Effects of propofol on ultrasonic indicators of haemodynamic function in rabbits

Abstract

ObjectiveTo evaluate the cardiovascular effects of intravenous propofol in rabbits. Study designRandomized, prospective, experimental study. AnimalsThirty-one female New Zealand White rabbits. MethodsRabbits were allocated to one of two groups [propofol (P) or conscious (C)]. In C (n = 16) vascular dimensions were measured using ultrasound of the left common carotid artery (ACC) and the abdominal aorta (AA). Group P (n = 15) received propofol 4.0–8.0 mg kg−1 intravenously (IV). Anaesthesia was maintained with propofol at 1.2–1.3 mg kg−1 minute−1. Subsequently, three propofol injections (8 mg kg−1) were given. Before and for 10 minutes after each injection the following vascular and haemodynamic variables were recorded (a) at the ACC after the first injection; and (b) at the AA after the second injection: vessel diameter [D, (mm)], peak systolic, minimum diastolic, end-diastolic and average blood flow velocities [psBFV, mdBFV, edBFV, Vave (cm second−1)], average volumetric flow [VFave (mL s−1)], resistance index (RI) and pulsatility index (PI) mean arterial pressure (MAP), heart rate (HR), arterial oxygen saturation (SpO2) and end-tidal CO2 (Pe′CO2). Echocardiography was performed after the third propofol bolus injection to investigate changes in cardiac parameters [fractional shortening, FS (%)]. ResultsIntravenous propofol injections caused a significant decrease in vessel diameter, volumetric flow and edBFV, and significant increases in psBFV, RI and PI. Baseline levels for vessel diameter and psBFV were restored 6–8 minutes after injection. Propofol injection decreased FS significantly by 7 minutes after injection while MAP and HR were significantly reduced for 4 minutes.Conclusion and clinical relevance Injections of propofol (8 mg kg−1) produced an immediate, transient decrease in vascular diameters, a significant decrease in ventricular performance and an increase in peripheral vascular resistance (ACC and AA). Propofol should probably not be or only carefully used in rabbits with ventricular dysfunction.