Continuous infusion of dipyrone in bitches in the intraoperative period: cardiorespiratory effects

Dipyrone is an effective analgesic for managing moderate or severe postoperative pain and can be used alone for mild pain or in combination with other analgesics for any type of pain. This study aimed to examine the administration of dipyrone by continuous infusion (CI) as an adjuvant analgesic in the intraoperative period for bitches undergoing elective ovariohysterectomy (OH) and its effect on these patients’ cardiorespiratory parameters. Twenty bitches underwent an elective OH procedure. The pre-anesthetic agent was a combination of acepromazine and morphine. Propofol was used to induce anesthesia, and isoflurane was used for maintenance. Subsequently, the animals were randomly allocated into two groups: the dipyrone group (DG) received a bolus dose of dipyrone (25 mg kg-1) by CI at a rate of 10 mg kg-1 h, and the control group (CG) received a bolus dose and a CI of 0.9% NaCl solution, both groups at a rate of 5 mL kg-1 h. The parametric variables were analyzed by ANOVA, followed by Tukey's test (p<0.05). The paired t-test (p<0.05) was used for comparison between the groups. Statistical differences were observed for heart rate, systolic, diastolic, and mean arterial pressure, respiratory rate, and blood glucose between the periods in both groups. There were differences only in the basal values of MAP between the groups; however, most values remained within the physiological range for the species. Using the drug as an adjuvant to anesthesia did not alter cardiorespiratory parameters, and it can be used as an adjuvant in analgesia during the intraoperative period of OH.