Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Clinical TrialThe effect of epidural fentanyl on the minimum local analgesic concentration of epidural chloroprocaine in labor.
The minimum local analgesic concentration (MLAC) has been defined as the median effective local analgesic concentration (EC50) in a 20-mL volume in the first stage of labor. The aim of this study was to determine the local anesthetic sparing efficacy of epidural fentanyl by its effect on the MLAC of chloroprocaine. Fifty-six parturients, not exceeding 7 cm cervical dilation, who requested epidural analgesia were allocated to one of two groups in this double-blind, randomized, prospective study. ⋯ Analgesic efficacy was assessed using 100-mm visual analog pain scores with 10 mm or less within 30 min defined as effective. The MLAC of chloroprocaine was reduced from 0.43% wt/vol to 0.26% wt/vol by fentanyl (P = 0.023). Thus, the addition of epidural fentanyl 3 micrograms/mL (60 micrograms resulted in a significant 40% reduction in the MLAC of chloroprocaine in the first stage of labor.
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Comparative Study Clinical TrialA minimum dose of clonidine added to mepivacaine prolongs the duration of anesthesia and analgesia after axillary brachial plexus block.
This study assessed the minimum dose of clonidine required to prolong the duration of both anesthesia and analgesia after axillary brachial plexus blockade. Eighty patients scheduled for elective hand surgery were divided into eight groups in a randomized, double-blind fashion. An axillary brachial plexus block was performed with 40 mL 1% mepivacaine plus 1:200,000 epinephrine. ⋯ The minimum dose of clonidine required to significantly prolong the duration of analgesia and anesthesia was, respectively, 0.1 and 0.5 microgram/kg. No side effects (sedation, drowsiness, bradycardia, arterial hypotension) were reported. We conclude that the dose of clonidine required to prolong significantly the duration of both anesthesia and analgesia after axillary brachial plexus blockade is 0.5 microgram/kg and that, at this dose, clonidine may be used without important reported side effects even in outpatients.
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of cisatracurium and atracurium: onset of neuromuscular block after bolus injection and recovery after subsequent infusion.
Cisatracurium is a new nondepolarizing muscle relaxant. In patients randomized to receive either cisatracurium (n = 40) or atracurium (n = 20) we compared the time course of neuromuscular block. The initial bolus dose of cisatracurium was 0.1 mg/kg, that of atracurium 0.5 mg/kg. ⋯ The infusion rates for a 95% +/- 4% neuromuscular block were 1.5 +/- 0.4 micrograms.kg-1.min-1 for cisatracurium and 6.6 +/- 1.7 micrograms.kg-1.min-1 for atracurium, 3.3 times those of cisatracurium when referenced to the active cations. After the infusion, the spontaneous recovery intervals 25%-75% of 18 +/- 11 min and 18 +/- 8 min for cisatracurium and atracurium (P = 0.896) were shortened to 5 +/- 2 min and 4 +/- 3 min (P = 0.921) after neostigmine. While attributing different onset times also to differences in the initial doses, we conclude that time profiles for neuromuscular block of both muscle relaxants, when given in equipotent doses, are not different.
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Clinical TrialDexamethasone decreases vomiting by children after tonsillectomy.
We evaluated the effect of dexamethasone on vomiting after elective tonsillectomy in 133 healthy children aged 2-12 yr in a randomized, stratified, blocked, double-blind, placebo-controlled study. General anesthesia was induced by inhalation of N2O and halothane or intravenously (IV) with propofol. Anesthesia was maintained with N2O and halothane. ⋯ Vomiting, both in-hospital and postdischarge, was decreased by the prophylactic administration of dexamethasone. Each episode of in-hospital vomiting prolonged discharge by 13 +/- 2 min, mean +/- SD (P < 0.001). In conclusion, dexamethasone markedly decreased vomiting by healthy children after elective tonsillectomy in an ambulatory hospital setting.
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Clinical TrialEffects of a hemoglobin-based oxygen carrier (HBOC-201) on hemodynamics and oxygen transport in patients undergoing preoperative hemodilution for elective abdominal aortic surgery.
We conducted a pilot study to evaluate the effects of HBOC-201, a bovine hemoglobin-based oxygen carrier, on hemodynamics and oxygen transport in patients undergoing preoperative hemodilution for elective abdominal aortic surgery. After induction of anesthesia and isovolemic hemodilution with 1 L of lactated Ringer's solution, 13 patients were randomly assigned to receive, within 30 min, 3 mL/kg of either HBOC-201 or 6% hydroxyethyl starch (HES). Monitored variables included invasive arterial and pulmonary artery pressures, arterial and mixed venous blood gases, and calculations of cardiac index (CI), systemic and pulmonary vascular resistance indices, oxygen delivery index (DO2I), oxygen consumption index (VO2I), and oxygen extraction ratio (O2ER). ⋯ No significant changes were noticed in heart rate and pulmonary vascular resistance index. DO2I and VO2I, 30 min after the infusion of HBOC-201, were 79% (P = 0.046) and 76% (P = 0.028) of the preinfusion values, respectively, whereas CaO2 and O2ER remained unaffected. We conclude that HBOC-201, at a dose of 3 mL/kg, impairs oxygen delivery because of adverse effects on cardiac output.