Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of three doses of a commercially prepared oral midazolam syrup in children.
Midazolam is widely used as a preanesthetic medication for children. Prior studies have used extemporaneous formulations to disguise the bitter taste of IV midazolam and to improve patient acceptance, but with unknown bioavailability. In this prospective, randomized, double-blinded study we examined the efficacy, safety, and taste acceptability of three doses (0.25, 0.5, and 1.0 mg/kg, up to a maximum of 20 mg) of commercially prepared Versed((R)) syrup (midazolam HCl) in children stratified by age (6 mo to <2 yr, 2 to <6 yr, and 6 to <16 yr). All children were ASA class I-III scheduled for elective surgery. Subjects were continuously observed and monitored with pulse oximetry. Ninety-five percent of patients accepted the syrup, and 97% demonstrated satisfactory sedation before induction. There was an apparent relationship between dose and onset of sedation and anxiolysis (P < 0.01). Eight-eight percent had satisfactory anxiety ratings at the time of attempted separation from parents, and 86% had satisfactory anxiety ratings at face mask application. The youngest age group recovered earlier than the two older age groups (P < 0.001). There was no relationship between midazolam dose and duration of postanesthesia care unit stay. Before induction, there were no episodes of desaturation, but there were two episodes of nausea and three episodes of emesis. At the time of induction, during anesthesia, and in the postanesthesia care unit, there were several adverse respiratory events. Oral midazolam syrup is effective for producing sedation and anxiolysis at a dose of 0.25 mg/kg, with minimal effects on respiration and oxygen saturation even when administered at doses as large as 1.0 mg/kg (maximum, 20 mg) as the sole sedating medication to healthy children in a supervised clinical setting. ⋯ Commercially prepared oral midazolam syrup is effective in producing sedation and anxiolysis in doses as small as 0.25 mg/kg; there is a slightly faster onset with increasing the dose to 1.0 mg/kg. At all doses, 97% of patients demonstrated satisfactory sedation, whereas 86% demonstrated satisfactory anxiolysis when the face mask was applied.
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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 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.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialThe preemptive analgesic effect of rofecoxib after ambulatory arthroscopic knee surgery.
Nonsteroidal antiinflammatory drugs (NSAIDs) provide effective postoperative analgesia after arthroscopic knee surgery. Some investigators have suggested that the preemptive administration of NSAIDs may reduce postoperative analgesic requirements and hypersensitivity. We evaluated the analgesic effect of administering rofecoxib either before or after surgical incision in patients undergoing arthroscopic knee surgery under local anesthesia. Sixty patients undergoing arthroscopic meniscectomy were randomized into three groups. All patients received intraarticular bupivacaine 0.25% pre- and postsurgery together with IV sedation using midazolam and propofol. The Preincisional group received a single 50 mg dose of rofecoxib 1 h before surgery, the Postincisional group received rofecoxib 50 mg after the completion of surgery, and the Placebo group received a placebo tablet before surgery. Pain scores, the time to first opioid use, and 24-h analgesic use were recorded. Analgesic duration, defined as the time from completion of surgery until first opioid use, was significantly longer in those patients receiving pre- (803 +/- 536 min) versus postincisional (461 +/- 344 min) rofecoxib or placebo (318 +/- 108 min). The 24 h acetaminophen/oxycodone use was less in the Preincisional group (1.5 +/- 0.6 pills) versus the Postincisional group (3.3 +/- 1.3 pills) or the Placebo group (5.5 +/- 1.6 pills). Pain scores with movement were lower in the Preincisional group at all postoperative time intervals. We conclude that rofecoxib provides effective postoperative analgesia for arthroscopic meniscectomy. Further, the administration of rofecoxib 50 mg before surgery provides a longer duration of postoperative analgesia, less 24 h opioid use, and lower incidental pain scores compared with administering the drug after the completion of surgery. ⋯ The administration of rofecoxib 50 mg before arthroscopic knee surgery provides a longer duration of analgesia, less 24-h opioid use, and lower pain scores than administering the drug after the completion of surgery.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialRemifentanil provides hemodynamic stability and faster awakening time in transsphenoidal surgery.
In this prospective study, we evaluated the effects of remifentanil in ASA I-II patients undergoing transsphenoidal surgery. After the induction of anesthesia, patients were randomly allocated to the Isoflurane (n = 22, 60% nitrous oxide, isoflurane up to 2% end-tidal) or Remifentanil group (n = 21, 60% nitrous oxide, 0.5% end-tidal isoflurane, remifentanil up to 2 microg x kg(-1) x min(-1)). If mean arterial pressure (MAP) increased >80 mm Hg during maximal dosage of isoflurane or remifentanil, labetalol was administered. At the end of anesthesia, extubation and awakening times, respiratory rate, SpO(2), MAP, heart rate, and adverse effects were recorded. Hemodynamics and bleeding (minimal, mild, moderate, severe) were not different between groups. Bleeding grade increased with MAP >80 mm Hg (P < 0.001). Labetalol was administered to 20 patients in the Isoflurane group, and 10 patients in the Remifentanil group (P < 0.01). The dose of labetalol was larger in the Isoflurane group (1.0 +/- 0.6 versus 0.5 +/- 0.7 mg/kg, P < 0.05). Time to extubation did not differ, whereas time to follow commands was shorter in Remifentanil patients (16 +/- 8 versus 10 +/- 2 min, P < 0.01). No adverse effects occurred in the early postoperative period. ⋯ In patients undergoing transsphenoidal surgery, balanced anesthesia with remifentanil (0.22 +/- 0.17 microg x kg(-1) x min(-1)) provides faster awakening time, as compared with large-dose volatile-based anesthesia, without the risk of postoperative opioid respiratory depression.