From the Guidelines
Heparin-induced thrombocytopenia (HIT) can resolve with plasma exchange (PLEX) while on extracorporeal membrane oxygenation (ECMO), but this approach is not universally effective and should be part of a comprehensive treatment strategy. The primary management of HIT on ECMO involves immediate discontinuation of all heparin products and switching to non-heparin anticoagulants such as argatroban, bivalirudin, or fondaparinux 1. PLEX can be added as an adjunctive therapy to accelerate the clearance of pathogenic anti-PF4/heparin antibodies from circulation. Typically, PLEX is performed daily or every other day for 3-5 sessions, with each session exchanging 1-1.5 plasma volumes.
Key Considerations
- The effectiveness of PLEX varies between patients, with some showing rapid improvement in platelet counts while others experience minimal benefit 1.
- PLEX works by physically removing the antibodies responsible for HIT, potentially reducing the time to platelet count recovery from weeks to days.
- However, PLEX alone is insufficient without alternative anticoagulation, and the technical challenges of performing PLEX while on ECMO must be carefully managed to prevent circuit complications.
- Monitoring platelet counts daily is essential to assess response to therapy, and treatment should continue until platelet counts normalize and clinical thrombotic events resolve 1.
Anticoagulation Management
- For argatroban, a starting infusion of 0.2 μg/kg/min is recommended for anticoagulation in patients with HIT on ECMO, as higher doses may increase the risk of bleeding complications 1.
- The dose of argatroban should be adjusted to achieve a target aPTT of 2–2.5 times above the normal level, and clinicians should be aware of the risk of underdosing due to aPTT confounding, especially when treating patients with HIT 1.
Conclusion is not allowed, so the response is ended here.
From the Research
HIT Resolution with PLEX on ECMO
- The use of therapeutic plasma exchange (TPE) in patients with heparin-induced thrombocytopenia (HIT) on extracorporeal membrane oxygenation (ECMO) has been demonstrated to be effective in managing the condition 2.
- A study found that TPE can be used to facilitate heparin exposure during cardiopulmonary bypass surgery (CPB) in patients with HIT, and it is also used as initial therapy or treatment of refractory HIT 3.
- However, the management of HIT in patients on ECMO requires careful consideration of anticoagulation management, circuit size, and flow rates, as well as the risk of air embolus 2, 4.
- There are case reports of patients with HIT on ECMO who were treated with TPE and alternative anticoagulants, such as bivalirudin, with successful outcomes 5, 6.
- The optimal application of TPE and intravenous immune globulin (IVIG) in the treatment of HIT is unknown, and outcomes data are limited, highlighting the need for further research 3.