Dempfle Carl-Erik, Kälsch Thorsten, Elmas Elif, Suvajac Nenad, Lücke Thomas, Münch Elke, Borggrefe Martin
First Department of Medicine, Germany bDepartment of Anaesthesiology and Operative Intensive Care, University Hospital of Mannheim, Mannheim, Germany.
Blood Coagul Fibrinolysis. 2008 Dec;19(8):765-70. doi: 10.1097/MBC.0b013e32830f1b68.
Fibrinogen concentration influences mechanical and functional properties of the clot. The purpose of the present study was to identify threshold concentrations of fibrinogen resulting in relevant changes in whole blood clot elastic modulus and platelet contractile force, as well as plasma prothrombin time and activated partial thromboplastin time. We measured clot elastic modulus, platelet contractile force, and other hemostasis parameters in whole blood samples from 552 patients admitted to a surgical intensive care unit. Platelet contractile force and clot elastic modulus were measured using the Hemodyne apparatus. Fibrinogen levels were between less than 0.10 and 9.44 g/l, with a mean of 2.41 g/l. Mean platelet count was 203 x 10(9) l(-1), with a range of 16 x 10(9) l(-1) to 682 x 10(9) l(-1). High levels of fibrinogen result in improved mechanical stability and improved interaction of platelets with the fibrin network. Clot elastic modulus and platelet contractile force are correlated positively with plasma fibrinogen concentration. However, there was no threshold concentration or ceiling effect concerning the mechanical properties of the clots. In contrast, clotting time assays such as prothrombin time, thrombin time, or activated partial thromboplastin time are influenced by the fibrinogen concentration only at levels below 1 g/l. In linear regression analysis, clot elastic modulus was mainly influenced by fibrinogen concentration (F = 185.4, P < 0.0001), whereas platelet contractile force was influenced by fibrinogen (F = 197.0, P < 0.0001) and platelet count (F = 104.7, P < 0.0001). The present data show that 1 g/l is a threshold fibrinogen concentration for an effect on coagulation assays such as prothrombin time, thrombin time, or activated partial thromboplastin time, but increasing fibrinogen concentrations above this level results in further continuous improvement of mechanical properties of the whole blood clot.
纤维蛋白原浓度会影响血凝块的力学和功能特性。本研究的目的是确定导致全血凝块弹性模量和血小板收缩力以及血浆凝血酶原时间和活化部分凝血活酶时间发生相关变化的纤维蛋白原阈值浓度。我们测量了552名入住外科重症监护病房患者的全血样本中的凝块弹性模量、血小板收缩力及其他止血参数。使用Hemodyne仪器测量血小板收缩力和凝块弹性模量。纤维蛋白原水平在低于0.10至9.44 g/l之间，平均为2.41 g/l。平均血小板计数为203×10⁹ l⁻¹，范围为16×10⁹ l⁻¹至682×10⁹ l⁻¹。高水平的纤维蛋白原可改善力学稳定性以及血小板与纤维蛋白网络的相互作用。凝块弹性模量和血小板收缩力与血浆纤维蛋白原浓度呈正相关。然而，关于凝块的力学特性，不存在阈值浓度或上限效应。相比之下，诸如凝血酶原时间、凝血酶时间或活化部分凝血活酶时间等凝血时间测定仅在纤维蛋白原浓度低于1 g/l时受到影响。在线性回归分析中，凝块弹性模量主要受纤维蛋白原浓度影响（F = 185.4，P < 0.0001），而血小板收缩力受纤维蛋白原（F = 197.0，P < 0.0001）和血小板计数（F = 104.7，P < 0.0001）影响。目前的数据表明，1 g/l是影响凝血酶原时间、凝血酶时间或活化部分凝血活酶时间等凝血测定的纤维蛋白原阈值浓度，但纤维蛋白原浓度高于此水平会导致全血凝块力学特性进一步持续改善。
