Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2006
Randomized Controlled Trial Comparative StudyA randomized comparison of programmed intermittent epidural bolus with continuous epidural infusion for labor analgesia.
Bolus injection through an epidural catheter may result in better distribution of anesthetic solution in the epidural space compared with continuous infusion of the same anesthetic solution. In this randomized, double-blind study we compared total bupivacaine consumption, need for supplemental epidural analgesia, quality of analgesia, and patient satisfaction in women who received programmed intermittent epidural boluses (PIEB) compared with continuous epidural infusion (CEI) for maintenance of labor analgesia. The primary outcome variable was bupivacaine consumption per hour of analgesia. ⋯ The median total bupivacaine dose per hour of analgesia was less in the PIEB (n = 63) (10.5 mg/h; 95% confidence interval, 9.5-11.8 mg/h) compared with the CEI group (n = 63) (12.3 mg/h; 95% confidence interval, 10.5-14.0 mg/h) (P < 0.01), fewer manual rescue boluses were required (rate difference 22%, 95% confidence interval of difference 5% to 38%), and satisfaction scores were higher. Labor pain, PCEA requests, and delivered PCEA doses did not differ. PIEB combined with PCEA provided similar analgesia, but with a smaller bupivacaine dose and better patient satisfaction compared with CEI with PCEA for maintenance of epidural labor analgesia.
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Anesthesia and analgesia · Mar 2006
Comparative StudyVasotrac arterial blood pressure and direct arterial blood pressure monitoring during liver transplantation.
During liver transplantation two arterial catheters are often placed. The Vasotrac is a noninvasive monitor that provides radial arterial blood pressures by a tonometric method. We investigated whether the Vasotrac would be an accurate substitute for an arterial catheter by comparing Vasotrac blood pressures with simultaneous direct radial blood pressures recorded from the contralateral arm in 14 patients undergoing liver transplantation. ⋯ Correlation was 0.82. Vasotrac bias was +3.3 mm Hg and limits of agreement +/-15 mm Hg. We conclude that the Vasotrac is not adequately accurate to substitute for direct arterial blood pressure monitoring in liver transplantation.
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Anesthesia and analgesia · Mar 2006
Case ReportsCerebral ischemia as an apparent complication of anterior cervical discectomy in a patient with an incomplete circle of Willis.
A 58-yr-old patient sustained a cerebral ischemic injury in the distribution of the carotid artery ipsilateral to retraction during an anterior cervical discectomy. Relative hypotension was permitted during the anesthetic. Angiography revealed an anatomic variant of the circle of Willis that resulted in minimal collateralizaton of the left internal carotid artery territory. The combination of that vascular variant with relative hypotension and some degree of carotid compression appears to have resulted in clinically significant cerebral ischemia.
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Anesthesia and analgesia · Mar 2006
Case ReportsNegative arterial to end-tidal carbon dioxide gradient: an additional sign of malignant hyperthermia during desflurane anesthesia.
Widespread use of desflurane anesthesia has changed the clinical presentation of malignant hyperthermia (MH). Delayed onset of MH symptoms has been reported previously. ⋯ The same conditions exist in cases of MH crisis. We describe an unusual case of MH in which a negative value of (a-ET) Pco2 gradient has been used as diagnostic and monitoring tool.
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Anesthesia and analgesia · Mar 2006
Comparative StudyDeterminants of volatile general anesthetic potency: a preliminary three-dimensional pharmacophore for halogenated anesthetics.
We investigated the molecular basis for the immobilizing activity of halogenated volatile anesthetics using comparative molecular field analysis. In vivo potency data (expressed as minimum alveolar concentrations) for 69 structurally diverse anesthetics were obtained from the literature. The drugs were randomly divided into a training set (n = 52) used to derive the activity model and a test set (n = 17) used to independently assess the model's predictive power. ⋯ The final model explained 94.2% of the variance in the observed activities of the training set compounds. The model showed good predictive capability for both the training set (cross-validated r2 = 0.705) and randomly excluded test set anesthetics (r2 = 0.837). Three-dimensional pharmacophoric maps were derived to identify the spatial distribution of key areas where steric and electrostatic interactions are important in determining immobilizing activity of the halogenated drugs and were compared with our previously published maps obtained for nonhalogenated volatile anesthetics.