Renal Failure and Uremia

Uremia is a toxic condition resulting from renal failure, when kidney function is compromised and urea, a waste product normally excreted in the urine, is retained in the blood. Uremia can lead to disturbances in the platelets and hypersomnia, among other effects.

General weakness with evidence of fluid overload on physical examination is common, but uremia may occur in nonoliguric renal failure and normal volume status. Seizures can also be associated with the dialysis dysequilibrium syndrome (includes headache, nausea, muscle cramps, agitation, delirium, and convulsions), which usually occurs near the end of or after a rapid dialysis or ultrafiltration procedure.

Causes

Uremia most commonly develops when the kidneys fail to function properly. In some cases, however, uremia occurs when blood flow to the kidneys is reduced due to severe bleeding, serious burns, or heart attack, or when more wastes are formed in the bloodstream as a result of traumatic injuries or large surgical incisions than can be removed by the kidneys. A kidney stone, a tumor in the urinary tract, or a severely enlarged prostate in males may also cause uremia.

Symptoms

• Neurologic symptoms: confusion, tremor, and generalized weakness
• Symptoms of renal failure: oliguria, anuria, nausea, vomiting, fatigue, edema, and shortness of breath

Signs

• Neurologic findings: tremor, weakness, myoclonus, tetany, asterixis, and encephalopathy
• Signs of fluid overload: edema, hepatosplenomegaly, rales, increased jugular venous distention, and an S3
• AV grafts and dialysis catheters in unconscious patients
• Seizures are usually generalized; however, focal motor seizures are not uncommon. Status epilepticus is rare.

Treatment

The main goal of treatment is to rapidly correct the cause of the prerenal azotemia before damage occurs to the internal kidney structures. Hospitalization is often required, and may involve treatment in an intensive care unit. Treatment may include hemodialysis or peritoneal dialysis.

If other symptoms of acute renal failure are present, treatment for it should continue, including medications, dietary restrictions, or dialysis.