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J D Borel

Publications and source records attributed to J D Borel.

6 recordsLinked to original sources

New narcotics in anesthesia.

Recent research has led to the development of a new family of synthetic narcotic fentanyl derivatives. Two of these, sufentanil and alfentanil, are already in clinical use abroad and are presently under clinical investigation in the United States. Sufentanil is more potent than fentanyl and is claimed to have fewer side effects and less variability in patient cardiovascular responses under stress. It appears that its primary application will be for high-dose narcotic anesthesia in patients with cardiovascular disease. Alfentanil has a shorter duration of action and is claimed to have less postoperative ventilatory depression than fentanyl. It is being recommended for use via continuous intravenous infusion. It will probably become a popular anesthetic agent for outpatient and short surgical procedures. It should be remembered that at this time very little information concerning these agents is in print. Most of the research has been done by a handful of investigators and much has not been published in peer review publications. Based on the clinical impressions of our European colleagues, one can say that these agents should be as safe and as reliable as fentanyl, but any clinically significant advantages over their parent compound, especially in the case of sufentanil, will have to await more widespread use and controlled investigation.

Alfentanil↗

Enflurane blood-gas solubility: influence of weight and hemoglobin.

The blood-gas partition coefficient of enflurane was measured in nine nonobese and eight morbidity obese patients and correlated with weight, body mass index, and blood hemoglobin. The enflurane blood-gas partition coefficient was lower in the obese patients than in nonobese patients (mean +/- SEM: 2.03 +/- 0.02 versus 1.76 +/- 0.03, respectively, p less than 0.025). There was a negative correlation between enflurane blood solubility and both body mass index and weight (r = 0.59 and -0.55, respectively, p less than 0.01). A positive correlation was found between hemoglobin and the enflurane blood-gas partition coefficient (r = 0.69, p less than 0.01). Equilibrium between inspired and alveolar enflurane concentration should be faster in morbidity obese and anemic patients than in healthy, nonobese patients.

Adult↗

Age and fentanyl pharmacokinetics.

Fentanyl pharmacokinetics was compared in two groups of adult patients, one group (n = 5) aged less than 50 years, and one group (n = 4) aged greater than 60 years. Despite equivalent doses of fentanyl (10 microgram/kg IV), serum drug concentrations were significantly higher in the older patient group. This was reflected by a prolonged terminal elimination half-life in the elderly compared with the younger patients (945 versus 265 minutes, respectively, p less than 0.005). Volumes of the central compartment and volumes of drug distribution were similar in both patient groups. However, drug clearance was markedly decreased in the elderly (265 versus 991 ml/min, p less than 0.005). These data suggest that a given dose of fentanyl will be clinically effective for a longer period in older patients than in younger patients.

Adult↗

General anesthetics directly inhibit electron mobility: dipole dispersion theory of anesthetic action.

A model system of gaseous electron mobility, excitation, and plasma activity was used to study direct effects of six gases, including four general anesthetics, in oxygen. Helium increased, and nitrogen had minimal effects on gaseous excitation. Nitrous oxide, as well as the potent anesthetics halothane, enflurane, and isoflurane, inhibited gaseous excitation, nitrous oxide having the weakest anesthetic effect. The data are compatible with the view that anesthetic inhibition is mediated by Van der Waals dipole dispersion interactions among anesthetic molecules (e.g., halogenated hydrocarbons) and electrons accelerated by the applied field. Dipole dispersion interactions may also mediate anesthetic effects on synaptic protein conformational control.

Anesthesia, General↗