Understanding Disseminated Intravascular Coagulation (DIC)- Clotting Mechanisms, Diagnostic Indicators, and Associated Conditions

Clotting Mechanism

The clotting process has four mechanisms. Vasoconstriction is the first response after vessel injury and is mediated by Endothelin-1 (Garmo et al., 2021). The second step is platelet adhesion, consisting of the adhesion of platelets to the exposed subendothelial collagen (Garmo et al., 2021). Consistently, the third stage is platelet activation, characterized by an irreversible change in the shape of platelets and secretion of cytoplasmic granules. Finally, platelet activation is the last step. This is mediated through proteolytic cleavage by thrombin (Garmo et al., 2021). The following stages involve activating clotting factors, converting prothrombin to thrombin, and converting fibrinogen to fibrin, stabilizing the clot (Garmo et al., 2021).

Prolonged PT and aPTT Tests

Prolonged PT and aPTT are used to monitor a patient’s response to heparin therapy, evaluation of hemorrhage, and preoperative screening (Harrold & Oladipo, 2018). Prolonged PT and aPTT will reveal spontaneous bleeding, liver disease, and Vitamin K deficiency (Harrold & Oladipo, 2018). This indicated a problem with a common pathway factor.

Fibrin Degradation and Split Products in DIC Patients

Fibrin split products are used to diagnose DIC. DIC happens due to systemic activation of the clotting mechanism. The result is fibrin deposition, causing microvascular thrombi in several organs (Papageorgiou et al., 2018). In DIC, there is an inefficiency to downgrade the fibrinolytic process resulting in the accumulation of fibrin split products in the bloodstream (Papageorgiou et al., 2018).

Two Additional Causes of DIC

Cancer is a cause of DIC. In cancers, there is overexpression of the Tissue Factor (TF). The Tissue factor is a significant activator of the coagulation process (Papageorgiou et al., 2018). Overexpression of TF will trigger the coagulation process in DIC. The second cause is sepsis. The formation of Phospholipid microparticles (MPs) is enhanced in sepsis (Papageorgiou et al., 2018). MPs result in the expression of TF, which activates the coagulation process.

References

Garmo, C., Bajwa, T., & Burns, B. (2021, September 8). Physiology, clotting mechanism – StatPearls – NCBI bookshelf. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK507795/

Harrold, I. M., & Oladipo, O. (2018). Elevated PT and aPTT. Clinical chemistry, 64(12), 1790-1790. https://doi.org/10.1373/clinchem.2018.290361

Papageorgiou, C., Jourdi, G., Adjambri, E., Walborn, A., Patel, P., Fareed, J., Elalamy, I., Hoppensteadt, D., & Gerotziafas, G. T. (2018). Disseminated intravascular coagulation: An update on pathogenesis, diagnosis, and therapeutic strategies. Clinical and Applied Thrombosis/Hemostasis, 24(9_suppl), 8S-28S. https://doi.org/10.1177/1076029618806424