The effect of neuroleptanalgesia on some cardiorespiratory variables in the rabbit.

A technique of neuroleptanalgesia during which rabbits breathed spontaneously for as long as 6 h without any outward sign of stress and with full recovery within 12 h is described. The method involved the constant infusion of a solution comprising fentanyl (0.05 mg/ml) and droperidol (0.13 mg/ml) in 5% dextrose following an intramuscular dose of fentanyl and droperidol. Hourly measurements of blood gases, lung mechanics, mean arterial blood pressure and heart rate were made to assess changes in ventilation and in these physiological parameters for the length of the study. The animals' tracheas were intubated under direct vision with an uncuffed tube. The animals breathed spontaneously and their cardiovascular and respiratory systems were stable throughout the entire monitoring period. There was no statistical difference between the values for all the parameters measured (P less than 0.1). A two-way analysis of variance statistical test was applied to all the measurements.