General Anesthesia in Geriatric Dogs with Propofol-Isoflurane, PropofolSevoflurane, Alphaxalone-Isoflurane, Alphaxalone-Sevoflurane and Their Comparison of Biochemical, Hemodynamic and Cardiopulmonary Effects

Background: Geriatric is defined as the life-cycle in which the physical state, organ functions, sensory functions, mental function and immunity progressively regress. Aging causes progressive and irreversible changes in the functional capacities of organ systems, which in turn alter the response to stress and anesthetic drugs. Propofol is an anesthetic agent with sedative and hypnotic effects. Anesthesia induction with propofol is fast and smooth. Alphaxalone (3α-hydroxy-5α-pregnane11,20-dione) is a central nervous system depressant in the form of synthetic neuroactive steroids. This allows anesthesia and muscle relaxation by increasing the inhibition of gamma amino butyric acid type A (GABA) receptors. The aim of this study is to compare effects of propofol-isoflurane and propofol-sevoflurane with relatively a new anesthetic combination alphaxalone-isoflurane and alphaxalone-sevoflurane on hematological, biochemical and physiological parameters. Materials, Methods & Results: Dogs were randomly divided into 4 groups and anesthesia protocols were applied. After induction of anesthesia with 6 mg/kg propofol in groups 1 and 2, isoflurane anesthesia was continued in group 1 and sevoflurane in group 2. After induction of 3 mg/kg alphaxalone anesthesia in groups 3 and 4, isoflurane anesthesia was continued in group 3 whereas sevoflurane in group 4. Vena cephalica was catheterized for blood collection. At the preanesthetic period, 15, 30, 45, 60 min and 60 min after the anesthesia, complete blood counts were performed. Serum ALT, AST, urea, creatinine values were measured during preanesthesia, perianesthesia 15-30 min and 60 min after anesthesia. Cardiopulmonary parameters and reflexes were evaluated before anesthesia and recorded at perianesthetic 5, 10, 15, 30, 45, 60 min and 60 min after full recovery. Patients were monitored during anesthesia. The average age of the dogs in the study was 10.83. All of the dogs were anesthetized in a few seconds with intravenous injection of propofol or alphaxalone. During anesthesia the respiratory rate (fR) was recorded by counting the movements of the reservoir bag. A pulse oximeter was used to monitor pulse rate (fH) and haemoglobin oxygen saturation (SpO2). Body temperature was measured from rectum with a thermometer. Geriatric dogs were anesthetized for a variety of clinical reasons, concerning laparatomy (12.5%), orthopedic (7.5%), soft tissue (60%), dental (10%) and ophthalmologic surgery (10%). Duration of anesthesia was 94.44 (± 12.6) for group I, 81(± 10.54) for group II, 93.88 (± 11.6) for group III and 64.5 (± 3.97) min for group IV. Serum urea and creatinine concentrations were not significantly different in the four groups. Discussion: The mean duration of anesthesia recovery was 6.0 ± 2.0 in group 1, 4.6 ± 1.45 in group 2, 3.7 ± 1.23 in group 3 and 9.7 ± 3.09 min in group 4. In group 4 recovery was longer than other groups and statistically significant (P < 0.05). In our research, the recovery is shorter in the isoflurane treated groups than in the sevoflurane treated groups. When the effect of different groups on heart rate was examined, the difference between them was not significant. Duration and depth of the anesthesia with propofol-isoflurane, propofol-sevoflurane, alphaxalone–isoflurane and alphaxalone-sevoflurane were found to be satisfactory for surgery. Four anesthetic agents applied in geriatric dogs did not adversely affected the hematological and biochemical parameters. In conclusion anesthesia on geriatric dogs after induction of propofol and alphaxalone maintained with isoflurane or sevoflurane found to be safe. However, they did not provide analgesia in painful operations, so it would be appropriate to use analgesics in the pre or intraoperative period.