Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Comparative Study Clinical TrialSuprascapular nerve block for ipsilateral shoulder pain after thoracotomy with thoracic epidural analgesia: a double-blind comparison of 0.5% bupivacaine and 0.9% saline.
Despite receiving thoracic epidural analgesia, severe ipsilateral shoulder pain is common in patients after thoracotomy. We recruited 44 patients into a double-blinded randomized placebo-controlled study to investigate whether suprascapular nerve block would treat postthoracotomy shoulder pain effectively. All patients received a standard anesthetic with a midthoracic epidural. Thirty patients who experienced shoulder pain within 2 h of surgery were randomly assigned to receive a suprascapular nerve block with either 10 mL of 0.5% bupivacaine or 10 mL of 0.9% saline. Shoulder pain was assessed before nerve blockade, at 30 min, and then hourly for 6 h after the block using a visual analog scale (VAS) and a 5-point verbal ranking score (VRS). The incidence of shoulder pain before nerve block was 78%. There was no significant decrease in either VAS or VRS in the Bupivacaine group. These results suggest that this pain is unlikely to originate in the shoulder and lead us to question the role of a somatic afferent in referred visceral pain. We conclude that suprascapular nerve block does not treat ipsilateral shoulder pain after thoracotomy in patients with an effective thoracic epidural. ⋯ This randomized, double-blinded, placebo-controlled trial showed that suprascapular nerve block does not treat the severe ipsilateral shoulder pain that patients experience after thoracotomy. This has implications for established theories of referred pain and indicates that this pain is unlikely to originate in the shoulder.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Comparative Study Clinical TrialDolasetron for preventing postanesthetic shivering.
We designed this study to assess the efficacy of dolasetron compared with clonidine and placebo in prophylaxis of postanesthetic shivering. We included 90 patients undergoing elective abdominal or urologic surgery. The patients were randomly assigned to one three groups (each group n = 30) using a double-blinded study protocol: Group A received 12.5 mg dolasetron, Group B 3 microg/kg clonidine, and Group C saline 0.9% as placebo. The medication was given after the induction of anesthesia. Postanesthetic shivering was judged by using a five-point scale. In the Clonidine group, 86.6% showed no shivering, whereas in the Dolasetron and Placebo groups, only 63.3% and 66.6%, respectively, were symptom free. Only clonidine, but not dolasetron, significantly reduced the incidence and the severity of shivering. We conclude that clonidine is effective in preventing shivering when given before surgery, whereas dolasetron, at the dose used, is not effective. ⋯ Shivering, an irregular muscular fasciculation lasting longer than 15 s, is a common complication secondary to general anesthesia. We compared dolasetron with clonidine (an established antishivering drug) in the prevention of postanesthetic shivering. Dolasetron 12.5 mg was not effective.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Comparative Study Clinical TrialHyperbaric spinal levobupivacaine: a comparison to racemic bupivacaine in volunteers.
Levobupivacaine is the isolated S-enantiomer of bupivacaine and may be a favorable alternative to spinal bupivacaine. However, its clinical efficacy relative to bupivacaine and its dose-response characteristics, in spinal anesthesia, must first be known. This double-blinded, randomized, cross-over study was designed to compare the clinical efficacy of hyperbaric levobupivacaine and bupivacaine for spinal anesthesia. Eighteen healthy volunteers were randomized into three equal groups to receive two spinal anesthetics, one with bupivacaine and the other with levobupivacaine, of equal-milligram doses (4, 8, or 12 mg). We assessed blockade quality and duration with pinprick, transcutaneous electrical stimulation, thigh tourniquet, abdominal and quadriceps muscle strength, modified Bromage scale, and time until achievement of discharge criteria. Sensory and motor block were similar between the same doses of levobupivacaine and bupivacaine (P > 0.56 to 0.86). For example, in the 12-mg groups of levobupivacaine versus bupivacaine, mean duration of tolerance to transcutaneous electrical stimulation at T12 was 100 min for both. The duration of motor block at the quadriceps was 71 versus 73 min, and time until achievement of discharge criteria was 164 min for both. Hyperbaric spinal levobupivacaine has equivalent clinical efficacy to racemic bupivacaine for spinal anesthesia in doses from 4 to 12 mg. ⋯ Hyperbaric spinal levobupivacaine has equivalent clinical efficacy to hyperbaric spinal bupivacaine over the 4-12-mg ranges.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialOral midazolam premedication in preadolescents and adolescents.
We sought to determine the influence of preoperative oral midazolam on 1) sedation score, 2) measures of anesthetic emergence, 3) recovery times, and 4) bispectral index (BIS) measurements during sevoflurane/N(2)O anesthesia in adolescent patients. Fifty ASA I and II patients 10-18 yr of age were enrolled in a prospective double-blinded study. Patients were randomized to receive either 20 mg of midazolam (M group) or midazolam vehicle (P group) as premedication. Before the induction, sedation scores and BIS values were determined in all patients. After inhaled induction and intubation, expired sevoflurane was stabilized at 3% in 60% N(2)O and the corresponding BIS (BIS I) recorded. Upon completion of surgery, sevoflurane was stabilized at 0.5% and the BIS (BIS E) again recorded. Plasma midazolam levels were measured at the time of BIS I and BIS E. There were no significant differences between groups in awakening time, sevoflurane/N(2)O awakening concentrations, time to postanesthesia care unit discharge, or BIS I and BIS E measurements. Sedation scores and preinduction BIS values were significantly lower in Group M than in Group P, although only 40% of midazolam-treated patients exhibited detectable sedation, with marked interindividual variability in achieved plasma midazolam levels. Detectable preoperative sedation was predictive of delayed emergence. ⋯ We demonstrated a measurable sedative effect of oral midazolam in adolescents which correlated with simultaneous bispectral index (BIS) measurement. Considering the overall group, midazolam premedication did not affect intraoperative BIS, emergence times, or recovery times compared with placebo controls. Detectable preoperative sedation, and not merely midazolam administration, was predictive of prolonged emergence.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Comparative Study Clinical TrialLevobupivacaine versus racemic bupivacaine for spinal anesthesia.
Levobupivacaine is the pure S(-)-enantiomer of racemic bupivacaine but is less toxic to the heart and central nervous system. Although it has recently been introduced for routine obstetric and nonobstetric epidural anesthesia, comparative clinical studies on its intrathecal administration are not available. We therefore performed this prospective randomized double-blinded study to evaluate the anesthetic potencies and hemodynamics of intrathecal levobupivacaine compared with racemic bupivacaine. Eighty patients undergoing elective hip replacement received either 3.5 mL levobupivacaine 0.5% isobaric or 3.5 mL bupivacaine 0.5% isobaric. Sensory blockade was verified with the pinprick test; motor blockade was documented by using a modified Bromage score. Hemodynamic variables (e.g., blood pressure, heart rate, pulse oximetry) were also recorded. Intergroup differences between levobupivacaine and bupivacaine were insignificant both with regard to the onset time and the duration of sensory and motor blockade (11 +/- 6 versus 13 +/- 8 min; 10 +/- 7 versus 9 +/- 7 min; 228 +/- 77 versus 237 +/- 88 min; 280 +/- 84 versus 284 +/- 80 min). Both groups showed slight reductions in heart rate and mean arterial pressure, but there was no intergroup difference in hemodynamics. We conclude that intrathecal levobupivacaine is equal in efficacy to, but less toxic than, racemic bupivacaine. ⋯ Levobupivacaine, the pure S(-)-enantiomer of racemic bupivacaine is an equally effective local anesthetic for spinal anesthesia compared with racemic bupivacaine.