Incidence, kinetics, and clinical impact of thrombocytopenia in venovenous ECMO: insights from the multicenter observational PROTECMO study

Critical Care volume 29, Article number: 349, Published: 07 August 2025

Background

Thrombocytopenia is a recognized risk factor for bleeding during extracorporeal membrane oxygenation (ECMO). This study determines the incidence, risk factors, and clinical relevance of thrombocytopenia and platelet transfusions during venovenous (VV) ECMO.

Methods

The multicenter, prospective observational PROTECMO study included 652 adult patients who received VV ECMO for respiratory failure. Thrombocytopenia was classified as mild (100–149·10⁹/L), moderate (50–99·10⁹/L), or severe (< 50·10⁹/L). Bleeding events were evaluated using a modified Bleeding Academy Research Consortium score. Cox proportional hazards and logistic regression analyses were done to identify predictors, and quantify the association between platelet counts and bleeding risk.

Results

A total of 182 patients (27.9%) had thrombocytopenia at baseline (mild in 14.7%, moderate in 8.7%, and severe in 4.4%). Thrombocytopenia during ECMO, at least once in 80.2% of patients, was mild in 21.3% of cases, moderate in 32.2%, and severe in 26.7%. A 10·10⁹/L decrease in platelet count was associated with a 3.7% (95% CI: 2.4–5.0%) increase in risk of bleeding. There was no strong evidence of nonlinear relationship within the platelet count range between 25,000 and 300,000. This relation remained consistent across all ECMO weeks. Mild thrombocytopenia increased the risk of experiencing a bleeding event by 61% (hazard ratio (HR) 1.611, 95% CI 1.230–2.109, p = 0.0005), while moderate and severe thrombocytopenia increased the risk by roughly 90% (moderate: HR 1.944 (CI 1.484–2.545), p < 0.0001; severe: HR 1.876 (CI 1.275–2.7680), p = 0.0014). The risk for thrombocytopenia < 100·10⁹/L during ECMO significantly increased with ICU days prior to ECMO start, postoperative admission, immunocompromised state, renal replacement therapy, septic shock, low hemoglobin, and circuit exchange.

Conclusions

Thrombocytopenia is highly prevalent in VV ECMO, and associated with a significant increase in the risk of bleeding, and a reduction in 6-month survival, particularly at platelet counts below 100·10⁹/L. Further research is needed to better define the outcomes associated with specific thresholds for transfusion of platelets.

 

Bleeding and thrombotic events in patients with severe COVID-19 supported with extracorporeal membrane oxygenation: a nationwide cohort study

 

Intensive Care Medicine volume 48, pages 1039–1052 (2022) Published: 13 July 2022

 

Purpose

To describe bleeding and thrombotic events and their risk factors in patients receiving extracorporeal membrane oxygenation (ECMO) for severe 

coronavirus disease 2019

 (COVID-19) and to evaluate their impact on in-hospital mortality.

Methods

The ECMOSARS registry included COVID-19 patients supported by ECMO in France. We analyzed all patients included up to March 31, 2022 without missing data regarding bleeding and thrombotic events. The association of bleeding and thrombotic events with in-hospital mortality and pre-ECMO variables was assessed using multivariable logistic regression models.

Results

Among 620 patients supported by ECMO, 29% had only bleeding events, 16% only thrombotic events and 20% both bleeding and thrombosis. Cannulation site (18% of patients), ear nose and throat (12%), pulmonary bleeding (9%) and intracranial hemorrhage (8%) were the most frequent bleeding types. Device-related thrombosis and pulmonary embolism/thrombosis accounted for most of thrombotic events. In-hospital mortality was 55.7%. Bleeding events were associated with in-hospital mortality (adjusted odds ratio (adjOR) = 2.91[1.94–4.4]) but not thrombotic events (adjOR = 1.02[0.68–1.53]). Intracranial hemorrhage was strongly associated with in-hospital mortality (adjOR = 13.5[4.4–41.5]). Ventilation duration before ECMO ≥ 7 days and length of ECMO support were associated with bleeding. Thrombosis-associated factors were fibrinogen ≥ 6 g/L and length of ECMO support.

Conclusions

In a nationwide cohort of COVID-19 patients supported by ECMO, bleeding incidence was high and associated with mortality. Intracranial hemorrhage incidence was higher than reported for non-COVID patients and carried the highest risk of death. Thrombotic events were less frequent and not associated with mortality. Length of ECMO support was associated with a higher risk of both bleeding and thrombosis, supporting the development of strategies to minimize ECMO duration.

 

 

Comparison of Bivalirudin Versus Heparin for Maintenance Systemic Anticoagulation During Adult and Pediatric Extracorporeal Membrane Oxygenation

 

Seelhammer, Troy G.; Bohman, John K.; Schulte, Phillip J.; Hanson, Andrew C.; Aganga, Devon O.

Critical Care Medicine: September 2021 - Volume 49 - Issue 9 - p 1481-1492

OBJECTIVES: 

To provide a comparative analysis of conventional heparin-versus bivalirudin-based systemic anticoagulation in adult and pediatric patients supported on extracorporeal membrane oxygenation.

DESIGN: 

Retrospective chart review study of adult and pediatric patients receiving extracorporeal membrane oxygenation from January 1, 2014, to October 1, 2019.

SETTING: 

A large, high-volume tertiary referral adult and pediatric extracorporeal membrane oxygenation center.

PATIENTS: 

Four hundred twenty-four individuals requiring extracorporeal membrane oxygenation support and systemically anticoagulated with either unfractionated heparin (223 adult and 65 pediatric patients) or bivalirudin (110 adult and 24 pediatric patients) were included.

INTERVENTIONS: 

None.

MEASUREMENTS AND MAIN RESULTS: 

Digital data abstraction was used to retrospectively collect patient details. The majority of both groups were cannulated centrally (67%), and the extracorporeal membrane oxygenation type was predominantly venoarterial (84%). The adult bivalirudin group had a greater occurrence of heparin-induced thrombocytopenia (12% vs 1%; p < 0.01) and was more likely to require postcardiotomy extracorporeal membrane oxygenation (36% vs 55%; p < 0.01). There were no statistical differences between the groups in regards to age, sex, and extracorporeal membrane oxygenation initiation location. The main finding was a reduced mortality in the adult bivalirudin group (odds ratio, 0.39; p < 0.01), whereas no difference was noted in the pediatric group. A significant reduction in the composite transfusion requirement in the first 24 hours was noted in the pediatric bivaluridin group with an odds ratio of 0.28 (p = 0.02). Groups did not differ in regard to laboratories per day, anticoagulant dose adjustments, or ischemic complications.

CONCLUSIONS: 

When compared with heparin-based systemic anticoagulation, bivalirudin demonstrated feasibility and safety as established by the absence of increases in identifiable adverse outcomes while manifesting substantial improvements in hospital mortality in adult patients. Further studies are necessary to corroborate these findings and further elucidate the role of bivalirudin during extracorporeal membrane oxygenation support.