Haemo Filtration : Ultra filtration during open heart surgery helps in removing excess fluid, especially in renal failure patients. Patients are haemo diluted (haematocrit 18-20) during bypass. Haemo filtration helps in blood preservation, especially platelets and coagulation factors. It reduces post operative complement activation and cardio pulmonary bypass induced inflmmatory response. There is also improvement in pulmonary d neurologic function. Ultra filtration equipment is connected to the circuit. In children and babies, it is carried out just before coming off bypass. This is called modification ultra filtration (MUF).