Complications of chronic renal failure

1. Anaemia:

a. Erythropoietin deficiency

b. Bone marrow toxins retained in renal failure

c. Increased red cell destruction

d. Abnormal red cell membranes causing increased osmotic fragility

e. Increased blood loss due to occult gastrointestinal bleeding, blood sampling, blood loss during haemodialysis or because of platelet dysfunction

f. ACE inhibitors interfere with control of endogenous erythropoietin release.

2. Bone disease: renal osteodystrophy (various bone disease in chronic renal failure). Decreased renal production of 1a-hydoxylase enzyme leads to decreased 1,25-(OH)2D3. This results in gut calcium malabsorption.

a. Hyperparathyroid bone disease: Phosphate retention due to reduced excretion by kidney results in increased PTH synthesis and release. PTH promotes reabsorption of Ca from bone and increase renal tubular reabsorption of Ca.

b. Osteomalacia: 1,25-(OH)2D3 deficiency and hypocalcaemia impairs osteoid mineralization and cause osteomalacia.

c. Osteosclerosis: Sustained excess PTH cause increased bone density and leads to osteosclerosis.

3. Skin disease such as pruritus (itching) mainly due to retention of nitrogenous waste products of protein catabolism.

4. Gastrointestinal complications:

a. Increased risk of peptic ulceration and acute pancreatitis.

b. Constipation

Probably attributable to serum amylase elevation of up to 3 times normal due to retention of high-molecular-weight forms of amylase normally excreted in urine.

5. Metabolic abnormalities:

a. Gout: urea retention due to chronic renal failure may results in gout.

6. Cardiovascular disease

7. Cardiac failure