Hepatic circulation in acute hemorrhage with reference to renal circulation

Area of Science:

• Physiology
• Hemorrhage and Retransfusion Studies
• Hepatic and Renal Hemodynamics

Background:

• Hemorrhage significantly impacts organ hemodynamics.
• Understanding the regulation of hepatic and renal blood flow during shock is crucial.

Purpose of the Study:

• To investigate liver and kidney hemodynamics during hemorrhage and retransfusion.
• To assess the role of the hepatic periarterial nerve plexus in these responses.

Main Methods:

• Hemodynamic measurements in 20 anesthetized dogs undergoing hemorrhage and retransfusion.
• Comparison between dogs with intact and resected hepatic periarterial nerve plexus.

Main Results:

• Hemorrhage caused significant decreases in hepatic arterial flow, portal venous pressure, portal venous flow, and renal artery flow.
• Portal venous and renal vascular resistances increased, while hepatic arterial resistance varied.
• Nerve plexus resection did not significantly alter hepatic arterial flow or renal artery flow decreases.
• Hepatic arterial flow decrease appears largely passive, with possible minor neurogenic, humoral, and autoregulatory influences.

Conclusions:

• Hepatic arterial flow reduction during hemorrhage is primarily passive, linked to systemic blood pressure.
• Neurogenic regulation plays a minor role; humoral and autoregulation may be involved.
• Hepatic and renal circulations exhibit distinct responses to hemorrhage and retransfusion.
• No clear interrelation was observed between hepatic and renal circulations.