Medicine
Fact-checked

At TheHealthBoard, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is Hemofiltration?

Hemofiltration is a lifesaving medical procedure that purifies blood by filtering out waste and excess water, akin to kidney function. It's often used for patients with acute kidney injury. This intricate process involves sophisticated equipment and skilled healthcare professionals. Intrigued by how this technology sustains life? Discover the mechanics and impact of hemofiltration on patient care in our detailed visual journey. Ready to explore further?
Niki Foster
Niki Foster
Niki Foster
Niki Foster

Hemofiltration is a therapy similar to hemodialysis, used to replace the function of the kidneys in the case of renal failure. Unlike hemodialysis, hemofiltration is nearly always used in intensive care settings in cases of acute renal failure. The therapy works by passing the patient's blood through a machine that filters out waste products and water, and then adds replacement fluid before returning the blood to the body. The replacement fluid maintains fluid volume in the blood and provides electrolytes.

Hemofiltration is a lengthy, continuous procedure, usually requiring 12 to 24 hours per session. It is usually performed daily for as long as necessary. Acute renal failure can be reversed if treatment begins early enough.

Hemofiltration therapy works a patient's blood through a dialysis machine to filter out waste and water.
Hemofiltration therapy works a patient's blood through a dialysis machine to filter out waste and water.

Hemofiltration mainly differs from dialysis in the method of filtration. Both procedures use a semi-permeable membrane to filter the blood, but hemofiltration uses convection along with diffusion, while dialysis uses diffusion alone. Convection allows positive fluid pressure to drive water and solutes through the filtering membrane. Diffusion is simply the random motion of particles in the blood, so larger solutes are not filtered as quickly as smaller ones because they move more slowly.

Hemofiltration performs the function of the the kidneys in the case of renal failure.
Hemofiltration performs the function of the the kidneys in the case of renal failure.

The convection method solves the problem inherent in diffusion alone, allowing solutes of all sizes to be filtered at a similar rate. The rate of filtration of both large and small solutes can be even more balanced by the use of hemofiltration and dialysis in tandem. This procedure is known as hemodiafiltration.

The replacement fluid used in hemofiltration contains either lactate or acetate to generate the electrolyte bicarbonate, or bicarbonate on its own. Lactate can cause problems for certain patients, such as those with liver disease or lactate acidosis, a condition in which the buildup of lactic acid in the bloodstream causes the blood to become acidic. Bicarbonate is commonly used for such patients.

Hemofiltration can replace kidney function during renal failure.
Hemofiltration can replace kidney function during renal failure.

Hemofiltration and hemodiafiltration may be performed either continuously or intermittently. The on-line, intermittent method can be used for outpatient treatment, while the continuous method is normally used in intensive care. The intermittent method prepares replacement fluid on-line by filtering the dialysis fluid, while the continuous method uses pre-packaged, sterile, commercially prepared replacement fluid.

An outpatient procedure, such as intermittent hemofiltration and hemodiafiltration, does not require a patient to stay overnight in a hospital.
An outpatient procedure, such as intermittent hemofiltration and hemodiafiltration, does not require a patient to stay overnight in a hospital.

Intermittent filtration therapies are not currently approved by the United States regulatory agencies, and hemodiafiltration is rarely used in outpatient care in the United States. In Europe, however, the practice is more common, though still somewhat controversial. Recent studies have suggested that intermittent hemodiafiltration may be a more effective therapy than dialysis, but more extensive studies, including randomized controlled clinical trials, are required before the issue can be settled.

Niki Foster
Niki Foster

In addition to her role as a TheHealthBoard editor, Niki enjoys educating herself about interesting and unusual topics in order to get ideas for her own articles. She is a graduate of UCLA, where she majored in Linguistics and Anthropology.

Learn more...
Niki Foster
Niki Foster

In addition to her role as a TheHealthBoard editor, Niki enjoys educating herself about interesting and unusual topics in order to get ideas for her own articles. She is a graduate of UCLA, where she majored in Linguistics and Anthropology.

Learn more...

You might also Like

Discuss this Article

Post your comments
Login:
Forgot password?
Register:
    • Hemofiltration therapy works a patient's blood through a dialysis machine to filter out waste and water.
      By: picsfive
      Hemofiltration therapy works a patient's blood through a dialysis machine to filter out waste and water.
    • Hemofiltration performs the function of the the kidneys in the case of renal failure.
      By: maya2008
      Hemofiltration performs the function of the the kidneys in the case of renal failure.
    • Hemofiltration can replace kidney function during renal failure.
      By: stockshoppe
      Hemofiltration can replace kidney function during renal failure.
    • An outpatient procedure, such as intermittent hemofiltration and hemodiafiltration, does not require a patient to stay overnight in a hospital.
      By: Konstantin L
      An outpatient procedure, such as intermittent hemofiltration and hemodiafiltration, does not require a patient to stay overnight in a hospital.