Anesthesia and analgesia
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Anesthesia and analgesia · Dec 1991
Randomized Controlled Trial Comparative Study Clinical TrialEffects of epidural anesthesia and analgesia on coagulation and outcome after major vascular surgery.
To examine the interaction of epidural anesthesia, coagulation status, and outcome after lower extremity revascularization, 80 patients with atherosclerotic vascular disease were prospectively randomized to receive general anesthesia combined with postoperative epidural analgesia (GEN-EPI) or general anesthesia with on-demand narcotic analgesia (GEN). Demographics did not differ between groups except that the GEN-EPI group had a higher incidence of diabetes mellitus and of previous myocardial infarction. Coagulation status was monitored using thromboelastography. ⋯ The rates of cardiovascular, infectious, and overall postoperative complications, as well as duration of intensive care unit stay, were significantly reduced in the GEN-EPI group. Stepwise logistic regression demonstrated that the only significant predictors of postoperative cardiovascular complications were preoperative congestive heart failure and general anesthesia without epidural analgesia. We conclude that in patients with atherosclerotic vascular disease undergoing arterial reconstructive surgery (a) thromboelastographic evidence of increased platelet-fibrinogen interaction is associated with early postoperative thrombotic events, and (b) epidural anesthesia and analgesia is associated with beneficial effects on coagulation status and postoperative outcome compared with intermittent on-demand opioid analgesia.
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Anesthesia and analgesia · Dec 1991
Comparative StudyTransesophageal Doppler cardiac output monitoring: performance during aortic reconstructive surgery.
Transesophageal Doppler (TED) monitoring provides continuous, noninvasive monitoring of cardiac output by measurement of aortic flow velocities. Because of the effects on aortic flow dynamics resulting from atherosclerosis, aortic cross-clamping, and wide variations in arterial blood pressure, the validity of TED monitoring during aortic surgery is unresolved. The authors prospectively evaluated a second-generation TED cardiac output monitor in 42 patients undergoing aortic reconstructive surgery. ⋯ Placement of an aortic cross-clamp resulted in significant reductions in the accuracy of Doppler measurements. Arterial blood pressure variations did not systematically affect the accuracy of the transesophageal technique. Limitations of TED monitoring, including a difficult calibration procedure, poor performance during aortic cross-clamping, and the need for probe repositioning, suggest further development is warranted.
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Anesthesia and analgesia · Dec 1991
Valsalva maneuver in obstetrics: the influence of peripheral circulatory changes on function of the pulse oximeter.
Strenuous expulsive efforts involving sequential Valsalva maneuvers may result in maternal hypoxemia during the second stage of labor. Pulse oximetry has been used to assess oxygen saturation in laboring parturients, and this study was undertaken to evaluate the performance of the pulse oximeter (Nellcor) during the Valsalva maneuver. In both pregnant patients and nonpregnant volunteers, there were consistent interruptions in the transmission of oxygen saturation data during the Valsalva maneuver. ⋯ A marked decrease in pulse volume amplitude was noted, which adversely affected the oximeter's ability to distinguish physiologic arterial pulsations from background noise. Each Valsalva maneuver was associated with abrupt and transient changes in peripheral vascular volumes, thus presenting the oximeter with a rapidly changing signal for analysis that violated predetermined software criteria for pulse uniformity and caused an interruption in data transmission. The authors conclude that the Valsalva maneuver interferes with the ability of pulse oximeter technology to provide useful oxygen saturation data.
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Anesthesia and analgesia · Dec 1991
Comparative StudyAnesthetic modification of hemodynamic and neuroendocrine stress responses to cesarean delivery in women with severe preeclampsia.
We conducted a prospective evaluation of the comparative effects of lumbar epidural and general anesthesia on the hemodynamic and neuroendocrine stress response to cesarean delivery in 21 women with severe preeclampsia. In the epidural group (n = 11), anesthesia extending to the T-4 dermatome level was obtained using 2% plain lidocaine in divided doses. In the general anesthesia group (n = 10), anesthesia was induced after pretreatment with labetalol or nitroglycerin. ⋯ In the general anesthesia group, both adrenocorticotropic hormone and beta-endorphin-like immunoactivity increased significantly from base levels at skin incision. The catecholamines also increased significantly and remained so throughout the study period. In the epidural group, the concentrations of these hormones decreased or remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)