Anesthesia and analgesia
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Anesthesia and analgesia · Feb 1998
Randomized Controlled Trial Clinical TrialThe effect of timing of ondansetron administration on its efficacy, cost-effectiveness, and cost-benefit as a prophylactic antiemetic in the ambulatory setting.
Although ondansetron (4 mg I.V.) is effective in the prevention and treatment of postoperative nausea and vomiting (PONV) after ambulatory surgery, the optimal timing of its administration, the cost-effectiveness, the cost-benefits, and the effect on the patient's quality of life after discharge have not been established. In this placebo-controlled, double-blind study, 164 healthy women undergoing outpatient gynecological laparoscopic procedures with a standardized anesthetic were randomized to receive placebo (Group A), ondansetron 2 mg at the start of and 2 mg after surgery (Group B), ondansetron 4 mg before induction (Group C), or ondansetron 4 mg after surgery (Group D). The effects of these regimens on the incidence, severity, and costs associated with PONV and discharge characteristics were determined, along with the patient's willingness to pay for antiemetics. Compared with ondansetron given before induction of anesthesia, the administration of ondansetron after surgery was associated with lower nausea scores, earlier intake of normal food, decreased incidence of frequent emesis (more than two episodes), and increased times until 25% of patients failed prophylactic antiemetic therapy (i.e., had an emetic episode or received rescue antiemetics for severe nausea) during the first 24 h postoperatively. This prophylactic regimen was also associated with the highest patient satisfaction and lowest cost-effectiveness ratios. Compared with the placebo group, ondansetron administered after surgery significantly reduced the incidence of PONV in the postanesthesia care unit and during the 24-h follow-up period and facilitated the recovery process by reducing the time to oral intake, ambulation, discharge readiness, resuming regular fluid intake and a normal diet. When ondansetron was given as a "split dose," its prophylactic antiemetic efficacy was not significantly different from that of the placebo group. In conclusion, the prophylactic administration of ondansetron after surgery, rather than before induction, may be associated with increased patient benefits. ⋯ Ondansetron 4 mg I.V. administered immediately before the end of surgery was the most efficacious in preventing postoperative nausea and vomiting, facilitating both early and late recovery, and improving patient satisfaction after outpatient laparoscopy.
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Anesthesia and analgesia · Feb 1998
Randomized Controlled Trial Clinical TrialThe analgesic effect of fentanyl, morphine, meperidine, and lidocaine in the peripheral veins: a comparative study.
Using venous retention with a tourniquet (70 mm Hg), we performed a randomized, double-blind study to assess the efficacy of I.V. pretreatment with fentanyl, morphine, meperidine, or lidocaine in reducing propofol injection pain. Immediately after venous occlusion with a tourniquet, I.V. fentanyl 150 microg (Group A, n = 35), morphine 4 mg (Group B, n = 35), meperidine 40 mg (Group C, n = 35), 2% lidocaine 3 mL (Group D, n = 35), or normal saline 3 mL (Group E, n = 35; as placebo control) was given to adult patients. The venous retention of the drug was maintained for 1 min, followed by tourniquet release and I.V. administration of propofol 100 mg. Pain assessment was made immediately after the propofol injection. Lidocaine and meperidine significantly reduced propofol injection pain more than placebo (P < 0.05), but there were more side effects in the meperidine group. Fentanyl and morphine reduced the intensity of propofol injection pain (P < 0.05) and had some effect in reducing the incidence of propofol injection pain, but the difference did not reach statistical significance. The order of efficacy was lidocaine approximately meperidine > morphine approximately fentanyl. We postulate that the peripheral analgesic effect of these opioid is due to their local anesthetic activity. ⋯ Propofol, a commonly used anesthetic, often causes pain on injection. Given as venous retention pretreatments 1 min before propofol, meperidine and lidocaine were found to significantly reduce the propofol injection pain, whereas fentanyl and morphine only slightly reduced the propofol injection pain.
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Anesthesia and analgesia · Feb 1998
Randomized Controlled Trial Comparative Study Clinical TrialFast-track eligibility after ambulatory anesthesia: a comparison of desflurane, sevoflurane, and propofol.
This study was designed to test the hypothesis that using the less soluble volatile anesthetics, desflurane and sevoflurane, as alternatives to propofol for maintenance of anesthesia facilitates the ability of outpatients to achieve postanesthesia care unit (PACU) discharge criteria (i.e., fast-track eligibility) on arrival in the PACU after laparoscopic surgery. One hundred-twenty consenting women undergoing laparoscopic tubal ligation procedures were randomly assigned to one of three treatment groups. After a standardized induction of anesthesia and tracheal intubation sequence, anesthesia was maintained with either desflurane 2%-6%, sevoflurane 0.6%-1.75%, or propofol 50-150 microg x kg(-1) x min(-1) in combination with nitrous oxide 60% in oxygen. Recovery times, postanesthesia recovery scores, and the number and type of therapeutic interventions in the PACU were recorded. Compared with the propofol group, the times to awakening and to achieve a recovery score of 10 were significantly shorter, and the percentage of patients judged fast-track eligible on arrival in the PACU was significantly higher, in the desflurane and sevoflurane groups (90% and 75% vs 26%). In conclusion, compared with propofol, the use of desflurane and sevoflurane for the maintenance of general anesthesia resulted in a higher percentage of patients being judged fast-track eligible after outpatient laparoscopic tubal ligation procedures. ⋯ Bypassing the recovery room by transferring outpatients directly to the step-down unit after ambulatory surgery ("fast-tracking") could result in significant cost-savings. We examined the effects of three different maintenance anesthetics--desflurane, sevoflurane, and propofol--on the fast-track eligibility of outpatients after laparoscopic tubal ligation surgery. Compared with propofol, desflurane and sevoflurane resulted in a higher percentage of outpatients being judged eligible for fast-tracking.
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Anesthesia and analgesia · Feb 1998
Randomized Controlled Trial Clinical TrialSubhypnotic doses of propofol do not relieve pruritus induced by intrathecal morphine after cesarean section.
The purpose of this study was to determine whether subhypnotic doses of propofol effectively relieve pruritus in women who received intrathecal morphine for postoperative analgesia after cesarean delivery. Twenty-nine women who developed pruritus after undergoing an elective cesarean section and receiving intrathecal morphine (0.25 mg) for postoperative analgesia were enrolled in this randomized, prospective, double-blind study. The women were randomly assigned to receive either 1 mL of propofol (n = 17) or 1 mL of placebo (n = 12) I.V. Pruritus was evaluated 5 min after treatment. In the absence of successful treatment, the women received another 1 mL of the same drug. Pruritus was again evaluated 5 min after the second dose. We found that pruritus was successfully treated twice in the propofol group and once in the placebo group (P = not significant). The antipruritic action of propofol lasted for up to 6 h in one woman and 15 min in the other. The one success in the placebo group lasted for 15 min. We conclude that the success rate of propofol in treating pruritus in women who received intrathecal morphine for postoperative analgesia after cesarean delivery is not significantly different from that of placebo. ⋯ Pruritus is a common and bothersome side effect of neuraxial opioids after cesarean section. Subhypnotic doses of I.V. propofol (10 mg) have been used to treat pruritus caused by neuraxial opioids. In this prospective, randomized, double-blind study, we found that propofol does not relieve pruritus in women who underwent cesarean section and received intrathecal morphine sulfate (0.25 mg) for postoperative pain relief.
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Anesthesia and analgesia · Feb 1998
Randomized Controlled Trial Clinical TrialOral clonidine premedication reduces the awakening concentration of isoflurane.
Because clonidine has analgesic and sedative properties, it may influence the awakening concentration or dose of an anesthetic. To investigate the effects of oral clonidine premedication on emergence from isoflurane anesthesia, we studied 61 ASA physical status I or II patients undergoing superficial operations. They were randomly allocated to one of three groups according to the dose of clonidine they received: the clonidine-2.5 group (n = 21), clonidine-5 group (n = 20), and control group (n = 20) received approximately 2.5, 5, or 0 microg/kg oral clonidine, respectively, in addition to 20 mg of famotidine 90 min before general anesthesia induction. Anesthesia was induced by thiamylal 5 mg/kg, and tracheal intubation was facilitated with succinylcholine 1.5 mg/kg I.V. Anesthesia was maintained with a 1.1% end-tidal isoflurane concentration and 67% N2O in oxygen, while ventilation was controlled to maintain end-tidal CO2 tension between 33 and 38 mm Hg. After surgery, N2O was discontinued while the end-tidal isoflurane concentration was maintained at 1.1%. After confirming the end-tidal N2O concentration of 0%, isoflurane was discontinued. The end-tidal isoflurane concentration at the time when patients responded to a standardized verbal command to open their eyes was recorded as MAC-Awake. The MAC-Awake values in the clonidine-5 group (0.22% +/- 0.09% [mean +/- SD]) was significantly less than those in the clonidine-2.5 and control groups (0.28% +/- 0.07% and 0.30% +/- 0.07%, respectively, P < 0.05). The wake-up time, from discontinuance of isoflurane until arousal, was longer in the clonidine-2.5 and clonidine-5 groups than in the control group (17.3 +/- 8.0, 16.9 +/- 7.0, and 10.6 +/- 5.3 min, respectively; P < 0.05). In conclusion, oral clonidine premedication 5 microg/kg decreases the awakening concentration of isoflurane, and arousal from isoflurane anesthesia is prolonged with oral clonidine in a dose of 2.5-5 microg/kg. ⋯ Preanesthetic medication with oral clonidine, 2.5-5 microg/kg, is associated with prolonged recovery from isoflurane anesthesia in adults.