Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Multicenter Study Clinical TrialPostoperative analgesic effects of three demand-dose sizes of fentanyl administered by patient-controlled analgesia.
Many studies have demonstrated the postoperative analgesic efficacy of fentanyl delivered i.v. by patient-controlled analgesia (PCA) devices at demand doses ranging from 10 to 50 microg, but none has sought to define the optimal fentanyl PCA dose. In this randomized, double-blind, multicenter study, we compared the safety and efficacy of three administered demand-dose sizes of fentanyl (20, 40, and 60 microg) in 150 patients after major surgery. Efficacy was dose-dependent; positive response rates (i.e., a global assessment score of "very good" or "excellent" and the absence of severe opioid adverse effects) were 42%, 52%, and 68% for the 20, 40, and 60 microg demand-dose groups, respectively, and were significantly higher in the 60 microg demand-dose group. The number of doses administered and missed attempts were significantly smaller in the 40 and 60 microg demand-dose groups compared with the 20 microg demand-dose group. This suggests that the 20 microg demand dose provided inadequate pain relief. Adverse respiratory events were more frequent and mean respiratory rates were significantly slower with the 60 microg demand dose, compared with the 20 or 40 microg demand doses. These results indicate that, of these three doses, the 40 microg demand dose was optimal for fentanyl PCA management of moderate to severe pain after major surgery. ⋯ The postoperative analgesic efficacy of fentanyl delivered i.v. by patient-controlled analgesia devices has been demonstrated for demand doses ranging from 10 to 50 microg, but the optimal fentanyl dose remains unknown. In this randomized, double-blind study, we compared three demand dose sizes of fentanyl (20, 40, and 60 microg) and found that the 40 microg demand dose was the most appropriate for fentanyl patient-controlled analgesia management of postoperative pain.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Multicenter Study Clinical TrialIntrathecal clonidine and fentanyl with hyperbaric bupivacaine improves analgesia during cesarean section.
Seventy-eight pregnant women at term, scheduled for elective cesarean section, were enrolled in this multicenter trial to compare the analgesic efficacy and side effect profile of a spinal block with hyperbaric bupivacaine alone (Group B) or combined with 75 microg of clonidine (Group BC) or with clonidine 75 microg and fentanyl 12.5 microg (Group BCF). Intraoperatively, clonidine increased the spread of the sensory block and decreased pain (pain scores 23+/-7 mm vs 17+/-6 and 2+/-1 mm for Group B versus Groups BC and BCF; P < 0.05) and analgesic supplementation. This improved analgesia was best with the clonidine-fentanyl combination (Group BC versus Group BCF; P < 0.05). Postoperative analgesia was prolonged only in Group BCF (215+/-79 min vs 137+/-35 and 183+/-80 min for Group BCF versus Groups B and BC; P < 0.05). Blood pressure and heart rate changes were not significantly different among groups, whereas sedation and pruritus were significantly more frequent in Group BCF. Nausea and vomiting were decreased in Groups BC and BCF. Apgar scores and umbilical artery blood pH were not different among groups. We conclude that adding a small dose of intrathecal clonidine to bupivacaine increases the quality of intraoperative analgesia and decreases pain during cesarean section. Combining clonidine with fentanyl further improved analgesia. ⋯ In this study, we demonstrate improved intraoperative spinal analgesia by adding 75 microg of clonidine to bupivacaine; side effects were not increased. The combination of clonidine and fentanyl further improved analgesia but moderately increased sedation and pruritus.
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Anesthesia and analgesia · Apr 1998
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialA comparison of the efficacy, safety, and patient satisfaction of ondansetron versus droperidol as antiemetics for elective outpatient surgical procedures. S3A-409 and S3A-410 Study Groups.
Two identical, randomized, double-blind, placebo-controlled studies enrolled 2061 adult surgical outpatients at high risk of postoperative nausea and vomiting (PONV) to compare i.v. ondansetron 4 mg with droperidol 0.625 mg and droperidol 1.25 mg for the prevention of PONV. The antiemetic drugs or placebo were administered i.v. 20 min before the induction of anesthesia with a barbiturate compound, followed by maintenance with N2O/isoflurane/enflurane. Nausea, emetic episodes, adverse events, and patient satisfaction were analyzed for the 0 to 2 h and 0 to 24 h postoperative periods. In the 0 to 2 h postoperative period, there was a complete response (no emesis or rescue antiemetic) in 46% of subjects given placebo (P < 0.05 versus antiemetic groups), in 62% given ondansetron, in 63% given droperidol 0.625 mg, and in 69% given droperidol 1.25 mg (P < 0.05 versus ondansetron). In the 0 to 24-h postoperative period, there were no significant differences in complete response between the ondansetron and droperidol 0.625 or 1.25 mg groups; all groups remained superior to placebo. The proportion of patients without nausea during the 0 to 24 h postoperative period was greater in the antiemetic groups compared with the placebo group; however, droperidol 1.25 mg was more effective than ondansetron 4 mg or droperidol 0.625 mg (43% vs 29% or 29%, respectively). Headache incidence was higher in the ondansetron group compared with either droperidol group. Patient satisfaction scores did not differ significantly among antiemetic treatment groups, although all were superior to placebo. In conclusion, all antiemetic treatment regimens were superior to placebo for the prevention of PONV in the immediate postoperative period; however, droperidol 1.25 mg was more efficacious than ondansetron during the early recovery period (0-2 h). There were no significant differences between ondansetron and either droperidol dose for emesis prevention during the 0 to 24 h postoperative period. ⋯ More than 2000 patients at high risk of postoperative nausea and vomiting were given either placebo, ondansetron 4 mg, or droperidol 0.625 mg or 1.25 mg i.v. before the administration of general anesthesia. After surgery, the incidence of nausea, vomiting, medication side effects, and patient satisfaction were evaluated for 24 h. Droperidol 0.625 or 1.25 mg i.v. compared favorably with ondansetron 4 mg i.v. for the prevention of postoperative nausea and vomiting after ambulatory surgery.
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Anesthesia and analgesia · Apr 1998
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialA multicenter, randomized, blind comparison of amrinone with milrinone after elective cardiac surgery.
Amrinone and milrinone are phosphodiesterase inhibitors with positive inotropic effects useful for the treatment of ventricular dysfunction after cardiac surgery. Forty-four patients undergoing elective cardiac surgery at four centers received either amrinone (n = 22) or milrinone (n = 22) in a randomized, blind fashion. Immediately after separation from cardiopulmonary bypass (CPB), two bolus doses of either amrinone 0.75 mg/kg or milrinone 25 microg/kg were administered over 30 s, separated by 5 min. Hemodynamic measurements were recorded before each dose and at the end of the 10-min study. Both amrinone and milrinone increased the cardiac index (48% vs 52%, P = not significant [NS] for amrinone and milrinone, respectively). There was a small increase in mean arterial pressure (MAP) after amrinone administration (from 68 +/- 3 to 72 +/- 3 mm Hg at 10 min, P < 0.05) with no significant change in MAP after milrinone administration. Central venous pressure was significantly higher in the amrinone group at baseline and 5 min (12 vs 10 mm Hg and 11 vs 10 mm Hg, respectively; P < 0.05). Systemic and pulmonary vascular resistances decreased significantly and to a similar extent after either amrinone or milrinone administration. Phenylephrine was required in 11 of 22 patients receiving amrinone and in 11 of 22 patients receiving milrinone to maintain arterial blood pressure. The proportion of patients requiring an intravascular volume infusion (15 of 22 vs 17 of 22, P = NS) and the total fluid volume infused were similar (402 +/- 57 vs 350 +/- 49 mL, P = NS for amrinone and milrinone, respectively). Amrinone and milrinone seem to have similar hemodynamic effects after CPB, with the exception of blood pressure, although the need for vasopressor support of blood pressure did not differ. Selection between these two drugs may include nonhemodynamic considerations such as cost. ⋯ Amrinone and milrinone are drugs that improve cardiac contraction. Their effects have never been directly compared in patients. We found that amrinone and milrinone produced similar hemodynamic effects in adult patients undergoing cardiac surgery. Choice between the two drugs can be based on nonhemodynamic considerations such as cost.
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Anesthesia and analgesia · Mar 1998
Randomized Controlled Trial Multicenter Study Clinical TrialTropisetron for treating established postoperative nausea and vomiting: a randomized, double-blind, placebo-controlled study.
Tropisetron can prevent postoperative nausea and vomiting (PONV) at doses smaller than those used to control chemotherapy-induced nausea and vomiting. In this placebo-controlled study, the efficacy and tolerability of three different doses of tropisetron were compared for the treatment of established PONV after surgical procedures in general anesthesia. Of 1513 patients who satisfied inclusion criteria, 314 experiencing PONV during the first 2 h after recovery from anesthesia were treated with one of three different doses of tropisetron (0.5, 2, or 5 mg) or placebo, administered i.v. as a single dose. Patients were then observed during 24 h for efficacy and tolerability. All three doses of tropisetron were significantly better than placebo in controlling emetic episodes and in reducing the need for rescue treatment. There were no significant differences among the three doses. However, in the subgroup of patients who had previous PONV, and in those randomized for nausea alone, the 2-mg and 5-mg doses controlled emetic episodes better than the 0.5-mg dose. All studied doses of tropisetron were well tolerated and did not affect vital signs. We conclude that a single i.v. administration of tropiestron significantly reduces the recurrence of emetic episodes in patients with established PONV after elective surgery with general anesthesia. Its optimal dose seems to be 2 mg. ⋯ Three hundred-fourteen patients suffering from postoperative nausea and vomiting received different i.v. doses of a new antiemetic drug, tropisetron, to determine the lowest effective dose. We found that a single i.v. administration of tropisetron significantly reduced postoperative nausea and vomiting after elective surgery with general anesthesia.