The aim of this study was to evaluate comparatively the effects of buprenorphine administered intramuscularly or intravenously on cardiovascular variables in dogs anesthetized with desflurane. Sixteen adult healthy male and female mongrel dogs were randomly distributed in two groups of eigth animals each (GI and GII). The anesthetic induction was done using propofol (IV), and immediately, the dogs were intubated and submited to desflurane anaesthesia administrated at 1.5 MAC. Thirty minutes after beginning the inhalatory anaesthesia, the GI received buprenorphine (0.02 mg/kg) intravenously whereas the GII group received the opioid at the same dose, by IM injection. Heart Rate (HR); Systolic, Diastolic and Mean Arterial Blood Pressure (SAP, DAP and MAP); Cardiac Output (CO); Central Venous Pressure (CVP) and Pulmonar Arterial Pressure (PAP) were evaluated. The measurements were registered 30 minutes after beginning the inhalatory anaesthesia and before opioid administration (M1); 15 minutes after buprenorphine administration (M2). Serial measurements were carried out in 15-minute intervals after the administration of buprenorphine up to 45 minutes (M3, M4 and M5). The numerical data were submited to Profile Analysis (p<0.05). In both groups, SAP, MAP, CO, CVP and PAP values were not significant. However, only in GI, the HR and DAP decreased significantly after opioid administration. The results allow us to conclude that buprenorphine IV or IM did not produce alterations on the cardiovascular parameters that could provide any significant clinics effects in dogs anesthetized with desflurane.
opioids; cardiovascular; inhalatory anesthesia
