Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2004
Multicenter StudyThe incidence of awareness during anesthesia: a multicenter United States study.
The incidence of awareness-with-recall under general anesthesia in the United States is 1-2 cases per 1,000 patients.
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Anesthesia and analgesia · Sep 2004
Case ReportsManagement of an unusual complication during placement of a pulmonary artery catheter.
We describe an unusual complication during flotation of a pulmonary artery catheter through a preexisting percutaneous introducer sheath. A malfunctioning pulmonary artery catheter, which was placed through an introducer sheath in the right internal jugular vein, was removed. ⋯ Under continuous fluoroscopy, the introducer sheath and the pulmonary artery catheter were withdrawn as one unit, which resulted in relaxation of the acute angulation in the introducer sheath and allowed the pulmonary artery catheter to unfold, thus facilitating their complete extraction. We conclude that complications may occur during placement of a pulmonary artery catheter through a well positioned introducer sheath and that fluoroscopy is a valuable tool for safe management of such a complication.
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Anesthesia and analgesia · Sep 2004
The effects of cervical and lumbar epidural anesthesia on heart rate variability and spontaneous sequence baroreflex sensitivity.
A high level of neuroaxial block may produce profound bradycardia and hypotension, possibly as a result of an imbalance between sympathetic and parasympathetic control of heart rate. We designed this study to test the hypothesis that cervical epidural anesthesia would increase the high-frequency (HF) component of heart rate variability (HRV) as a result of cardiac sympathectomy, whereas lumbar epidural anesthesia would cause sympathetic predominance. HRV and spontaneous baroreflex (SBR) sensitivity were assessed before and after cervical and lumbar epidural anesthesia by using plain 1.5% lidocaine (median upper/lower sensory block: C3/T8 for cervical and T11/L5 for lumbar) in healthy patients (n = 10 each). ⋯ HF power correlated well with SBR sensitivities under most of our study conditions. Respiratory rates and Paco(2) were unchanged by either epidural technique. Our results indicate that cervical, but not lumbar, epidural anesthesia depresses phasic and tonic dynamic modulation of the cardiac cycle by the vagal nerve in conscious humans.
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Anesthesia and analgesia · Sep 2004
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of intrathecal plain solutions containing ropivacaine 20 or 15 mg versus bupivacaine 10 mg.
Ropivacaine, which blocks sensory nerve fibers more readily than motor fibers, is considered to be less potent than bupivacaine. Our hypothesis was that, when used in spinal anesthesia for day surgery, ropivacaine 15 and 20 mg would provide faster motor recovery than bupivacaine 10 mg. This prospective, randomized, double-blinded study included 90 ambulatory lower-extremity surgery patients who received 2 mL of ropivacaine 1%, ropivacaine 0.75%, or bupivacaine 0.5%. ⋯ Ropivacaine 15 mg provided faster recovery of motor block (150 min) than did bupivacaine 10 mg (210 min; P = 0.005), but the median duration of sensory block at T10 (140 min) did not differ significantly from that with bupivacaine 10 mg (140 min). The median duration of sensory block at T10 was significantly longer with ropivacaine 20 mg (170 min) than with bupivacaine 10 mg (140 min; P = 0.005), but the median recovery from motor block (210 min) did not differ significantly. We conclude that the duration of sensory block of ropivacaine was two thirds and the duration of motor block was half when compared with bupivacaine, with calculations based on the duration-per-milligram of the local anesthetic.
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Anesthesia and analgesia · Sep 2004
Randomized Controlled Trial Clinical TrialThe effect of intravenous infusion of adenosine on electrically evoked hyperalgesia in a healthy volunteer model of central sensitization.
Human pain models invoking central sensitization, one of the key mechanisms of chronic pain, may be useful for characterizing new analgesics. A new model of electrical hyperalgesia can detect the efficacy of several analgesic mechanisms. Because IV adenosine can alleviate neuropathic pain, we investigated its effect on experimental sensitization. ⋯ Thus, in accordance with reports on neuropathic pain, adenosine reduced central sensitization in the human model of electrical hyperalgesia. However, adenosine did not have the long-term effects seen in patients. The model can investigate mechanisms of drugs for the treatment of chronic pain.