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Effects of Different Filter Positions and Combinations in Extracorporeal Circulation
Author(s) -
Krebber Hans J.,
Hill J. Donald,
Osborn John J.,
Iatridis Angelo,
Gerbode Frank
Publication year - 1980
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/j.1525-1594.1980.tb03928.x
Subject(s) - filtration (mathematics) , extracorporeal circulation , arterial line , filter (signal processing) , materials science , suction , particle (ecology) , biomedical engineering , particle size , medicine , chemistry , surgery , physics , mathematics , computer science , biology , computer vision , ecology , statistics , meteorology
Even though filtration of the blood return from the coronary suction line has become widely accepted, there is still some question as to the benefit of arterial line filters and combinations of different filter positions. During 29 extracorporeal circulations, blood was sampled at 5, 15 and 30 minutes of bypass and at the end of bypass. All added donor blood was filtered through microporous filters (F 1 ). In 12 instances a coronary suction line filter (F 2 ) was in place and in all instances an arterial line filter (F 3 ) was in place. Blood samples were taken before and after the arterial line filter and from the venous blood. All samples were studied for screen filtration pressure and electronic particle count using apertures from 8 to 120 microns. Particle counts were summarized under two groups: large particles ranging from 12.8 to 120 microns and small particles ranging from 8 to 12.7 microns. The filter combinations FI F 2 , F 1 F 3 and F 1 F 2 F 3 were studied. All of the filters were found to be capable of filtering large sized particles: however, slight improvement was seen by using the F 1 F 2 F 3 combination. A high gradient of the large particle count was found across the arterial line filter. Small particles were found to be derived predominantly from the coronary suction line filter. While the low‐flow coronary suction line filter was well capable of removing particles of small size, no gradient in the particle count was found across the arterial line filter. Combinations of filters did not improve the filtering of small particles. A significant increase in the number of circulating small particles was found toward the end of bypass. An increasing differential between particles in the arterial line and venous blood was found toward the end of bypass. The number of circulating platelets dropped to 50% of the preoperative number within five minutes on bypass. No differences were found when using different filter combinations. The filtering of very small particles in the size range of the cellular elements of the blood is still an unsolved problem. With available systems, the Dacron mesh filter in the coronary suction line had the best results due to the lower flow and low velocity, while arterial line filters with high velocity are not capable of removing the smaller particles. Arterial‐to‐venous blood differences in the particle count suggest that some of the micro‐aggregates were removed from the blood within the patient. As the difference became larger toward the end of bypass, i.e., with rewarming of the patient and recirculation through the lung, increased capillary filtration seemed to play an important role.