Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2009
Cricoid pressure results in compression of the postcricoid hypopharynx: the esophageal position is irrelevant.
Sellick described cricoid pressure (CP) as pinching the esophagus between the cricoid ring and the cervical spine. A recent report noted that with the application of CP, the esophagus moved laterally more than 90% of the time, questioning the efficacy of this maneuver. We designed this study to accurately define the anatomy of the Sellick maneuver and to investigate its efficacy. ⋯ The location and movement of the esophagus is irrelevant to the efficiency of the Sellick's maneuver (CP) in regard to prevention of gastric regurgitation into the pharynx. The hypopharynx and cricoid ring move together as an anatomic unit. This relationship is essential to the efficacy and reliability of Sellick's maneuver. The magnetic resonance images show that compression of the alimentary tract occurs with midline and lateral displacement of the cricoid cartilage relative to the underlying vertebral body.
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Anesthesia and analgesia · Nov 2009
The reproducibility of Stewart parameters for acid-base diagnosis using two central laboratory analyzers.
Acid-base derangements can be interpreted using the Stewart-Fencl approach, which includes calculation of the apparent strong ion difference (SID(app)), the effective SID (SID(eff)), and the strong ion gap (SIG). These calculations require the measurement of several variables. We hypothesized that the SID and SIG calculated by different analyzers would not be reproducible because of variability in the measured values. ⋯ The results of the Stewart-Fencl approach for interpretation of acid-base status can vary according to the analyzer used. These differences may have important clinical and research implications..
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Anesthesia and analgesia · Nov 2009
Inotropic support during experimental endotoxemic shock: part I. The effects of levosimendan on splanchnic perfusion.
Septic shock may cause splanchnic hypoperfusion. We hypothesized that levosimendan would improve systemic and hepatosplanchnic perfusion during endotoxemic shock. ⋯ Levosimendan administered after the establishment of endotoxemic shock to pigs receiving moderate fluid resuscitation prevented further increases in MPAP and maintained a low SVR. There were, however, no improvements in CO, MAP decreased, and levosimendan neither prevented the development of circulatory shock nor improved hepatosplanchnic perfusion.
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Anesthesia and analgesia · Nov 2009
Comparative StudyThe effects of sevoflurane and propofol on glucose metabolism under aerobic conditions in fed rats.
Recent studies reported that intraoperative hyperglycemia is an independent risk factor for mortality and morbidity related to surgery. Volatile anesthetics, such as sevoflurane, impair glucose use, suggesting their possible contributions to intraoperative hyperglycemia. However, the effects of IV anesthetics, such as propofol, on glucose metabolism are poorly understood. Thus, we compared the effects of sevoflurane and propofol on glucose metabolism under aerobic conditions in fed rats. ⋯ During surgery, hyperglycemia was observed under sevoflurane and sevoflurane/buprenorphine anesthesia, but blood glucose levels were relatively stable under propofol and propofol/buprenorphine anesthesia. Whereas sevoflurane exaggerates glucose intolerance, propofol has no significant effects on glucose tolerance. We speculate that this feature of propofol contributes, at least in part, to the stable glucose metabolism during surgery observed in this study. The results of this study confirm the marked difference in the effects of sevoflurane and propofol on glucose metabolism.
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Anesthesia and analgesia · Nov 2009
Case ReportsMisalignment of disposable pulse oximeter probes results in false saturation readings that influence anesthetic management.
We report a small case series in which misaligned disposable pulse oximeter sensors gave falsely low saturation readings. In each instance, the sensor performed well during preinduction oxygen administration and the early part of the case, most notably by producing a plethysmographic trace rated as high quality by the oximeter software. The reported pulse oximeter oxygen saturation eventually decreased to concerning levels in each instance, but the anesthesiologists, relying on the reported high-quality signal, initially sought other causes for apparent hypoxia. ⋯ When the malpositioned sensors were discovered and repositioned, the apparent hypoxia was quickly relieved in each case. We then undertook a survey of disposable oximeter sensors as patients entered the recovery room, and discovered malposition of more than 1 cm in approximately 20% of all sensors, without apparent consequence. We conclude that the technology is quite robust, but that the diagnosis of apparent hypoxia should include a quick check of oximeter position early on.