Global tests of haemostasis in critically ill patients with severe sepsis syndrome compared to controls


Dr P. W. Collins, Department of Haematology, School of Medicine, Cardiff University and University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK.


Haemostatic changes in septic patients are complex, with both procoagulant and anticoagulant changes. Thirty-eight patients with severe sepsis and 32 controls were investigated by coagulation screens, individual factor assays, calibrated automated thrombography (CAT), whole blood low-dose-tissue factor activated (LD-TFA) Rotem and LD-TFA waveform analysis. Thirty-six of 38 patients had an abnormal coagulation screen. The mean levels of factors II, V (P < 0·05), VII, X, XI and XII, antithrombin and protein C (P < 0·01) was decreased in sepsis compared with controls. The mean factor VIII and fibrinogen level (P < 0·001) was increased. CAT in platelet rich and poor plasma showed a prolonged lag time (P < 0·02), decreased peak thrombin (P < 0·02) and delayed time to peak thrombin (P < 0·001) in sepsis patients, however, the endogenous thrombin potential was equivalent in sepsis and controls. In LD-TFA Rotem, septic patients had delayed clot times (P = 0·04) but an increased maximum velocity of clot formation (P < 0·01) and area under the clot elasticity curve (P < 0·01). LD-TFA waveform analysis showed a delayed onset time but an increased rate of clot formation (P < 0·005). In conclusion, global tests of haemostasis suggest that in this patient group, activation of haemostasis is delayed but once initiated thrombin generation and clot formation are normal or enhanced.