Evaluation of Diazepam-Ketamine-Pentazocine Anaesthesia in Rabbits
Selected anaesthetic indices of the intramuscular administration of diazepam 5mg/kg followed 10 min later by ketamine 60mg/kg, with pentazocine 10mg/kg (D-K-P) or without pentazocine (D-K) as control, were evaluated in five healthy rabbits that were not undergoing any clinical procedure. Heart rate (HR), respiratory rate (RR) and rectal temperature (RT) of the anaesthetized rabbits were also determined over the initial 60-min period.Time to loss of the righting reflex with the D-K-P (1.9 ± 0.6 min) was similar to the control value of 2.0 ± 0.0 min. Whereas D-K lacked analgesic activity, the onset and duration of analgesia with the D-K-P were respectively 3.6 ± 1.4 min and 95.0 ± 10.6 min. Recumbency time with the D-K-P (128.6 ± 9.3 min) was significantly (P < 0.05) shorter than the control value of 184 ± 3.3 min. Time to standing with the D-K-P (17.4 ± 1.6 min ) was also significantly shorter than the control value of 42.0 ± 1.4 min. Mean HR with the D-K-P ranged between 140.8 ± 16.1 and 166.4 ± 19.9 beats/ min and were below the control range of 188.6 ± 6.4 and 201.0 ± 3.1 beats/min. Range of mean RR with the D-K-P (34.4 ± 3.1 to 68.0 ± 10.7) breaths/ min was below the control range of 71.4 ± 6.9 and 121.2 ± 12.6 breaths/min. Mean RT with the D-K-P ranged between 38.0 ± 0.4 and 39.9 ± 0.50C and were similar to the control range of 39.9 ± 0.10 C.It was concluded that the intramuscular administration of D-K-P at the dose rates employed in this study provided satisfactory immobility, analgesia and muscle relaxation of long duration, albeit with some clinically insignificant degree of cardiorespiratory depression, in healthy rabbits.
Key Words: diazepam, ketamine, pentazocine, rabbit.