Figure 19-7 Schematic of pathways for cirrhosis-induced portal hypertension: the forward and backward theories. Cirrhosis and portal hypertension induce circulatory changes that decrease the effective blood volume. This activates volume receptors and stimulates neurohumoral and intrarenal reflexes to decrease renal blood flow and to increase renal retention of sodium. PVBF, portal venous blood flow; HABF, hepatic arterial blood flow; THBF, total hepatic blood flow; A-V, arteriovenous; PG's, prostaglandins; ADH, antidiuretic hormone; ANF, atrial natriuretic factor; PAF, platelet activating factor. (Reprinted with permission from Mushlin PS, Gelman S: Anesthesia and the liver. In Barash PG, Cullen BF, Stoelting RK [eds]: Clinical Anesthesia, 4th ed. Philadelphia, Lippincott Williams & Wilkins, 2001, p. 1088.)