Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2006
Controlled Clinical TrialThe effects of age on the median effective concentration of ropivacaine for motor blockade after epidural anesthesia with ropivacaine.
Minimal local analgesic concentrations have been defined as the median effective concentration (EC50). In this study, we sought to examine the effect of age on motor blockade and determine the motor block EC50 of elderly patients after epidural administration of ropivacaine in patients undergoing urological or minor lower limb surgery. ASA physical status I-II patients were enrolled in 1 of 2 age groups (Group 1: > or =70 yr; Group 2: <70 yr). ⋯ Effective motor blockade was defined as a modified Bromage score >0 within 30 min. The motor blockade EC50 of ropivacaine was 0.383% (95% confidence interval, 0.358%-0. 409%) in group 1 and 0.536% (95% confidence interval, 0.512%-0.556%) in group 2 (P < 0.01). We conclude that age is a determinant of motor blockade EC50 of ropivacaine with epidural administration.
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Anesthesia and analgesia · Jun 2006
A new method for estimating arterial occlusion pressure in optimizing pneumatic tourniquet inflation pressure.
To reduce pressure-related injuries resulting from pneumatic tourniquet use, the lowest possible inflation pressure is recommended. Arterial occlusion pressure (AOP) is a measure of the cuff pressure required to maintain a bloodless surgical field. However, its determination method is time consuming, requires operator skill, and is therefore seldom used in current practice. ⋯ Our results revealed tissue padding coefficients for extremities 20 to 75 cm in circumferences. An estimation method of AOP was developed [AOP = (systolic blood pressure + 10)/Tissue padding coefficient]. The new AOP estimation method may be a simple, rapid, and clinically practical alternative to the AOP determination method.
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Anesthesia and analgesia · Jun 2006
Comment Letter Comparative StudyRocuronium versus succinylcholine for rapid tracheal intubation.
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Anesthesia and analgesia · Jun 2006
Meta AnalysisA systematic review (meta-analysis) of the accuracy of the Mallampati tests to predict the difficult airway.
The original and modified Mallampati tests are commonly used to predict the difficult airway, but there is controversy regarding their accuracy. We searched MEDLINE and other databases for prospective studies of patients undergoing general anesthesia in which the results of a preoperative Mallampati test were compared with the subsequent rate of difficult airway (difficult laryngoscopy, difficult intubation, or difficult ventilation as reference tests). Forty-two studies enrolling 34,513 patients were included. ⋯ The Mallampati tests were poor at identifying difficult mask ventilation. Publication bias was not detected. Used alone, the Mallampati tests have limited accuracy for predicting the difficult airway and thus are not useful screening tests.
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Anesthesia and analgesia · Jun 2006
Randomized Controlled Trial Comparative StudyThe effect of desflurane and sevoflurane on cerebral oximetry under steady-state conditions.
We studied the effect of sevoflurane and desflurane on regional cerebral oxygenation (rSO2). Twenty-two patients undergoing abdominal hysterectomy received sevoflurane and desflurane for 15 min each and 30 min apart under steady-state conditions in a randomized, crossover manner to maintain a bispectral index (BIS) of 40-50. In another 22 patients undergoing the same anesthesia and surgery BIS was maintained at 20-30. ⋯ The MAC(BIS) values required to maintain BIS at 40-50 and at 20-30 were 1.0 versus 1.2 (P = 0.004) and 1.6 versus 1.8 (P < 0.001) for desflurane and sevoflurane respectively. Higher rSO2 values were obtained by 1.6 MAC (71 +/- 13) than by 1 MAC of desflurane (66 +/- 10; P < 0.001) and by 1.8 MAC (72 +/- 11) than by 1.2 MAC of sevoflurane (66 +/- 13; P < 0.001). In conclusion, equipotent concentrations of desflurane or sevoflurane in terms of BIS are associated with similar rSO2 values, but larger anesthetic concentrations of both anesthetics increased the rSO2 values.