title: Acute and chronic changes in platelet volume and count after cardiopulmonary bypass induced thrombocytopenia in man.
abstract: Patients undergoing surgery for coronary artery bypass graft or heart valve replacement had their platelet count and mean volume measured pre-operatively, immediately post-operatively and serially for up to 48 days after the surgical procedure. The mean pre-operative platelet count of 1.95 +/- 0.11 X 10(11)/1 (n = 26) fell significantly to 1.35 +/- 0.09 X 10(11)/1 immediately post-operatively (p less than 0.001) (n = 22), without a significant alteration in the mean platelet volume. The average platelet count rose to a maximum of 5.07 +/- 0.66 X 10(11)/1 between days 14 and 17 after surgery while the average mean platelet volume fell from preparative and post-operative values of 7.25 +/- 0.14 and 7.20 +/- 0.14 fl respectively to a minimum of 6.16 +/- 0.16 fl by day 20. Seven patients were followed for 32 days or longer after the operation. By this time they had achieved steady state thrombopoiesis and their average platelet count was 2.44 +/- 0.33 X 10(11)/1, significantly higher than the pre-operative value (p less than 0.05), while their average mean platelet volume was 6.63 +/- 0.21 fl, significantly lower than before surgery (p less than 0.001). The pre-operative values for the platelet volume and counts of these patients were significantly different from a control group of 32 young males, while the chronic post-operative values were not. These long term changes in platelet volume and count may reflect changes in the thrombopoietic control system secondary to the corrective surgery.
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000166:cytology*; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D013921:Thrombocytopenia / Q000209:etiology*