Anesthesia and analgesia
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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
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.