From the Guidelines
For a critically elevated PTT >139 seconds on heparin, immediately hold the heparin infusion and notify the physician. This is based on the most recent and highest quality evidence available, which emphasizes the importance of promptly addressing excessive anticoagulation to minimize the risk of bleeding complications 1.
Key Considerations
- The therapeutic range for PTT on heparin is typically between 60-80 seconds or 1.5-2.5 times the baseline, as suggested by guidelines for managing patients with ST-elevation myocardial infarction 1.
- After stopping the heparin infusion, it is recommended to recheck the PTT in 4-6 hours to assess the need for further intervention.
- If the patient is experiencing bleeding, protamine sulfate may be administered as an antidote at a dose of 1 mg per 100 units of heparin received in the previous 2-3 hours (maximum 50 mg), as strongly recommended by guidelines for reversal of antithrombotics in intracranial hemorrhage 1.
- Once the PTT decreases to the therapeutic range, heparin can be restarted at a reduced rate, usually 2-4 units/kg/hour less than the previous infusion rate, to maintain appropriate anticoagulation levels while minimizing the risk of bleeding.
Monitoring and Adjustment
- Regular PTT monitoring (every 6 hours initially, then daily when stable) is essential to maintain appropriate anticoagulation levels and adjust the heparin dose as needed.
- Factors affecting heparin sensitivity, such as renal dysfunction, advanced age, low body weight, and concurrent medications, should be considered when adjusting the heparin dose to minimize the risk of bleeding complications.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Critical PTT >139 on Heparin
- A critical PTT (partial thromboplastin time) value of greater than 139 seconds on heparin indicates a potential coagulation abnormality that may require attention 2.
- The management of such a condition may involve the use of fresh frozen plasma (FFP) to "normalize" the heparin-ACT dose-response curve in heparin-resistant patients and to lessen total heparin requirements during cardiopulmonary bypass (CPB) 2.
- However, the effectiveness of FFP in correcting coagulopathy is still a topic of debate, with some studies suggesting that it may not be effective in normalizing prothrombin time (PT) and international normalized ratio (INR) values in patients with mild coagulation abnormalities 3.
- Other studies have investigated the role of protamine sulfate in reversing the effects of heparin, with findings suggesting that it may not fully neutralize the anticoagulant activity of low molecular weight heparins (LMWH) 4.
- The use of protamine sulfate may also be contraindicated in certain situations, such as heparin-induced thrombocytopenia, due to its potential to exacerbate the condition 5.
- In some cases, the treatment of postperfusion bleeding may involve the use of epsilon-aminocaproic acid, cryoprecipitate, fresh-frozen plasma, and protamine sulfate, depending on the underlying coagulation disorder 6.