Evaluation of Cardiopulmonary, Blood Gases and Clinical Effects of Dexmedetomidine-Ketamine and Midazolam-Ketamine Anesthesia in New Zealand White Rabbits

Abstract

This study aimed to investigate the effects of dexmedetomidine-ketamine and midazolam-ketamine combinations on cardiopulmonary and clinical parameters in New Zealand white rabbits. The DXK group (n=8) received dexmedetomidine (50 µg/kg) and ketamine (20 mg/kg), and the MDK group (n=8) received midazolam (0.6 mg/kg) and ketamine (20 mg/kg) in the same syringe through the intramuscular (IM) route. Before anaesthesia and for 120 minutes, reflexes, haemodynamic values and blood gas changes were monitored. It was determined that anaesthesia was induced within a shorter time and lasted longer in DXK. The difference between the groups in terms of the time of loss of the pedal reflex (2.0 min in DXK, 7.5 min in MDK) was statistically significant (p<0.05). It was observed that, in both groups, the heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR) and oxy-haemoglobin saturation (SpO2) values decreased, and the end-tidal CO2 (EtCO2) values increased, but these changes were greater in DXK. With regard to arterial blood gasses, a reduction in pH and pO2 and an increase in pCO2 were also more noticeable in DXK. Consequently, at the doses applied, dexmedetomidine-ketamine caused more noticeable changes in the haemodynamic values and blood gasses in comparison to midazolam-ketamine. High-dose dexmedetomidine (50 µg/kg) and low-dose ketamine (20 mg/kg) achieved induction in a shorter time but led to a significant reduction in RR. It was concluded that the combination of midazolam (0.6 mg/kg) and ketamine (20 mg/kg) could be regarded as appropriate for the anaesthesia of New Zealand white rabbits.