Editing Anatomy and Physiology – RN Practice Questions (section)

==Question 10==
A nurse is caring for a patient with liver cirrhosis who has 3+ pitting edema of the lower extremities and abdominal ascites. The serum albumin is 2.1 g/dL. Which statement best explains the mechanism of this patient's edema?
# Increased capillary hydrostatic pressure from excess circulating blood volume.
# Decreased plasma oncotic pressure allowing fluid to remain in the interstitial space.
# Increased lymphatic drainage pulling fluid into the tissues.
# Sodium loss causing water to shift out of the vascular compartment.

'''Answer:''' 2 (B). Decreased plasma oncotic pressure allowing fluid to remain in the interstitial space.

''Rationale:'' Albumin is synthesized by the liver and is the major contributor to plasma oncotic pressure, the force that draws fluid from the interstitium back into the capillary at its venous end. With cirrhosis, albumin production falls, oncotic pressure drops, and filtered fluid stays in the tissues, producing edema and ascites even though the intravascular volume may be low. Option 1 is incorrect because the intravascular volume in this setting is often depleted rather than excessive, though portal hypertension does contribute a hydrostatic component. Option 3 is incorrect because lymphatic drainage removes interstitial fluid rather than adding to it. Option 4 is incorrect because water follows sodium, so sodium loss would not draw water out of the vessels into the tissues in this pattern.