Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyThe sitting versus right lateral position during combined spinal-epidural anesthesia for cesarean delivery: block characteristics and severity of hypotension.
In the present study we evaluated whether the sitting position during initiation of small-dose combined spinal-epidural anesthesia (CSE) would induce less hypotension as compared with the lateral position. Sixty women undergoing elective cesarean delivery were randomly assigned to receive a spinal injection consisting of 6.6 mg hyperbaric bupivacaine with sufentanil 3.3 microg in either the lateral or the sitting position. After securing the epidural catheter, patients were turned to a 15 degrees left lateral supine position. ⋯ In the lateral group, blocks extended more cephalad than with the sitting position (P = 0.014). Apgar scores did not differ, but umbilical artery pH values were significantly higher in patients of the sitting group (7.31 +/- 0.04 versus 7.26 +/- 0.03; P = 0.02). We conclude that performing a CSE technique for cesarean delivery in the sitting position was technically easier and induced less severe hypotension.
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyContinuous positive airway pressure breathing increases the spread of sensory blockade after low-thoracic epidural injection of lidocaine.
Factors affecting the distribution of sensory blockade after epidural injection of local anesthetics remain incompletely clarified. To evaluate if increasing intrathoracic pressure affects the spread of thoracic epidural anesthesia, we randomized 20 patients who received an epidural catheter at the T7-8 or T8-9 intervertebral space into 2 groups. The control group (n = 10) received an epidural test dose of 4 mL lidocaine 2% during spontaneous breathing at ambient pressure. ⋯ The total number of segments blocked was 7 (median, interquartile range 2.25) in the control group and 11 (interquartile range 3.5) in the continuous positive airway pressure group (P = 0.004). The number of segments blocked caudad to the injection site was 3 (median, interquartile range 3.5) in the control group and 6 (interquartile range 2.25) in the continuous positive airway pressure group (P = 0.005). We conclude that continuous positive airway pressure increases the spread of sensory blockade in thoracic epidural anesthesia, primarily by a more caudad extension of sensory blockade.
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyPatient satisfaction with awake craniotomy for tumor surgery: a comparison of remifentanil and fentanyl in conjunction with propofol.
In this study we compared the effectiveness of the use of remifentanil to fentanyl in conjunction with propofol in providing conscious sedation for awake craniotomy for tumor surgery and to assess patient satisfaction with both techniques. The ability to maintain appropriate levels of sedation, adequate analgesia, and hemodynamic stability was assessed in 50 patients randomized to receive either fentanyl or remifentanil. All complications were documented. ⋯ Respiratory complications occurred in 9 (18%) patients (fentanyl 6, remifentanil 3). The recall and satisfaction scores were not different; 93% of all patients were completely satisfied at all interview times. The use of remifentanil infusion in conjunction with propofol is a good alternative to fentanyl and propofol for conscious sedation for the awake craniotomy and these techniques are both well accepted by the patient.
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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.