Halothane-induced intrahepatic portovenous shunting reduces hepatic microvascular sinusoidal perfusion during contrast angiographic procedures.
OBJECTIVE
Reduced intrahepatic perfusion that occurs during contrast angiography performed after administration of halothane anesthesia is thought to result from halothane-induced systemic hemodynamic alterations, such as reduced splanchnic blood flow, rather than intrahepatic microvascular alterations. The authors postulate that intrinsic hepatic effects caused by inhalational anesthetic agents rather than contrast materials, further reduce liver perfusion.


METHODS
With use of dynamic video microscopy, intrahepatic microvascular flow rates and patterns, hepatic cord/sinusoidal diameters, portal venous pressure changes, and quantitative and qualitative Kupffer cell phagocytic activity were continuously recorded in isolated perfused rat livers before and during exposure to 1.5% halothane in O2/CO2, with and without the addition of iothalamate meglumine.


RESULTS
Exposure of livers to halothane resulted in intrahepatic portovenous shunting secondary to obstruction to sinusoidal outflow, diminished sinusoidal perfusion, and a mean elevation in terminal portal venous pressure of 12.8 mm Hg. Kupffer cell phagocytic activity was reduced even when normalized for flow within sinusoids. None of these changes were attributed to use of contrast material.


CONCLUSIONS
Alterations in hepatic blood flow during exposure to halothane result, in part, from increased intrinsic hepatic vascular resistance, sinusoidal outflow obstruction, and portovenous shunting, and not only from systemic hemodynamic changes. Iothalamate meglumine produced no microvascular alterations.
Kruskal
J B
JB
Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
Lunderquist
A
A
Clouse
M E
ME
D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000792:Angiography; D000818:Animals; D003287:Contrast Media / Q000494:pharmacology; D006221:Halothane / Q000494:pharmacology*; D007728:Kupffer Cells / Q000502:physiology; D008102:Liver Circulation / Q000187:drug effects*; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D018715:Microscopy, Video; D010587:Phagocytosis / Q000187:drug effects; D017082:Portal Pressure / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
D018685:Anesthetics, Inhalation; D003287:Contrast Media; D006221:Halothane