Anesthesiology
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Comparative Study
Effects of sevoflurane and isoflurane on hepatic circulation in the chronically instrumented dog.
To compare the effects of sevoflurane and isoflurane on hepatic circulation, eighteen dogs were chronically instrumented for measurements of mean aortic blood pressure and cardiac output and for simultaneous measurements of hepatic and portal blood flows. Each animal was studied while awake and during 1.2 and 2 MAC of either isoflurane or sevoflurane. Both anesthetics induced tachycardia and a dose-dependent decrease in mean aortic blood pressure (isoflurane -27% and -39%; sevoflurane -22% and -37%). ⋯ During isoflurane, the only significant change was a decrease in portal blood flow (-16%) at 1.2 MAC. Neither anesthetic significantly changed renal blood flow. Therefore, both anesthetics led to similar systemic and hepatic vasodilation.
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Comparative Study
Prolongation of spinal anesthesia. Differential action of a lipid drug carrier on tetracaine, lidocaine, and procaine.
This study evaluates prolongation of spinal anesthesia by incorporating local anesthetics in lipid formulation. The duration and intensity of local anesthetic effect produced by different concentrations of procaine (1%, 2%, 4%), lidocaine (1%, 2%, 4%), or tetracaine (0.5%, 1%, 2%) dissolved in normal saline were compared to those produced by the same concentration of drugs in lipid (iophendylate) solution. Fifty rabbits with chronic indwelling subarachnoid catheters were divided into ten equal groups. ⋯ Our data show that iophendylate preparations of local anesthetics produce prolonged but less intense motor blockade than the aqueous solutions, except for tetracaine 0.5% in iophendylate, which produced shorter duration of motor blockade. The reduced intensity of motor blockade may be explained by decreased availability of local anesthetic at the nerve tissue due to storage of drug in the lipid depot. The increased duration of blockade signifies a sustained release of drug from the depot.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Evaluation of risk factors for laryngeal edema after tracheal extubation in adults and its prevention by dexamethasone. A placebo-controlled, double-blind, multicenter study.
Because laryngeal edema (LE) after tracheal extubation is likely to result from an exudative response, corticosteroids often are given routinely as a preventive treatment. No adequate controlled study supports this strategy, however. A prospective, randomized, placebo-controlled, double-blind, multicenter trial that included 700 consecutive patients requiring tracheal intubation and mechanical ventilation was conducted to determine risk factors for LE occurrence after tracheal extubation in adults and to evaluate the efficacy of corticosteroids in its prevention. ⋯ Laryngeal edema occurred more frequently after LDI than after SDI (7.2 vs. 0.9%; P less than 0.001). It also was more frequent in female than in male patients (20/284 vs. 8/379; P less than 0.05), irrespective of intubation duration and treatment. There was no association between LE and either difficulty/route of intubation or admission diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Postoperative pain management by intranasal demand-adapted fentanyl titration.
The aim of the present study was to investigate whether intranasal administration of fentanyl allows a demand-adapted postoperative opioid titration. Forty-two patients who had undergone surgery for lumbar intervertebral disk protrusion were included in a prospective randomized double-blind study. When complaining about intense pain, 22 patients received six sprays of fentanyl (0.027 mg) intranasally and 6 ml sodium chloride 0.9% intravenously and 20 patients received six sprays of sodium chloride 0.9% intranasally and 6 ml of a diluted fentanyl solution (0.027 mg) intravenously. ⋯ Only at the (10-), 20- and 30-min measurement points was the pain intensity significantly lower in the intravenous than in the intranasal group. One patient of the intravenous group showed a decrease in arterial hemoglobin oxygen saturation to less than 90%. Other serious side effects were not observed.(ABSTRACT TRUNCATED AT 250 WORDS)