Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2006
Randomized Controlled Trial Comparative StudyCombined spinal epidural causes higher level of block than equivalent single-shot spinal anesthesia in elective cesarean patients.
Combined spinal epidural (CSE) is an established technique for lower segment cesarean delivery. In this study we tested the hypothesis that the spinal block from a CSE technique results in a more extensive spread of local anesthetic in the subarachnoid space than the single-shot spinal (SSS) technique. We recruited 30 ASA physical status I parturients admitted for elective lower segment cesarean delivery into our randomized, controlled, double-blind study. ⋯ Time taken to reach maximal sensory block was significantly longer in group CS. There were no differences in the time taken for the block to recede to T10, hemodynamic profile, or side effects. In conclusion, the CSE technique without placing an epidural catheter or administering epidural medication resulted in a significantly higher level of sensory block when compared with the SSS technique when the same dose of local anesthetic was given intrathecally.
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Anesthesia and analgesia · Mar 2006
Comparative StudyPostoperative upper airway obstruction after recovery of the train of four ratio of the adductor pollicis muscle from neuromuscular blockade.
Anesthetics, and even minimal residual neuromuscular blockade, may lead to upper airway obstruction (UAO). In this study we assessed by spirometry in patients with a train-of-four (TOF) ratio >0.9 the incidence of UAO (i.e., the ratio of maximal expiratory flow and maximal inspiratory flow at 50% of vital capacity [MEF50/MIF50] >1) and determined if UAO is induced by neuromuscular blockade (defined by a forced vital capacity [FVC] fade, i.e., a decrease in values of FVC from the first to the second consecutive spirometric maneuver of > or =10%). Patients received propofol and opioids for anesthesia. ⋯ The mean maximal expiratory flow and maximal inspiratory flow at 50% of vital capacity ratio after tracheal extubation was significantly increased from baseline (by 20%; 1.39 +/- 1.01 versus 1.73 +/- 1.02; P < 0.01), and subsequently decreased significantly to values observed at baseline (1.49 +/- 0.93). A statistically significant FVC fade was not present, and a FVC fade of > or =10% was observed in only 2 patients after extubation. Thus, recovery of the TOF ratio to 0.9 predicts with high probability an absence of neuromuscular blocking drug-induced UAO, but outliers, i.e., persistent effects of neuromuscular blockade on upper airway integrity despite recovery of the TOF ratio, may still occur.
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Anesthesia and analgesia · Jan 2006
Comparative StudyA comparison of state and response entropy versus bispectral index values during the perioperative period.
Cerebral monitoring indices are associated with a large degree of inter-patient variability and electrical signal interference during surgery. We designed this clinical study to test the hypothesis that use of the spectral entropy (Entropy) module is associated with less frequent intraoperative interference with the displayed indices than the bispectral index (BIS) monitor when used during general anesthesia with propofol and desflurane. Thirty consenting patients scheduled for major laparoscopic surgery procedures were enrolled in this prospective study. ⋯ During the maintenance period, the responses to changes in propofol and desflurane concentrations were consistent with all three indices. Finally, the entropy indices were less interfered with by the electrocautery unit during the operation (12% versus 62% for the BIS monitor). Because the average selling prices of the Entropy and BIS disposable electrode strips (14.25 dollars versus 14.95 dollars USD, respectively) are comparable, we conclude that the Entropy module is a cost-equivalent alternative to the BIS monitor.
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Anesthesia and analgesia · Jan 2006
Comparative StudyThe effects of sevoflurane and propofol on QT interval and heterologously expressed human ether-a-go-go related gene currents in Xenopus oocytes.
Sevoflurane can induce prolongation of the cardiac QT interval by inhibiting the repolarization phase of the action potential. This may occur as a result of inhibition of the human ether-a-go-go related gene (HERG) channel. To clarify the mechanisms of anesthetics on HERG channels, we monitored the electrocardiogram and measured QT intervals in the guinea pig in the presence of sevoflurane and propofol. ⋯ The time constant of the converging current was decreased in the presence of sevoflurane, but the inactivation and activation curves were not shifted. Propofol did not affect these currents within the clinically relevant concentration. In conclusion, compared with steady-state currents, sevoflurane was more potent in inhibiting the outward tail currents, suggesting that sevoflurane may modulate the HERG channel kinetics in its inactivated state.
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Anesthesia and analgesia · Jan 2006
Comparative StudyDuration of dialysis is a significant predictor of prolonged postoperative mechanical ventilation in dialysis-dependent patients undergoing cardiac surgery.
Prolonged mechanical ventilation is reported to correlate with increased risk of mortality after cardiac surgery. We designed the present study to determine the preoperative and intraoperative risk factors that could predict postoperative prolonged mechanical ventilation in dialysis-dependent patients undergoing cardiac surgery with cardiopulmonary bypass. Forty-four dialysis-dependent patients were divided into two groups; patients of group E were tracheally extubated within 24 h after admission to the intensive care unit postoperatively (n = 19) and patients of group L (n = 25) required more than 24 h of mechanical ventilation. ⋯ On admission to the intensive care unit, Pao2/Fio2 of group L was significantly lower than that of group E (294 +/- 135 versus 415 +/- 99 mm Hg) and the circulatory status of group L was worse than that of group E. The median (interquartile range) duration of intensive care unit stay in group E was 3 (3.00) days, which was significantly shorter than that of group L (5 [2.75] days). It is possible that longer surgery increases the likelihood of cardiac dysfunction and poor oxygenation in patients with a long history of dialysis.