Cardiorespiratory, anaesthetic and recovery effects of morphine combined with medetomidine and alfaxalone in rabbits

摘要: Ten New Zealand White rabbits were used in a crossover experimental study: 200 µg/kg medetomidine and 1 (M1) or 2 mg/kg (M2) morphine administered intramuscularly. After preoxygenation, anaesthesia was induced with alfaxalone at 10 mg/kg intravenously. The trachea intubated 60 per cent oxygen provided. Heart respiratory rates (HR RR), direct arterial pressures (APs), pH (pHa), PaO2, PaCO2 SaO2 taken baseline, after premedication every 10 minutes during the 90 minutes following induction. times to return ear pinch, toe pinch righting reflexes recorded. Data analysed using two-way analysis of variance paired samples t test. Compared baseline values, HR, RR, APs, PaO2 decreased significantly both groups. Postinduction apnoea 20±10 M1 27±18 minutes M2 experienced administration, intermitent positive pressure ventilation applied until spontaneous breathing efforts appeared. Cardiovascular variables, RR pHa remained below, over values anaesthetic period. No significant differences observed recovery times. Morphine combined produced suitable level anaesthesia, although profound cardiorespiratory depression found.