There will be blood

Everything ECMO 046: Bleeding and ECMO

Author: Dr Zoe Guo
Peer reviewers: Dr Paddy Joyce

The bedside nurse alerts you to a new haemoglobin drop from 90 to 70g/L for a patient who is day 3 on V-A ECMO post cardiac arrest.

You suspect a bleeding complication. 

Q1. How common is a bleeding complication during an ECMO run?

Clinical overt bleeding is the most common complication of ECMO, affecting nearly 60% of patients during ECMO treatment.

Approximately half of these cases meet the criteria for major bleeding as established by the International Society on Thrombosis and Haemostasis (Kalbhenn and Zieger, 2022). Retrospective data showed comparable major bleeding rates between V-A and V-V ECMO patients (Nguyen et al, 2022).  

Major bleeding (Arachchilage et al, 2021) 
1. Fatal bleeding, and/or

2. Bleeding in a critical area or organ, such as intracranial, intraspinal, intraocular, retroperitoneal, intra‐articular or pericardial, or intramuscular with compartment syndrome, and/or

3. Bleeding causing a fall in haemoglobin level of ≥ 20 g/ L or leading to transfusion of two or more units of whole blood or red cells.

Q2. Why is bleeding so common in ECMO patients? 

ECMO significantly perturbs the normal balance of haemostasis through multiple mechanisms (Kalbhenn and Zieger, 2022): 

  • Thrombocytopenia is common due to circuit induced platelet activation and aggregation 
  • Platelet dysfunction due to loss of key platelet surface molecules and P-selectin due to circuit 
  • Shear mediated loss of high molecular weight von Willebrand multimers and acquired von Willebrand syndrome 
  • Circuit induced diffused activation of the coagulation system leads to waste coagulopathy, which is associated with hyperfibrinolysis and factor XIII deficiency 
  • Heparin anticoagulation – recommended by ELSO to be continuously administered during ECMO
  • Coagulopathy due to underlying pathology, e.g., post-cardiac arrest syndrome.

Q3. Where are the common sites of bleeding in a patient on ECMO? 

Common sites of bleeding include (Kawauchi et al, 2022; Nguyen et al, 2022) :

  • ECMO cannulation sites 
  • Intrapulmonary 
  • Gastrointestinal tract 
  • Nasopharyngeal region 
  • Intracranial

Q4. What are the possible causes of anaemia in an ECMO patient? 

Patients on ECMO commonly develop anaemia even without bleeding. The many causes of anaemia include:

  • Decreased production
    • Malnutrition 
    • Bone marrow suppression (e.g., due to medications or critical illness)
  • Increased destruction
    • Haemolysis 
  • Increased loss
    • ECMO-related bleeding complications 
    • Post-operative blood loss 
    • Coagulopathy 
    • Other
      • Stress induced GI bleeding 
      • Frequent blood sampling

Upon exposure of the patient, you noticed that there is ongoing ooze as well as a significant amount of clotted blood around the arterial return cannula.

Figure 1. Cannula site bleeding. Image source: Thakar et al (2001), available at URL:

Q5. What is your action now? 

Consider the following (Alfred Health, 2020; Kalbhenn and Zieger, 2022):

  • Local actions
    • Reinforce dressing/dressing care 
    • Pressure bandage 
    • Surgical revision 
    • Endovascular treatment ie stent graft or embolisation (Zheng et al, 2019)
    • Re-advancing of the arterial return cannula
      • This is rarely performed due to the risks associated with it such as cannulation site infection, bloodstream infection, haematoma and arterial dissection. 
      • This may be performed under strict sterile condition if cannula continues to migrate out with worsening bleeding despite other measures
    • Note: suturing of the site is generally advised against, due to risk of damage to cannulae 
  • Systemic actions
    • Pause heparin 
    • Reverse acidosis and maintain normothermia 
    • Replace clotting element deficiencies and optimise coagulation profile – Platelet >80, fibrinogen >1.5, INR <1.3 
    • Tranexamic Acid 
    • Consider careful use of protamine or recombinant factor VII if uncontrollable bleeding despite optimisation of above
      • This therapy especially has to be weighed carefully against the risk of acute clot formation within the extracorporeal system and possible thrombotic pump failure. 

Q6. What specific advice would you give regarding heparin infusion for this patient?

Reasonable advice includes:

  • Pause heparin until bleeding controlled
  • Vigilant monitoring of circuit health: D-dimer, fibrinogen, plasma free Hb, transmembrane pressure, oxygenation
  • Once bleeding controlled, re-introduce heparin at 500 IU/h and uptitrate as per local protocol 
  • May aim for the lower end of therapeutic APTT range, e.g.; 50-60.

Q7. What is an appropriate “trigger threshold” for blood transfusion in ECMO patients?

Commonly, clinicians use a trigger of 80g/L (Tenure et al, 2020).

Blood transfusion is common in ECMO patients, as evidenced by almost 90% of all patients receiving at least one packed red blood cell transfusion during VV-ECMO support (Kalbhenn and Zieger, 2022). Despite this, transfusion thresholds for patients on ECMO support are currently subject to variation due lack of expert consensus and lack of robust, high-quality evidence. Despite a recent meta-analysis indicating statistically significant benefits associated with restricted transfusion, like reduced risks of acute kidney injury and mortality, these findings were notably influenced by considerable heterogeneity, methodological limitations, and publication bias in the analyzed studies (Abbasciano et al, 2020).


  1. Abbasciano RG, Yusuff H, Vlaar APJ, Lai F, Murphy GJ. Blood Transfusion Threshold in Patients Receiving Extracorporeal Membrane Oxygenation Support for Cardiac and Respiratory Failure-A Systematic Review and Meta-Analysis. J Cardiothorac Vasc Anesth. 2021 Apr;35(4):1192-1202. doi: 10.1053/j.jvca.2020.08.068. Epub 2020 Sep 10. PMID: 33046363.
  2. Alfred Health (2020, April 18). Anticoagulation & bleeding. ECMO.ICU. Retrieved August 16, 2023, from 
  3. Arachchillage, D.J., et al. Impact of major bleeding and thrombosis on 180-day survival in patients with severe COVID-19 supported with veno-venous extracorporeal membrane oxygenation in the United Kingdom: a multicentre observational study. Br J Haematol, 196: 566-576. PMID: 34622443 PMCID: PMC8653259
  4. Kalbhenn J, Zieger B. Bleeding During Veno-Venous ECMO: Prevention and Treatment. Front Med (Lausanne). 2022 May 23;9:879579. doi: 10.3389/fmed.2022.879579. PMID: 35677828; PMCID: PMC9168900.
  5. Kawauchi, A, Liu, K, Nakamura, M, Suzuki, H, Fujizuka, K, Nakano, M. Risk factors for bleeding complications during venovenous extracorporeal membrane oxygenation as a bridge to recovery. Artif. Organs. 2022; 46: 1901–1911. PMID: 35451086 PMCID: PMC9543801
  6. Nguyen TP, et al. Major Bleeding in Adults Undergoing Peripheral Extracorporeal Membrane Oxygenation (ECMO): Prognosis and Predictors. Crit Care Res Pract. 2022 Jan 15;2022:5348835. doi: 10.1155/2022/5348835. PMID: 35075397; PMCID: PMC8783736.
  7. Tenure, R. (2020). Blood Transfusion in Extracorporeal Membrane Oxygenation—Defining Thresholds and Unresolved Questions. Journal of Cardiothoracic and Vascular Anaesthesia, 35(4), 1203-1204. PMID: 33293218
  8. Zheng, L., et al. Interventional treatment of bleeding complications due to percutaneous acannulation for peripheral extracorporeal membrane oxygenation. Diagnostic and Interventional Imaging, 2019, 100(6), 337-345, ISSN 2211-5684, PMID: 30691971

All case-based scenarios on INTENSIVE are fictional. They may include realistic non-identifiable clinical data and are derived from learning points taken from clinical practice. Clinical details are not those of any particular person; they are created to add educational value to the scenarios.

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