Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2006
Randomized Controlled Trial Comparative StudyA comparison of epidural blockade produced by plain 1% lidocaine and 1% lidocaine prepared by dilution of 2% lidocaine with the same volume of saline.
Local anesthetics are commonly diluted with saline, but the influence of the dilution on the epidural anesthesia remains unclear. We randomized 40 patients scheduled for gynecological abdominal surgery under epidural anesthesia to one of two groups; those in group P received plain commercially prepared 1% lidocaine and those in group D received 1% lidocaine derived from 2% lidocaine and the same volume of saline was infused epidurally with an epidural catheter at L1-2. The pH and sodium and chloride ion concentrations of the solutions were measured. ⋯ The increase of foot temperature and decrease of mean arterial blood pressure were significantly faster in group P than in group D. Although the mean pH values of the two solutions were similar, sodium and chloride ion concentrations of the diluted solution were significantly larger than those of the plain solution. We conclude that 2% lidocaine diluted with the same volume of saline produces less potent epidural blockade than commercially prepared plain 1% lidocaine.
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Anesthesia and analgesia · Jun 2006
Randomized Controlled TrialIntraoperative administration of tramadol for postoperative nurse-controlled analgesia resulted in earlier awakening and less sedation than morphine in children after cardiac surgery.
In adults, intraoperative administration of tramadol could result in earlier recovery and less sedation than morphine. In this controlled, randomized, double-blind study, we investigated whether an intraoperative initial dose of tramadol could cause more rapid awakening from general anesthesia, less sedation, and earlier tracheal extubation than morphine in children during the immediate postoperative period. Forty children aged 1-6 yr, scheduled for atrial or ventricular septal defect repair and tracheal extubation in the pediatric intensive care unit, were randomly allocated to receive morphine, initial dose 0.2 mg/kg, or tramadol 2 mg/kg given at the end of sternal closure, followed by nurse-controlled analgesia (bolus 0.02 mg/kg of morphine and 0.2 mg/kg of tramadol) with background infusions (0.015 mg x kg(-1) x h(-1) for morphine and 0.15 mg x kg(-1) x h(-1) for tramadol). ⋯ Times to first trigger of nurse-controlled analgesia bolus and objective pain scores during the 48 h observation period were comparable between groups. The incidence of desaturation and emesis were similar between groups. The patients ate well and did not differ on Day 1 or Day 2.
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Anesthesia and analgesia · Jun 2006
ReviewMorphine-6-glucuronide: morphine's successor for postoperative pain relief?
In searching for an analgesic with fewer side effects than morphine, examination of morphine's active metabolite, morphine-6-glucuronide (M6G), suggests that M6G is possibly such a drug. In contrast to morphine, M6G is not metabolized but excreted via the kidneys and exhibits enterohepatic cycling, as it is a substrate for multidrug resistance transporter proteins in the liver and intestines. M6G exhibits a delay in its analgesic effect (blood-effect site equilibration half-life 4-8 h), which is partly related to slow passage through the blood-brain barrier and distribution within the brain compartment. ⋯ At analgesic doses, M6G causes similar reduction of the ventilatory response to CO2 as an equianalgesic dose of morphine but significantly less depression of the hypoxic ventilatory response. Preliminary data indicate that M6G is associated less than morphine with nausea and vomiting, causing 50% and 75% less nausea in postoperative and experimental settings, respectively. Although the data from the literature are very promising, we believe that more studies are necessary before we may conclude that M6G is superior to morphine for postoperative analgesia.
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Anesthesia and analgesia · Jun 2006
Randomized Controlled TrialDevelopment of acute opioid tolerance during infusion of remifentanil for pediatric scoliosis surgery.
We tested the hypothesis that continuous intraoperative infusion of remifentanil is associated with the development of clinically relevant acute opioid tolerance in adolescents undergoing scoliosis surgery. Thirty adolescents were randomly assigned to receive an intraoperative analgesic regimen consisting of continuous remifentanil infusion or intermittent morphine alone. Postoperative analgesic consumption was assessed with a patient-controlled analgesia device that was used to self-administer morphine. ⋯ At 24 h after surgery, cumulative morphine consumption was 30% greater in the remifentanil group (1.65 +/- 0.41 mg/kg) than in the morphine group (1.27 +/- 0.32 mg/kg) (95% confidence interval for the difference, 0.11 to 0.65 mg/kg). Differences in pain and sedation scores were not statistically significant. These data suggest that intraoperative infusion of remifentanil is associated with the development of clinically relevant acute opioid tolerance in adolescents undergoing scoliosis surgery.
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Anesthesia and analgesia · Jun 2006
Randomized Controlled TrialN-acetylcysteine for the prevention of kidney injury in abdominal aortic surgery: a randomized, double-blind, placebo-controlled trial.
In this prospective, randomized, placebo-controlled, double-blind trial we studied the effects of IV N-acetylcysteine for prevention of renal injury in patients undergoing abdominal aortic surgery. Seventy patients without previously documented renal dysfunction were randomly allocated to receive either N-acetylcysteine (150 mg/kg mixed in 250 mL of 5% dextrose infused in 20 min, followed by an infusion of 150 mg/kg in 250 mL of 5% dextrose over 24 h) or placebo. The infusion was started after the induction of anesthesia. ⋯ However, the changes in the NAG/creatinine ratio and the albumin/creatinine ratio were not significantly different between the two groups. Plasma creatinine and serum cystatin C values remained unchanged during the study period in both groups. In conclusion, N-acetylcysteine did not offer any significant protection from renal injury during elective aortic operation in patients with normal preoperative renal function, and some degree of tubular injury seems to occur before aortic crossclamp.