What is the treatment for uremia?

Treatment of Uremia

The primary treatment for uremia is dialysis, with the minimal "delivered" dose of total small-solute clearance being a total (peritoneal and kidney) Kt/V urea of at least 1.7 per week. 1

Understanding Uremia

Uremia is a clinical syndrome that occurs in advanced kidney failure (CKD stage 5) when the kidneys can no longer adequately filter waste products from the blood. It is characterized by:

• Accumulation of uremic toxins in the circulation and tissues, which increases proportionally with CKD progression, particularly in advanced stages (G4 and G5) 2
• Clinical manifestations affecting multiple organ systems due to the kidney's central role in maintaining the "milieu intérieur" 3
• Symptoms including nausea, vomiting, appetite suppression, and decreased dietary protein intake 1

Diagnosis and Clinical Manifestations

Uremia presents with various signs and symptoms:

• Systemic manifestations: uremic frost, renal osteodystrophy, asterixis, coagulation defects, congestive heart failure, and ammonia taste and breath 1
• Oral manifestations: xerostomia, parotitis, altered saliva composition with increased concentrations of urea, creatinine, sodium, potassium, chloride, and phosphorus 1
• Inflammatory responses: uremic toxins trigger systemic inflammation through stimulation of polymorphonuclear lymphocytes and release of inflammatory cytokines 2
• Oxidative stress: production of reactive oxygen species causing tissue damage 2

Treatment Algorithm

1. Initiation of Kidney Replacement Therapy (KRT)

• Dialysis should be initiated when GFR falls below 15 mL/min/1.73 m² (CKD stage 5) 1
• Consider earlier initiation if:
  • Protein-energy malnutrition develops or persists despite attempts to optimize protein-energy intake 1
  • Symptoms of uremia are present with no alternative explanation 1
  • Patient has significant comorbidities 1

2. Dialysis Modalities

Hemodialysis (HD)

• Delivered dose should be measured at least monthly 1
• The dose should be expressed as (Kurea × Td)/Vurea (abbreviated as Kt/V) 1
• Preferred method for measurement is formal urea kinetic modeling 1

Peritoneal Dialysis (PD)

• Minimal "delivered" dose should be a total (peritoneal and kidney) Kt/V urea of at least 1.7 per week 1
• Total solute clearance should be measured within the first month after initiating dialysis and at least once every 4 months thereafter 1
• For patients with residual kidney function (>100 mL/d urine output), 24-hour urine collection for volume and solute clearance should be obtained at least every 2 months 1

Continuous Renal Replacement Therapy (CRRT)

• Recommended for patients with acute kidney injury who have, or are at risk for, cerebral edema 1
• Marker clearance should be used as the primary basis for CRRT dosing 1

3. Monitoring and Adjustments

• Monthly evaluation of nutritional status, including serum albumin levels 1
• When obtaining 24-hour total solute clearances, estimate dietary protein intake (DPI) 1
• Monitor for decreased appetite and early satiety in PD patients 1
• Repeat clearance measurements if clinically indicated, particularly with:
  • Failure to thrive with no alternative explanation
  • Loss of residual kidney function
  • Changes in dialysate concentration
  • Changes in blood pressure control
  • Patient non-adherence to prescription 1

4. Additional Therapeutic Approaches

• Kidney transplantation: provides the most definitive treatment for uremia by eliminating the underlying cause 2
• Targeting the gut-kidney axis: dietary modifications to reduce uremic toxin production 2, 4
• Consider probiotics and prebiotics to maintain a metabolically balanced gastrointestinal tract and potentially reduce progression of CKD and associated uremia 4

Special Considerations

• Patients with diabetes and uremia require a multidisciplinary approach involving nurse-educators, podiatrists, cardiologists, urologists, endocrinologists, and gastroenterologists 5
• Recognize that symptoms of early uremia are nonspecific and may overlap with symptoms of comorbidities 1
• Be aware that patients vary tremendously in their physiological response to uremia and to dialysis treatment 1

Common Pitfalls and Caveats

• Avoid using isolated serum levels of urea or creatinine to diagnose uremia; these should be interpreted in the context of their rates of change over time 1
• Be cautious of decreased ultrafiltration and clearance due to decreased dialysate dextrose concentration in PD patients 1
• Watch for overzealous blood pressure control leading to loss of residual kidney function 1
• Consider non-adherence to prescription if the patient is not doing well on dialysis 1
• Recognize that different dialysis modalities may have varying efficacy in removing specific uremic toxins, highlighting the need for personalized treatment approaches 2