Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1996
Comparative StudyA comparison of the local anesthetic effects of meperidine, fentanyl, and sufentanil on dorsal root axons.
The local anesthetic effects of opioids have been demonstrated in both clinical and laboratory studies. Clinically, both meperidine and sufentanil can produce segmental sensory anesthesia. However, previous studies of the effects of opioids on nerve conduction have all made use of peripheral nerve preparations and yielded conflicting results. ⋯ Fentanyl (0.6 microM and 3 microM) and sufentanil (1.04 microM) failed to affect the nerve conduction in any dorsal root axon. The discrepancy between laboratory and clinical observations is discussed. We suggest that the site of conduction block may occur at the proximal end of the dorsal root as it passes through the dorsal root entry zone, an anatomically unique segment of the primary sensory pathway with decreased conduction safety for action potential propagation.
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Anesthesia and analgesia · Oct 1996
Comparative StudyModerate primary pulmonary hypertension in patients undergoing liver transplantation.
Primary pulmonary hypertension (PPH) in patients with hepatic cirrhosis is often considered an unacceptable condition for liver transplantation because of increased morbidity and mortality during the procedure. We studied the incidence, characteristics, and final outcome of patients with PPH undergoing liver transplantation in our institution. Among the 226 patients undergoing 257 liver transplantations, eight (3.5%) fulfilled the conditions of PPH and responded to vasodilator therapy. ⋯ All patients with PPH required pulmonary vasodilator therapy after reperfusion of the new liver, while none in the group of patients without PPH required this therapy. Furthermore, after graft reperfusion, patients with PPH in which venovenous bypass was not used (n = 3), had a more compromised right ventricular function with a greater increase of central venous pressure (CVP) (90%) and MPAP (140%) when compared with patients with bypass or preservation of the recipient's vena cava (n = 5) in whom the increase of CVP and MPAP was 50% and 60%, respectively. Moderate PPH without a fixed level of pulmonary hypertension in patients undergoing liver transplantation is not related to an adverse outcome.
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Anesthesia and analgesia · Oct 1996
Practice patterns of anesthesiologists regarding situations in obstetric anesthesia where clinical management is controversial.
A survey consisting of 47 questions, 40 regarding clinical practice and 7 regarding demographics, was mailed to 153 directors of obstetric anesthesia in academic practice and to 153 anesthesiologists in private practice. Questions relating to the following areas of practice were asked: 1) preoperative laboratory testing; 2) preeclampsia and possible coagulopathies; 3) epidural catheter placement in women with "spinal problems"; and 4) use of epidural opioids and intravenous supplementation. ⋯ These eight questions related to preoperative laboratory testing in the healthy parturient, preoperative laboratory testing in the preeclamptic patient, and the use of intravenous supplementation during a cesarean section with regional anesthesia. Although there were some differences in the responses between anesthesiologists in academic and private practice, overall the responses were similar.
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Anesthesia and analgesia · Oct 1996
Regional cerebral oxygen saturation during electroconvulsive therapy: monitoring by near-infrared spectrophotometry.
Electroconvulsive therapy (ECT) increases neuronal energy consumption and alters systemic hemodynamics. We examined the effects of ECT on regional cerebral oxygen saturation (rSo2) using a near-infrared spectro-photometer. ⋯ A close correlation was demonstrated between the increase in rSo2 and the mean blood pressure after the electrical shock (r2 = 0.832, P < 0.0001). We conclude that ECT initially may increase cerebral metabolic rate of oxygen more than cerebral blood flow and that rapidly increasing blood pressure transiently may overwhelm cerebral pressure autoregulation.
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Anesthesia and analgesia · Oct 1996
Letter Case ReportsDifficult intubation: a case of "gone with the wind".