Effects of propofol administered via the supravertebral sinus in red-eared sliders

Abstract

Objective-To characterize the effects of propofol administered at 10 and 20 mg/kg (4.5 and 9 mg/lb) via the supravertebral venous sinus in red-eared sliders (Trachemys scripta). Design-Prospective, masked randomized crossover study. Animals-10 adult female red-eared sliders. Procedures-Propofol was administered via the supravertebral sinus. Skeletal muscle tone of neck, forelimbs, hind limbs, and tail; heart rate; palpebral, corneal, and tap reflexes; response to deep pain; and spontaneous movement were recorded. Results-Mean induction times were 1.7 ± 2.4 minutes and 0.9 ± 1.4 minutes at propofol doses of 10 and 20 mg/kg, respectively. Significant differences between the 2 doses were found in anesthetic duration, duration of the plateau phase, and time to recovery of skeletal muscle tone. A greater proportion of turtles in 20 mg/kg trials had loss of palpebral reflexes and sensation of deep pain, whereas corneal and spinal reflexes remained highly conserved at both doses. No significant differences were detected in time to maximal loss of skeletal muscle tone or in time to loss or recovery of reflexes. Total anesthetic times were 63.2 ± 23.8 minutes and 90.5 ± 32.3 minutes for 10 and 20 mg/kg trials, respectively. Heart rates remained constant between 30 and 40 beats/min with both doses. Conclusions and Clinical Relevance-Propofol administration via the supravertebral sinus was a rapid and reliable means of achieving anesthesia in healthy red-eared sliders. Doses of 10 to 20 mg/kg should be adequate for short procedures or for induction prior to inhalation anesthesia.