Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Clinical TrialRapid onset of cutaneous anesthesia with EMLA cream after pretreatment with a new ultrasound-emitting device.
In this randomized, double-blinded, placebo-controlled, crossover trial of 42 human subjects, we examined the speed of onset of cutaneous anesthesia by eutectic mixture of local anesthetics (EMLA) cream after brief (approximately 10-s) pretreatment of the underlying skin with low-frequency (55 kHz) ultrasound. Four treatments were compared: ultrasound pretreatment followed by application of 1 g EMLA or placebo cream for 5 min, 10 min, 15 min, and 60 min without ultrasound pretreatment as positive control. Pain was tested by pricks with a 20 g needle. Pain scores and patient preference for EMLA or placebo cream were measured at each time point. Based on both pain scores and patient preference, cutaneous anesthesia was achieved in the EMLA groups as compared with placebo at all time points. After ultrasound pretreatment and then 5, 10, or 15 min after EMLA cream application, pain scores and overall preference were statistically indistinguishable from EMLA cream application for 60 min (without ultrasound pretreatment). There were no significant adverse effects. Low-frequency ultrasound pretreatment appears to be safe and effective in producing rapid onset of EMLA cream in this model, with results as early as 5 min. ⋯ A prospective, randomized, double-blinded, placebo-controlled clinical trial demonstrated rapid onset of cutaneous anesthesia by pretreatment of the skin with ultrasound before application of EMLA cream.
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Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Comparative Study Clinical TrialEpidural levobupivacaine 0.1% or ropivacaine 0.1% combined with morphine provides comparable analgesia after abdominal surgery.
Ropivacaine appears attractive for epidural analgesia because it produces less motor block than racemic bupivacaine. The potential benefits of levobupivacaine with regard to motor blockade require further investigations. In this study, we compared the efficacy, dose requirements, side effects, and motor block observed with epidural levobupivacaine and ropivacaine when given in combination with small-dose morphine for 60 h after major abdominal surgery. Postoperatively, 50 patients were randomly allocated, in a double-blinded manner, to patient-controlled epidural analgesia with the same settings and without basal infusion, using 0.1% levobupivacaine or 0.1% ropivacaine. Both were combined with an epidural infusion of 0.1 mg/h morphine. Pain scores, side effects, motor block, and local anesthetic consumption were measured for 60 h. Pain scores measured on a 100-mm visual analog scale were approximately 20 mm at rest and 40 mm during mobilization in both groups. Bromage scores were 1 for all patients after the fourth postoperative hour. Consumption of levobupivacaine and ropivacaine were similar: 344 +/- 178 mg levobupivacaine versus 347 +/- 199 mg ropivacaine 48 h postoperatively. On postoperative day 2, 19 patients in the ropivacaine group versus 12 in the levobupivacaine group were able to ambulate (P < 0.05). No difference was noted concerning incidence of side effects. We conclude that when used as patient-controlled epidural analgesia and combined with small-dose epidural morphine, 0.1% levobupivacaine and 0.1% ropivacaine produce comparable postoperative analgesia with a similar incidence of side effects. ⋯ Small concentrations (0.1%) of epidural levobupivacaine and ropivacaine combined with morphine (0.1 mg/h) produce comparable analgesia and have similar side effects for similar dose requirements.
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Anesthesia and analgesia · Feb 2004
Meta AnalysisA dose-response meta-analysis of prophylactic intravenous ephedrine for the prevention of hypotension during spinal anesthesia for elective cesarean delivery.
We systematically reviewed available studies to determine the dose-response characteristics of prophylactic i.v. ephedrine for the prevention of hypotension during spinal anesthesia for cesarean delivery. We searched for randomized controlled trials (RCTs) or cohort studies-obtained through MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and reference lists of published articles-in which two or more different doses of prophylactic i.v. ephedrine were used to prevent hypotension during spinal anesthesia for cesarean delivery. Four RCTs and one cohort study were found (total n = 390). There was a significant dose-response relationship in the RCTs pooled for hypotension (slope = -0.0128; 95% confidence interval [CI], -0.0213 to -0.0044), hypertension (slope = 0.0563; 95% CI, 0.0235 to 0.0892), and umbilical arterial pH (slope = -0.03; 95% CI, -0.05 to 0.00). The efficacy of ephedrine for preventing hypotension was small. At 14 mg, the number-needed-to-treat was only 7.6 (95% CI, 4.8-21.1), and this was the same as the number-needed-to-harm (7.6; 95% CI, 3.7-23.4). At larger doses, the likelihood of causing hypertension was actually more than that of preventing hypotension, and there was also a minor decrease in umbilical arterial pH. ⋯ The authors performed a systematic review of dose-response studies of i.v. bolus ephedrine for preventing hypotension during spinal anesthesia for cesarean delivery. Prophylactic ephedrine cannot be recommended. The efficacy is poor at smaller doses, whereas at larger doses, the likelihood of causing hypertension is actually more than that of preventing hypotension.
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Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Clinical TrialDoes a preemptive block of the great auricular nerve improve postoperative analgesia in children undergoing tympanomastoid surgery?
We performed a double-blinded randomized controlled trial to evaluate the efficacy of preemptive analgesia in children undergoing tympanomastoid surgery. Children were divided into two groups: group block-block (BB) received a preemptive great auricular nerve block (GAN-block) with 0.25% bupivacaine with 1:200,000 epinephrine before incision followed by a second GAN-block with 0.25% bupivacaine with 1:200,000 epinephrine 1 h before the end of the procedure. Group sham block-block (SB-B) received a preemptive GAN-block with normal saline before surgical incision followed by a GAN-block with 0.25% bupivacaine with 1:200000 epinephrine 1 h before the completion of the procedure. All patients were evaluated for pain with the objective pain score (OPS) by a blinded observer. There was no difference in pain rescue requirements in the postanesthesia care unit (BB versus SB-B, 1 of 20 versus 3 of 20, P= 0.60) or in the short-stay unit (BB versus SB-B, 5 of 20 versus 11 of 20, P = 0.107) or for the entire hospital stay (P = 0.20). There was no significant difference between groups in the time to first rescue pain medication (BB versus SB-B, 226 +/- 71 min versus 201 +/- 94 min). There was no significant difference between groups regarding vomiting in the postoperative period (P = 0.52). We conclude that a preoperative GAN-block does not offer significant advantages for postoperative pain relief in children undergoing tympanomastoid surgery. ⋯ This double-blinded randomized controlled trial compared the efficacy of preemptive analgesia with a peripheral nerve block of the great auricular nerve for decreasing postoperative pain in children undergoing tympanomastoid surgery. Preemptive analgesia did not improve the quality or duration of postoperative analgesia in our cohort.
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Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Comparative Study Clinical TrialThe effect of caudal analgesia on emergence agitation in children after sevoflurane versus halothane anesthesia.
Sevoflurane anesthesia in young children has been associated with an increased incidence of emergence agitation compared with halothane. Postoperative pain may be an etiologic factor. We designed a study to compare the incidence of emergence agitation after halothane and sevoflurane anesthesia in children whose pain was managed with caudal analgesia. Eighty children undergoing inguinal hernia repair between the ages of 12 mo and 6 yr were randomly assigned to receive either halothane or sevoflurane anesthesia. Baseline preoperative anxiety was assessed with the Yale Preoperative Anxiety Scale. The children were sedated with oral midazolam, underwent a mask induction, and had a caudal block placed for postoperative analgesia. After surgery, the children's behavior was assessed with a four-point agitation scale. At 5 min after arrival in the postanesthesia care unit (PACU), sevoflurane was associated with a greater incidence of emergence agitation than halothane (26% vs 6%; P < 0.05), but not during the remainder of the PACU stay. Higher levels of preoperative anxiety were associated with difficult mask induction, agitation on admission to the PACU, and more severe agitation episodes. Emergence agitation appears to be an early and transient phenomenon after sevoflurane anesthesia in children with effective postoperative analgesia. ⋯ Effective postoperative analgesia may reduce the incidence of emergence agitation reported with sevoflurane anesthesia. The Yale Preoperative Anxiety Scale appears to be helpful in identifying young children who are at risk for developing emergence agitation.