Search PubMed⌕ Search

Biomedical subjects

C J Hull

Publications and source records attributed to C J Hull.

At least 37 records · Page 2Linked to original sources
PubMed1985

Incremental propofol for short procedures.

Propofol was used to induce and maintain anaesthesia in patients undergoing minor gynaecological procedures. Quality of anaesthesia, the rate of recovery and the influence of different methods of premedication were assessed. Unpremedicated patients required a higher induction dose than those premedicated with either lorazepam or papaveretum and hyoscine, but maintenance dose requirements were comparable. Regardless of premedication, there were similar decreases in mean arterial pressure, although respiratory function recovered more rapidly in patients premedicated with lorazepam. No significant changes in heart rate were noted in any group. The overall incidence of pain on injection was 3.7% (lignocaine 0.5 mg added to each 9.5 mg of propofol) and a skin rash occurred in 6% of patients. All patients recovered rapidly and uneventfully.

Adolescent↗
PubMed1985

Acute tolerance to fentanyl during anesthesia in dogs.

The effect of fentanyl on increases in heart rate and mean arterial pressure elicited by electric stimulation of a branch of the radial nerve was studied in anesthetized, paralyzed, and artificially ventilated dogs. In one group, a bolus of 100 micrograms/kg of fentanyl depressed the evoked changes in heart rate and arterial pressure by 82 and 75%, respectively, by 5 min, and recovery occurred within 90 min. A second group was given increasing bolus doses of fentanyl from 1.5 to 100 micrograms/kg every 20 min for 200 min. The doses and intervals were chosen to give a logarithmic increase in plasma concentration of fentanyl to include a final bolus dose of 100 micrograms/kg and were predicted by a two-compartment pharmacokinetic model derived from data of the first group. In the second group, the bolus dose of 100 micrograms/kg after 5 min had no significant effect on evoked cardiovascular responses. Over the following 2 h, the evoked changes in heart rate and arterial pressure increased above those preceding the 100 micrograms/kg dose. An additional bolus dose of 100 micrograms/kg given 2 h after the first did not depress the evoked reflexes below the control values. It was concluded that tolerance to the effects of fentanyl can occur within 3 h and that for evoked responses to arterial pressure, rebound withdrawal effects can be seen within an additional 90 min.

Animals↗
PubMed1983

Extradural versus intramuscular diamorphine. A controlled study of analgesic and adverse effects in the postoperative period.

The effects of diamorphine hydrochloride 0.1 mg/kg, given either extradurally or intramuscularly for postoperative analgesia were compared in two randomised double-blind studies involving 39 patients undergoing thoracotomy and major gynaecological surgery. Assessments were made at fixed intervals after the administration of diamorphine and consisted of the measurement of pain or analgesic effect. Segmental, sympathetic and any adverse effects were sought. There was no significant difference in the quality of analgesia between the two groups in either trial. Extradural diamorphine provided safe and effective analgesia of rapid onset, with no specific undesirable side-effects. In both studies, analgesia was more prolonged following extradural administration. The relative proportion of spinal binding may be increased after extradural administration and this may be reflected in the prolonged analgesia observed.

Adult↗
PubMed1983

A clinical trial of alfentanil as an adjuvant for short anaesthetic procedures.

Alfentanil 700 micrograms and fentanyl 100 micrograms were compared as anaesthetic adjuvants in 90 patients undergoing short duration gynaecological procedures. The results show that, at the chosen dose ratio, alfentanil causes a higher frequency of post-induction apnoea, but thereafter the respiratory effects of the two drugs were comparable. No differences in incremental requirements or evoked movements were found. Among patients who had been given ergometrine, the alfentanil group suffered a greater frequency of nausea and vomiting in the period immediately after operation. It is concluded that in single i.v. doses, alfentanil 700 micrograms is more potent than fentanyl 100 micrograms. Moreover, the results suggest that, unlike fentanyl, this very short acting agent would be used to greater effect if given in divided doses during surgery.

Abortion, Induced↗
PubMed1982

Comparative pharmacokinetics of fentanyl and alfentanil.

The pharmacokinetics of fentanyl and alfentanil were compared by the simultaneous i.v. administration of both drugs, measurement of plasma concentrations and compartmental analysis. In addition, plasma protein binding, erythrocyte:plasma partition, and heptane:water partition were compared. Alfentanil was found to have a very much smaller apparent volume of distribution, smaller total clearance, and shorter terminal half-time in plasma. Alfentanil was also found to have a greater plasma protein binding, but in contrast to fentanyl, no binding to erythrocytes. It is concluded that alfentanil is less cumulative than fentanyl, has restricted hepatic clearance, and will exhibit non-linear kinetics at very high doses. An appendix describes the model-fitting procedure in detail.

Adult↗
PubMed1981

Control of postoperative pain by interactive demand analgesia.

A demand analgesia apparatus is described. It communicates with the patient by means of spoken messages in any desired language, so that preliminary instruction is unnecessary. Dosage is limited by a reduction in respiratory rate, and by a series of electronic fail-safe circuits. Operation of the system is illustrated in a series of 10 patients given fentanyl "on demand" for the first 12 h after operation. The mean dose rate 0.73 +/- 0.49 microgram min-1. There was no evidence of cumulation or tolerance during the period of study.

Analgesia↗
PubMed1980

Fazadinium and pancuronium: a pharmacodynamic study.

The neuromuscular blocking characteristics of fazadinium and pancuronium were compared using a general pharmacodynamic model. Since it characterizes the overall relationship between dose and effect, the model can be used to determine precisely equipotent doses, compare time-effect curves, and reconcile the apparently inconsistent clinical and pharmacokinetic characteristics of the two drugs. Fazadinium was shown to have a shorter duration than pancuronium, and appeared to exhibit less variation between subjects. The potency ratio varied between 3.4 : 1 and 7.2 : 1, depending upon the definition chosen. A general solution for the three-compartment open mammillary model, following any set of initial conditions if presented as an appendix. These equations allow explicit computation of any pattern of drug incrementation into any compartment of the model.

Adult↗