Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Clinical TrialPreoperative epidural ketamine in combination with morphine does not have a clinically relevant intra- and postoperative opioid-sparing effect.
In this prospective, randomized, and double-blinded clinical trial, we evaluated the efficacy of preincisional administration of epidural ketamine with morphine compared with epidural morphine alone for postoperative pain relief after major upper-abdominal surgery. We studied 50 ASA I and II patients undergoing major upper-abdominal procedures. These patients were randomly allocated to one of the two treatment groups: patients in Group 1 received epidural morphine 50 microg/kg, whereas those in Group 2 received epidural ketamine 1 mg/kg combined with 50 microg/kg of morphine 30 min before incision. Intraoperative analgesia was provided in addition, with IV morphine, and the requirement was noted. A blinded observer using a visual analog scale for pain assessment observed patients for 48 h after surgery. Additional doses of epidural morphine were provided when the visual analog scale score was more than 4. Analgesic requirements and side effects were compared between the two groups. There were no differences between the two groups with respect to age, sex, weight, or duration or type of the surgical procedures. The intraoperative morphine requirement was significantly (P = 0.018) less in Group 2 patients (median, 6.8 mg; range, 3-15 mg) compared with patients in Group 1 (median, 8.3 mg; range, 4.5-15 mg). The time for the first requirement of analgesia was significantly (P = 0.021) longer (median, 17 h; range, 10-48 h) in Group 2 patients than in Group 1 (median, 12 h; range, 4-36 h). The total number of supplemental doses of epidural morphine required in the first 48 h after surgery was comparable (P = 0.1977) in both groups. Sedation scores were similar in both groups. One patient in Group 2 developed hallucinations after study drug administration. None of the patients in either group developed respiratory depression. Other side effects, such as pruritus, nausea, and vomiting, were also similar in both groups. Although the addition of ketamine had synergistic analgesic effects with morphine (reduced intraoperative morphine consumption and prolonged time for first requirement of analgesia), there was no long- lasting preemptive benefit seen with this combination (in terms of reduction in supplemental analgesia) for patients undergoing major upper-abdominal procedures. ⋯ Ketamine added to epidural morphine given before surgery can decrease postoperative pain by its preemptive effect, opioid potentiation, and prevention of acute opioid tolerance. A single epidural bolus of 1 mg/kg of ketamine with morphine given before major upper-abdominal surgery did not result in a clinically relevant reduction in postoperative pain relief.
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Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Clinical TrialPlasma lidocaine concentrations during continuous thoracic epidural anesthesia after clonidine premedication in children.
There is no report concerning oral clonidine's effects on epidural lidocaine in children. Therefore, we performed a study to assess the concentrations of plasma lidocaine and its major metabolite (monoethylglycinexylidide [MEGX]) in children receiving continuous thoracic epidural anesthesia after oral clonidine premedication. Ten pediatric patients, aged 1-9 yr, were randomly allocated to the Control or Clonidine 4 microg/kg group (n = 5 each). Anesthesia was induced and maintained with sevoflurane in oxygen and air (FIO2 40%). Epidural puncture and tubing were carefully performed at the Th11-12 intervertebral space. An initial dose of 1% lidocaine (5 mg/kg) was injected through a catheter into the epidural space, followed by 2.5 mg x kg(-1) x h(-1). Plasma concentrations of lidocaine and MEGX were measured at 15 min, 30 min, and every 60 min for 4 h after the initiation of continuous epidural injection. The concentrations of lidocaine and MEGX were measured using high-pressure liquid chromatography with ultraviolet detection. Hemodynamic variables were similar between members of the Control and Clonidine groups during anesthesia. The Clonidine group showed significantly smaller lidocaine concentrations (p < 0.05) and the concentration of MEGX tended to be smaller in the plasma of the Clonidine group for the initial 4 h after the initiation of epidural infusion. In conclusion, oral clonidine preanesthetic medication at a dose of 4 microg/kg decreases plasma lidocaine concentration in children. ⋯ Oral clonidine decreases the plasma lidocaine concentration in children. Our finding may have clinical implications in patients receiving continuous epidural anesthesia. Additionally, perhaps an additional margin of safety regarding lidocaine toxicity is gained through the use of oral clonidine in children who will receive epidural lidocaine.
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Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Comparative Study Clinical TrialThe use of midazolam and small-dose ketamine for sedation and analgesia during local anesthesia.
Small-dose ketamine in combination with sedative drugs has increasingly been used for sedation and analgesia in local anesthesia. We compared the clinical efficacy of midazolam with two different ketamine infusion regimens during plastic surgery under local anesthesia. Sixty patients undergoing plastic surgery procedures with local anesthesia were randomly assigned to two groups of 30 patients each in a double-blinded fashion. All patients received a bolus of 0.05 mg/kg midazolam, followed by a stepwise infusion: 1.67 microg x kg(-1) x min(-1) for the first 30 min, then reduced to 1.33 microg x kg(-1) x min(-1) for 90 min and subsequently to 1 microg x kg(-1) x min(-1). Two minutes before the infiltration of local anesthetic solution, a bolus of ketamine 0.3 mg/kg IV was administered, followed by a stepwise infusion of ketamine: Group A, 16.67 microg x kg(-1) x min(-1) for 30 min, 13.3 microg x kg(-1) x min(-1) for 90 min, and subsequently 10 microg x kg(-1) x min(-1); Group B, 8.33 microg x kg(-1) x min(-1) for 30 min, 6.67 microg x kg(-1) x min(-1) for 90 min, and then 5 microg x kg(-1) x min(-1). The level of sedation was evaluated by using the modified Observer's Assessment of Alertness/Sedation scale. We observed the effects of the two ketamine infusion regimens on sedation levels, respiratory and cardiovascular variables, and perioperative side effects. In both groups, midazolam and ketamine produced adequate sedation (with Observer's Assessment of Alertness/Sedation scores of 2-4) without significant respiratory and cardiovascular depression during surgery. However, there were fewer disruptive movements and there was less postoperative vomiting in Group B (P < 0.01). In conclusion, ketamine and midazolam provided satisfactory intraoperative sedation, analgesia, and amnesia in both groups. However, side effects associated with ketamine occurred less often in the smaller-dose ketamine group. ⋯ Sedation and analgesia are often provided during local anesthesia. This study demonstrates that a small-dose ketamine infusion in combination with midazolam provided satisfactory intraoperative sedation, analgesia, and amnesia in healthy plastic-surgery patients when it was used to supplement local anesthesia.
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Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Comparative Study Clinical TrialUlnar nerve block induced by the new local anesthetic IQB-9302 in healthy volunteers: a comparison with bupivacaine.
We evaluated the duration of sensory anesthesia after blockade of the ulnar nerve of IQB-9302, a new local amide anesthetic, compared with bupivacaine. A double-blinded, randomized, cross-over study in 12 healthy volunteers aged 18 to 35 yr was performed. Three milliliters of 0.25% IQB-9302 was administered in one wrist and bupivacaine in the other. A week later, the blocks were repeated with a concentration of 0.5%. These concentrations were chosen because they seemed to be equipotent in previous studies. The duration of sensory anesthesia was the main variable measured; secondary outcomes were motor block, time to onset, and time to recovery from block. The duration of sensory block was similar for IQB-9302 and bupivacaine at a concentration of 0.25%; median and range: 409 min (0-800 min) for IQB-9302 and 258 min (0-665 min) for bupivacaine (95% confidence interval for the difference from -47 to 545, P = 0.82, Wilcoxon's test). The results with 0.5% were: 525 min (440-735 min) and 690 min (365-1098 min), respectively (P = 0.026). There were no significant differences in the other variables measured. No important adverse reactions were seen. We conclude that IQB-9302 is an effective new local anesthetic for blockade of ulnar nerve at the concentrations tested. ⋯ IQB-9302 is a new local anesthetic that has shown a long duration of action and low cardiovascular toxicity in preclinical studies. We report the results of a phase I clinical trial to compare this new drug with bupivacaine for ulnar nerve block.
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Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Comparative Study Clinical TrialInduction of anesthesia in the elderly ambulatory patient: a double-blinded comparison of propofol and sevoflurane.
Hypotension during induction of anesthesia is common and particularly undesirable in elderly patients. This study has shown that inhaled induction with sevoflurane is well tolerated by the elderly and is associated with higher mean arterial pressure than slow propofol induction.