Clotting analysis of blood samples from intensive care unit patients.

Abstract

Introduction: Patients in the intensive care unit have complex haemostatic changes, which may be either procoagulant or anticoagulant. Global assays may reflect a patient’s net haemostatic balance and can contribute to pro- or anti-coagulant assessment. In this project, global assays were used to investigate both coagulation and fibrinolysis in samples taken from intensive care unit patients.

Materials and Methods: Comparative clotting analysis was carried out on whole blood and plasma samples from twelve samples from intensive care unit patients. Nine haemophiliac samples and 14 healthy individual samples were used as controls. Several assays were used to assess coagulation in these sample groups. These included coagulation screens, individual factor assays and global assays [calibrated automated thrombography, whole blood and plasma low- dose tissue factor activated rotational thromboelastometry and the clot formation and lysis assay].

Results: Clot initiation in both whole blood and plasma analysis was prolonged in the intensive care unit samples. This was observed in the global assay analysis and was elucidated by the standard laboratory tests such as the clotting screens and the individual factor assays. However, once initiation commenced, the intensive care unit samples showed a clot formation comparable to that seen in healthy volunteers.

Conclusion: Clot formation in intensive care unit patients is abnormal compared to that observed in healthy volunteer samples. Several factors such as the fibrinogen and procoagulant factors influence coagulation and the rate of thrombin production. The clot stability in intensive care unit samples was found to be more robust in comparison to that observed in the healthy volunteer sample group. This study showed that the initiation of coagulation is delayed intensive care unit patient samples but, once started, clot formation was comparable to that in healthy volunteer samples.