The Annals of Thoracic Surgery, Vol 19, 639-647, Copyright © 1975 by The Society of Thoracic Surgeons
Functional changes in platelets during extracorporeal circulation
Y Tamari, L Aledort, E Puszkin, TJ Degnan, N Wagner, MJ Kaplitt and EC Peirce 2nd
An in vitro trauma test was conducted to determine the effects of
extracorporeal circulation on platelet count and function. Fresh human
blood was circulated in two identical in vitro circuits for six hours at a
rate of 500 ml per minute (500 recirculations). One circuit included a
G.E.--Peirce membrane lung and the other was a control. Platelet
aggregation induced by adenosine diphosphate (ADP), epinephrine, or
collagen was studied before and after six hours of perfusion. No important
drop in platelet count occurred in the control circuit (Control-C)
following bypass, but there was a 20% drop for the lung circuit (Lung-C).
Platelet aggregation was reduced by about 30% for the control circuit and
65% for the lung circuit. The large decrease in platelet function
accompanied by only a moderate decrease in platelet count is discussed in
terms of loss of the youngest and most active platelets, platelet
inhibition due to ADP released by red blood cell lysis, and platelet
trauma.