thiopental and alphadolone

Prolonged, stable, non-recovery anaesthesia is required for the assessment of the effects of novel compounds on the cardiovascular system. A comparison of injectable anaesthetic agents and combinations (thiobarbital, fentanyl-fluanisone and midazolam, propofol, fentanyl-fluanisone and propofol, and alphaxalone/alphadolone) was made in laboratory rats and the following parameters assessed over 3 h: blood pressure, heart rate and rhythm, respiration rate and depth, analgesia, ease of induction and maintenance of anaesthesia. It was found that propofol, with fentanyl-fluanisone premedication, provided stress-free induction, easily controlled anaesthesia, good analgesia and muscle relaxation for surgery, for up to 3 h duration. Heart rate, blood pressure and respiration remained stable and within normal limits during this time. The other anaesthetics/combinations assessed did not rate as highly in these respects. Propofol, following fentanyl-fluanisone premedication, would appear to be a useful and safe anaesthetic for use in rodents, which avoids significant effects on heart rate or blood pressure.

Topics: Anesthesia, Intravenous; Anesthetics; Animals; Blood Pressure; Butyrophenones; Female; Fentanyl; Heart Rate; Male; Midazolam; Pentobarbital; Pregnanediones; Propofol; Rats; Respiration; Thiopental

The anaesthetic induction agents thiopentone, propofol and alphaxalone-alphadolone were administered to cats intravenously and ketamine and xylazine-ketamine-atropine were administered intramuscularly in order to determine their effects on gastric pressure, lower oesophageal sphincter pressure, and barrier pressure. Manometric measurements were made with a non-perfused catheter tip pressure transducer. All the anaesthetic induction agents decreased the tone of the lower oesophageal sphincter but the reduction was least with ketamine. Lower oesophageal sphincter tone was significantly higher in cats anaesthetised with either xylazine-ketamine-atropine or propofol than in cats anaesthetised with either thiopentone or alphaxalone-alphadolone. Despite a higher gastric pressure in the cats anaesthetised with ketamine rather than with the other drugs except propofol, the barrier pressure was also significantly higher in cats anaesthetised with ketamine than in cats anaesthetised with any of the other drugs except xylazine-ketamine-atropine. The risk of gastrooesophageal reflux seemed to be higher with alphaxalone-alphadolone than with thiopentone if the lower oesophageal sphincter pressure and gastric pressure are used as indicators of likely reflux.

Topics: Anesthetics; Animals; Cats; Esophagogastric Junction; Female; Ketamine; Male; Pregnanediones; Pressure; Propofol; Random Allocation; Stomach; Thiopental; Xylazine

Testosterone and androstenedione were measured in the plasma of mature tom-cats before, during and after anesthesia with thiopentone, ketamine, xylazine and alphaxolone/alphadolone. Samples were collected via an indwelling jugular catheter at 30 min intervals before anesthesia (5 samples) and during the recovery phase (8 samples), and at intervals of 15 min during anesthesia (7 samples). Thiopentone and ketamine anesthesia significantly depressed testosterone and androstenedione concentrations during and after anesthesia. Xylazine significantly increased testosterone concentrations during anesthesia but they returned to pre-anesthetic concentrations during recovery. Androstenedione concentrations were significantly depressed during the recovery phase from xylazine anesthesia. Alphaxolone/alphadolone anesthesia had no significant effect of testosterone concentrations but significantly increased and androstenedione concentrations during anesthesia and recovery. Testosterone and androstenedione concentrations in cats were significantly altered by these 4 commonly used anesthetics and this must be taken into account if hormone concentrations are measured while cats are anesthetised.

Topics: Androstenedione; Anesthesia, Intravenous; Anesthetics; Animals; Animals, Domestic; Cats; Ketamine; Male; Pregnanediones; Testosterone; Thiopental; Time Factors; Xylazine

Topics: Adolescent; Anesthetics; Brain; Brain Injuries; Coma; Drug Therapy, Combination; Electroencephalography; Humans; Intracranial Pressure; Male; Monitoring, Physiologic; Pregnanediones; Thiopental

Topics: Anesthetics; Animals; Blood Pressure; Carbon Dioxide; Cats; Heart Rate; Ketamine; Oxygen; Pregnanediones; Respiration; Thiopental