81245
document
Hemostatic function of aspirin-treated platelets vulnerable to cardiopulmonary bypass . Altered shear-induced pathway . The impaired hemostasis of aspirin-treated patients is an annoying problem during and after cardiopulmonary bypass . The hemostatic function of platelets comprises two mechanisms : the shear-induced and the cyclooxygenase pathways . Because the latter is inhibited in aspirin-treated patients , the hemostatic function depends mainly on the former pathway . To investigate the effect of cardiopulmonary bypass on the shear-induced pathway , a double-blind study of preoperative aspirin treatment ( 325 mg ) and placebo was conducted in 40 patients undergoing coronary artery bypass grafting . Postoperative blood loss was higher in the aspirin-treated patients than in the placebo-treated patients ( p < 0.05 ) . The shear-induced hemostasis was monitored by the in vitro bleeding test ( Thrombostat ) , which mimics bleeding through an injured arteriole . The shear-induced pathway of aspirin-treated platelets was not affected before cardiopulmonary bypass , but it was impaired more during the operation ( p < 0.01 ) and remained worse afterward ( p < 0.05 ) , compared with that of placebo-treated platelets . The inhibitory effects of aspirin on thromboxane production and on collagen-induced platelet aggregation remained throughout the operation . In aspirin-treated platelets , the aggregation capacity induced by adenosine diphosphate was inhibited before the operation ( p < 0.05 ) and showed substantial recovery during the operation ( p < 0.05 ) . These results suggest that the shear-induced pathway of aspirin-treated platelets is more vulnerable to cardiopulmonary bypass than the pathway in normal platelets and causes severe impairment of hemostasis afterward .
81246
Intervention_Pharmacological
aspirin-treated
81247
Intervention_Pharmacological
aspirin-treated
81248
Intervention_Pharmacological
aspirin-treated
81249
Intervention_Pharmacological
aspirin
81250
Intervention_Pharmacological
placebo
81251
Intervention_Surgical
coronary artery bypass grafting
81252
Intervention_Pharmacological
aspirin-treated
81253
Intervention_Pharmacological
aspirin-treated
81254
Intervention_Control
placebo-treated
81255
Intervention_Pharmacological
aspirin
81256
Intervention_Pharmacological
aspirin-treated
81257
Intervention_Pharmacological
aspirin-treated
81258
Outcome_Physical
Hemostatic function
81259
Outcome_Physical
hemostatic function
81260
Outcome_Physical
Postoperative blood loss
81261
Outcome_Mental
shear-induced hemostasis
81262
Outcome_Physical
shear-induced pathway of aspirin-treated platelets
81263
Outcome_Mental
thromboxane production
81264
Outcome_Mental
collagen-induced platelet aggregation
81265
Outcome_Physical
aggregation capacity
81266
Participant_Condition
aspirin-treated
81267
Participant_Condition
cardiopulmonary bypass
81268
Participant_Condition
aspirin-treated
81269
Participant_Condition
coronary artery bypass grafting
81270
Participant_Condition
aspirin-treated