Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1999
Randomized Controlled Trial Clinical TrialPremedication with midazolam delays recovery after ambulatory sevoflurane anesthesia in children.
We studied the effect of oral premedication with midazolam on the recovery characteristics of sevoflurane anesthesia in small children. In a randomized, double-blinded study, 60 children (1-3 yr, ASA physical status I or II) undergoing ambulatory adenoidectomy received either midazolam 0.5 mg/kg (Group M) or placebo (Group P) PO approximately 30 min before the induction of anesthesia. All children received atropine 0.01 mg/kg IV and alfentanil 10 microg/kg IV before the induction of anesthesia with sevoflurane up to 8 vol% inspired concentration in N2O 67% in O2. Tracheal intubation was facilitated with mivacurium 0.2 mg/kg. Anesthesia was continued with sevoflurane adjusted to maintain hemodynamic stability. In the postanesthesia care unit, predetermined recovery end points (emergence, recovery, discharge) were recorded. A pain/ discomfort scale was used to determine the quality of recovery. A postoperative questionnaire was used to evaluate the well-being of the patient at home 24 h after surgery. Emergence (spontaneous eye opening), recovery (full points on the modified Aldrete scale), and discharge were achieved later in Group M than in Group P (15+/-6 vs. 11+/-3 min [P = 0.002], 25+/-17 vs. 16+/-6 min [P = 0.01], and 80+/-23 vs. 70+/-23 min [P = 0.03]). Side effects, postanesthetic excitement, and analgesic treatment did not differ significantly between groups. At home, more children in Group P (30%) experienced disturbed sleep during the night compared with those in Group M (4%) (P = 0.007). ⋯ In this randomized, double-blinded, placebo-controlled study, premedication with midazolam 0.5 mg/kg PO delayed recovery in children 1-3 yr of age after brief (<30 min) sevoflurane anesthesia. Except for more peaceful sleep at home, premedication did not affect the quality of recovery.
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Anesthesia and analgesia · Jul 1999
Randomized Controlled Trial Clinical TrialSmall-dose ketamine enhances morphine-induced analgesia after outpatient surgery.
Small-dose ketamine may enhance the analgesic effect of opiates. We studied the effect of IV coadministration of small-dose ketamine 50-100 microg/kg with morphine 50 microg/kg on postoperative morphine requirements and pain in 140 patients undergoing outpatient surgery. Midazolam 1-2 mg was administered in the holding area. Anesthesia was induced with propofol 2-2.5 mg/kg and was maintained with desflurane in a nitrous oxide/oxygen mixture. Patients received morphine 50 microg/kg with placebo (Group 1, n = 35) or ketamine 50 microg/kg IV (Group 2, n = 35), 75 microg/kg IV (Group 3, n = 35), or 100 microg/kg IV (Group 4, n = 35) 15 min before the end of the operation. Pain and drowsiness were assessed using visual analog scales on arrival in the recovery room, then every 15 min until the time of discharge to phase 2 recovery (phase 1 recovery). Morphine consumption in Groups 3 and 4 was approximately 40% less than that in the control group (91+/-9 and 89+/-8 microg/kg vs. 145+/-9 microg/kg; P<0.05 for both). Pain scores in Groups 3 and 4 were approximately 35% less than those in the control group at all time periods (P<0.0001 for all). There was no significant group difference in drowsiness scores. Small-dose ketamine 75-100 microg/kg IV, enhanced morphine-induced analgesia after outpatient surgery. Simultaneous use of small doses of ketamine with morphine enhances the pain relief produced by morphine. ⋯ Simultaneous use of small doses of ketamine with morphine enhances the pain relief produced by morphine.
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Anesthesia and analgesia · Jul 1999
Randomized Controlled Trial Clinical TrialOndansetron pretreatment to alleviate pain on propofol injection: a randomized, controlled, double-blinded study.
We used a randomized, controlled, double-blinded design to study the effect of ondansetron (OND) pretreatment on the pain produced by the IV injection of propofol. Eighty patients were randomly assigned to one of two groups: Group I received 2 mL of IV 0.9% saline pretreatment, and Group II received OND (4 mg in 2 mg/mL solution) pretreatment in the dorsum of the hand, followed by propofol 1 min later. Pain was reduced significantly in the OND group (P<0.05). Approximately one third of the patients in each group had myoclonic movements or skin rashes in the limb that received propofol. We conclude that the OND pretreatment may be used to reduce the incidence of pain on injection of propofol and to prevent postoperative nausea and vomiting. ⋯ In a double-blinded, controlled study, IV ondansetron (4 mg) pretreatment was used to alleviate pain on injection of propofol. Ondansetron was successful in relieving pain without any adverse effect in a significant number of patients.
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Anesthesia and analgesia · Jul 1999
Randomized Controlled Trial Clinical TrialRopivacaine epidural anesthesia and analgesia versus general anesthesia and intravenous patient-controlled analgesia with morphine in the perioperative management of hip replacement. Ropivacaine Hip Replacement Multicenter Study Group.
The aim of our study was to compare epidural anesthesia and analgesia (EDA) with ropivacaine versus general anesthesia followed by IV patient-controlled analgesia with morphine (GA/PCA) after hip replacement regarding pain, side effects, and discharge from the postanesthesia care unit. After ethics committee approval, randomization, and informed consent, 90 patients were enrolled. In Group EDA, epidural anesthesia (ropivacaine 10 mg/mL, 15-25 mL) was followed by an epidural infusion (2 mg/mL, 4-6 mL/h for 24 h, plus top-up doses of 6-10 mL for 48 h). GA/PCA patients received general anesthesia (isoflurane/N2O/fentanyl) followed by IV patient-controlled analgesia with morphine postoperatively. Pain was assessed by using visual analog scales (0-100 mm) at rest and during physiotherapy. Pain at rest was less in the EDA (n = 43) group than in the GA/PCA (n = 45) group (at 10 h: 11.8+/-12.9 vs. 28.4+/-17.1 [P< 0.001]; at 24 h: 14.3+/-11.7 vs. 24.0+/-17 [P<0.01]; in 48 h: 14.3+/-9.3 vs. 21.1+/-17.4 [P = 0.1]). Whereas EDA patients were deemed ready for discharge from the postanesthesia care unit earlier than GA/PCA patients (5.6+/-8.9 vs. 39.7+/-41.5 min), the actual discharge time was comparable. The median time for first passage of flatus was shorter in the EDA group than in the GA/PCA group (26 vs. 47 h). Nausea and vomiting were more common in the GA/PCA group than in the EDA group (16% vs. 28% and 11% vs. 22%, respectively), whereas hypotension (11% vs. 4%) and bradycardia (14% vs. 2%) were less frequent. Under the conditions of the present study, EDA with ropivacaine provided pain control after hip replacement superior to that provided by IV patient-controlled analgesia with morphine, particularly during the first 24 h. Both approaches to pain management were equally safe. ⋯ Compared with general anesthesia and postoperative IV patient-controlled analgesia with morphine, epidural anesthesia and analgesia with the new local anesthetic ropivacaine enables patients to be discharged sooner from a postanesthesia care unit and provides superior pain relief during the first 24 h after hip replacement.
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Anesthesia and analgesia · Jul 1999
Randomized Controlled Trial Clinical TrialThe effects of clonidine premedication on sevoflurane requirements and anesthetic induction time.
We assessed the effects of oral clonidine preanesthetic medication (4.5 microg/kg) on the vital capacity rapid-inhalation anesthetic induction time (VCRII time) and minimum alveolar anesthetic concentration (MAC) to prevent a response to a verbal command in 50% of patients (MAC-Awake) by its hypnotic effect, and on MAC-Skin incision for the analgesic effect in patients anesthetized with sevoflurane. We studied 104 adult patients (control group: n = 52, clonidine group: n = 52) aged 30-48 yr scheduled to undergo general anesthesia. Fifty-two patients received oral clonidine 4.5 microg/kg 1.5 h before arrival in the operating room (clonidine group). The patients exhaled to residual volume and took three vital capacity breaths of 5% sevoflurane in oxygen. The VCRII time was defined as the time interval between the initiation of the VCRII and the disappearance of the response to verbal command. Anesthesia was maintained with sevoflurane in oxygen and air. The end-tidal (ET) sevoflurane concentration reached a predetermined value, then the ratio of predetermined ET to inspiratory concentration was maintained at > or =0.95 for at least 15 min before skin incision. After skin incision, the patients were observed for gross purposeful muscular movements. MAC was defined as the average of the cross-over midpoints in each cross-over. After maintaining the ET sevoflurane concentration for 15 min, patients were judged to be awake or asleep. Average times for VCRII using 5% sevoflurane were achieved in 44+/-11 s (mean +/- SD) and 27+/-6 s in the control and clonidine groups, respectively (P = 0.0001). MAC-Awake values of sevoflurane were 0.66%+/-0.03% and 0.35%+/-0.02% (P = 0.0001), and MAC-Skin incision values were 1.97%+/-0.19% and 1.29%+/-0.13% (P = 0.0001) in the control and clonidine groups, respectively. These results suggest that clonidine may have a more potent hypnotic effect than analgesic effect. ⋯ Oral clonidine preanesthetic medication (4.5 microg/kg) significantly reduces vital capacity rapid inhalation anesthetic induction time and minimum alveolar anesthetic concentration awake for sevoflurane.