Renal Failure, Chronic

– Slow, insidious, and irreversible impairment of renal excretory and regulatory function.

Causes and Incidence

The causes of chronic renal failure (CRF) include chronic glomerular disease (e.g., glomerulonephritis); chronic infection (e.g., pyelonephritis or tuberculosis); congenital anomalies (e.g., polycystic kidneys); vascular disease (e.g., hypertension); endocrine disease (e.g., diabetes); collagen disease (e.g., systemic lupus erythematosus); obstructive processes (e.g., calculi); and nephrotoxins.

Disease Process

In CRF, the renal system experiences ischemia, inflammation, necrosis, fibrosis, sclerosis, and scarring. Nephrons are permanently destroyed, and the kidneys become unable to respond to excessive or decreased salt and fluid intake. Synthesis of erythropoietin diminishes, and the kidneys are unable to excrete end products of metabolism. CRF occurs in three stages: diminished renal reserve, then renal insufficiency, and finally renal failure and uremia. As failure is occurring, a number of substances that are normally excreted accumulate in the body, including nitrogenous waste, electrolytes, and uremic toxins. Eventually all organ systems are affected.

Symptoms

Individuals with diminished renal reserve are asymptomatic. Those with moderate renal insufficiency may have only vague symptoms such as nocturia or fatigue. Lassitude and decreased mental acuity are often the first signs of CRF. These may be followed by neuromuscular twitching, cramps, and seizure activity. Anorexia, nausea, vomiting, stomatitis, and a metallic taste in the mouth are uniformly present. Advanced disease symptoms include tissue wasting; itching, uremic frost, and yellow-brown discoloration of the skin; gastrointestinal (GI) bleeding; hypertension; and coma.

Potential Complications

All organ systems are affected by end-stage renal disease, and death is imminent without renal transplantation although life may be prolonged with dialysis.

Diagnostic Tests

Urine
Acidic pH, low osmolality, fixed specific gravity, proteinuria, casts; WBCs and RBCs may be present in sediment

Serum
Decreased pH, bicarbonate, magnesium; increased potassium, sodium, hydrogen, phosphate, calcium ions; increased uric acid, blood urea nitrogen, osmolality; decreased iron and iron-binding capacity; decreased creatinine clearance

Complete blood count
Decreased hemoglobin, hematocrit, RBC survival time; reduced platelets and decreased adhesiveness

Xray of kidneys, ureter, and bladder/ ultrasound
Small, contracted kidneys

Treatments

Surgery
Renal transplantation; insertion of Tenckhoff catheter for peritoneal dialysis; insertion of internal arteriovenous fistula for hemodialysis.

Drugs
Alkalinizing agents for acidosis; potassium-removing resins for hyperkalemia; antihypertensives for hypertension; diuretics for edema and hypertension; phosphate binders for hyperphosphatemia; antiinfective drugs for infection; anticonvulsants for seizures; antiemetics for nausea; H2receptor antagonists for GI irritation; antipruritics for itching; laxatives and stool softeners for constipation; calcium, iron, and vitamin replacements.

General
Diet low in protein, sodium, potassium, and phosphate, high in calories and calcium and supplemented with essential amino acids; balanced fluid intake and output; monitoring of intake and output, weight changes, vital signs, electrolytes, and cardiac and mental status; careful skin care; energy conservation with activities of daily living; peritoneal dialysis or hemodialysis to treat end-stage disease; long-term emotional support, counseling for adaptation to chronic, potentially fatal disease.