Effect of propofol on hepatic blood flow and oxygen balance in rabbits

Abstract

reports of original investigations CAN J ANESTH 55: 6 www.cja-jca.org June, 2008 Purpose: Propofol has been reported to alter hepatic blood flow and to increase hepatic oxygen consumption. This study was designed to determine the effect of propofol on hepatic blood flow and oxygenation in rabbits, in order to establish its net effect on hepatic oxygen balance.Methods: Twenty, adult male, New Zealand white rabbits were randomly divided into two groups: Group P (propofol, 0.6 mg·kg). An electromagnetic flowmeter was used to measure hepatic blood flow, and blood, from the carotid artery, the portal vein, and the hepatic vein, was used to determine hepatic oxygenation. After we obtained baseline values, we repeated measurements ten, 30, and 60 min after initiating the infusion.Results: Intralipid did not affect systemic hemodynamics, hepatic blood flow, or oxygenation during the 60 min infusion; however, propofol caused a time-dependent decrease in mean arterial blood pressures and an increase in portal venous flow and total hepatic blood flow. In contrast, hepatic arterial blood flow remained unchanged during the propofol infusion. Hepatic oxygen delivery and consumption increased in a time-dependent manner to maximums of 25% and 21.4% (both, P < 0.05) above baseline, respectively. Hepatic venous oxygen saturation and extraction was unchanged throughout the study period. Conclusion:Propofol increases total hepatic blood flow, primarily by increasing hepatic portal venous flow. The increase in liver oxygen consumption was fully compensated by an increase in oxygen supply to the liver, resulting in a preserved, hepatic oxygen balance.

The effect of propofol and desflurane anaesthesia on human hepatic blood flow: a pilot study*

“…Our finding of higher hepatic blood flow during propofol compared with desflurane anaesthesia is supported by two studies in animals that have demonstrated a dose‐dependant increase in total hepatic blood flow under continuous propofol administration [5, 8]. Using a rat model, Carmichael et al.…”

“…The increase in hepatic blood flow was based on an increase in both hepatic arterial and portal venous blood flows. Recently, it has been shown that propofol‐increased hepatic blood flow in rabbits [8]. Interestingly, in both of these studies, the propofol‐induced increase in liver blood flow was associated with an increase in hepatic oxygen consumption.…”

Effect of MK‐467 on organ blood flow parameters detected by contrast‐enhanced ultrasound in dogs treated with dexmedetomidine

“…Nyman et al (2005) reported a faster time to peak enhancement of contrast agent in the liver of propofol-treated animals compared to awaken, conscious dogs. However, propofol affects the cardiocirculatory system (Langley & Heel 1988), increasing hepatic blood flow (Wouters et al 1995;Zhu et al 2008). The dose of propofol used in the study of Nyman et al (2005) was not mentioned, thus no further comparisons with our results are possible.…”

Propofol Protects against Ischemia/Reperfusion Injury Associated with Reduced Apoptosis in Rat Liver

“…The lack of a protective effect of propofol in an in vitro liver model might be because of the use of oxygen during its own metabolism, resulting in an oxygenation debt. In contrast, in vivo, the increase in hepatic oxygen consumption by propofol is fully compensated for by an increased oxygen supply owing to increased hepatic blood flow in rat [35] and rabbit models [36]. There is good evidence that vasodilators protect against I/R injury by improving hepatic blood flow and thus maintaining an oxygen balance and energy metabolism [37].…”