Anesthesia and analgesia
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Anesthesia and analgesia · Mar 1996
Comparative StudyComparative electrophysiologic and hemodynamic effects of several amide local anesthetic drugs in anesthetized dogs.
Large and equipotent doses of several local anesthetics were administered in a cardiac electrophysiologic model on closed-chest dogs. Five groups of pentobarbital-anesthetized dogs were each given intravenously 16 mg/kg lidocaine, 12 mg/kg mepivacaine, 4 mg/kg or 8 mg/kg etidocaine, and 4 mg/kg bupivacaine. Lidocaine induced bradycardia, slowing of atrioventricular node conduction (AH), and marked hemodynamic depression, represented by a decrease in mean aortic pressure (MAoP), in the peak of first derivative of left ventricular pressure (LVdP/dt(max)) and by an increase in left ventricular end-diastolic pressure (LVEDP). ⋯ We conclude that mepivacaine induced moderate cardiotoxicity. In contrast, lidocaine induced dramatic hemodynamic depression while etidocaine and bupivacaine markedly impaired both electrophysiologic and hemodynamic variables. This double impairment could explain the great difficulty in resuscitating patients who have had cardiotoxic accidents induced by etidocaine or bupivacaine.
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Anesthesia and analgesia · Mar 1996
Randomized Controlled Trial Comparative Study Clinical TrialPreoperative oral ondansetron for pediatric tonsillectomy.
This prospective, randomized, double-blind, placebo-controlled study evaluated the antiemetic efficacy of preoperative oral ondansetron, 0.075 mg/kg or 0.15 mg/kg, in 136 preadolescent children premedicated with midazolam 0.5 mg/kg per os and dexamethasone 0.1 mg/kg intravenously prior to undergoing tonsillectomy with isoflurane anesthesia. The incidence of vomiting during the 24 h after tonsillectomy was significantly reduced (P < 0.04) by ondansetron 0.15 mg/kg compared with placebo and ondansetron 0.075 mg/kg (15%, 38%, and 36%, respectively). ⋯ We conclude that ondansetron 0.15 mg/kg, administered orally prior to tonsillectomy, is associated with reduced postoperative vomiting in preadolescent children. In addition, the preoperative oral administration of ondansetron 0.075 mg/kg is no more effective than placebo in preventing posttonsillectomy vomiting in preadolescent children.
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Anesthesia and analgesia · Mar 1996
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of bolus administration of opioids on cerebrospinal fluid pressure in patients with supratentorial lesions.
In many studies reporting an increase in cerebrospinal fluid pressure (CSFP) after opioid administration, concomitant decreases in mean arterial pressure (MAP) have been observed. Autoregulatory cerebral vasodilation may therefore have been a factor in the CSFP increases. We tested the hypothesis that increases in CSFP after bolus injection of opioids could be minimized by modifying concomitant decreases in MAP with phenylephrine. ⋯ No significant changes in MAP or CSFP were observed in the saline-treated patients. HR decreased after injection of either study drug (P < 0.01) but remained unchanged in the saline group. In summary, during stable anesthesia with isoflurane in oxygen, bolus injections of fentanyl or sufentanil, despite producing rapidly corrected mean decreases in MAP of 18% and 25%, respectively, were not associated with any change in CSFP.
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Anesthesia and analgesia · Mar 1996
Randomized Controlled Trial Clinical TrialReducing pain during propofol injection: the role of the solvent.
We hypothesized that the concentration of propofol in the aqueous phase may be the most important variable responsible for the pain experienced during injection of the drug. The concentration of propofol in the aqueous phase (18.57 micrograms/mL) can be decreased by increasing the fat content of the solvent. To test this hypothesis, 36 patients were randomly allocated to one of three groups, each receiving a different formulation of propofol. ⋯ Our results suggest that a smaller concentration of propofol in the aqueous phase of the emulsion reduces pain on injection. With the addition of more lipid (10 mL), a higher percentage of propofol is absorbed by fat particles. If solvents that permit a smaller concentration of the drug in the aqueous phase of oil-in-water emulsions were used for propofol and other drugs that cause pain on injection, pain would be reduced and patient satisfaction may be increased.
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Anesthesia and analgesia · Mar 1996
The response to varying concentrations of inhaled nitric oxide in patients with acute respiratory distress syndrome.
We investigated the response to varying concentrations of inhaled nitric oxide (NO) in 18 patients with acute respiratory distress syndrome (ARDS). The study was divided into two parts. In Part 1, 5-40 ppm of inhaled NO was evaluated in 10 patients with ARDS. ⋯ While the maximum hemodynamic and oxygenation responses to inhaled NO are achieved at approximately 1 ppm, it appears that the maximum hemodynamic response is observed at lower concentrations (0.1 ppm) of inhaled NO than the improvement in oxygenation (1-10 ppm). Higher concentrations of NO do not produce any further change in these variables. It appears that the baseline PVRI may be the best marker predicting a beneficial response to NO.