No abstract

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.

This study shows that adolescents having major jaw surgery are helped by the blood pressure-decreasing drug clonidine. This drug allows smaller doses of anesthetics, pain relievers, and blood pressure-decreasing drugs to be used; reduces changes in heart rate and blood pressure; and provides faster recovery from the anesthetic.