What is the plasma protamine test for

The plasma protamine test is mainly used to detect fibrin monomers or fibrin degradation products in the blood, and is commonly used clinically to diagnose disseminated intravascular coagulation (DIC) or assess thrombus risk. The test results are affected by factors such as blood collection procedures, anticoagulant ratios, and sample storage conditions.

1. DIC screening:

Plasma protamine test is an important auxiliary tool for diagnosing disseminated intravascular coagulation. When extensive microthrombi form in blood vessels, fibrin monomers combine with fibrin degradation products to form soluble complexes. This experiment uses protamine to precipitate and color the complexes, and a positive result suggests the possibility of DIC. It is necessary to make a comprehensive judgment based on indicators such as platelet count and D-dimer.

2. Thrombosis monitoring: A positive

test may reflect hypercoagulability or a tendency towards thrombosis. This test can detect abnormal coagulation activation early in high-risk populations such as surgical patients and malignant tumor patients with thrombosis. However, attention should be paid to the possibility of false positives, such as sample hemolysis and rheumatoid factor interference.

3. Heparin therapy evaluation: Patients receiving heparin anticoagulant therapy may experience heparin induced thrombocytopenia HIT, in which plasma protamine test can assist in determining the presence of platelet activation and microthrombus formation. But diagnosis requires a combination of 4T score and anti PF4 heparin antibody testing.

4. Obstetric complications:

Obstetric emergencies such as gestational hypertension and placental abruption are prone to coagulation dysfunction. This experiment can quickly reflect changes in fibrinogen monomer levels and has important value for early identification of acute DIC such as amniotic fluid embolism. Positive results require immediate initiation of coagulation support therapy.

5. Sample quality control:

The accuracy of detection depends on standardized sampling. When collecting blood, a 3.2% sodium citrate anticoagulant tube should be used, and the ratio of blood sample to anticoagulant should be strictly maintained at 9:1. After mixing well, it should be sent for testing immediately. Sample storage for more than 4 hours or incomplete centrifugation may result in false negatives, while hemolytic samples are prone to false positives. Before and after the plasma protamine test, it is necessary to maintain a normal daily routine and avoid vigorous exercise that may affect coagulation status. Before testing, there is no need to fast, but the doctor should be informed of recent medication history, especially the use of anticoagulant drugs. If the results are abnormal, it is recommended to conduct further examinations such as coagulation tests and thromboelastography. Pay attention to observing bleeding tendencies or thrombotic symptoms in daily life, such as gum bleeding, lower limb swelling, etc., and seek medical attention for follow-up examination in a timely manner.