How is hemofiltration used?

From the Guidelines

Hemofiltration is used as a form of renal replacement therapy to remove excess fluids and solutes from the blood in patients with acute or chronic kidney disease.

Key Principles

• Hemofiltration works on the principle of convection, where a solvent (water) carries solutes across a semipermeable membrane, allowing for the removal of excess fluids and solutes 1.
• It can be used in combination with diffusion, as in hemodiafiltration, to enhance solute removal 1.

Clinical Applications

• Hemofiltration is commonly used in critically ill patients with acute kidney injury (AKI) or acute renal failure (ARF) to manage fluid overload and electrolyte imbalances 1.
• It can also be used in patients with chronic kidney disease (CKD) or end-stage renal disease (ESRD) as a form of renal replacement therapy 1.

Technical Considerations

• The choice of replacement fluid is crucial, and it should contain physiologic concentrations of electrolytes, except in patients with extreme imbalances 1.
• The use of pre-dilution or post-dilution can enhance the achievable ultrafiltration rate and may be useful in patients with frequent filter clotting or limited extracorporeal clearance 1.

Benefits and Risks

• Hemofiltration has been associated with improved outcomes in patients with AKI or CKD, including reduced mortality and morbidity 1.
• However, it also carries risks, such as hemodynamic instability, circulatory stress, and loss of beneficial substances, such as amino acids or water-soluble vitamins 1.

From the Research

Hemofiltration Usage

Hemofiltration is used in various medical applications, including:

• Removal of large volumes of fluids without inducing hemodynamic instability 2
• Removal of small, medium, and high-molecular weight substances 2
• Treatment of septic shock and refractory or catecholamine-resistant hypodynamic septic shock 3
• Adjunctive therapy in severe sepsis 3
• Removal of pathogenic, toxic, or waste substances not easily cleared by hemodialysis or hemofiltration 4

Techniques and Modalities

Different techniques and modalities of hemofiltration are used, including:

• Sequential hemofiltration-hemodiafiltration (SHF/HDF) 2
• High volume hemofiltration 3
• Continuous high volume hemofiltration 3
• Early goal-directed hemofiltration therapy 3

Applications and Patient Groups

Hemofiltration is applied in various patient groups, including:

• Chronic hemodialysis patients 2
• Patients with acute renal failure (ARF) 3
• Patients with septic acute renal failure 3
• Patients with severe sepsis and septic shock 3, 5
• Intensive care unit (ICU) patients 6, 3