Total intravenous anesthesia with propofol for experimental surgical transposition of the carotid artery in sheep

ABSTRACT

Background: The carotid artery transposition may be used in research when continuous measurements of arterial pressureor serial blood sampling are needed. In sheep, this procedure has usually been performed under inhalational or barbiturateanesthesia; however, these anesthetic techniques may cause cardiorespiratory depression and delayed recovery. Conversely,propofol is a general anesthetic that promotes rapid induction, smooth recovery, and hemodynamic stability. The aim ofthis study was to assess physiological and anesthetic effects of total intravenous anesthesia with propofol to establish itssafety and efficacy for performing permanent carotid transposition, in sheep.Materials, Methods & Results: Seven young healthy ewes, weighing 35.00 ± 4.43 kg and subjected to a new techniqueof permanent transposition of the carotid artery were used. Propofol was administered by constant rate infusion (0.5 mg/kg/min; IV) after anesthetic induction with this same drug. Heart rate (HR), cardiac rhythm, oxyhemoglobin saturation(SpO2), respiratory rate (f), rectal temperature (RT), systolic arterial pressure (SAP), and venous blood gas parameters(SvO2, PvO2, PvCO2, and HCO3-) were evaluated before induction and every 10 min up to 1 h of anesthesia. Recoveryperiod was also evaluated. Data were submitted to Shapiro-Wilk normality test followed by one-way repeated measuresanalysis of variance and Tukey-Kramer multiple comparisons test (P < 0.05) to analyze possible effects over time. Therewas no occurrence of apnea or regurgitation after anesthetic induction; however, all sheep presented hypersalivation. Inrelation to baseline, HR was greater at 10 min, whereas PvO2, PvCO2, and SvO2 increased at all evaluation points, andHCO3- was higher at 40 min and 60 min. There was a decrease in RT from 20 min to 60 min...(AU)