title: Reductions in platelet contractile force correlate with duration of cardiopulmonary bypass and blood loss in patients undergoing cardiac surgery.
abstract: Blood loss secondary to platelet dysfunction is known to be increased when the duration of cardiopulmonary bypass (CPB) is prolonged. The ability to correlate alterations in platelet function with the duration of bypass and early postoperative blood loss, however, has remained elusive. Platelet contractile force, a novel measure of platelet-mediated clot retraction, is known to be reduced following cardiac surgery and blockade of platelet adhesion receptors. The aim of this study was to determine if alterations in platelet contractile force (measured using whole blood) correlated with the duration of CPB and early postoperative blood loss. Thirty patients were entered into a study designed to measure platelet function before, during, and after CPB. Platelet aggregometry and surface expression of CD42b and CD61 were also measured (using whole blood) in a subset of subjects (n=10) to further characterize the intrinsic structural and functional defects induced by CPB. Reductions in platelet contractile force had a significant correlation with duration of CPB (r=0.564; P=0.002) and early blood loss (r=0.545; P=0.003). Although decreases in platelet contractile force and aggregation both correlated with CPB time in the smaller subset of patients tested, only platelet contractile force correlated with decreases in CD42b, CD61 and blood loss. The results of this study suggest that prolongation of CPB is related to increasing degrees of platelet dysfunction and that reductions in platelet contractile force are related to decreases in platelet adhesion receptors and early postoperative blood loss.
authors.affiliation: Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center-Dallas and Veterans Affairs North Texas Health Care System, Dallas, TX 75216, USA. philip.greilich@email.swmed.edu
authors.forename: Philip E
authors.initials: PE
authors.lastname: Greilich
authors.forename: Chad F
authors.initials: CF
authors.lastname: Brouse
authors.forename: Joseph
authors.initials: J
authors.lastname: Beckham
authors.forename: Michael E
authors.initials: ME
authors.lastname: Jessen
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Martin
authors.forename: Marcus E
authors.initials: ME
authors.lastname: Carr
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D016063:Blood Loss, Surgical / Q000503:physiopathology*; D001792:Blood Platelets / Q000502:physiology*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003018:Clot Retraction; D005340:Fibrinogen / Q000032:analysis; D006801:Humans; D039661:Integrin beta3 / Q000032:analysis; D008875:Middle Aged; D010974:Platelet Aggregation; D010979:Platelet Function Tests; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000032:analysis; D013997:Time Factors
chemical_list: D039661:Integrin beta3; D019038:Platelet Glycoprotein GPIb-IX Complex; D005340:Fibrinogen