Continuous infusion of propofol at variable rates in a time dependent in cats

Abstract

Felines biotransforms propofol slowly developing cumulative effect. The aim this study was to develop a scheme of continuous infusion of propofol at time dependent variable rate in cats. Sixteen healthy female cats undergoing elective ovariohysterectomy and received as premedication dexmedetomidine (2.5 ?g/kg), methadone (0.5 mg/kg) and ketamine (0.5 mg/kg) administrated at intramuscular rote. After 15 minutes , the animals were allocated into two groups : Fixed Rate (GFR), which received propofol 4mg/kg, followed by continuous infusion (CI ) at the rate of 0.3 mg/kg/min for 60 minutes; and Variable Rate (GVR) receiving the same induction protocol exchange with the IC starting at 0.3 mg/ kg/min for 10 minutes, 0.25 mg/kg/min up to 25 minutes, 0.2 mg/ kg/min up to 45 minutes and 0.15 mg/kg /min to 60 min of infusion based on simulation STAMPUMP®. We evaluated the cardiac frequency (HR), respiratory rate (RR), systolic blood pressure (SBP) and maintenance of anesthesia during 60 minutes of infusion , as well as time to extubation, sternal recumbency and to full recovery. We observed similar anesthesia in both groups, but the GVR was used propofol least 30% for maintenance anesthesia. There was a reduction of HR and f in both groups after induction, with one animal the GFR developed apnea during all periods evaluated . Decreased SBP in GFR at all times in relation to the baseline, as the GVR, SBP decreased in just a moment. There was no significant difference between groups with respect to time to extubation (GFR 43.2 ± 19.5 min and 30.7 ± 13.2 min GVR) , deambulation ( GFR 60.7 ± 29.6 min and 41.6 ± GVR 17.2 min ) and total recovery (GFR 136 ± 34.3 min and 101.5 ± 29.6 min GVR) . We conclude that the two techniques keeps similar anesthetic plans, being safe for use in cats, and that the rate has varied propofol consumption 30 % lower.