Is a microfilter necessary in a single unit blood transfusion

Area of Science:

• Medical Science
• Physiology
• Transfusion Medicine

Background:

• Microaggregates in transfused blood can potentially cause pulmonary dysfunction.
• Standard blood filters have a pore size of 170 mu.

Purpose of the Study:

• To compare the effects of 27 mu and 170 mu pore filters on lung function during autologous blood transfusion in sheep.
• To determine if a finer pore filter (27 mu) is necessary for small volume transfusions.

Main Methods:

• Repeated autologous blood transfusions were administered to a sheep.
• Lung function was assessed by monitoring cardiac output, pulmonary shunt, and alveolar-arterial oxygen tension gradient.
• Measurements were taken before, during, and after transfusions with both 27 mu and 170 mu filters.

Main Results:

• No significant changes in cardiac output, pulmonary shunt, or alveolar-arterial oxygen tension gradient were observed with either filter type.
• The study found no evidence that microaggregates passing through a 170 mu filter caused pulmonary dysfunction in the sheep model.

Conclusions:

• The use of a more expensive 27 mu pore filter is not justified for small volume transfusions, based on these findings in sheep.
• Results suggest that standard 170 mu filters are adequate for preventing pulmonary dysfunction in limited transfusion volumes.