Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
A randomized, double-blind comparison of the effects of interpleural bupivacaine and saline on morphine requirements and pulmonary function after cholecystectomy.
The effect of interpleural bupivacaine and saline placebo on morphine requirements and pulmonary function after cholecystectomy was investigated. Twenty-six patients were randomly assigned on postoperative day 1 to receive either 20 ml preservative-free saline (group 1) or 20 ml 0.5% bupivacaine with epinephrine, 5 micrograms/ml (group 2) through an interpleural catheter. Adequacy of pain relief was determined by the amount of morphine used by the patient following interpleural injection. ⋯ Mean PCA use in group 2 was 0.52 +/- 0.2 mg/h (73% reduction vs. control) for the third hour after bupivacaine (P less than 0.05). At the fourth and fifth hours after bupivacaine injection, mean PCA morphine use was not significantly different from that in group 1. FVC and FEV1 did not improve after interpleural saline.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Perioperative pulmonary function in acute respiratory failure: effect of ventilator type and gas mixture.
Whether maintaining pulmonary nitrogenation and/or a stable ventilatory pattern during surgery would minimize changes in perioperative pulmonary function in two groups of patients with acute respiratory failure (ARF) whose lungs were being mechanically ventilated was examined. Group 1 (n = 39 cases) (inspired oxygen fraction [FIO2] less than or equal to 0.5, minute ventilation less than or equal to 15 l/min, peak inspiratory pressure less than or equal to 50 cmH2O, positive end-expiratory pressure [PEEP] less than or equal to 10 cmH2O) were assigned randomly to one of four intraoperative ventilator-gas mixture (FIO2 approximately 0.5) combinations: 1) Siemens 900C ventilator, N2/O2; 2) Siemens 900C ventilator, N2O/O2; 3) Ohio anesthesia ventilator, N2/O2; or 4) Ohio anesthesia ventilator, N2O/O2. Group 2 (n = 15 cases) (ventilatory requirements exceeding any of those in Group 1) had their lungs ventilated intraoperatively with the Siemens 900C ventilator and a gas mixture determined by their anesthesiologist (FIO2 approximately 0.6-1.0). ⋯ In patients whose lungs were ventilated with the Ohio N2/O2 combination, PaO2/FIO2 decreased significantly from 270 +/- 86 mmHg preoperatively to 174 +/- 74 mmHg intraoperatively. These variables did not change significantly in patients ventilated with the Siemens ventilator (groups 1 and 2). Pulmonary oxygen gas exchange returned to preoperative values by the first hour postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Onset and duration of neuromuscular blockade following high-dose vecuronium administration.
To determine the onset time and duration of high doses of vecuronium, 40 ASA Physical Status 1 and 2 patients were randomly assigned to receive either 100, 200, 300, or 400 micrograms/kg of vecuronium bromide for muscle relaxation during elective general surgery. Neuromuscular blockade was continuously quantitated by recording the electromyographic response to stimulation of the ulnar nerve train-of-four. The rate of onset of neuromuscular blockade, endotracheal intubating conditions, duration of neuromuscular blockade, and hemodynamic effects of vecuronium at each dose were evaluated and compared. ⋯ No significant hemodynamic differences between the four groups were observed. Endotracheal intubating conditions were good or excellent in all patients. High doses of vecuronium may, therefore, be a useful alternative to succinylcholine when a rapid onset of neuromuscular blockade is required.
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Randomized Controlled Trial Clinical Trial
Isoproterenol is an effective marker of intravenous injection in laboring women.
The purpose of this randomized, double-blind study was to determine if isoproterenol 5 micrograms iv produces a consistent, noticeable tachycardia in healthy, laboring women. Maternal heart rate, fetal heart rate, and uterine contractions were continuously recorded and maternal blood pressure was measured every minute for 10 min before and after each patient received either normal saline (NS group; n = 10) or isoproterenol 5 micrograms (ISO group; n = 10) iv. The data-collecting investigator and a nurse palpating the patient's radial artery determined which solution they thought had been administered. ⋯ Diastolic and mean blood pressures did not change. No fetal distress occurred. Isoproterenol 5 micrograms is an effective marker of intravascular injection in laboring women; however, the safety and efficacy of epidural isoproterenol must be demonstrated in animals before isoproterenol can be incorporated in an epidural anesthesia test dose.
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Randomized Controlled Trial Clinical Trial
Dose-response relationships for edrophonium and neostigmine as antagonists of atracurium and vecuronium neuromuscular blockade.
To determine the potencies of edrophonium and neostigmine as antagonists of nondepolarizing neuromuscular blockade produced by atracurium and vecuronium, dose-response curves were constructed for both antagonists when given at 10% spontaneous recovery of first twitch height. Ninety ASA physical status 1 and 2 adults were given either 0.4 mg/kg atracurium or 0.08 mg/kg vecuronium during thiopental-nitrous oxide-enflurane anesthesia. Train-of-four stimulation was applied to the ulnar nerve every 12 s, and the force of contraction of the adductor pollicis muscle was recorded. ⋯ The edrophonium ED80 was 0.44 +/- 0.11 mg/kg with atracurium and 0.46 +/- 0.12 mg/kg with vecuronium, giving a neostigmine:edrophonium potency ratio of 20. Atracurium train-of-four fade could be antagonized more easily with edrophonium, whereas that of vecuronium was more easily antagonized by neostigmine. It is concluded that edrophonium and neostigmine are not equally effective against atracurium and vecuronium.