Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1997
Antinociceptive effect of bupivacaine encapsulated in poly(D,L)-lactide-co-glycolide microspheres in the acute inflammatory pain model of carrageenin-injected rats.
Encapsulating bupivacaine in poly(D,L)-lactide-coglycolide microspheres may prolong analgesia and diminish systemic toxicity. The antinociceptive effect of bupivacaine-loaded microspheres (1, 2.5, and 5 mg) and plain bupivacaine solutions (1, 2.5, and 5 mg) were compared using the vocalization threshold to paw pressure test (VTPP) in rats. Local anesthetic solutions were injected subcutaneously in the plantar hindpaw. ⋯ Duration of antinociception was 60 min with plain bupivacaine (1 mg) and increased to 90, 120, and 180 min, respectively, for the different doses of bupivacaine-loaded microspheres (1, 2.5, and 5 mg). Larger doses of plain bupivacaine (2.5 and 5 mg) induced systemic toxicity. The encapsulation of bupivacaine in microspheres induced a dose-dependent increase in duration of antinociception as compared with plain bupivacaine.
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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.