Prothrombin index (PTI)
Prothrombin index (PTI) is used to assess the external blood coagulation pathway state. Allows detection of hemostasis disorders, bleeding risk assessment, and anticoagulant therapy efficacy monitoring.
Test composition:
- Material: venous blood
- Method: coagulometric method
- Measured indicator: ratio of control prothrombin time to patient blood clotting time, expressed as percentage
- Used together with PT and INR for comprehensive coagulation system assessment
- Deviation causes: reduced PTI — elevated blood clotting. Elevated — coagulation factor deficiency, liver diseases, or anticoagulant intake.
Biomaterial: Venous blood
- Draw blood fasting
- Exclude alcohol 24 hours before
- Avoid physical activity and stress before testing
Medications:
Inform physician of anticoagulant, antiplatelet, or hormonal drug intake before testing
Prescribed for:
- Suspected blood clotting disorders
- Bleeding or thrombosis tendency
- Liver diseases
- Anticoagulant therapy monitoring
- Preoperative preparation
Recommended for:
- Patients with hemostasis disorders
- People with cardiovascular diseases
- Pre-surgery patients
Reference values depend on laboratory methodology and are indicated on result form.
Deviations require physician consultation and comprehensive assessment.
Note: PTI evaluated together with other coagulation indicators and not used as
standalone diagnostic criterion.
With deviations, consultation with general practitioner, hematologist, or cardiologist is recommended.
