Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Comparative Study Clinical TrialSmall-dose propofol sedation attenuates the formation of reactive oxygen species in tourniquet-induced ischemia-reperfusion injury under spinal anesthesia.
The release of a tourniquet produces reactive oxygen species (ROS), which can cause ischemia-reperfusion injury. We investigated the effects on ROS production in 22 adult ASA physical status I-II patients sedated with small-dose propofol infusion and IV midazolam undergoing elective total knee replacement under intrathecal anesthesia, allocated randomly to one of two groups. In the Propofol group, sedation was performed with propofol 0.2 mg/kg followed by infusion at a rate of 2 mg. kg(-1). h(-1). In the Control group, IV midazolam 5 mg was given. ROS production was measured by lucigenin chemiluminescence analysis. Blood samples were obtained from the radial artery after spinal anesthesia, 1 min before release of the tourniquet and 5 and 20 min after reperfusion. The ischemic time was approximately 70 min. ROS production decreased nonsignificantly before reperfusion in both groups but increased significantly 5 and 20 min after reperfusion in the Midazolam group. In the Propofol group, no significant increase of ROS production was found. We conclude that small-dose propofol infusion attenuates ROS production in tourniquet-induced ischemia-reperfusion injury. ⋯ Small-dose propofol sedation, compared with IV midazolam, attenuates free radical production after release of the tourniquet during total knee replacement under spinal anesthesia.
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Clinical TrialEpidural morphine delays the onset of tourniquet pain during epidural lidocaine anesthesia.
We conducted a randomized, double-blinded study to examine the onset time of tourniquet pain during epidural lidocaine anesthesia either with or without morphine in the epidural solution. Forty-five patients undergoing knee surgery with a thigh tourniquet were randomly allocated into 3 groups of 15 patients each: epidural morphine (EM; epidural administration of 17 mL of 2% lidocaine plus 2 mg of morphine, followed by IV injection of 0.2 mL of normal saline), IV morphine (IVM; 17 mL of 2% lidocaine plus 0.2 mL of normal saline, followed by IVM 2 mg IV), and control (17 mL of 2% lidocaine plus 0.2 mL of normal saline, followed by 0.2 mL of normal saline IV). The onset time of tourniquet pain was recorded. The level of sensory block was determined by the pinprick method at the occurrence of tourniquet pain. Hemodynamic changes and side effects of EM were also recorded. The onset time of tourniquet pain from both the epidural injection and the tourniquet inflation were significantly longer in the EM group (103 +/- 15 min and 80 +/- 15 min, respectively) compared with the IVM group (74 +/- 12 min and 50 +/- 12 min, respectively; P < 0.05) and the Control group (67 +/- 9 min and 45 +/- 9 min, respectively; P < 0.05). The level of sensory block at the onset of tourniquet pain and hemodynamic changes were not different among the three groups. Only two and three patients in the EM group complained of nausea/vomiting and pruritus, respectively. Respiratory depression was not observed in any patient. We conclude that epidural injection of the mixture of 2 mg of morphine and 2% lidocaine solution delayed the onset of tourniquet pain during epidural lidocaine anesthesia without significant morphine-related side effects. ⋯ We examined the effect of epidural morphine on the onset of tourniquet pain during epidural lidocaine anesthesia. We found that the addition of 2 mg of morphine to epidural 2% lidocaine significantly delayed the onset of tourniquet pain without increasing morphine-related side effects.
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Comparative Study Clinical TrialLidocaine iontophoresis versus eutectic mixture of local anesthetics (EMLA) for IV placement in children.
Pain during venipuncture is a major source of concern to children and their caretakers. Iontophoresis is a novel technique that uses an electrical current to facilitate movement of solute ions (lidocaine) across the stratum corneum barrier to provide dermal analgesia. In this study, we compared dermal analgesia provided by lidocaine iontophoresis and eutectic mixture of local anesthetics (EMLA). After informed consent, 26 children, aged 7-16 yr, who required venous cannulation on multiple occasions, were enrolled in this prospective, randomized, crossover study to receive EMLA and iontophoresis on separate occasions. During a third session, each subject received his or her preferred treatment. Pain during venipuncture was assessed by the subject, parent, observer, and technician performing the procedure, by use of a 100-mm visual analog scale. The observer also used the Children's Hospital of Eastern Ontario Pain Scale to rate the subject's pain. Ratings of subject satisfaction were also assessed. There were no significant differences between the two groups in the subject-rated visual analog scale or the Children's Hospital of Eastern Ontario Pain Scale scores. Eleven (50%; 95% confidence interval [CI], 31%-69%) of the 22 subjects who completed both sessions preferred iontophoresis. Five subjects (23%; 95% CI, 10%-44%), including two who did not tolerate treatment with iontophoresis, preferred EMLA, and six (27%; 95% CI, 13%-48%) had no preference for the intervention to provide dermal analgesia. We conclude that lidocaine iontophoresis provides similar pain relief for insertion of IV catheters as EMLA and is a useful noninvasive alternative to establish dermal analgesia for venous cannulation. ⋯ Iontophoresis is a technique that uses an electrical current to facilitate movement of solute ions (lidocaine) across the stratum corneum barrier to provide dermal analgesia. Lidocaine iontophoresis provides similar pain relief for insertion of IV catheters as eutectic mixture of local anesthetics and is a useful noninvasive alternative to establish dermal analgesia for venous cannulation.
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Clinical TrialThe minimum local anesthetic concentration of ropivacaine for caudal analgesia in children.
Ropivacaine is a new long-acting amino-amide local anesthetic. The concentrations of ropivacaine used in caudal analgesia range from 0.1% to 0.5%. The purpose of this study was to determine the minimum local analgesic concentration of ropivacaine to provide caudal analgesia in children. In a prospective, randomized, double-blinded clinical study, we studied 26 ASA grade I patients aged 1 to 5 yr who were scheduled for hypospadias operation under general anesthesia with caudal ropivacaine analgesia. General anesthesia was maintained with an end-tidal enflurane concentration of 0.8% in 100% oxygen (0.5 minimum alveolar anesthetic concentration [MAC]). Each child received 1 mL/kg of ropivacaine solution through a caudal catheter. The first child received ropivacaine 0.2%, and subsequent concentrations were determined by the analgesic response of the previous patient to the initial skin incision by use of Dixon's up-and-down sequential allocation. The testing interval was set at 0.025%. The minimum local analgesic concentration of ropivacaine for caudal analgesia under general anesthesia with 0.5 MAC enflurane was 0.11% (95% confidence interval [CI], 0.09%-0.12%), and the 95% effective concentration was 0.13% (95% CI, 0.12%-0.21%). In conclusion, the minimum local analgesic concentration of ropivacaine to provide effective caudal analgesia in children under general anesthesia with 0.5 MAC enflurane was found to be 0.11% (95% CI, 0.09%-0.12%). ⋯ Ropivacaine is a new long-acting amino-amide local anesthetic. The concentrations of ropivacaine used in caudal analgesia ranged from 0.1% to 0.5%. This study determined the minimum local analgesic concentration of ropivacaine to establish effective caudal analgesia under general anesthesia with 0.5 minimum alveolar anesthetic concentration enflurane in children.
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Clinical TrialMusic and preoperative anxiety: a randomized, controlled study.
Music may decrease the anxiety experienced by patients before surgery. Previous studies of this issue were hindered with multiple methodological problems. In this investigation, we examined this hypothesis while using a rigorous study design and objective outcome measures. Adult patients undergoing anesthesia and surgery were randomly assigned to two study groups. Subjects in Group 1 (n = 48) listened to a 30-min patient-selected music session, and subjects in Group 2 (n = 45) received no intervention. By using self-report validated behavioral (State-Trait Anxiety Inventory) and physiological measures of anxiety (heart rate, blood pressure, and electrodermal activity and serum cortisol, epinephrine, and norepinephrine), patients were evaluated before, during, and after administration of the intervention. We found that after intervention, subjects in the Music group reported significantly lower anxiety levels as compared with the Control group (F(1,91) = 15.4, P = 0.001). That is, the postintervention anxiety level of subjects in the Music group decreased by 16% as compared with the preintervention level, whereas the anxiety level of the Control group did not change significantly. Two-way repeated-measures analysis of variance performed for the electrodermal activity, blood pressure, heart rate, cortisol, and catecholamine data demonstrated no group difference and no time x group interaction (P = not significant). In conclusion, under the conditions of this study, patients who listened to music before surgery reported lower levels of state anxiety. Physiological outcomes did not differ, however, between the two study groups. ⋯ Patients who listen to music of their choice during the preoperative period report less anxiety.