Comparative Studies on the Effect of S(+)-Ketamine-Medetomidine and Racemic Ketamine-Medetomidine in Mouse

In this study, the cardiopulmonary and clinical effects of S (+) ketamine/medetomidine (S-K/MED) and ketaminrazemat/medetomidine (K-R/MED) combination on mice for anaesthesia were compared. A total of 20 adult female NMRImice (body weight 33-58 g) were used for this trial. Mice were divided into two groups. 75 mg/kg S-K and 0.25 mg/kg MED intraperitoneally (IP) were given to the Group 1 (G1), while 50 mg/kg K-R and 0.25 mg/kg MED intraperitoneally were given to the Group 2 (G2). The efficiency of anaesthetic agents were determined by clinical observations, which duration of induction, analgesia and immobilization, body temperature, respiratory rate (RR), peripheral oxygen saturation (SpO2 ), heart rate (HR). These parameters were measured and recorded at 10-minute intervals before and after administration of the anaesthetic agents. Analgesia lasted as a mean of 25 (15-35) min in G1 and 40 (30-60) min in G2 (p<0.05). The immobilization periods conducted in G1 and G2 were 56 (ranged between 50 and 65) min and 87 (ranged between 75 and 100) min, respectively (p<0.05). Temperatures reduced in both groups during anaesthesia. No significant differences between individual groups in the heart or respiratory rate as well as SpO2 value. Atipamezole (AT) application resulted in an increase in respiratory rate, and a small numbers of animals showed hyperventilation. As a results, it could be suggested that using S-K in combination with MED causes shorter duration time and less side effects after antagonisation of MED compared with K-R.