What are the symptoms and management of uremia?

Symptoms and Management of Uremia

Uremia is a clinical syndrome characterized by the accumulation of toxins normally cleared by the kidneys, resulting in a wide range of neurological, gastrointestinal, cardiovascular, and other systemic manifestations that significantly impact morbidity and mortality if left untreated.

Clinical Manifestations of Uremia

Neurological Symptoms

• Mental status changes including confusion, altered awareness, and cognitive disturbances that may fluctuate in severity 1
• Progression from mild confusional states to deep coma in severe cases 1
• Movement disorders such as asterixis (flapping tremor) 1
• Sleep disorders including restless legs syndrome (Ekbom's syndrome) 1
• Seizures and coma in advanced cases 2

Gastrointestinal Symptoms

• Nausea and vomiting 2
• Anorexia and malnutrition 3
• Metallic taste in mouth 3

Cardiovascular and Pulmonary Manifestations

• Pericarditis 3
• Pleuritis 3
• Non-cardiogenic pulmonary edema in severe cases 2

Other Systemic Manifestations

• Calciphylaxis (calcification of blood vessels leading to skin necrosis) 2
• Uremic frost (crystallization of urea on skin) 2
• Systemic microinflammation 3
• Immunodeficiency 3
• Anemia 3
• Bone metabolism disorders 3
• Polyneuropathy 3

Complications of Severe Uremia

Dialysis Disequilibrium Syndrome (DDS)

• Central nervous system disorder characterized by neurological symptoms ranging from nausea to cerebral edema 2
• Occurs in patients with extremely high blood urea nitrogen levels (above 175 mg/dL) during initial hemodialysis 2
• Pathophysiology involves:
  • Reverse urea effect: delayed equilibration of urea between brain and plasma 2
  • Paradoxical metabolic acidosis in the central nervous system 2

Dialysis-Related Neurological Complications

• Acute dialysis encephalopathy 4
• Chronic dialysis encephalopathy (formerly known as dialysis dementia) 4
• Nerve entrapment syndromes, particularly carpal tunnel syndrome 4

Management of Uremia

Renal Replacement Therapy

• Initiation of dialysis is the primary treatment for uremic symptoms, particularly cognitive impairment 1
• Prevention of DDS during initial dialysis:
  • Start with low-intensity dialysis and gradually increase in subsequent sessions 4
  • Consider continuous renal replacement therapies in high-risk patients 2
  • Supportive therapy once DDS is established 2

Specific Management Approaches

• Kidney transplantation is the definitive treatment for chronic uremia 3
• For dialysis patients:
  • Use high-flux dialyzers to provide better clearance of middle molecules like β2-microglobulin 4
  • Consider daily hemodialysis for better toxin clearance 4
  • Avoid aluminum exposure to prevent dialysis dementia 4

Management of Associated Conditions

• Treatment of secondary hyperparathyroidism for uremic myopathy 4
• Correction of electrolyte abnormalities, particularly hyponatremia which is common in these patients 5
• Careful fluid management to address volume status issues 5

Special Considerations

• Elderly patients may present with atypical symptoms such as altered mental status, functional decline, fatigue, or falls 6
• Chronic mild uremia can lead to cognitive impairment, gait disturbances, and increased risk of falls and fractures 5
• Monitoring for adequacy of dialysis is essential to prevent recurrence of uremic symptoms 4
• Even with dialysis therapy, some uremic toxins may not be adequately removed due to:
  • Insufficient treatment time 3
  • Molecular weight range hampering elimination 3