood patch. The authors conclude that the choice between a 27-gauge Quincke and a 24-gauge Sprotte needle does not influence the incidence of PDPH after spinal anesthesia for cesarean section.
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Anesthesia and analgesia · Sep 1992
Should all children with suspected or confirmed malignant hyperthermia susceptibility be admitted after surgery? A 10-year review.
Children otherwise suitable for same-day discharge may be admitted to the hospital solely because they are known or suspected to be malignant hyperthermia-susceptible (MHS). To determine whether their hospitalization is necessary, the medical charts of 303 children labeled MHS who had undergone surgery with anesthesia free of malignant hyperthermia-triggering agents on 431 occasions between 1981 and 1990 were reviewed. Eighteen of these patients (25 cases) who were subsequently identified as biopsy-negative were excluded from the study. ⋯ These episodes were not considered to be malignant hyperthermia and were not treated with dantrolene. None of the remaining 275 patients exhibited any features of malignant hyperthermia, although one had an adverse reaction to radiologic contrast medium. On the basis of our retrospective analysis, postoperative admission to the hospital solely on the basis of the MHS label is not warranted.