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Biomedical subjects

I W Carson

Publications and source records attributed to I W Carson.

9 recordsLinked to original sources
PubMed1991

Comparison of the haemodynamic effects of pipecuronium and pancuronium during fentanyl anaesthesia.

Haemodynamic variables were measured following administration of pipecuronium 70 micrograms.kg-1 and pancuronium 90 micrograms.kg-1 (approximately equivalent to 1.5 x ED95) in patients anaesthetised with fentanyl 50 micrograms.kg-1 and scheduled to undergo coronary artery bypass grafting. There were significant increases in heart rate (22%), mean arterial pressure (10%), cardiac index (16%), and the rate pressure product (35%) following administration of pancuronium. The absolute values of these parameters were, however, within acceptable clinical limits. Administration of pipecuronium produced minimal and insignificant changes in these parameters. Other measured or derived indices showed only small changes with both agents and these were generally insignificant. There were no incidences of significant bradycardia following pipecuronium administration. The results from the present study suggest that pipecuronium would have advantages for use in patients with significant cardiovascular disease.

Androstane-3,17-diol↗
PubMed1990

Propofol sedation after open heart surgery. A clinical and pharmacokinetic study.

One hundred adult patients who required mechanical ventilation after open heart surgery for coronary revascularisation were studied. All received a standard premedication and a high dose opioid anaesthetic. On arrival in the intensive care unit they were allocated randomly to receive either propofol or midazolam to maintain sedation within a predetermined range. Patients who received propofol underwent extubation of the trachea, using standard criteria, after a mean time (log-transformed) of 7.6 minutes after sedation for approximately 17 hours. The corresponding time was 125 minutes in those given midazolam. There were significantly higher morphine requirements during sedation, and higher arterial carbon dioxide tensions 30 minutes after extubation of the trachea, in patients who received midazolam. Pharmacokinetic analysis in 20 patients showed that the elimination half-life of propofol was prolonged (470 minutes) and clearance was reduced (1.14 litres/minute) compared with subjects who had not undergone cardiopulmonary bypass. The rapid clinical recovery was reflected in a rapid redistribution half-life (13.4 minutes), but this was also longer than the redistribution time of 2-4 minutes in other patients.

Blood Pressure↗
PubMed1987

Haemodynamic effects of vecuronium, pancuronium and atracurium in patients with coronary artery disease.

Thirty patients with ischaemic heart disease scheduled for coronary artery bypass grafting were randomly allocated to three equal groups. Following morphine, hyoscine and pentobarbitone premedication, anaesthesia was induced with diazepam 0.3 mg kg-1. Five minutes later neuromuscular blockade was induced with pancuronium 0.1 mg kg-1, vecuronium 0.1 mg-1 or atracurium 0.5 mg kg-1, followed after 6 min by fentanyl 25 micrograms kg-1. Pancuronium and atracurium caused significant increases in heart rate, while vecuronium induced little change. Systemic vascular resistance decreased significantly from 1515 dyn s cm-5 to 1200 dyn s cm-5 following atracurium. Cardiac index was increased transiently in the atracurium group, but a more sustained increase was observed following pancuronium. Nine patients in the atracurium group showed skin flushing and one developed skin weals.

Atracurium↗
PubMed1985

Haemodynamic changes during induction of anaesthesia with midazolam and diazepam (Valium) in patients undergoing coronary artery bypass surgery.

Midazolam 0.3 mg/kg and diazepam 0.5 mg/kg were used for induction of anaesthesia in two groups of 10 patients each undergoing coronary artery bypass surgery. Haemodynamic variables were measured during induction of anaesthesia, after pancuronium and following tracheal intubation. Haemodynamic indices were derived from these measurements using standard formulae. The induction of anaesthesia with midazolam produced a slight but significant increase in heart rate. There was a significant fall in systemic arterial pressure and pulmonary artery pressure following both drugs. Despite the fall in systemic arterial pressure, the cardiac index was maintained in patients who received midazolam. The cardio-stimulatory effect of laryngoscopy and tracheal intubation was not prevented by either of the benzodiazepines and morphine in the dosage used. Midazolam is a suitable alternative to diazepam as part of an intravenous induction regimen in patients with ischaemic heart disease.

Anesthesia, Intravenous↗
PubMed1975

Clinical studies of induction agents. XLIII: recovery from althesin--a comparative study with thiopentone and methohexitone.

A detailed assessment of recovery endpoints and a simple performance test were employed to investigate recovery from anaesthesia. 150 patients participated in a comparative study using different doses of Althesin, thiopentone and methohexitone. Althesin was found to be suitable anaesthetic agent for the outpatient practice, although recovery was not as rapid as that following methohexitone.

Adult↗
PubMed1975

The speed of onset and potency of althesin.

The speed of onset of anaesthesia with Althesin has been compared with that of other intravenous anaesthetics. Like thiopentone, Althesin appears to be a truly rapidly acting drug, producing sleep in one arm-brain circulation time. The relative potencies of the drugs studied were approximately Althesin 60 mulitre/kg equivalent to thiopentone 4 mg/kg, equivalent to methohexitone 1.2 mg/kg, although by some criteria Althesin 80 mulitre/kg is required to produce an effect equivalent to thiopentone 4 mg/kg.

Alfaxalone Alfadolone Mixture↗