Investigation of hematological, biochemical and cardiovascular influence of propofol or thiopental induction in sevoflurane-anesthetized dogs

This study was aimed at determining the clinical usability of propofol and thiopental for anaesthesia induction and investigating any haematological, biochemical and cardiovascular alterations caused by these induction agents in dogs under sevoflurane anaesthesia. Twenty dogs weighing 6-33 kg (on average 22.35±9.43 kg), 14 of which were male and 6 were female, and all which were referred to the Surgery Clinic of Burdur Mehmet Akif Ersoy University (MAKÜ), Faculty of Veterinary Medicine, constituted the study material. The dogs were randomly assigned to two groups, one which received propofol induction (n=10), and the other thiopental induction (n=10). Both groups were administered firstly with 1 mg/kg bw of morphine and next with 0.3 mg/kg bw of midazolam as preanesthetics. Subsequently, the first group received 4 mg/kg bw of propofol and the second group received 11 mg/kg bw of thiopental sodium for the induction of anaesthesia. In this study, the cardiovascular, haematological and biochemical parameters of each dog were recorded during preanaesthesia and for a 60-minute period as from the start of ventilation. According to the mean pulse rates of each animal recorded at 5-min intervals during preanaesthesia and the intraoperative period, a statistically significant decrease was detected in the propofol group as of 30 min and in the thiopental group as of the start of ventilation. The mean pulse rates recorded for the two groups showed significant differences as of 50 min. The mean RBC, HGB and HCT values of both the propofol group and the thiopental group showed a progressive decrease as from the start of ventilation. This decrease gained statistical significance as of 15 min and converted to a statistically insignificant increase as of 45 min in both groups. The urea levels of the two groups displayed an insignificant increase throughout the intraoperative period. It was observed that in the thiopental group, the urea levels exceeded the limit of the reference range (8-28 mg/dl) as of the start of ventilation. While the ALT values first increased at the beginning of ventilation and later decreased until the end of anaesthesia in the propofol group, they showed a progressive decrease throughout the intraoperative period in the thiopental group. The decrease observed in both groups was statistically insignificant. In view of the data obtained in this study, it is suggested that precaution should be taken in the use of thiopental sodium for anaesthesia induction in dogs with cardiovascular and renal disease, and in the use of propofol for induction in dogs with severe hepatic disease, with precaution requirements applying to the use of both induction agents in anaemic patients.