Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1995
In vitro plasma protein binding of neuromuscular blocking agents in different subpopulations of patients.
In vitro protein binding of several neuromuscular blocking agents (NMBAs) was measured by ultrafiltration in plasma from patients susceptible to demonstrate changes in their protein constituents. First, the relationship between the free fraction of atracurium and plasma lipoproteins levels in young volunteers (22-32 yr old, n = 6) and hyperlipidemic patients (44-68 yr old, n = 13) was studied, and second, the free fraction of atracurium, mivacurium, doxacurium, and vecuronium was determined in plasma of healthy young (27-47 yr old, n = 10), elderly (72-89 yr old, n = 11) and obese (21-57 yr old, n = 9, 200%-360% ideal body weight) patients scheduled for elective surgery. In hyperlipidemic patients, atracurium free fraction was significantly less than in young volunteers (40% +/- 5% vs 50% +/- 5%, mean +/- SD), and decreased as total cholesterol, low-density lipoprotein cholesterol and triglycerides increased (P < 0.05). ⋯ Higher triglyceride concentrations in obese patients and lower high-density-lipoprotein cholesterol concentrations in both obese and elderly patients were observed when compared with young subjects. However, there was no significant difference in protein binding of NMBAs among these three groups. We conclude that, in otherwise healthy patients, age and weight are not likely to alter the free fraction of NMBAs.
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Anesthesia and analgesia · Nov 1995
Randomized Controlled Trial Clinical TrialThe effect of carrier intravenous fluid speed on the injection pain of propofol.
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Anesthesia and analgesia · Nov 1995
Effect of hemidiaphragmatic paresis caused by interscalene brachial plexus block on breathing pattern, chest wall mechanics, and arterial blood gases.
We investigated the effects of hemidiaphragmatic paresis caused by interscalene brachial plexus block on breathing patterns, chest wall mechanics, and arterial blood gas tensions using respiratory inductive plethysmography. Ten healthy patients received interscalene block with 20-40 mL 1.5% lidocaine with epinephrine. Rib cage contribution to tidal volume (%RC) increased from 28.9% +/- 9.7% to 50.0% +/- 8.3% (P < 0.01), respiratory frequency (f) increased from 14.6 +/- 3.2/min to 16.3 +/- 2.4/min (P < 0.05), and PaO2 decreased from 84.7 +/- 7.3 mm Hg to 78.0 +/- 9.5 mm Hg (P < 0.05). ⋯ These results indicated that VT, VE, and PaCO2 were maintained after interscalene block, apparently by increases in f and %RC to compensate for hemidiaphragmatic paresis caused by interscalene block. Nevertheless, PaO2 was reduced, presumably due to increased ventilation-perfusion mismatching. Recognizing that we studied healthy patients, the decrease in PaO2 may be more in patients with cardiopulmonary disease.
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Anesthesia and analgesia · Nov 1995
Letter Case ReportsTransesophageal echocardiography and normal variants.