hemofiltración

Hemofiltration is a medical procedure used to remove waste products and excess fluid from the blood when the kidneys are not functioning properly. It is a type of renal replacement therapy that operates on the principle of convection, where solutes and water are moved across a semipermeable membrane by a pressure gradient. This process is distinct from hemodialysis, which primarily uses diffusion.

During hemofiltration, blood is drawn from the patient's body and passed through a hemofilter. This filter contains a membrane with pores that allow small molecules like urea, creatinine, and excess electrolytes to pass through, along with water. Larger molecules, such as proteins and blood cells, are retained in the blood and returned to the patient. A special replacement fluid is added to the blood during the process to maintain electrolyte balance and prevent excessive removal of essential substances.

Hemofiltration can be performed continuously, often referred to as continuous veno-venous hemofiltration (CVVH). This method is typically used in critically ill patients in intensive care units who are hemodynamically unstable. The continuous nature of the treatment allows for gradual and controlled fluid and solute removal, minimizing stress on the cardiovascular system. Intermittent hemofiltration is also possible, though less common than continuous forms.

The primary indications for hemofiltration include acute kidney injury, chronic kidney disease, fluid overload, and electrolyte imbalances. It can also be used in cases of poisoning or drug overdose to help clear toxins from the blood. The procedure is generally well-tolerated, but potential complications can include clotting of the extracorporeal circuit, infection, and electrolyte disturbances if not managed carefully.