Management of Thrombocytopenia in ECMO Patients
Maintain platelet count >100,000/μL through aggressive platelet transfusion while continuing heparin anticoagulation (ACT 180-220 seconds), as stopping anticoagulation risks catastrophic circuit thrombosis despite bleeding concerns. 1, 2
Core Management Strategy
The fundamental challenge in ECMO is managing simultaneous thrombotic and bleeding risks created by blood exposure to large foreign surface areas. 1, 2 The American Heart Association explicitly recommends maintaining platelet count >100,000 per mm³ in ECMO patients, particularly those with postcardiotomy support or ongoing bleeding risk. 1, 2
Anticoagulation Protocol During Thrombocytopenia
Continue heparin anticoagulation targeting ACT 180-220 seconds even with severe thrombocytopenia, while providing platelet transfusion support. 1, 2 Stopping anticoagulation risks catastrophic outcomes—autopsy studies show one-third of ECMO patients develop venous thrombus and systemic emboli, most undetected before death. 1, 2
Check ACT hourly and adjust heparin infusion accordingly, but never rely on ACT alone—confirm with anti-Factor Xa levels (target 0.3-0.7 U/mL) and PTT (target 1.5-2.5 times control) at least daily. 1
Monitor daily: anti-FXa levels, PT, PTT, fibrinogen, platelet count, hemoglobin, hematocrit, and antithrombin III levels. 1
Visually inspect the ECMO circuit regularly for clot formation regardless of laboratory values. 1, 2
Comprehensive Hematologic Support Targets
Beyond platelets, maintain these specific thresholds to optimize hemostasis: 1, 2
- Hemoglobin >10 mg/dL with packed red blood cell transfusion 1, 2
- Fibrinogen >200 mg/dL by replacing with cryoprecipitate or fibrinogen concentrate 1, 2
- Antithrombin III >1 U/mL by supplementing with fresh frozen plasma or AT III concentrate 1, 2
Antithrombin III Deficiency Management
- Suspect AT III deficiency if escalating heparin doses are needed to maintain target ACT, especially in infants <1 year who commonly develop this deficiency. 1, 2
- Transfuse fresh-frozen plasma or supplement with AT III concentrate to correct deficiency. 1
- Perform follow-up laboratory testing to confirm correction of the coagulation defect. 1
Bleeding Control Hierarchy
Every effort must be made to identify and surgically control bleeding sites—this is the single most important intervention for bleeding on ECMO. 1, 2 Ongoing bleeding despite transfusion support is associated with poor survival. 1, 2
Pharmacologic Adjuncts for Persistent Bleeding
Consider epsilon-aminocaproic acid (EACA) for persistent bleeding despite surgical hemostasis and correction of coagulation deficiencies: loading dose 100 mg/kg followed by 30 mg/kg/hour infusion for up to 72 hours. 1, 2
Recombinant Factor VIIa (90 μg/kg) may reduce bleeding but carries significant thrombotic risk, including oxygenator occlusion requiring emergent circuit change and limb ischemia requiring amputation—reserve for life-threatening hemorrhage only. 1, 2
Alternative Strategies for High-Risk Bleeding Patients
Heparin-Bonded Circuits with Minimal Anticoagulation
- Consider heparin-bonded ECMO circuits with minimal heparinization as a strategy to decrease bleeding risk in high-risk patients. 1, 2
- Small series show some patients can be maintained for extended periods with reduced or no systemic heparin using these circuits. 1, 2
- However, thromboembolic complications remain common: limb ischemia (70%), oxygenator failure (43%), cerebrovascular accidents (10%), and intracardiac thrombus (20%). 1
Alternative Anticoagulants for Heparin-Induced Thrombocytopenia
- Argatroban can be used if heparin-induced thrombocytopenia (HIT) is suspected, with average maintenance dose of 0.1 mg/kg/min. 1, 3
- Bivalirudin is another alternative, though studies show no difference in thrombotic or bleeding complications compared to heparin. 1
Evidence on Restrictive Platelet Transfusion
Recent research challenges the >100,000/μL threshold in specific contexts:
- A 2025 pediatric study found that severe thrombocytopenia (<50,000/μL) occurred in 56% of platelet counts during ECMO but was not associated with increased bleeding in the subsequent 6 hours (18% vs 20%, p=0.95). 4
- However, thrombocytopenia <100,000/μL significantly increases bleeding risk—mild thrombocytopenia increases bleeding events by 61%, while moderate and severe increase risk by approximately 90%. 5
- A linear relationship exists: each 10,000/μL decrease in platelet count increases bleeding risk by 3.7%. 5
Despite this research, the guideline recommendation of maintaining platelets >100,000/μL remains the standard of care, particularly for postcardiotomy ECMO patients. 1, 2
Special Considerations for Postcardiotomy ECMO
For patients who cannot be weaned from cardiopulmonary bypass, forego the loading dose of heparin before ECMO initiation, as the patient should already be suitably anticoagulated and additional heparin increases bleeding risk. 1, 2
Postcardiotomy ECMO patients have greatly increased bleeding risk, especially those in whom heparin was not reversed after bypass. 1
Critical Pitfalls to Avoid
- Never discontinue anticoagulation based solely on thrombocytopenia—provide platelet transfusion support instead. 2
- Do not rely on ACT alone—confirm with anti-Factor Xa and PTT levels. 2
- Do not normalize platelet counts as a treatment goal—target is >100,000/μL to reduce bleeding risk while maintaining anticoagulation. 2
- Do not ignore antithrombin III deficiency, particularly in infants, as this causes heparin resistance. 2