Difference Between Prothrombin and Partial Thromboplastin Time

When a myocardial infarction or a stroke occurs, or in any case where a thrombus is threatening to dislodge in the system, it is important to apply anti-coagulation therapy. Coumadin (Warfarin) and Heparin are two of the most common drugs used a hospital setting  in order to keep the blood from clotting. Though these are effective in episodes of myocardial infarction or in the event of a stroke, it is still important to have a baseline measurement in order to determine if the medication needs to be stopped or not. Without any measurement of baseline values, the patient will be prone to bleeding and may even experience more damage.

Two of the most effective measurements relating to anti-coagulants are prothrombin time and partial thromboplastin time. PT and PTT are always different in terms of the coagulation process.

PT or prothrombin time is derived from the prothrombin ratio along with the international normalized ratio to measure the extrinsic coagulation pathway. PT also measures the clotting factors I, II V VII and X. PT is also the indicator for Warfarin levels in the body, as well as the vitamin K status. The normal value for PT is 11-16 seconds.

The rationale behind the number of clotting factors checked by PT is the fact that prothrombin is factor II of the clotting factors and thus serves as the one for checking the other four clotting factors. Abnormality in the PT can be caused by liver problems or a lack of any of the clotting factors mentioned above, such as in cases of hemophilia. If the patient is using a lot of his clotting factors concentrated in a specific area rather than circulating around the body, it could be caused by DIC or disseminated intravascular coagulation, a complication commonly found in pregnant women.

On the other hand, PTT, or the partial thromboplastin time, is the measurement of the intrinsic coagulation pathway and the common coagulation pathway. This also measures the level of Heparin needed in the body if the patient is on anti-coagulation therapy. Unlike PT, which gives us an idea of how much Warfarin to use, PTT measures Heparin. The normal value for PTT is within the 25-39 second mark. Within this range, it is important to see clotting factors I,  II, V, VIII, IX, X, XI and XII. Although PTT can detect a number of clotting factors, it can’t detect clotting factors VII and XIII.

Typically, PTT and PT are conducted at the same time in order to trace the source of the disease if clotting factors are lacking or if clotting factors are being used up faster than they should be. In medicine, it is important to have a good grasp of data collection. This is the reason why PT and PTT make everything easier for physicians and nurses to deliver the best healthcare possible in a healthcare facility.

1. PT and PTT are used in the practice of medicine to trace bleeding problems.
2. PT stands for prothrombin time and is used to ascertain whether the dosage of Warfarin needs to be adjusted or not. Heparin is measured by PTT, which stands for partial thrombpoplastin time.
3. clotting factors II, V, VII and X are checked by PT while clotting factors I, II, V, VII, IX, XI and XII are measured by PTT.
4. Both are used in order to identify what type of hemophilia is afflicting a patient, or for other bleeding problems.
5. PT measures extrinsic coagulation while PTT measures intrinsic coagulation.