Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1997
Randomized Controlled Trial Clinical TrialSmall-dose propofol by continuous infusion does not prevent postoperative vomiting in females undergoing outpatient laparoscopy.
This study was designed to test the hypothesis that there is a direct prophylactic antiemetic effect of small-dose propofol given by continuous infusion. Sixty female patients undergoing outpatient laparoscopy under general anesthesia were randomized to receive, in a double-blind fashion, either a bolus of 0.1 mg/kg followed by a constant infusion of 1 mg.kg-1.h-1 of propofol or an equivalent volume of 10% Intralipid (placebo) beginning 30 min before induction of anesthesia and continuing until discharge from Stage I postanesthesia care unit (PACU). Anesthesia was induced and maintained in a standard fashion in all patients. ⋯ No significant differences between Intralipid and propofol were found for any of the outcome variables tested. While small-dose propofol is an effective adjuvant in reducing chemotherapy-induced emesis, we were unable to demonstrate any beneficial effect of propofol in reducing postoperative nausea and vomiting when used as the sole prophylactic medication in this patient population. Propofol may have a synergistic effect when administered with other antiemetics, or the specific antiemetic effect of propofol, if it exists, may be dose-dependent and the dose used in this study was below the efficacy threshold.
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Anesthesia and analgesia · Jan 1997
Randomized Controlled Trial Clinical TrialEffects of epidural and intravenous buprenorphine on halothane minimum alveolar anesthetic concentration and hemodynamic responses.
There is limited information regarding the effects of epidural or intravenous (i.v.) buprenorphine on minimum alveolar anesthetic concentration (MAC) of volatile anesthetic and hemodynamic responses to tracheal intubation and surgical incision. This study was conducted to find the effects of i.v. and epidural buprenorphine required for postoperative pain relief on halothane MAC and hemodynamic responses to tracheal intubation and surgical incision in 126 female patients. Patients were randomly assigned to the four groups: Group I received i.v. and epidural saline as a control; Group II was given buprenorphine 4 micrograms/kg i.v.; and Groups III and IV received buprenorphine 2 and 4 micrograms/kg epidurally, respectively. ⋯ Systolic blood pressure did not change significantly in Groups II-OR and IV-OR after tracheal intubation and in Group III-Ward and IV-Ward after surgical incision but increased significantly (P < 0.05) in the remaining groups in response to noxious stimuli. Heart rate responses to tracheal intubation and surgical incision were similar to those in systolic blood pressure. These results indicate that preanesthetic administration of epidural or IV buprenorphine required for postoperative analgesia reduces halothane MAC and attenuates hemodynamic responses to tracheal intubation and surgical incision according to the dose, route, and timing of administration.
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Anesthesia and analgesia · Jan 1997
Comparative StudyNephrotoxicity of sevoflurane versus desflurane anesthesia in volunteers.
Present package labeling for sevoflurane recommends the use of fresh gas flow rates of 2 L/min or more when delivering anesthesia with sevoflurane. This recommendation resulted from a concern about the potential nephrotoxicity of a degradation product of sevoflurane, "Compound A," produced by the action of carbon dioxide absorbents on sevoflurane. To assess the adequacy of this recommendation, we compared the nephrotoxicity of 8 h of 1.25 minimum alveolar anesthetic concentration (MAC) sevoflurane (n = 10) versus desflurane (n = 9) in fluid-restricted (i.e., nothing by mouth overnight) volunteers when the anesthetic was given in a standard circle absorber anesthetic system at 2 L/min. ⋯ These effects varied greatly (e.g., on postanesthesia Day 3, the 24-h albumin excretion was < 0.03 g (normal) for one volunteer; 0.03-1 g for five others; 1-2 g for two others; 2.1 g for one volunteer; and 4.4 g for another volunteer). Neither anesthetic affected serum creatinine or BUN, nor changed the ability of the kidney to concentrate urine in response to vasopressin, 5 U/70 kg subcutaneously (i.e., these measures failed to reveal the injury produced). In addition, sevoflurane, but not desflurane, caused small postanesthetic increases in serum alanine aminotransferase (ALT), suggesting mild, transient hepatic injury.
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Anesthesia and analgesia · Jan 1997
Cocaine screening of parturients without prenatal care: an evaluation of a rapid screening assay.
Illicit drugs are used widely by inner city patients in our society. Because cocaine ingestion can produce life-threatening arrhythmias and interact with anesthetic drugs, it is potentially useful for the anesthesiologist to know a high-risk patient's cocaine status before administering anesthesia. The commonly used methods to detect cocaine abuse, however, often require 1-3 days for laboratory processing. ⋯ A new rapid latex agglutination assay for urinary metabolites of cocaine (OnTrak Abuscreen; Roche Diagnostic Systems Inc., Branchburg, NJ) was compared with an assay used by many hospital laboratories. The prevalence of cocaine abuse in the group of unregistered parturients was found to be 68%, with the latex agglutination results exactly matching the hospital laboratory results (kappa = 1.0). A sensitive and specific method now exists that allows anesthesiologists to assess cocaine use rapidly, so that they can use this information when planning a patient's anesthetic.
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Anesthesia and analgesia · Jan 1997
Biotransformation of halothane, enflurane, isoflurane, and desflurane to trifluoroacetylated liver proteins: association between protein acylation and hepatic injury.
In susceptible patients, halothane, enflurane, isoflurane, and desflurane can produce severe hepatic injury by an immune response directed against reactive anesthetic metabolites covalently bound to hepatic proteins. The incidence of hepatotoxicity appears to directly correlate with anesthetic metabolism catalyzed by cytochrome P450 2E1 to trifluoroacetylated hepatic proteins. In the present study, we examined whether the extent of acylation of hepatic proteins in rats by halothane, enflurane, isoflurane, and desflurane correlated with reported relative rates of metabolism. ⋯ Sera from patients with a clinical diagnosis of halothane hepatitis showed antibody reactivity against hepatic proteins from rats exposed to halothane or enflurane. No reactivity was detected in rats exposed to isoflurane, desflurane, or oxygen alone. These results indicate that production of acylated proteins may be an important mediator of anesthetic-induced hepatotoxicity.