Rapid Estimation of Fibrinogen

COAGULATION AND FIBRINOLYSIS IN INJURED PATIENTS

Serial changes in coagulation and fibrinolysis studied among 42 patients admitted to hospital with a wide variety of injuries are reported. The first hours after trauma are dominated by an acceleration of fibrinolysis (clot lysis) and clotting time which are often followed by an abrupt rebound to prolonged fibrinolysis and normal clotting. Evidence is presented that acceleration of fibrinolysis is due to flooding of the circulation by plasminogen activator and that prolongation is probably due to an inhibitor. A prolonged prothrombin time, increased prothrombin consumption index, an acceleration of the heparin-retarded clotting time, and a fall in the platelet count are also frequent during the first hours after injury. There is evidence also of an early deficiency in factor V and the onset of a fall in factor VII and prothrombin. The following days are characterized by continued prolongation of fibrinolysis, a lengthening of clotting time, and an increased prothrombin consumption index suggestive of a defect in thrombo-plastin generation. Subsequent periods of prolonged fibrinolysis may develop. Prothrombin time often continues prolonged for one to three weeks and may vary phasically; plasma prothrombin and factor VII are reduced but there is now little change in factor V. The platelet count continues to fall for one to three days, then a thrombocytosis develops, often with abnormally high platelet levels, a week or so later. Plasma fibrinogen rises within 24 hours to reach a plateau maximum a few days later and levels remain high for prolonged periods in the severely injured. Various changes are related to or influenced by the severity of trauma. Mechanisms are discussed, including thrombosis in vivo, and reference is made to homeostatic significance and its possible breakdown.

Comparison of fibrin networks in plasma and fibrinogen solution

Mass-Length ratio of fibrin fibres (microT and microP) derived independently from turbidity and permeability respectively, in networks made in fibrinogen solution and plasma, have been compared under similar conditions of clotting. Amount of fibrinogen conversion to fibrin was similar in both systems when high thrombin concentrations were used. But networks in plasma had significantly thicker fibres (higher microT and microP) than those in fibrinogen solution. This difference arises from differing kinetics of fibrin assembly in the two systems. When lower thrombin concentration is used, fibrin fibre thickness (as indicated by microP and microT) is increased in fibrinogen solution but the fibrin content of the network remains unaltered. In plasma, on the other hand, the fibrin content of the network is decreased, microT remains relatively unchanged while microP increases. The thrombin concentration dependence of the fibrin content of the network in plasma and the bimodal distribution of fibrin fibre thickness explain the breakdown in correlation between microP and microT.

A comparison of the erythrocyte sedimentation rate and plasma viscosity in detecting changes in plasma proteins

The Westergren erythrocyte sedimentation rate (ESR) and plasma viscosity were compared in 114 patients and their correlations with total and differential plasma protein fractions were analysed. There is a linear correlation between these two screening tests. Higher correlation coefficients were obtained between the plasma viscosity and fibrinogen and alpha and gamma globulins than with the ESR. Albumin affected the two tests in opposite directions. The ESR was falsely increased by a fall in haemoglobulin even within two standard deviations from the mean. Both tests gave an appreciable number of incorrect values--the plasma viscosity in 21 cases and the ESR in 33. The cause for these is discussed. It is concluded that the plasma viscosity is the more sensitive and reliable measure of changes in acute phase protein reactants and more useful for monitoring clinical progress.

Intraoperative physiologic monitoring and management during hepatic lobectomy using the liver isolation-perfusion technic

The high operative mortality of major hepatic resection for tumor can be improved by a technic of resection using complete vascular isolation and hypothermic perfusion of the liver. Complete clamping of the portal vein, vena cava, and hepatic artery was necessary and well tolerated. Major physiologic, biochemical, and coagulation changes, however, can occur with this technic that requires close monitoring by the anesthesiologist. With astute observation and prompt corrective measures when indicated, these changes can be minimized to enable a safe and smooth resection to be carried out.

Fibrinogen survival and fibrinolysis in acute leukemia

Fibrinogen survival using 125I-labelled homologous fibrinogen was studied in 17 adults with acute leukemia. Five patients in complete remission had normal fibrinogen survival and turnover rate. Five of 6 patients undergoing induction therapy and 4 of 6 in relapse had shortened fibrinogen survival; the turnover rate was increased in all 12 patients. Nine of 12 patients with active disease had elevated levels of fibrinogen degradation products in the serum. Serial coagulation studies did not support the diagnosis of overt disseminated intravascular coagulation. There was no correlation between the morphological type of leukemia, chemotherapy, the presence of fever and sepsis, or liver dysfunction and fibrinogen survival. Other possible causes of the accelerated fibrinogen turnover in patients with active disease are discussed.

Hypofibrinogenemia associated with vincristine and prednisone therapy in lymphoblastic leukemia

Three patients with acute lymphoblastic leukemia and one with lymphosarcoma cell leukemia developed transient hypofibrinogenemia during a course of treatment with vincristine and prednisone. There was no evidence of overt, disseminated intravascular coagulation or significant liver impairment. Fibrinogen survival using homologous-125-I-labelled fibrinogen was measured in two patients; it was moderately shortened in both, perhaps indicating subclinical intravascular coagulation. Rapid lysis of leukemic cells might have been responsible for activating coagulation and fibrinolysis in vivo. These four patients, however, were not different in any clinical or laboratory parameter from nine others with lymphoblastic leukemia similarly treated and investigated without observing any defect in their fibrinogen. There were no bleeding complications and the fibrinogen level became normal within 13 to 30 days.