Portal hypertension pathophysiology

FIGURE 19-1. The portal venous system. (From Timm EJ, Stragand JJ. Portal hypertension and cirrhosis. In DiPiro JT, Talbert RL, Yee GC, et al, (eds.) Pharmacotherapy A Pathophysiologic Approach. 6th ed. New York McGraw-Hill 2005 694, with permission.)... 

The pathophysiologic mechanisms of portal hypertension and of cirrhosis itself are entwined with the mechanisms of ascites (Fig. 19-3). Cirrhotic changes and the subsequent decrease in synthetic function lead to a decrease in production of albumin (hypoalbuminemia). Albumin is the major intravascular protein involved in maintaining oncotic pressure in the vascular system low serum albumin levels and increased capillary permeability allow fluid to leak from the vascular space into body tissues. This can result in peripheral edema, ascites, and fluid in the pulmonary system. The obstruction of hepatic sinusoids and... 

Cirrhosis results in elevation of portal blood pressure because of fibrotic changes within the hepatic sinusoids, changes in the levels of vasodilatory and vasoconstrictor mediators, and an increase in blood flow to the splanchnic vasculature. The pathophysiologic abnormalities that cause it result in the commonly encountered problems of ascites, portal hypertension and esophageal varices, HE, and coagulation disorders. 

Tab. 14.8 Characteristic morphological, haemodynamic and pathophysiological sequelae of portal hypertension...

Smart, H.L., Triger, D.R Clinical features, pathophysiology and relevance of portal hypertensive gastropathy. Endoscopy 1991 23 224-228... 

The existence of portal hypertension is probably the decisive factor in the development of HPS. The pathophysiological principles of HPS and the change in haemodynamics in cirrhotic patients have been presented as a review. (6) A marked pulmonary vasodilation due to vasodilative substances is deemed to be the essential causative factor of HPS (K.R. Reismann, 1956). 

Robalino, B.J., Moodie, D.S. Association between primary pulmonary hypertension and portal hypertension analysis of its pathophysiology and chnical, laboratory and hemodynamic manifestations. J. Amer. Coll. Cardiol. 1991 17 492-498... 

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