Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialAcetaminophen as an adjunct to morphine by patient-controlled analgesia in the management of acute postoperative pain.
Opioids play a fundamental role in the management of postoperative pain, but their use is associated with a number of side effects, including nausea and vomiting, sedation, and respiratory depression. Co-administration of a nonopioid has been proposed as a method of reducing opioid intake and minimizing side effects. Sixty-one ASA physical status I and II patients were enrolled in a double-blind, randomized, placebo-controlled, parallel study to investigate the effect of a combination of acetaminophen and morphine after open reduction and internal fixation of acute limb fractures. Patients were randomized to receive either oral acetaminophen (1 g every 4 h) or placebo as an adjuvant to morphine by patient-controlled analgesia (PCA) postoperatively. They were assessed daily for 72 h or until the PCA was discontinued according to standardized guidelines. The outcome variables collected were pain scores (11-point scale), amount of morphine self-administered, duration of PCA use, compliance with study design, incidence of nausea and sedation, and overall patient satisfaction. The acetaminophen group had lower pain scores on Day 1 (2.1 vs 3.3; P = 0.03) and a shorter average duration of PCA use (35.8 vs 45.5 h; P = 0.03). Overall patient satisfaction was also significantly greater in the acetaminophen group (8.7 vs 7.9; P = 0.04). These data suggest that acetaminophen is a useful adjunct to morphine PCA. ⋯ This study assesses the benefit of combining two analgesics for the treatment of postoperative pain. Such a combination improves the quality of pain relief and patient satisfaction.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Comparative Study Clinical TrialEffects of spinal needle type on lateral distribution of 0.5% hyperbaric bupivacaine.
To evaluate the influence of needle type on the lateral distribution of 0.5% hyperbaric bupivacaine, 30 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent and underwent dural puncture by either a 25-gauge Whitacre (n = 15) or a 25-gauge Quincke (n = 15) spinal needle. The needle hole was turned toward the dependent side and 8 mg of 0.5% hyperbaric bupivacaine was injected over 30 s. The lateral position was maintained for 15 min while a blind observer recorded loss of pinprick sensation and degree of motor block on both the dependent and nondependent sides every 5 min until regression of motor block by 1 degree on the dependent side. Thirty minutes after the patients were placed in the supine position, unilateral sensory block was observed in 10 patients in the Whitacre group (66%) and in 2 patients in the Quincke group (13%) (P < 0.05). No differences in the rate of unilateral motor block were observed (73% and 40% in Whitacre and Quincke groups, respectively). We conclude that when a small dose of 0.5% hyperbaric bupivacaine is injected slowly into patients in the lateral position for 15 min, the Whitacre spinal needle provides a more marked differential block of sensory nerve roots between dependent and nondependent sides compared with the Quincke needle. ⋯ Because unilateral spinal anesthesia can be advantageous for lower limb surgery, we evaluated the influence of the Whitacre and Quincke spinal needle types on the lateral distribution of small-dose 0.5% hyperbaric bupivacaine injected slowly into adult patients.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialOnset time, endotracheal intubating conditions, and plasma histamine after cisatracurium and vecuronium administration.
Cisatracurium is a nondepolarizing muscle relaxant with a slow onset. We performed a prospective, randomized, double-blind clinical trial in 60 patients (ASA physical status I or II) to assess whether cisatracurium (0.15 or 0.25 mg/kg) or vecuronium (0.15 mg/kg), administered as a bolus immediately after induction of anesthesia with fentanyl and thiopental, would provide a faster onset time and better tracheal intubating conditions than previously reported. We sought to determine whether patients given muscle relaxants in this commonly used induction sequence would exhibit cutaneous, systemic, or chemical evidence of histamine release. Onset time of the relaxants was determined by using mechanomyography. Intubating conditions were scored on a defined interval scale by an anesthesiologist blinded to the relaxant administered. Heart rate and arterial blood pressure were measured noninvasively every minute from 10 min before to 5 min after the application of the muscle relaxant. Mean (+/- SD) onset times for 0.25 mg/kg cisatracurium (68.3 +/- 19.5 s) and for 0.15 mg/kg vecuronium (69.5 +/- 29.2 s) were significantly different from those in the 0.15 mg/kg cisatracurium group (105 +/- 41.2 s). The intubating conditions were better with the larger dose of cisatracurium or vecuronium (P < 0.03). Although plasma histamine levels were not statistically different among groups, levels >1 ng/mL were observed in 5 of 40 patients who received cisatracurium but in none of the 20 patients who received vecuronium. There were no significant hemodynamic differences among the groups. In a dose of 0.25 mg/kg, cisatracurium has as rapid an onset time as vecuronium 0.15 mg/kg, but the former shows evidence of histamine release. ⋯ Cisatracurium has been considered a drug with a relatively slow onset but that has the significant benefit of being devoid of chemically mediated histamine release. In this study, we describe an onset time faster than previously reported when cisatracurium was given immediately after thiopental. We also note that several patients had abnormal histamine levels after cisatracurium administration.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of clonidine with conventional preanesthetic medication in patients undergoing coronary artery bypass grafting.
In this controlled study, we compared clonidine with conventional premedication in 35 patients undergoing coronary artery bypass grafting (CABG). After premedication with clonidine 5 microg/kg p.o. (Group C, n = 11), lorazepam 60 microg/kg p.o. (Group L, n = 13), or morphine 0.1 mg/kg plus scopolamine 6 microg/kg i.m. (Group M, n = 11), sedation, anxiety, and quality of premedication were graded. After the administration of sufentanil 2.0 microg/kg over 12.5 min, a computer-assisted infusion device targeted a sufentanil effect-site concentration of 0.75 ng/mL. Hemodynamic variables, end-tidal isoflurane concentration (ET-ISO), the electroencephalographic spectral edge, and the serum sufentanil concentration (SUF) were measured. There were no intergroup differences in anxiety, sedation, quality of premedication, the dose of sufentanil causing unconsciousness, or the electroencephalographic (EEG) response to induction. Intraoperative SUF was stable, with no intergroup difference. The average prebypass ET-ISO was lower in Group C than in Group M. The ET-ISO and peak ET-ISO after intense surgical stimulation were lower in Group C versus Groups L and M. Mean arterial blood pressure was lower in Group C versus Groups L and M. There were no intergroup differences in pharmacologic intervention, time to extubation, or intensive care unit stay. Clonidine produces sedation, anxiolysis, and quality of premedication comparable to conventional premedication. Compared with other drugs, clonidine does not alter the dose of sufentanil inducing unconsciousness or EEG slowing, but it uniquely reduces isoflurane requirements. ⋯ In patients undergoing coronary artery bypass grafting, clonidine produces sedation and relieves anxiety as effectively as conventional premedication. Clonidine does not uniquely alter the dose of sufentanil inducing unconsciousness or electroencephalographic slowing, but it significantly reduces isoflurane requirements.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Comparative Study Clinical TrialIntrathecal hypobaric versus hyperbaric bupivacaine with morphine for cesarean section.
Both hyper- and hypobaric solutions of bupivacaine are often combined with morphine to provide subarachnoid anesthesia for cesarean section. Differences in the baricity of subarachnoid solutions influence the intrathecal distribution of anesthetic drugs and would be expected to influence measurable clinical variables. We compared the effects of hyper- and hypobaric subarachnoid bupivacaine with morphine to determine whether one has significant advantages with regard to intraoperative anesthesia and postoperative analgesia in term parturients undergoing elective cesarean section. Thirty parturients were randomized to receive either hyper- or hypobaric bupivacaine (15 mg) with morphine sulfate (0.2 mg). Intraoperative outcomes compared included extent of sensory block, quality of anesthesia, and side effects. Postoperative outcomes, including pain visual analog scale scores, systemic analgesic requirements, and side effects, were monitored for 48 h. Sedation effects were quantified and compared using Trieger and digit-symbol substitution tests. We detected no differences in sensory or motor block, quality of anesthesia, quality of postoperative analgesia, incidence of side effects, or psychometric scores. Both preparations provide highly satisfactory anesthesia for cesarean section and effective postoperative analgesia. ⋯ Dextrose alters the density of intrathecal bupivacaine solutions and is thought to influence subarachnoid distribution of the drug. We randomized parturients undergoing cesarean section to one of two often used spinal bupivacaine preparations, hypobaric and hyperbaric. We detected no differences in clinical outcomes between groups.