Stepien RL, Bonagura JD, Bednarski RM & Muir WW
Cardiorespiratory effects of acepromazine maleate and buprenorphine hydrochloride in clinically normal dogs.

Am J Vet Res, 56(1): 78-84, 1995
ISSN: 0002-9645 American Journal of Veterinary Research (PubMed)

Abstract
Cardiorespiratory effects of the combination of acepromazine maleate (ACP) and buprenorphine hydrochloride (BPN) were studied in 11 healthy, conscious dogs. Values for systemic and pulmonary artery blood pressure, cardiac output, arterial and venous pH and blood gas tensions, and invasive and noninvasive estimates of ventricular systolic function, preload, and afterload were obtained before sedation and after administration of each drug. Acepromazine maleate (0.1 mg/kg, IV) depressed cardiac function, compared with baseline values for unsedated dogs. Cardiac output decreased from a mean (+/- SD) value of 4.2 (+/- 1.5) L/min to 3.1 (+/- 0.8) L/min (P < 0.001), a change not attributed to heart rate. Pulmonary capillary wedge pressure decreased from 8.3 (+/- 4.2) mm of Hg to 6.5 (+/- 4.3) mm of Hg (P < 0.01), but mean right atrial pressure did not change. Left ventricular measurement of the maximal positive rate of pressure change (dP/dtmax) decreased from 2,668 (+/- 356)/mm of Hg/s to 2,145 (+/- 463) mm of Hg/s (P < 0.001), and ventricular stroke volume decreased from 43.2 (+/- 15.2) ml/beat to 32.3 (+/- 8.6) ml/beat. Noninvasive indices of left ventricular function, ventricular shortening fraction, peak aortic velocity, and aortic average acceleration were decreased after ACP administration, but were not statistically different from baseline values. Mean systemic arterial blood pressure decreased from 121 +/- 12 mm of Hg to 96 +/- 13 mm of Hg 15 minutes after ACP administration (P < 0.001). Total systemic vascular resistance was not significantly different from the baseline value.