Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialCerebral physiologic effects of burst suppression doses of propofol during nonpulsatile cardiopulmonary bypass. CNS Subgroup of McSPI.
Central nervous system (CNS) complications are common after cardiac surgery. Death due to cardiac causes has decreased, but the number of deaths due to CNS injury has increased. As a first stage in the evaluation of its cerebral protection potential, we evaluated the cerebral physiologic effects of burst suppression doses of propofol during nonpulsatile cardiopulmonary bypass. ⋯ Pharmacologic burst suppression with propofol produced a statistically significant reduction in CBF, cerebral oxygen delivery (DO2), and cerebral metabolic rate (CMRO2) at each measurement interval (P < 0..05 vs control). Cerebral arterial venous oxygen difference (C(a-v)O2), and jugular bulb venous oxygen saturation (SJvO2) were not statistically different between groups, indicating maintenance of cerebral metabolic autoregulation (coupling). The reduction in CBF and CMRO2, prominent during the normothermic phases of cardiopulmonary bypass (CPB), indicates a potential for propofol to reduce cerebral exposure to the embolic load during CPB.
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialThe comparative effects of methohexital, propofol, and etomidate for electroconvulsive therapy.
The intravenous anesthetics which are commonly used for electroconvulsive therapy (ECT) possess dose-dependent anticonvulsant properties. Since the clinical efficacy of ECT depends on the induction of a seizure of adequate duration, it is important to determine the optimal dose of the hypnotic for use during ECT. We compared the duration of seizure activity and cognitive recovery profiles after different doses of methohexital, propofol, and etomidate administered to induce hypnosis prior to ECT. ⋯ There were no significant dose-related differences in motor and EEG seizure durations (means +/- SD) after the low, intermediate, and high doses of etomidate of 44 +/- 11 and 77 +/- 19, 43 +/- 10 and 76 +/- 34, 42 +/- 16 and 78 +/- 56 s, respectively. Conversely, both methohexital and propofol, 0.75, 1.0, and 1.5 mg/kg, produced dose-dependent decreases in motor and EEG seizure durations (i.e., 37 +/- 10 and 58 +/- 12, 36 +/- 8 and 62 +/- 24, and 29 +/- 13 and 48 +/- 20 for methohexital; 34 +/- 15 and 56 +/- 29, 31 +/- 8 and 50 +/- 17, and 20 +/- 6 and 33 +/- 12 for propofol, respectively). The awakening times were similar, regardless of the hypnotic or dose administered.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialElectromyographic comparison of obturator nerve block to three-in-one block.
Obturator nerve block during spinal, epidural, or general anesthesia without muscle relaxants has been recommended for transurethral surgery to prevent thigh adductor muscle contractions during operative electrocautery. We investigated the effectiveness of direct obturator and 3-in-1 nerve motor blocks in 44 patients undergoing transurethral surgery during spinal anesthesia with isobaric bupivacaine. Patients were randomly assigned to receive 3-in-1 block with 40 mL (n = 13) or 50 mL (n = 11) of 1.5% lidocaine plus epinephrine, or direct obturator nerve block with 10 mL of 2% lidocaine plus epinephrine (n = 20). ⋯ Peak lidocaine plasma levels of 1.6 +/- 0.2 micrograms/mL (range 1.0-2.8 micrograms/mL) were reached 60-90 min after the block in those patients receiving 50 mL of local anesthetic. The 3-in-1 technique fails to predictably result in effective motor block of the obturator nerve and thus may not prevent inadvertent thigh adductor muscle contractions during transurethral surgery. A direct approach to the obturator nerve is significantly more effective in producing motor block, and even when given in larger than recommended dosages it results in subtoxic peak plasma lidocaine concentrations.
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialComparison of ondansetron and droperidol in the prevention of nausea and vomiting after inpatient minor gynecologic surgery.
Ondansetron and droperidol are both effective in the prevention of postoperative nausea and vomiting (PONV). In this randomized, double-blind study, 80 inpatients scheduled for minor gynecologic surgery received either ondansetron 8 mg intravenously (i.v.) or droperidol 2.5 mg i.v. 5 min prior to induction of isoflurane-narcotic anesthesia. PONV was absent in 68% of the patients after ondansetron and in 88% after droperidol (P < 0.05). ⋯ After ondansetron and droperidol, the incidence of severe drowsiness, restlessness, anxiety, or dizziness was 5% and 28%, respectively (P < 0.01). Thus after minor gynecologic surgery, droperidol 2.5 mg i.v. was superior to ondansetron 8 mg i.v. in the prevention of PONV. However, relative to ondansetron, droperidol entailed an average 1-h delay in recovery from anesthesia.
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialA clinical and pharmacokinetic comparison of ropivacaine and bupivacaine in axillary plexus block.
The clinical and pharmacokinetic properties of ropivacaine and bupivacaine, both 5 mg/mL, used in axillary plexus block were compared in 60 patients in this randomized, double-blind, parallel-group study. The axillary plexus was identified with a nerve stimulator and 30, 35, or 40 mL of drug, depending on body weight, was injected into the perivascular sheath. In 20 patients, venous blood samples for the pharmacokinetic measurement were obtained over 24 h. ⋯ In the pharmacokinetic study the mean peak plasma concentrations (Cmax) were 1.28 +/- 0.21 mg/L in the ropivacaine group and 1.28 +/- 0.47 mg/L in the bupivacaine group and the median times to peak plasma concentration (tmax) were 0.86 h and 0.96 h, respectively. The median terminal half-lives (t1/2) were 7.1 h and 11.5 h in the ropivacaine group and the bupivacaine group, respectively (P = 0.07). No statistically significant differences were found between ropivacaine and bupivacaine in either the clinical or the pharmacokinetic comparisons.