A physiology-guided, multimodal monitoring framework that integrates pressure, flow, volumetric, and microcirculatory information with serial echocardiography is proposed to guide individualized clinical decision-making and avoid delayed recognition of ventricular failure or regional hypoperfusion.
Abstract
Extracorporeal membrane oxygenation (ECMO) is an established life-saving therapy for severe acute respiratory distress syndrome and cardiogenic shock, yet it profoundly alters cardiopulmonary physiology and challenges conventional hemodynamic monitoring. Both venovenous (VV) and venoarterial (VA) ECMO modify venous return, ventricular loading conditions, pulmonary vascular resistance, and ventriculo-arterial coupling, leading to complex interactions between native and extracorporeal circulation. As a result, many standard monitoring techniques, particularly indicator-based and pressure-derived methods, lose validity or require careful reinterpretation under ECMO conditions. This review summarizes current evidence on hemodynamic monitoring during VV- and VA-ECMO and critically evaluates commonly used modalities, including echocardiography, invasive arterial pressure monitoring and pulse wave analysis, transpulmonary thermodilution, pulmonary artery catheterization, and microcirculatory monitoring. We highlight configuration-specific pathophysiology, key methodological limitations, and typical sources of misinterpretation for each technique. Particular emphasis is placed on the dissociation between macrocirculatory variables and tissue perfusion, the impact of parallel circulation and flow mixing in VA-ECMO, and the persistence of occult shock despite apparently adequate systemic targets. We propose a physiology-guided, multimodal monitoring framework that integrates pressure, flow, volumetric, and microcirculatory information with serial echocardiography. No single monitoring modality adequately captures the hemodynamic complexity of ECMO patients; instead, informed interpretation of complementary parameters and longitudinal trends is essential to guide individualized clinical decision-making and avoid delayed recognition of ventricular failure or regional hypoperfusion.
An obese female patient with ischemic cardiomyopathy was placed on venoarterial extracorporeal membrane oxygenation (VA-ECMO) for cardiogenic shock after in-hospital cardiac arrest. Despite biventricular recovery by day 3, VA-ECMO weaning was deferred due to persistent severe hypoxemia. To investigate cardiopulmonary pathophysiology, electrical impedance tomography (EIT) assessment was performed. Electrical impedance tomography-guided positive end-expiratory pressure (PEEP) titration confirmed that set PEEP minimized lung collapse, reducing the likelihood that intrapulmonary shunt was the primary cause of hypoxemia. With ventilator settings unchanged, EIT-based lung perfusion was assessed at VA-ECMO blood flows of 4.2 and 2.0 L/min. At lower (2.0 L/min) VA-ECMO blood flow, ventilation/perfusion (V/Q) matching significantly improved, primarily due to increased transpulmonary blood flow, which was redistributed from dorsal to ventral regions. Thus, by bypassing pulmonary circulation, higher VA-ECMO blood flow worsened V/Q mismatch and significantly contributed to hypoxemia. With these insights and after a successful weaning trial the next day, VA-ECMO was removed, and extubation followed 10 days later. To our knowledge, this is the first report of EIT enabling bedside assessment of the impact of VA-ECMO on regional lung perfusion, revealing an underrecognized iatrogenic contributor to hypoxemia. These findings underscore the distinctive value of EIT in tailoring cardiorespiratory care for VA-ECMO patients.
I. Protti, J. Francovich, R. V. van Thiel et al.· ASAIO journal (1992)· 0 citations
Cerebral injury remains a major contributor to morbidity and mortality in VA‑ECMO patients. Disruption of cerebral autoregulation during extracorporeal support may predispose to neurological damage. This prospective study evaluated cerebral hemodynamics in 17 adults with cardiogenic shock supported by femoro‑femoral VA‑ECMO using transcranial Doppler (TCD) and regional cerebral oxygen saturation (rSO2), correlating these measurements with echocardiographic and clinical outcomes. Bilateral middle cerebral artery (MCA) velocities, peak systolic (PSV), mean flow (MFV), end‑diastolic (EDV), and pulsatility index (PI) were recorded and compared with ejection fraction (EF), left ventricular outflow tract velocity time integral (LVOT VTI), and cardiac index (CI). Pulsatile flow was detected in 85.9% of MCA readings, with mild left‑sided dominance and minimal rSO2 variation. A U‑shaped correlation emerged between rSO2 and PI, indicating optimal oxygenation at mid‑range PI values (0.6-1.2). Lower and higher PI values were associated with increased mortality. Transcranial Doppler‑derived indices, particularly PSV and MFV, correlated strongly with EF (p = 0.022) and LVOT VTI (p = 0.044), outperforming rSO2 in prognostic value. Ejection fraction < 10%, LVOT VTI < 3.08 cm, and CI < 0.52 L/min/m2 predicted nonpulsatile flow with high accuracy. Combined TCD and rSO2 monitoring offers bedside insight into cerebral perfusion and cardiac performance during VA‑ECMO. These exploratory findings are hypothesis‑generating and require confirmation in larger, prospective cohorts.
Dina Zeid Roushdy, Nourhan Ahmed Mohamed, A. Abdelbary et al.· ASAIO journal (1992)· 0 citations
Routine early VA-ECMO in infarct-related CS has not demonstrated mortality benefit in randomized trials and is associated with increased complications; therefore, VA-ECMO should be reserved for selected phenotypes, including refractory shock with severe hypoxemia, profound biventricular failure, or circulatory collapse.
Alexander M. Bernhardt, C. Volgmann, L. Bax et al.· European surgical research....· 0 citations
Interventional treatment for hemodynamically unstable pulmonary embolism (PE) is now common due to the fact that unstable PE carries a significant 30-day mortality. Unstable PE is characterized by acute right ventricular failure, hypotension, and hypoxia, leading to cardiovascular collapse and cardiac arrest. Implementation of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) acutely provides oxygenation support to improve hypoxia and offload the right ventricular (RV) pressure in the belief that rapid reduction of hypoxia and right ventricular (RV) pressure will provide a window for intervention. There are two strategies for using VA-ECMO during percutaneous pulmonary mechanical thrombectomy: VA-ECMO-assisted mechanical thrombectomy and mechanical thrombectomy with standby VA-ECMO. While the application of VA-ECMO in percutaneous mechanical thrombectomy is usually short-term, providers must be cognizant that it can be associated with substantial multisystem morbidity due to a systemic inflammatory response, hemorrhagic stroke, renal dysfunction, and bleeding, and these factors will impact outcomes. The evolving paradigm positions VA-ECMO combined with percutaneous pulmonary mechanical thrombectomy as the preferred combination for the high-risk PE patients (acute right ventricular failure, refractory shock, and cardiac arrest), while percutaneous pulmonary mechanical thrombectomy alone with standby VA-ECMO suffices for most intermediate PE patients.
Mark G. Davies, Joseph P. Hart· Frontiers in Cardiovascular...· 0 citations
INTRODUCTION
Venoarterial extracorporeal membrane oxygenation (V-A ECMO) is frequently combined with intra-aortic balloon pump (IABP) support in patients with refractory cardiogenic shock. Although IABP may reduce V-A ECMO-related afterload, its effect on cerebral perfusion remains uncertain. We aimed to assess the impact of IABP support on middle cerebral artery (MCA) blood flow velocity measured by transcranial Doppler ultrasonography in patients receiving V-A ECMO.
METHODS
We conducted a retrospective study in our tertiary intensive care unit between November 2021 and May 2022. Adults receiving femoro-femoral V-A ECMO with concomitant IABP support were screened. Patients with documented transcranial Doppler monitoring parameters were included. MCA blood flow velocities and systemic hemodynamic variables were compared between IABP standby mode and active IABP support at a 1:1 assist ratio.
RESULTS
Among 88 screened patients, 21 were included. IABP support was associated with lower peak systolic and pre-ejection arterial pressures, whereas mean arterial pressure remained unchanged. MCA systolic and late diastolic flow velocities decreased during IABP support, while early diastolic velocity increased. Overall, MCA mean flow velocity was significantly lower during IABP support than during standby mode (42 [39-55] vs. 59 [48-64] cm·s-1, p < 0.001). Higher unassisted pulse pressure and greater reduction in late diastolic flow velocity were associated with a larger decrease in MCA mean flow velocity during IABP support.
CONCLUSION
In patients receiving V-A ECMO, IABP support was associated with reduced MCA mean flow velocity despite unchanged mean arterial pressure, a TCD pattern consistent with a net decrease in cerebral blood flow, potentially related to IABP-induced changes in arterial waveform and cerebral hemodynamics.
Timothée Ayasse, David Levy, Ouriel Saura et al.· Journal of critical care· 0 citations
Extracorporeal membrane oxygenation (ECMO) is a vital therapy for patients with severe cardiac and pulmonary failure. Despite technological advances, oxygenator dysfunction remains common, yet comparative clinical data across devices are limited. This study evaluated the performance of four contemporary adult oxygenators used in ECMO in a clinical, real-world setting. This retrospective single-center study included adult patients who received venovenous (VV) or venoarterial (VA) ECMO between January 2020 and December 2023 (N = 282). Oxygenators evaluated included the Medtronic Nautilus/Nautilus Smart, Getinge Heart Lung Support Module Advanced 7.0, Getinge Quadrox-iD Adult, and Fresenius X-Lung. Analyses were performed using propensity weighting and included adjustments for Acute Physiology and Chronic Health Evaluation II severity scores and baseline Charlson Comorbidity Index (CCI). No statistically significant differences in oxygen transfer across the membrane lung (VO2) were observed among oxygenator types after adjustment for covariates. VO2 declined over time during support (p < 0.001) and was higher in VV than VA ECMO mode (p = 0.002). Higher CCI was associated with lower VO2 (p = 0.046). Finally, coagulation and hemolysis markers were comparable across all devices. Current-generation oxygenators provide similar gas exchange efficiency and hemocompatibility in clinical practice. Future prospective and multicenter studies incorporating direct measurements of gas transfer may further clarify device-specific characteristics and their impact on clinical outcomes.
Linda E. Sousse, Junya Hagiwara, Qianqian Liu et al.· ASAIO journal (1992)· 0 citations
