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Biomedical subjects

S A Feldman

Publications and source records attributed to S A Feldman.

At least 19 recordsLinked to original sources
PubMed1991

The effects of intravenous clonidine on ventilation.

The effects of clonidine, an alpha 2 adrenergic agonist, on ventilation were studied in a group of adult volunteers. The ventilatory variables measured were minute ventilation, respiratory rate, end-tidal carbon dioxide tension and the response to carbon dioxide challenge. We found no differences in minute ventilation, respiratory rate and end-tidal carbon dioxide tension, before and after clonidine administration. However, the ventilatory response to carbon dioxide was significantly attenuated following clonidine, suggesting that clonidine has respiratory depressant effects.

Adult↗
PubMed1991

The cuffed pharyngeal airway.

A new self-retaining nasopharyngeal airway is described. The clinical performance of this airway was assessed in 100 patients during anaesthesia with spontaneous respiration. The physical behaviour of the airway was investigated in four patients. In an additional 25 patients the tube was used via the oral route. Although designed for use by the nasal route, the airway can be used as a self-retaining oropharyngeal airway.

Adult↗
PubMed1989

Effect of rate of injection on the neuromuscular block produced by vecuronium.

A subparalytic dose (0.015 mg/kg) of vecuronium bromide was administered to matched pairs of patients undergoing routine dental surgery under enflurane-nitrous oxide/oxygen anesthesia either as a rapid bolus injection or as a slow infusion over 5 min. It was demonstrated that bolus injection produced peak plasma levels of drug considerably greater than those following slow infusion. Time to maximum block was more rapid following bolus (368 +/- 84 [SD] sec) than by infusion (615 +/- 88 sec), but the maximum block produced, either demonstrated by the reduction in amplitude of T1 from control or the T1:T4 ratio on the integrated electromyogram (Datex IEMG), was similar in each group irrespective of rate of injection, T1 and T4 referring to the first and last twitch in a train of four series.

Adult↗
PubMed1987

Vecuronium--a variable dose technique.

Vecuronium was administered to patients in doses of 100, 150, 200 and 250 micrograms/kg and the duration of action recorded by noting the time to recovery of the first twitch in a train-of-four to 10% of the control twitch. The recovery times ranged from a mean of 28.4 minutes (100 micrograms/kg) to 72.4 minutes (250 micrograms/kg). It is suggested that for operations of medium to long duration the use of a large initial bolus dose of vecuronium is a technique with advantages over the use of an infusion or frequent incremental doses.

Adolescent↗
PubMed1979

Plasma concentrations of pancuronium and neuromuscular blockade after injection into the isolated arm, bolus injection, and continuous infusion.

To establish whether the plasma concentration of pancuronium reflects magnitude of neuromuscular blockade, the authors determined times of recovery from neuromuscular blockade and associated plasma concentrations following equipotent doses of pancuronium using three methods of pancuronium administration: the isolated-arm technique in conscious volunteers (n = 4), and the bolus intravenous injection (n = 7) and continuous-infusion methods (n = 3) in anesthetized patients. Although maximum depressions of twitch tension were similar (85 +/- 11,91 +/- 6, and 92 +/- 4 per cent, respectively) with the three techniques, times to recovery from neuromuscular blockade differed significantly, being 10 +/- 2 min with the isolated-arm technique, 23 +/- 7 min with the bolus-injection technique, and 46 +/- 5 min with the continuous-infusion method. The plasma concentration of pancuronium necessary for neuromuscular blockade was least with the isolated-arm technique and greatest with continuous infusion. At 25 and 75 per cent recovery, mean plasma concentrations were 0.07 +/- 0.01 and 0.04 +/- 0.01 microgram/ml in the isolated arm; 0.13 +/- 0.04 and 0.09 +/- 0.02 microgram/ml after bolus injection, and 0.20 +/- 0.04 and 0.11 microgram/ml during continuous infusion, respectively. It is concluded that the relationship between plasma concentration of pancuronium and magnitude of neuromuscular blockade depends on the method of pancuronium administration.

Humans↗
PubMed1978

The interaction of halothane and pancuronium bromide. A study in dogs.

The interaction of halothane and pancuronium is demonstrated in the dog tibialis anterior-sciatic nerve preparation. The results show a dose related effect of halothane on the recovery index and the 50% recovery times. These results are compared to other reports and possible mechanisms are discussed.

Animals↗
PubMed1977

Sudden fatal pulmonary calcification following renal transplantation.

A 42-year-old male was hemodialyzed for 2 years with excellent control of calcium-phosphate metabolism. He received a cadaveric renal transplant but experienced a prolonged episode of acute tubular necrosis during which he could not tolerate phosphate-binding antacids. His calcium X phosphate product became markedly elevated for 20 days. Following a brief period of function, the homograft was removed on the 45th post-transplant day after severe rejection and subsequent infection. Chest X-ray was normal. Six days after graft nephrectomy, he became acutely dyspneic and markedly hypoxemic. Diffuse, flocculent pulmonary infiltrates appeared on the chest film. The patient expired 1 day later. At postmortem examination, there was severe, diffuse pulmonary alveolar calcification demonstrated by chemical and histologic examination. Although unlikely, the prolonged post-transplant period characterized by elevated calcium X phosphate product may have played a pathogenetic role. Calciphylaxis may have occurred, with hyperparathyroidism as the sensitizing agent and any of several drugs acting as challenger.

Adult↗
PubMed1976

The effect of blood flow upon the activity of gallamine triethiodide.

The onset, depth and recovery from paralysis produced by gallamine triethiodide were studied using the tibialis anterior muscle/sciatic nerve preparation in mongrel dogs, during changes in blood flow to this muscle. A roller pump was used to effect the blood flow changes via an aorto-femoral shunt. The onset and depth of paralysis were related directly to muscle blood flow. There was no correlation between the rate of recovery from paralysis and the blood flow to the muscle.

Animals↗