Medical Surgical Nursing

 Bile salts are then reabsorbed, primarily in the distal ileum, into portal blood for

return to the liver and are again excreted into the bile.

9. Bilirubin Excretion

 Bilirubin is a pigment derived from the breakdown of hemoglobin by cells of

the reticuloendothelial system.

 Hepatocytes remove bilirubin from the blood and modify it to be more soluble

in aqueous solutions.

 The conjugated bilirubin is secreted by the hepatocytes into the adjacent bile

canaliculi and is eventually carried in the bile into the duodenum.

 In the small intestine, bilirubin is converted into urobilinogen, which is in part

excreted in the feces and in part absorbed through the intestinal mucosa into the

portal blood.

 Some of the urobilinogen enters the systemic circulation and is excreted by the

kidneys in the urine.

Gerontologic Considerations

 The most common change in the liver in the elderly is a decrease in its size and

weight, accompanied by a decrease in total hepatic blood flow. Results of liver

function tests do not normally change in the elderly; abnormal results in an

elderly patient indicate abnormal liver function and are not the result of the

aging process itself.

 The immune system is altered in the aged, and a less responsive immune system

may be responsible for the increased incidence and severity of hepatitis B in the

elderly and the increased incidence of liver abscesses secondary to decreased

phagocytosis by the Kupffer cells.

Age-Related Changes of the Hepatobiliary System

 Steady decrease in size and weight of the liver, particularly in women.

 Decrease in blood flow.

 Decrease in replacement/repair of liver cells after injury.

 Reduced drug metabolism.

 Rapid progression of hepatitis C infection and lower response rate to therapy.

 Decline in drug clearance capability.