Impact of oxygenator design on hemolysis, shear stress, and white blood cell and platelet counts.
OBJECTIVE
To determine whether relative pressure drop, shear stress, hemolysis, and white blood cell and platelet counts are influenced by different oxygenator designs. To compare the oxygenator results with the average shear stress over an arterial cannula.


METHODS
Prospective; patients enrolled consecutively.


METHODS
University hospital.


METHODS
Three groups of 12 adults patients, scheduled for routine cardiac surgery.


METHODS
Each group was submitted to a different oxygenator design: group 1 to a high-pressure hollow-fiber membrane oxygenator (Sarns Turbo); group 2 to a medium-pressure hollow-fiber membrane oxygenator (Cobe optima); and group 3 to a flat-sheet membrane oxygenator (Cobe Duo).


RESULTS
Although the investigated oxygenators have important differences in pressure drop and shear stress, no statistical differences were found in hemolysis generation or blood handling among the different groups. Actually, the study shows much higher shear stress levels over an average arterial cannula than over any of the evaluated oxygenators.


CONCLUSIONS
The pressure drop over an oxygenator does not correlate well with shear stress and hemolysis because the dimensions of the system (radius and length) must be included in the calculation of shear stress from pressure drop.
De Somer
D
D
Department of Perfusion, University Hospital Gent, Belgium.
Foubert
L
L
Vanackere
M
M
Dujardin
D
D
Delanghe
J
J
Van Nooten
G
G
D000328:Adult; D000368:Aged; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006461:Hemolysis; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010107:Oxygenators, Membrane; D010976:Platelet Count; D011446:Prospective Studies; D013314:Stress, Mechanical
D006454:Hemoglobins