Dialysis is an essential medical procedure for patients with kidney failure, allowing them to filter toxins and excess fluids when their kidneys can no longer perform this function. Among the dialysis techniques, two terms often appear: ultrafiltration dialysis and hemodialysis. While they are related, these methods serve different purposes and meet distinct needs. This article explores their differences, objectives, and functioning.
1. What Is Hemodialysis?
Hemodialysis is a treatment method that purifies the patient’s blood by removing:
- Metabolic waste products, such as urea and creatinine.
- Excess electrolytes, like potassium and sodium.
- Excess fluids retained in the body.
How Hemodialysis Works:
- Blood is drawn from the patient using a vascular access point (arteriovenous fistula or catheter).
- It is then filtered through a dialyzer (also known as an “artificial kidney”), where a special fluid, the dialysate, helps remove waste and restore electrolyte balance.
- The purified blood is returned to the patient’s body.
Main Objective of Hemodialysis:
To treat the buildup of metabolic waste and excess fluids while restoring electrolyte balance.
2. What Is Ultrafiltration Dialysis?
Ultrafiltration dialysis is a more targeted technique used specifically to remove excess fluid from the body. Unlike hemodialysis, it does not aim to remove metabolic waste.
How Ultrafiltration Works:
- Blood passes through a semi-permeable membrane, similar to that used in hemodialysis.
- Using a pressure gradient created by the machine, water and excess fluids are extracted from the plasma.
- Toxins and electrolytes remain unchanged because the process does not involve dialysate.
Main Objective of Ultrafiltration:
To reduce edema and fluid overload, commonly seen in patients with kidney or heart failure.
3. Key Differences Between Ultrafiltration and Hemodialysis
| Aspect | Hemodialysis | Ultrafiltration Dialysis |
|---|---|---|
| Primary Goal | Remove waste, restore electrolyte balance, and reduce fluid overload. | Remove only excess fluid. |
| Use of Dialysate | Yes, to eliminate toxins and balance electrolytes. | No, pressure alone is used. |
| Typical Duration | 3 to 5 hours, several times per week. | Generally shorter, depending on needs. |
| Main Indications | Chronic or acute kidney failure requiring complete blood purification. | Severe fluid overload, often with edema or heart failure. |
| Complexity | Comprehensive process requiring frequent adjustments. | More targeted and simpler procedure. |
4. When to Choose One Over the Other?
Hemodialysis:
It is indicated for patients with chronic or acute kidney failure requiring complete blood filtration. Symptoms like fatigue, nausea, uncontrolled hypertension, and severe electrolyte imbalances justify this treatment.
Ultrafiltration:
It is particularly useful for patients with severe fluid overload, often associated with congestive heart failure or fluid retention after medical treatments.
5. Conclusion: Two Complementary Tools
Ultrafiltration dialysis and hemodialysis are not opposing techniques but rather complementary. Ultrafiltration focuses solely on fluid control, while hemodialysis provides a comprehensive solution for patients with complex needs. The choice between these two methods depends on the specific needs of the patient, as determined by their nephrologist.
For optimal care, medical teams must regularly assess the clinical condition of patients to determine the most suitable treatment option.
We are a large dialysis center in Agadir (centre de dialyse à Agadir), specialized in everything related to the treatment of nephrology diseases such as dialysis and hemodialysis.
