Anesthesia and analgesia
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Anesthesia and analgesia · Dec 1994
Randomized Controlled Trial Comparative Study Clinical TrialInfluence of duration of lateral decubitus on the spread of hyperbaric tetracaine during spinal anesthesia: a prospective time-response study.
Searching for a differential spinal block between dependent and nondependent sides, we evaluated a prospective randomized time-response study of the influence of the duration of lateral decubitus on the spread of hyperbaric local anesthetic solution during spinal anesthesia in 60 patients undergoing lower limb surgery. In a lateral position with the operated side dependent, all patients received 12 mg of lyophilized tetracaine with 0.2 mg epinephrine in 2.5 mL 10% dextrose and were randomized into four groups according to the duration of lateral decubitus after spinal injection: Group 0, patients immediately turned supine after spinal injection; Group 6, 6 min in lateral decubitus then supine; Group 12, 12 min in lateral decubitus then supine; Group 18, 18 min in lateral decubitus then supine. There was no difference in maximum sensory level between both sides in the same group nor between the four groups. ⋯ A positive correlation found between duration of lateral decubitus and duration of sensory block on the dependent side suggested a preferential spread of hyperbaric local anesthetics. This differential spread was confirmed by the positive correlation between the duration of lateral decubitus and the difference in duration between dependent and nondependent sides of both sensory and motor blocks. However, because of the minimal differences between groups, we believe there is no reason to routinely maintain patients in the lateral position after performing spinal anesthesia.
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Anesthesia and analgesia · Dec 1994
Randomized Controlled Trial Comparative Study Clinical TrialEffect of oral clonidine and intrathecal fentanyl on tetracaine spinal block.
We studied the effect of oral clonidine and intrathecal (IT) fentanyl on the onset and duration of a hyperbaric tetracaine-induced spinal block. Forty adult males undergoing elective surgery were studied according to a randomized, double-blind, placebo-controlled protocol involving four treatment regimens: Group I, placebo per os (PO) + tetracaine 12 mg IT; Group II, placebo PO+tetracaine 12 mg IT+fentanyl 10 micrograms IT; Group III, clonidine 200 micrograms PO+tetracaine 12 mg IT; Group IV, clonidine 200 micrograms PO+tetracaine 12 mg IT+fentanyl 10 micrograms IT. Onset time to highest sensory level was 8.5 +/- 3.1, 8.2 +/- 2.3, 6.1 +/- 1.6, and 6.8 +/- 1.4 min in Groups I, II, III, and IV, respectively. ⋯ Episodes of bradycardia and hypotension were more frequent in the clonidine-treated patients (40%-50% vs 10%). We conclude that oral clonidine (200 micrograms) shortened the onset time of tetracaine's sensory block and prolonged the duration of sensory and motor block. However, clonidine premedication increased the risk of hypotension and bradycardia.
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Anesthesia and analgesia · Dec 1994
Randomized Controlled Trial Comparative Study Clinical TrialEffects of enoximone and R 80122, a new selective phosphodiesterase III inhibitor, on hemodynamics and myocardial energetics in patients with ischemic heart disease.
The present study was designed to compare the effects of enoximone and R 80122, a highly selective phosphodiesterase (PDE) III inhibitor, on left ventricular hemodynamics and myocardial blood flow and metabolism in patients with coronary artery disease. Twenty male, anesthetized patients, ASA physical status III, were studied before they underwent coronary artery bypass grafting (CABG) surgery. They were allocated randomly to receive either 0.3 mg/kg R 80122 (Group 1) or 1 mg/kg enoximone (Group 2) intravenously (IV). ⋯ There were increases in heart rate (HR) by 10% and 19%, respectively, and in contractility (dp/dtmax) by 18% and 38%, respectively. Coronary perfusion pressure (CPP) decreased by 23% and 22%, respectively, and coronary vascular resistance (CVR) by 38% and 21%, respectively. Myocardial blood flow (MBF) and myocardial oxygen uptake (MVO2) increased in both groups, the increase in MBF being statistically significant (+34%) only in Group 1, whereas the changes in myocardial metabolism were not significant in either group.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Dec 1994
Randomized Controlled Trial Comparative Study Clinical TrialA first-pass cost analysis of propofol versus barbiturates for children undergoing magnetic resonance imaging.
Intravenous (IV) propofol was compared with IV thiopental/pentobarbital as a sedative for children undergoing magnetic resonance imaging (MRI) of the brain or spine. Fifty-eight outpatients (aged 11 mo to 6 1/2 yr, ASA grade I and II) were enrolled in the study and randomized to two groups. After IV cannulation, Group I received IV propofol (1-2 mg/kg), followed immediately by a propofol infusion (75-100 micrograms.kg-1.min-1). ⋯ Cost analysis of anesthesia services revealed added drug costs ($1600.76 per year for the propofol group) but significant savings of postanesthesia care unit (PACU) nursing time ($5086.67 per year). Outcomes such as patient morbidity and technical quality of the MRI scans did not differ significantly between the two groups. In conclusion, analysis of the clinical data suggests that propofol may be more suitable than barbiturates for children undergoing outpatient procedures despite its higher price.
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Anesthesia and analgesia · Dec 1994
Comparative StudyEffect of intracoronary infusions of amrinone and dobutamine on segment shortening, blood flow, and oxygen consumption in in situ canine hearts.
Previous in vivo studies assessing the effects of amrinone on myocardial contractility used intravenous infusions, and thus were complicated by varying cardiac loading conditions. Accordingly, the present study was performed in 15 open-chest, anesthetized (fentanyl and midazolam) dogs using infusions of amrinone and dobutamine directly into the left anterior descending artery (LAD). In the LAD bed, percentage of segment shortening (%SS), an index of local myocardial contractility, was assessed with ultrasonic crystals. ⋯ Amrinone and dobutamine caused individually increases in %SS that were comparable (range, 20%-45%). Myocardial oxygen consumption increased in parallel with %SS for both amrinone and dobutamine. For amrinone, coronary blood flow increased more than myocardial oxygen consumption, resulting in a modest (at highest dose approximately 10%) decrease in oxygen extraction; whereas for dobutamine, coronary blood flow increased in proportion to myocardial oxygen consumption, resulting in no change in oxygen extraction.(ABSTRACT TRUNCATED AT 250 WORDS)