Hemostasis Coagulogram

Introduction to the study of the coagulation system

In official clinical guidelines and medical nomenclature, the study of the hemostatic system is designated by the rigorous term — study of the blood coagulation system. In the registry of medical services, this procedure is recorded under the unique code B03.005.006 and is named "Coagulogram (screening study of the hemostatic system)."

This is a baseline diagnostic tool in pathophysiological and clinical practice. It does not cover all the subtleties of cellular composition, the fibrinolytic, or exclusively anticoagulation systems, but focuses precisely on the balance and functional activity of the factors ensuring adequate blood coagulation.

Clinical goals of performing a coagulogram

Ordering this screening test pursues several key clinical objectives:

1. Clarification of the state of hemostasis. This is a global goal allowing the physician to obtain a baseline understanding of how effectively the patient's blood coagulation system is currently functioning.
2. Assessment of the risk of hemorrhagic complications. Identifying deficiencies or dysfunction of coagulation factors is critically important to prevent spontaneous bleeding or massive blood loss during medical interventions.
3. Assessment of liver function. Since most protein coagulation factors are synthesized specifically in hepatocytes, changes in the coagulogram serve as a reliable indicator of the functional state of the liver.

The analysis acquires particular importance prior to aggressive treatment methods. For example, performing a coagulogram is strictly indicated in the period prior to the initiation of antineoplastic therapy.

Mandatory test parameters

To obtain an accurate picture of hemostasis, the coagulogram must include a strictly defined set of mandatory parameters tested in whole blood or plasma. These include:

• Prothrombin (thromboplastin) time (or prothrombin index) — evaluated in blood or plasma.
• aPTT (activated partial thromboplastin time) — may be used alongside prothrombin time.
• INR (international normalized ratio) — a standardized indicator for universal assessment.
• Thrombin time — tested directly in blood.
• Fibrinogen level — concentration of the main precursor protein of the fibrin clot (in blood).

Monitoring regimen and level of evidence

In clinical practice, a coagulogram is not exclusively a one-time test. The monitoring regimen involves evaluating indicators dynamically. At the same time, a strict frequency of testing is not regulated by days or weeks — studies are repeated as clinically indicated, guided by changes in the patient's condition or the stages of ongoing therapy.

From the perspective of evidence-based medicine, the recommendations for performing this screening test have the following status:

• When assessing risks prior to antineoplastic therapy: Level of recommendation validity C (Level of Evidence 5).
• During dynamic monitoring of liver function and the coagulation system: Level of recommendation validity C (Level of Evidence 4).

Class and exam questions

What else to study on this topic

• Pathophysiology of hemorrhagic complications during antineoplastic therapy
• The relationship between fibrinogen levels and bleeding risk
• Clinical difference between prothrombin time and activated partial thromboplastin time (aPTT)
• INR (international normalized ratio) as a standardization criterion
• Mechanisms of hepatic synthesis of blood coagulation factors

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.