Haemodynamic responses following meperidine and promazine induced neuroleptanalgesia in calves.

Induction of neuroleptanalgesia in 6 calves by i/v administration of a combination of meperidine (/ 12 mg/kg body weight) and promazine (/ 3 mg/kg body weight) elicited various haemodynamic responses. The MAP and CVP exhibited significant (p less than 0.01) overall variations with fluctuating fall and rise at different observation periods. A significant (p less than 0.01) rise could be observed in HR which manifested a maximum and an abrupt rise (104.31%) at 5 minutes postinjection. Cardiac output, cardiac index, stroke volume, stroke index and total peripheral resistance exhibited significant (p less than 0.01) overall variations with an initial fall in their values as compared to the respective base values. The cardiac output and cardiac index showed an alternate fall and rise from the preceeding value while the stroke volume, stroke index and total peripheral resistance manifested decreased values throughout the observation period as compared to base value. The values of all parameters measured, except heart rate, stroke volume, stroke index and total peripheral resistance, nearly returned to preinjection level by 120 minutes.