Chronic renal failure

Chronic renal failure (CRF) is a slowly progressive loss of renal function over a period of months or years.

Signs and symptoms

Initially it is without symptoms. As the kidney functions less:

• blood pressure is increased (leading to hypertension)
• urea accumulates, leading to uremia (lethargy and encephalopathy)
• potassium accumulates, leading to malaise and cardiac arrhythmias
• erythropoietin synthesis is decreased (leading to anemia)
• vitamin D3 synthesis is impaired (leading to renal osteodystrophy and secondary hyperparathyroidism)
• fluid balance disturbances are generally mild.

CRF patients suffer from accelerated atherosclerosis, mostly due to hypercholesterolemia. Coagulation is often disrupted, leading to a prothrombotic state (a high likelihood of developing thrombosis). Pericarditis occurs at an increased rate in CRF patients.

Diagnosis

In many CRF patients, previous renal disease or other underlying diseases are already known. A small number presents with CRF of unknown cause. In these patients, a cause is occasionally identified retrospectively.

Causes

• IgA nephropathy (Berger's disease)
• Glomerulonephritis (chronic or severe acute cases)
• Nephrotic syndrome (longstanding)
• Hypertension
• Diabetes mellitus (all types, dependant on duration and glycemic control)
• Amyloid
• Lupus erythematosus (lupus nephritis)
• more to be added

Treatment

CRF cannot be treated apart from by renal transplant. In the period usually required to find a transplant, dialysis (renal function replacement therapy) is the only way to clear waste products from the blood that are usually excreted through the urine (urea, potassium).

Replacement of erythropoietin and vitamin D3, two hormones processed by the kidney, is usually necessary, as is calcium.