A common complication of cardiopulmonary bypass (CPB) surgery is post-opera
tive bleeding that may result in re-exploration. Bleeding is often due to t
he coagulopathy that follows the procedure, rather than the surgical techni
que. Etiology of this coagulopathy has been attributed to platelet dysfunct
ion. We reviewed the medical records of 592 patients who had undergone CPB
surgery between 1992 and 1994. Bleeding times (both pre and post operative)
in treated (those who received platelets) and untreated patients were reco
rded where available. Both groups showed a rise in bleeding time (295 see v
ersus 192 see, respectively, p <0.001). However, the treated group had a gr
eater increase in the bleeding time compared to the un-treated (p <0.05). T
he result was the same v hen ve compared 2 subgroups with similar pre-opera
tive bleeding times. When the treated group was subdivided into those who r
eceived > 10 units of platelets and those who received < 10 units, there wa
s no significant difference in the increase in their bleeding times (P >0.1
). Administration of platelets did not improve bleeding time abnormalities
induced by CPB. Both treated and untreated groups had a significant rise in
their bleeding times, irrespective of the amount of platelets administered
. The mean rise in the bleeding time in patients who bled significantly to
require surgical re-exploration (but did not receive platelets) was not sig
nificantly different from those who received platelets. These observations
suggest that the administration of platelets has no clinical benefit in imp
roving bleeding time following CPB.