Anesthesiology
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Comparison of ondansetron versus placebo to prevent postoperative nausea and vomiting in women undergoing ambulatory gynecologic surgery.
Postoperative nausea and emesis, especially in ambulatory surgical patients, remains a troublesome problem. This study was performed to compare the incidence of nausea and emesis during the 24-h postoperative period in ondansetron-treated patients versus placebo-treated patients. ⋯ Ondansetron given intravenously to prevent postoperative nausea and emesis was highly effective in the 4- and 8-mg doses in women having ambulatory gynecologic surgery.
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Randomized Controlled Trial Comparative Study Clinical Trial
Midazolam enhances anterograde but not retrograde amnesia in pediatric patients.
Midazolam sedation has been shown to diminish recall of one to four cards shown prior to induction of general anesthesia in pediatric patients. This promising but limited finding prompted us to investigate the effect of midazolam sedation on retrograde and anterograde recall and recognition in children scheduled for elective surgery. ⋯ These results support and extend the inference that midazolam diminishes anterograde recall. In addition, our findings indicate that midazolam diminishes anterograde recognition, thereby providing partial anterograde amnesia without affecting retrograde memory in pediatric patients.
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Midazolam is being selected increasingly for use in patients with cardiovascular compromise. Although clinical doses of midazolam have minimal effects on cardiac function, the influence of midazolam (and other benzodiazepine sedatives) on cardiac arrhythmogenesis has yet to be elucidated fully. ⋯ This study has demonstrated that midazolam infusion results in either no effect (with clinical plasma midazolam concentrations) or flumazenil-reversible suppression (with supraclinical concentrations) of halothane-epinephrine arrhythmogenesis.
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Hyperventilation frequently is employed to reduce carbon dioxide partial pressure in patients in the operating room and intensive care unit. However the effect of hypocapnia on oxygenation is complex and may result in worsening in patients with preexisting intrapulmonary shunt. To better define the interplay between hypocapnia and oxygenation, the effects of hypocapnia and hypercapnia on the matching of ventilation (VA) and perfusion (Q) were studied in dogs with oleic acid-induced pulmonary edema, using the multiple inert gas elimination technique. ⋯ Both hypocapnia and hypercapnia were associated with an increased VA/Q inequality. However, PaO2 decreased and P[A-a]O2 increased with only hypocapnia. These results suggest that hyperventilation to reduce PaCO2 may be detrimental to arterial PO2 in some patients with lung disease.
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The transdermal therapeutic system (fentanyl), or TTS(fentanyl), continuously delivers fentanyl for up to 72 h. The transdermal therapeutic system (fentanyl)-100 delivers approximately 100 micrograms/h. The repeated dose pharmacokinetics of this drug using the recommended dosing interval have not been evaluated previously and were determined in the present study. ⋯ These results suggest that steady-state serum concentrations are approached by the second dose of TTS(fentanyl) and that the kinetics are stable with repeated dosing. The apparent half-life following system removal is relatively long, indicating ongoing absorption from a subcutaneous depot.