Echocardiography for adult patients supported with extracorporeal membrane oxygenation

Cardiogenic shock as a health issue. Physiology, classification, and detection

Cardiogenic shock (CS) is a heterogeneous syndrome with high mortality and a growing incidence. It is characterized by an imbalance between the tissue oxygen demands and the capacity of the cardiovascular system to meet these demands, due to acute cardiac dysfunction. Historically, acute coronary syndromes have been the primary cause of CS. However, non-ischemic cases have seen a rise in incidence. The pathophysiology involves ischemic damage of the myocardium and a sympathetic, renin-angiotensin-aldosterone system and inflammatory response, perpetuating the situation of tissue hypoperfusion and ultimately leading to multiorgan dysfunction. The characterization of CS patients through a triaxial assessment and the widespread use of the Society for Cardiovascular Angiography and Interventions (SCAI) scale has allowed standardization of the severity stratification of CS; this, coupled with early detection and the "hub and spoke" approach, could contribute to improving the prognosis of these patients.

Head-to-toe bedside ultrasound for adult patients on extracorporeal membrane oxygenation

Bedside ultrasound represents a well-suited diagnostic and monitoring tool for patients on extracorporeal membrane oxygenation (ECMO) who may be too unstable for transport to other hospital areas for diagnostic tests. The role of ultrasound, however, starts even before ECMO initiation. Every patient considered for ECMO should have a thorough ultrasonographic assessment of cardiac and valvular function, as well as vascular anatomy without delaying ECMO cannulation. The role of pre-ECMO ultrasound is to confirm the indication for ECMO, identify clinical situations for which ECMO is not indicated, rule out contraindications, and inform the choice of ECMO configuration. During ECMO cannulation, the use of vascular and cardiac ultrasound reduces the risk of complications and ensures adequate cannula positioning. Ultrasound remains key for monitoring during ECMO support and troubleshooting ECMO complications. For instance, ultrasound is helpful in the assessment of drainage insufficiency, hemodynamic instability, biventricular function, persistent hypoxemia, and recirculation on venovenous (VV) ECMO. Lung ultrasound can be used to monitor signs of recovery on VV ECMO. Brain ultrasound provides valuable diagnostic and prognostic information on ECMO. Echocardiography is essential in the assessment of readiness for liberation from venoarterial (VA) ECMO. Lastly, post decannulation ultrasound mainly aims at identifying post decannulation thrombosis and vascular complications. This review will cover the role of head-to-toe ultrasound for the management of adult ECMO patients from decision to initiate ECMO to the post decannulation phase.

Echocardiographic and Point-of-Care Ultrasonography (POCUS) Guidance in the Management of the ECMO Patient

Veno-arterial (V-A) and Veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) support is increasingly utilized for acute cardiogenic shock and/or respiratory failure. Echocardiography and point-of-care ultrasonography (POCUS) play a critical role in the selection and management of these critically ill patients, however, there are limited guidelines regarding their application. This comprehensive review describes current and potential application of echocardiography and POCUS for pre-ECMO assessment and patient selection, cannulation guidance with emphasis on dual-lumen configurations, diagnosis of ECMO complications and trouble-shooting of cannula malposition, diagnosis of common cardiac or pulmonary pathologies, and assessment of ECMO weaning appropriateness including identification of the aortic mixing point in V-A ECMO.

Use of point-of-care ultrasound (POCUS) to monitor neonatal and pediatric extracorporeal life support

Extracorporeal membrane oxygenation (ECMO) is an invasive life support technique that requires a blood pump, an artificial membrane lung, and vascular cannulae to drain de-oxygenated blood, remove carbon dioxide, oxygenate, and return it to the patient. ECMO is generally used to provide advanced and prolonged cardiopulmonary support in patients with refractory acute cardiac and/or respiratory failure. After its first use in 1975 to manage a severe form of meconium aspiration syndrome with resultant pulmonary hypertension, the following years were dominated by the use of ECMO to manage neonatal respiratory failure and limited to a few centers across the world. In the 1990s, evidence for neonatal respiratory ECMO support increased; however, the number of cases began to decline with the use of newer pharmacologic therapies (e.g., inhaled nitric oxide, exogenous surfactant, and high-frequency oscillatory ventilation). On the contrary, pediatric ECMO sustained steady growth. Combined advances in ECMO technology and bedside medical management have improved general outcomes, although ECMO-related complications remain challenging. Point-of-care ultrasound (POCUS) is an essential tool to monitor all phases of neonatal and pediatric ECMO: evaluation of ECMO candidacy, ultrasound-guided ECMO cannulation, daily evaluation of heart and lung function and brain perfusion, detection and management of major complications, and weaning from ECMO support.  Conclusion: Based on these considerations and on the lack of specific guidelines for the use of POCUS in the neonatal and pediatric ECMO setting, the aim of this paper is to provide a systematic overview for the application of POCUS during ECMO support in these populations. What is Known: • Extracorporeal membrane oxygenation (ECMO) provides advanced cardiopulmonary support for patients with refractory acute cardiac and/or respiratory failure and requires appropriate monitoring. • Point-of-care ultrasound (POCUS) is an accessible and adaptable tool to assess neonatal and pediatric cardiac and/or respiratory failure at bedside. What is New: • In this review, we discussed the use of POCUS to monitor and manage at bedside neonatal and pediatric patients supported with ECMO. • We explored the potential use of POCUS during all phases of ECMO support: pre-ECMO assessment, ECMO candidacy evaluation, daily evaluation of heart, lung and brain function, detection and troubleshooting of major complications, and weaning from ECMO support.

The intricate physiology of veno-venous extracorporeal membrane oxygenation: an overview for clinicians

During veno-venous extracorporeal membrane oxygenation (V-V ECMO), blood is drained from the central venous circulation to be oxygenated and decarbonated by an artificial lung. It is then reinfused into the right heart and pulmonary circulation where further gas-exchange occurs. Each of these steps is characterized by a peculiar physiology that this manuscript analyses, with the aim of providing bedside tools for clinical care: we begin by describing the factors that affect the efficiency of blood drainage, such as patient and cannulae position, fluid status, cardiac output and ventilatory strategies. We then dig into the complexity of extracorporeal gas-exchange, with particular reference to the effects of extracorporeal blood-flow (ECBF), fraction of delivered oxygen (FdO2) and sweep gas-flow (SGF) on oxygenation and decarbonation. Subsequently, we focus on the reinfusion of arterialized blood into the right heart, highlighting the effects on recirculation and, more importantly, on right ventricular function. The importance and challenges of haemodynamic monitoring during V-V ECMO are also analysed. Finally, we detail the interdependence between extracorporeal circulation, native lung function and mechanical ventilation in providing adequate arterial blood gases while allowing lung rest. In the absence of evidence-based strategies to care for this particular group of patients, clinical practice is underpinned by a sound knowledge of the intricate physiology of V-V ECMO.

Role of ultrasound in the critical ill patient with ECMO

Ultrasound is an essential diagnostic tool in critically ill patients with extracorporeal membrane oxygenation (ECMO). With it, we can make an anatomical and functional (cardiac, pulmonary and vascular) evaluation which allows us to execute an adequate configuration, guides implantation, helps clinical monitorization and detects complications, facilitates withdrawal and complete post-implant evaluation. In patients with ECMO as respiratory support (veno-venous), thoracic ultrasound allows monitoring pulmonary illness evolution and echocardiography the evaluation of biventricular function, especially right ventricle function, and cardiac output to optimize oxygen transport. In ECMO as circulatory support (veno-arterial), echocardiography is the guide of hemodynamic monitoring, allows detecting the most frequent complications and helps the weaning. In ECMO teams, for a proper management of these patients, there must be trained intensivists with advanced knowledge on this technique.

State of the art: Monitoring of the respiratory system during veno-venous extracorporeal membrane oxygenation

Monitoring the patient receiving veno-venous extracorporeal membrane oxygenation (VV ECMO) is challenging due to the complex physiological interplay between native and membrane lung. Understanding these interactions is essential to understand the utility and limitations of different approaches to respiratory monitoring during ECMO. We present a summary of the underlying physiology of native and membrane lung gas exchange and describe different tools for titrating and monitoring gas exchange during ECMO. However, the most important role of VV ECMO in severe respiratory failure is as a means of avoiding further ergotrauma. Although optimal respiratory management during ECMO has not been defined, over the last decade there have been advances in multimodal respiratory assessment which have the potential to guide care. We describe a combination of imaging, ventilator-derived or invasive lung mechanic assessments as a means to individualise management during ECMO.

Ultrasound-Enhancing Agent Safely Enhances Left Ventricular Visualization by Transthoracic Echocardiography in Patients on ECMO Support

OBJECTIVE

The authors investigated if the use of ultrasound-enhancing agents (UEA) can safely improve left ventricular (LV) image quality by transthoracic echocardiography (TTE) in patients on extracorporeal membrane oxygenation (ECMO).

DESIGN AND SETTING

This study was performed in a tertiary cardiothoracic and ECMO center in London, United Kingdom.

PARTICIPANTS

The authors included 18 prospectively identified consecutive patients requiring TEE supported on peripherally implanted ECMO.

INTERVENTION AND MEASUREMENTS

TTE was performed before and after the UEA administration. The authors assessed the LV image quality using the biplane (apical-4-chamber and apical-2-chamber views) endocardial border definition index (1 = good, 2 = suboptimal, 3 = poor, and 4 = unavailable), as well as the feasibility of LV ejection fraction (LVEF) measurement. The authors also gathered sequential clinical information for the next 24 hours.

MAIN RESULTS

The patients' median age was 47 years (35, 65), and 5 (28%) were women. The biplane endocardial border definition index improved from the suboptimal to the good range (2.167 [1.812, 3.042] v 1.500 [1.417, 1.792], p = 0.0004) after the use of UEA. The feasibility of LVEF tripled from 25% (n = 5) to 83% (n = 15) (p = 0.0008) with UEA use. The UEA did not set off the bubble alarm and did not impact clinical or ECMO parameters.

CONCLUSION

The use of UEA significantly improved the quality of LV biplane images by transthoracic echocardiography, transforming them from suboptimal to good in patients supported with peripherally implanted ECMO. UEA use tripled the feasibility of measuring LVEF by TTE without affecting clinical and ECMO parameters.

Role of cardiac imaging in management of heart failure

The significant advancement in cardiac imaging in recent years led to improved diagnostic accuracy in identifying the specific causes of heart failure and also provided physicians with guidelines for appropriately managing patients with heart failure. Diseases that were once considered rare are now more easily detected with the aid of cardiac imaging. Various cardiac imaging techniques are used to evaluate patients with heart failure, and each technique plays a distinct yet complementary role. This review aimed to discuss the comprehensive role of different types of cardiac imaging in the management of heart failure.

Extracorporeal Membrane Oxygenation (VA-ECMO) in Management of Cardiogenic Shock

Cardiogenic shock is a critical condition of low cardiac output resulting in insufficient systemic perfusion and end-organ dysfunction. Though significant advances have been achieved in reperfusion therapy and mechanical circulatory support, cardiogenic shock continues to be a life-threatening condition associated with a high rate of complications and excessively high patient mortality, reported to be between 35% and 50%. Extracorporeal membrane oxygenation can provide full cardiopulmonary support, has been increasingly used in the last two decades, and can be used to restore systemic end-organ hypoperfusion. However, a paucity of randomized controlled trials in combination with high complication and mortality rates suggest the need for more research to better define its efficacy, safety, and optimal patient selection. In this review, we provide an updated review on VA-ECMO, with an emphasis on its application in cardiogenic shock, including indications and contraindications, expected hemodynamic and echocardiographic findings, recommendations for weaning, complications, and outcomes. Furthermore, specific emphasis will be devoted to the two published randomized controlled trials recently presented in this setting.

Cardiac dysfunction in severe pediatric acute respiratory distress syndrome: the right ventricle in search of the right therapy

Severe acute respiratory distress syndrome in children, or PARDS, carries a high risk of morbidity and mortality that is not fully explained by PARDS severity alone. Right ventricular (RV) dysfunction can be an insidious and often under-recognized complication of severe PARDS that may contribute to its untoward outcomes. Indeed, recent evidence suggest significantly worse outcomes in children who develop RV failure in their course of PARDS. However, in this narrative review, we highlight the dearth of evidence regarding the incidence of and risk factors for PARDS-associated RV dysfunction. While we wish to draw attention to the absence of available evidence that would inform recommendations around surveillance and treatment of RV dysfunction during severe PARDS, we leverage available evidence to glean insights into potentially helpful surveillance strategies and therapeutic approaches.

Ultrasound vector flow imaging during veno-arterial extracorporeal membrane oxygenation in a thoracic aorta model

In veno-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment, the mixing zone is a key hemodynamic factor that determines the efficacy of the treatment. This study aimed to evaluate the applicability of a novel ultrasound technique called vector flow imaging (VFI) for visualizing complex flow patterns in an aorta phantom under VA-ECMO settings. VFI experiments were performed to image aortic hemodynamics under VA-ECMO treatment simulated in an anthropomorphic thoracic aorta phantom using a pulsatile pump (cardiac output: 2.7 L/min) and an ECMO pump with two different flow rates, 0.35 L/min and 1.0 L/min. The cardiac cycle of hemodynamics in the ascending aorta, aortic arch, and descending aorta was visualized, and the spatio-temporal dynamics of flow vectors were analyzed. VFI successfully visualized dynamic flow patterns in the aorta phantom. When the flow rate of the ECMO pump increased, ECMO flow was more dominant than cardiac output in the diastole phase, and the speed of cardiac output was suppressed in the systole phase. Vortex flow patterns were also detected in the ascending aorta and the arch under both ECMO flow rate conditions. The VFI technique may provide new insights into aortic hemodynamics and facilitates effective and safe VA-ECMO treatment.

Assessment of cardiac load-responsiveness in veno-arterial extracorporeal life support: A case series

INTRODUCTION

Well-timed explant of veno-arterial extracorporeal life support (V-A ECLS) depends on adequate assessment of cardiac recovery. Often, evaluation of cardiac recovery consists of reducing support flow while visualizing cardiac response using transoesophageal echocardiography (TEE). This method, however, is time consuming and based on subjective findings. The dynamic filling index (DFI) may aid in the quantitative assessment of cardiac load-responsiveness. The dynamic filling index is based on the relationship of support flow and pump speed, which varies with varying hemodynamic conditions. This case series intends to investigate whether the DFI may support TEE in facilitating the assessment of cardiac load-responsiveness.

METHODS

Measurements for DFI-determination were performed in seven patients while simultaneously assessing ventricular function by measuring the aortic velocity time integral (VTI) using TEE. Measurements consisted of multiple consecutive transient speed manipulations (∼100 r/min) during weaning trials, both at full support and during cardiac reloading at reduced support.

RESULTS

The VTI increased between full and reduced support in six weaning trials. In five of these trials DFI decreased or remained equal, and in one case DFI increased. Of the three trials in which VTI decreased between full and reduced support, DFI increased in two cases and decreased in one case. Changes in DFI, however, are mostly smaller than the detection threshold of 0.4 mL/rotation.

CONCLUSION

Even though current level of accuracy of the parameter requires further investigation to increase reliability and possibly predictability, DFI seems likely to be a potential parameter in supporting TEE for the assessment of cardiac load-responsiveness.

Rescue Transesophageal Echocardiography: A Narrative Review of Current Knowledge and Practice

Perioperative transesophageal echocardiography (TEE) has been part of clinical activity for more than 40 years. During this period, TEE has evolved in terms of technology and clinical applications beyond the initial fields of cardiology and cardiac surgery. The benefits of TEE in the diagnosis and management of acute hemodynamic and respiratory collapse have been recognized in noncardiac surgery and by other specialties too. This natural progress led to the development of rescue TEE, a relatively recent clinical application that extends the use of TEE and makes it accessible to a large group of clinicians and patients requiring acute care. In this review, the authors appraise the current clinical applications and evidence base around this topic. The authors provide a thorough review of the various image acquisition protocols, clinical benefits, and compare it with the more frequently used transthoracic echocardiography. Furthermore, the authors have reviewed the current training and credentialing pathways. Overall, rescue TEE is a highly attractive and useful point-of-care examination, but the current evidence base is limited and the technical protocols, training, and credentialing processes are not standardized. There is a need for adequate guidelines and high-quality research to support its application as a bedside rescue tool.

Effects of varying blood flow rate during peripheral veno-arterial extracorporeal membrane oxygen (V-A ECMO) on left ventricular function measured by two-dimensional strain

Background

We evaluated the effects of varying blood flow rate during peripheral veno-arterial extracorporeal membrane oxygen (V-A ECMO) on left ventricular function measured by two-dimensional strain.

Methods

Adult patients who were supported by peripheral V-A ECMO were recruited. Serial hemodynamic and cardiac performance parameters were measured by transthoracic echocardiogram within the first 48 h after implementation of V-A ECMO. Measurements at 100%, 120%, and 50% of target blood flow (TBF) were compared.

Results

A total of 54 patients were included and the main indications for V-A ECMO were myocardial infarction [32 (59.3%)] and myocarditis [6 (11.1%)]. With extracorporeal blood flow at 50% compared with 100% TBF, the mean arterial pressure was lower [66 ± 19 vs. 75 ± 18 mmHg, p < 0.001], stroke volume was greater [23 (12-34) vs. 15 (8-26) ml, p < 0.001], and cardiac index was higher [1.2 (0.7-1.7) vs. 0.8 (0.5-1.3) L/min/m², p < 0.001]. Left ventricular contractile function measured by global longitudinal strain improved at 50% compared with 100% TBF [-2.8 (-7.6- -0.1) vs. -1.2 (-5.2-0) %, p < 0.001]. Similarly, left ventricular ejection fraction increased [24.4 (15.8-35.5) vs. 16.7 (10.0-28.5) %, p < 0.001] and left ventricular outflow tract velocity time integral increased [7.7 (3.8-11.4) vs. 4.8 (2.5-8.5) cm, p < 0.001]. Adding echocardiographic parameters of left ventricular systolic function to the Survival After Veno-arterial ECMO (SAVE) score had better discriminatory value in predicting eventual hospital mortality (AUROC 0.69, 95% CI 0.55-0.84, p = 0.008) and successful weaning from V-A ECMO (AUROC 0.68, 95% CI 0.53-0.83, p = 0.017).

Conclusion

In the initial period of V-A ECMO support, measures of left ventricular function including left ventricular ejection fraction and global longitudinal strain were inversely related to ECMO blood flow rate. Understanding the heart-ECMO interaction is vital to interpretation of echocardiographic measures of the left ventricle while on ECMO.

Transesophageal Echocardiography-Guided Extracorporeal Membrane Oxygenation Cannulation in COVID-19 Patients

OBJECTIVES

A paucity of data supports the use of transesophageal echocardiography (TEE) for bedside extracorporeal membrane oxygenation (ECMO) cannulation. Concerns have been raised about performing TEEs in patients with COVID-19. The authors describe the use and safety of TEE guidance for ECMO cannulation for COVID-19.

DESIGN

Single-center retrospective cohort study.

SETTING

The study took place in the intensive care unit of an academic tertiary center.

PARTICIPANTS

The authors included 107 patients with confirmed SARS-CoV-2 infection who underwent bedside venovenous ECMO (VV ECMO) cannulation under TEE guidance between May 2020 and June 2021.

INTERVENTIONS

TEE-guided bedside VV ECMO cannulation.

MEASUREMENTS

Patient characteristics, physiologic and ventilatory parameters, and echocardiographic findings were analyzed. The primary outcome was the number of successful TEE-guided bedside cannulations without complications. The secondary outcomes were cannulation complications, frequency of cannula repositioning, and TEE-related complications.

MAIN RESULTS

TEE-guided cannulation was successful in 99% of the patients. Initial cannula position was adequate in all but 1 patient. Fourteen patients (13%) required cannula repositioning during ECMO support. Forty-five patients (42%) had right ventricular systolic dysfunction, and 9 (8%) had left ventricular systolic dysfunction. Twelve patients (11%) had intracardiac thrombi. One superficial arterial injury and 1 pneumothorax occurred. No pericardial tamponade, hemothorax or intraabdominal bleeding occurred in the authors' cohort. No TEE-related complications or COVID-19 infection of healthcare providers were reported during this study.

CONCLUSIONS

Bedside TEE guidance for VV ECMO cannulation is safe in patients with severe respiratory failure due to COVID-19. No tamponade or hemothorax, nor TEE-related complications were observed in the authors' cohort.

Echocardiographic Prediction of Successful Weaning From Venoarterial Extracorporeal Membrane Oxygenation

BACKGROUND

Weaning from venoarterial extracorporeal membrane oxygenation (VA-ECMO) support fails in 30% to 70% of patients.

OBJECTIVE

To explore the utility of echocardiographic parameters in predicting successful disconnection from VA-ECMO.

METHODS

Patients receiving VA-ECMO in a referral hospital were included. The relationships between echocardiographic parameters during the weaning trial and weaning success (survival > 24 hours after VA-ECMO explant and no death from cardiogenic shock, heart failure, or cardiac arrest during the hospital stay) and survival were evaluated.

RESULTS

Of 85 patients included, 61% had successful weaning. Parameters significantly related to weaning success were higher left ventricular ejection fraction (LVEF; 40% in patients with weaning success vs 30% in patients with weaning failure, P = .01), left ventricular outflow tract velocity time integral (15 cm vs 11 cm, P = .01), aortic valve opening in every cycle (98% vs 91% of patients, P = .01), and normal qualitative right ventricular function (60% vs 42% of patients, P = .02). The LVEF remained as an independent predictor of weaning success (hazard ratio, 0.938; 95% CI, 0.888-0.991; P = .02). An LVEF >33.4% was the optimal cutoff value to discriminate patients with successful weaning (area under the curve, 0.808; sensitivity, 93%; specificity, 72%) and was related to higher survival at discharge (60% vs 20%, P < .001).

CONCLUSION

Among weaning trial echocardiographic parameters, LVEF was the only independent predictor of successful VA-ECMO weaning. An LVEF >33.4% was the optimal cutoff value to discriminate patients with successful weaning and was related to final survival.

A phased intervention bundle to decrease the mortality of patients with extracorporeal membrane oxygenation in intensive care unit

Aim

To evaluate whether a phased multidimensional intervention bundle would decrease the mortality of patients with extracorporeal membrane oxygenation (ECMO) and the complication incidence.

Materials and methods

We conducted a prospective observational study in comparison with a retrospective control group in six intensive care units (ICUs) in China. Patients older than 18 years supported with ECMO between March 2018 to March 2022 were included in the study. A phased intervention bundle to improve the outcome of patients with ECMO was developed and implemented. Multivariable logistic regression modeling was used to compare the mortality of patients with ECMO and the complication incidence before, during, and up to 18 months after implementation of the intervention bundle.

Results

The cohort included 297 patients in 6 ICUs, mostly VA ECMO (68.7%) with a median (25th–75th percentile) duration in ECMO of 9.0 (4.0–15.0) days. The mean (SD) APECHII score was 24.1 (7.5). Overall, the mortality of ECMO decreased from 57.1% at baseline to 21.8% at 13–18 months after implementation of the study intervention (P < 0.001). In multivariable analysis, even after excluding the confounding factors, such as age, APECHII score, pre-ECMO lactate, and incidence of CRRT during ECMO, the intervention bundle still can decrease the mortality independently, which also remained true in the statistical analysis of V-V and V-A ECMO separately. Among all the ECMO-related complications, the incidence of bloodstream infection and bleeding decreased significantly at 13–18 months after implementation compared with the baseline. The CUSUM analysis revealed a typical learning curve with a point of inflection during the implementation of the bundle.

Conclusion

A phased multidimensional intervention bundle resulted in a large and sustained reduction in the mortality of ECMO that was maintained throughout the 18-month study period.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT05024786].

Radiographic assessment of lung edema (RALE) score is associated with clinical outcomes in patients with refractory cardiogenic shock and refractory cardiac arrest after percutaneous implantation of extracorporeal life support

VA-ECMO is a promising therapeutic option in refractory cardiogenic shock (RCS) and refractory cardiac arrest (RCA). However, increase in left ventricular afterload enhances further reduction of LV contractility and pulmonary edema. The aim of this study was to evaluate pulmonary edema based on the RALE score and the prognostic value of the score on ECLS weaning and mortality. In this retrospective study, data from 40 patients (16 RCAs and 24 RCSs) were analyzed. Demographic, clinical data and the RALE score for evaluating pulmonary edema were assessed. Descriptive statistics, intraclass correlation, and receiver operating characteristic (ROC) curves were computed. Weaning from ECLS was successful in 30 (75%) patients, 16 patients (40%) were discharged alive. Overall, the survivors were younger, presenting with a higher left ventricular ejection fraction (30 ± 2% vs.23 ± 9%;p < 0.01) and a lower initial serum lactate concentration 7.7 ± 4.5 mmol/l vs. 11.5 ± 4.9 mmol/l; p = 0.017). Survivors had lower RALE scores than non-survivors (16.3 ± 9.4 vs. 26.4 ± 10.4; p = 0.0034). The interobserver variability of the RALE score was good (0.832). The AUC predicting mortality and weaning from ECLS presented comparable results to the established parameters (SAVE, serum lactate). Implementation of the RALE score could support prediction of outcome parameters during VA-ECMO therapy.

Impact factors of POCUS-guided cannulation for peripheral venoarterial extracorporeal membrane oxygenation: One single-center retrospective clinical analysis

We aimed to evaluate associated factors for point-of-care ultrasound (POCUS)-guided percutaneous catheterization for venoarterial extracorporeal membrane oxygenation (VA-ECMO). VA-ECMO cases from March 2018 to October 2020 in Department of Intensive Care Unit, Binhaiwan Central Hospital of Dongguan, were enrolled. Clinical data, outcomes, and complications were recorded and summarized. Fifty-nine cases were enrolled, among which 88.1% succeeded in POCUS-guided catheterization via Seldinger technique, whereas 59.3% succeeded at the first puncture. Results showed that artery diameter and times of arterial punctures were independent associated factors for Seldinger puncture (P = .018, odds ratio [OR] = 23.374, 95% confidence interval [CI] = 1.706-320.270; P = .031, OR = 145.098, 95% CI = 1.592-13220.980), and artery diameter and cardiac ejection fraction value (≥30%/<30%) were independent associated factors for first puncture (P = .044, OR = 1.622, 95% CI = 1.014-2.596; P = .013, OR = 5.565, 95% CI = 1.441-21.488). For extracorporeal cardiopulmonary resuscitation patients, artery diameter was independent associated factor for Seldinger puncture (P = .022, OR = 2.070, 95% CI = 1.110-3.858), and cardiac ejection fraction value (≥30%/<30%) was independent associated factor for first puncture (P = .007, OR = 9.533, 95% CI = 1.847-49.204). Thirteen patients (22.0%) had local hemorrhage post puncture, 8 patients (13.6%) presented distal limb arterial ischemia, and 8 patients (13.6%) suffered puncture-related thrombosis. Vasoactive Inotropic Score was found to be independent associated factor for local hemorrhage (P = .039, OR = 0.994, 95% CI = 0.988-1.000), and the Acute Physiology and Chronic Health Evaluation II score was independent associated factor for thrombosis (P = .025, OR = 0.935, 95% CI = 0.882-0.992). Diabetes and cardiopulmonary resuscitation time before catheterization were independent factors for distal limb ischemia (P = .026, OR = 220.774, 95% CI = 1.905-25591.327; P = .017, OR = 1.054, 95% CI = 1.009-1.101). POCUS-guided percutaneous catheterization via Seldinger technique can be the first choice for VA-ECMO cannulation, especially for a team without angiotomy qualifications. Before cannulation, evaluating the target artery and heart function by ultrasound can help predict outcome of catheterization. Assessing risk factors (diabetes, cardiopulmonary resuscitation time before catheterization, Vasoactive Inotropic Score, the Acute Physiology and Chronic Health Evaluation II score) is helpful for prevention and treatment of complications.

When is tamponade not an echocardiographic diagnosis… Or is it ever?

Although cardiac tamponade remains a clinical diagnosis, echocardiography is an essential tool to detect fluid in the pericardial space. Interpretation of echocardiographic findings and assessment of physiologic and hemodynamic consequences of a pericardial effusion require a thorough understanding of pathophysiologic processes. Certain echocardiographic signs point toward the presence of cardiac tamponade: a dilated inferior vena cava (IVC), collapse of the cardiac chambers, an inspiratory bulge of the interventricular septum into the left ventricle (LV) (the "septal bounce"), and characteristic respiratory variations of Doppler flow velocity recordings. However, in certain circumstances (e.g., mechanical ventilation, post-surgical patients, and pulmonary hypertension), these echocardiographic signs can be missing, despite the presence of clinical tamponade. Failure to recognize a potentially life-threatening clinical condition due to the absence of corresponding echocardiographic findings can delay both diagnosis and life-saving treatment. Thus, in the context of critical care, echocardiography should only be used to confirm the presence of pericardial fluid or localized hematoma, and the diagnosis of tamponade should rely on clinical criteria.

Monitoring during extracorporeal membrane oxygenation

PURPOSE OF REVIEW

Extracorporeal membrane oxygenation (ECMO) offers advanced mechanical support to patients with severe acute respiratory and/or cardiac failure. Ensuring an adequate therapeutic approach as well as prevention of ECMO-associated complications, by means of timely liberation, forms an essential part of standard ECMO care and is only achievable through continuous monitoring and evaluation. This review focus on the cardiorespiratory monitoring tools that can be used to assess and titrate adequacy of ECMO therapy; as well as methods to assess readiness to wean and/or discontinue ECMO support.

RECENT FINDINGS

Surrogates of tissue perfusion and near infrared spectroscopy are not standards of care but may provide useful information in select patients. Echocardiography allows to determine cannulas position, evaluate cardiac structures, and function, and diagnose complications. Respiratory monitoring is mandatory to achieve lung protective ventilation and identify early lung recovery, surrogate measurements of respiratory effort and ECMO derived parameters are invaluable in optimally managing ECMO patients.

SUMMARY

Novel applications of existing monitoring modalities alongside evolving technological advances enable the advanced monitoring required for safe delivery of ECMO. Liberation trials are necessary to minimize time sensitive ECMO related complications; however, these have yet to be standardized.

Awakening in extracorporeal membrane oxygenation as a bridge to lung transplantation

Although the rate of lung transplantation (LTx), the last treatment option for end-stage lung disease, is increasing, some patients waiting for LTx need a bridging strategy for LTx due to the limited number of available donor lungs. For a long time, mechanical ventilation has been employed as a bridge to LTx because the outcome of using extracorporeal membrane oxygenation (ECMO) as a bridging strategy has been poor. However, the outcome after mechanical ventilation as a bridge to LTx was poor compared with that in patients without bridges. With advances in technology and the accumulation of experience, the outcome of ECMO as a bridge to LTx has improved, and the rate of ECMO use as a bridging strategy has increased over time. However, whether the use of ECMO as a bridge to LTx can achieve survival rates similar to those of non-bridged LTx patients remains controversial. In 2010, one center introduced awake ECMO strategy for LTx bridging, and its use as a bridge to LTx has been showing favorable outcomes to date. Awake ECMO has several advantages, such as maintenance of physical activity, spontaneous breathing, avoidance of endotracheal intubation, and reduced use of sedatives and analgesics, but it may cause serious problems. Nonetheless, several studies have shown that awake ECMO performed by a multidisciplinary team is safe. In cases where ECMO or mechanical ventilation is required due to unavoidable exacerbation in patients awaiting LTx, the application of awake ECMO performed by an appropriately trained ECMO multi-disciplinary team can be useful.

Application of POCUS in patients with COVID-19 for acute respiratory distress syndrome management: a narrative review

COVID-19 has inflicted the world for over two years. The recent mutant virus strains pose greater challenges to disease prevention and treatment. COVID-19 can cause acute respiratory distress syndrome (ARDS) and extrapulmonary injury. Dynamic monitoring of each patient's condition is necessary to timely tailor treatments, improve prognosis and reduce mortality. Point-of-care ultrasound (POCUS) is broadly used in patients with ARDS. POCUS is recommended to be performed regularly in COVID-19 patients for respiratory failure management. In this review, we summarized the ultrasound characteristics of COVID-19 patients, mainly focusing on lung ultrasound and echocardiography. Furthermore, we also provided the experience of using POCUS to manage COVID-19-related ARDS.

Increased N-terminal Pro-B-Type Natriuretic Peptide during Extracorporeal Life Support Is Associated with Poor Outcome in Neonates with Congenital Diaphragmatic Hernia

OBJECTIVES

To evaluate the prognostic information derived from the daily measurements of N-terminal pro-B-type natriuretic peptide (proBNP) in neonates with congenital diaphragmatic hernia undergoing extracorporeal life support (ECLS).

STUDY DESIGN

Plasma proBNP was prospectively measured daily during the first week of ECLS using an electrochemiluminescence immunoassay. Patients (n = 63) were allocated according to outcome: survivors (group 1, n = 35); nonsurvivors with successful weaning (defined as survival for >12 hours after ECLS discontinuation) (group 2, n = 16); nonsurvivors with unsuccessful weaning (group 3, n = 12). ProBNP kinetics were compared using Kruskal-Wallis testing and correlated with pulmonary hypertension and cardiac dysfunction on echocardiography using the Spearman correlation coefficient.

RESULTS

Infants in group 3 presented significantly higher proBNP values from day 3 to day 6 compared with group 1 and 2. Overall mortality among patients with the highest proBNP values on day 1 was 30.6% compared with 63% in those patients with at least 1 higher value on day 2 to day 7. In patients with a late increase (day 4 to day 7) in proBNP the mortality was 70%, compared with 32.6% in those with proBNP below the value on day 1. Weaning failure was 35% in patients with a late increase and 11.6% in those without a late increase. ProBNP correlated significantly with pulmonary hypertension and cardiac dysfunction before and during ECLS.

CONCLUSIONS

Absolute proBNP values are associated with weaning failure but not overall mortality in neonates with congenital diaphragmatic hernia undergoing ECLS. Echocardiographic findings correlate well with proBNP values.

Echocardiography for extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) provides advanced cardiopulmonary life support for patients in cardiac and/or respiratory failure. Echocardiography provides essential diagnostic and anatomic information prior to ECMO initiation, allows for safe and efficient ECMO cannula positioning, guides optimization of flow, provides a modality for rapid troubleshooting and patient evaluation, and facilitates decision-making for eventual weaning of ECMO support. Currently, guidelines for echocardiographic assessment in this clinical context are lacking. In this review, we provide an overview of echocardiographic considerations for advanced imagers involved in the care of these complex patients. We focus predominately on new cannulas and complex cannulation techniques, including a special focus on double lumen cannulas and a section discussing indirect left ventricular venting. Echocardiography is tremendously valuable in providing optimal care in these challenging clinical situations. It is imperative for imaging physicians to understand the pertinent anatomic considerations, the often complicated physiological and hemodynamic context, and the limitations of the imaging modality.

Basics of Extracorporeal Membrane Oxygenation

OVERVIEW

The use of extracorporeal membrane oxygenation (ECMO) is becoming commonplace worldwide in ICUs for the care of patients with respiratory and/or cardiac failure. Understanding the use of ECMO and the management of these complex patients will be vital to current and future clinicians as ECMO use continues to grow.

Role of Point of Care Ultrasonography in Patients with COVID-19 Associated Acute Kidney Injury

The severe acute respiratory virus covariate-2 (SARS CoV-2) that causes Corona Virus Disease 2019 (COVID-19) has affected more than 194 million people worldwide and has attributed to or caused more than 4 million deaths. Acute kidney injury (AKI) is a common complication of COVID-19. Point of care ultrasonography (POCUS) can be a useful tool for the nephrologist. POCUS can be used to elucidate the cause of kidney disease and then also help to manage volume status. Here, we review pearls and pitfalls of using POCUS to manage COVID-19 associated AKI with special attention to kidney, lung, and cardiac ultrasound.

SEDAR/SECCE ECMO management consensus document

ECMO is an extracorporeal cardiorespiratory support system whose use has been increased in the last decade. Respiratory failure, postcardiotomy shock, and lung or heart primary graft failure may require the use of cardiorespiratory mechanical assistance. In this scenario perioperative medical and surgical management is crucial. Despite the evolution of technology in the area of extracorporeal support, morbidity and mortality of these patients continues to be high, and therefore the indication as well as the ECMO removal should be established within a multidisciplinary team with expertise in the area. This consensus document aims to unify medical knowledge and provides recommendations based on both the recent bibliography and the main national ECMO implantation centres experience with the goal of improving comprehensive patient care.

Echocardiography, lung ultrasound, and cardiac magnetic resonance findings in COVID-19: A systematic review

BACKGROUND

The manifestations of COVID-19 as outlined by imaging modalities such as echocardiography, lung ultrasound (LUS), and cardiac magnetic resonance (CMR) imaging are not fully described.

METHODS

We conducted a systematic review of the current literature and included studies that described cardiovascular manifestations of COVID-19 using echocardiography, CMR, and pulmonary manifestations using LUS. We queried PubMed, EMBASE, and Web of Science for relevant articles. Original studies and case series were included.

RESULTS

This review describes the most common abnormalities encountered on echocardiography, LUS, and CMR in patients infected with COVID-19.

Transesophageal Echocardiography Compared to Fluoroscopy for Avalon Bicaval Dual-Lumen Cannula Positioning for Venovenous ECMO

The Avalon elite bicaval dual-lumen cannula for single site VenoVenous Extracorporeal Membrane Oxygenation (VV ECMO) offers several advantages. Correct placement of the Avalon cannula is safe using image guidance and needs either fluoroscopy or Transesophageal echocardiography (TEE). We assessed our institutional ECMO performance, cannulation related complications, instances of cannula malposition among patients cannulated using the two imaging modalities. We reviewed all patients who had Avalon cannula placement for VV ECMO at our institute. Ten patients were included in the study. Patients were cannulated using either fluoroscopy (Group A, n = 5) or TEE (Group B, n = 5). Data included patient demographics, diagnosis, evidence of cannula malposition, ECMO performance, cannulation related complications. The primary outcomes ease of cannulation; cannula malposition and the need for repositioning were compared between the two groups. Visualisation of guidewire, Avalon cannula and the average number of attempts to cannulate were similar (P > 0.05) between the two groups. Four patients cannulated using fluoroscopy had low flows whereas none of the patients cannulated using TEE had flow problems which was statistically significant (P = 0.024). Four cannulas (80%) placed under fluoroscopy required repositioning whereas one cannula (20%) placed under TEE needed repositioning. This difference was not statistically significant though (P = 0.099). TEE is the ideal imaging modality to guide Avalon elite cannula placement for VV ECMO.

Contrast-Enhanced Echocardiography Application in Patients Supported by Extracorporeal Membrane Oxygenation (ECMO): A Narrative Review

Extracorporeal membrane oxygenation (ECMO) is a lifesaving intervention increasingly used to support patients with severe respiratory and cardiac dysfunction. Echocardiography is an important tool, aiding implantation and monitoring during ECMO therapy, but often its use is limited by poor acoustic windows. This limitation may be overcome by the use of echocardiography contrast agents to improve diagnostic yield and reduce the need for other imaging modalities that may require patient transfer, involve ionizing radiation and, occasionally, nephrotoxic radio-opaque contrast medium. In this article the authors review the literature addressing the use of contrast-enhanced echocardiography (CEE) in ECMO-supported patients. The authors discuss the role of CEE in guiding implantation of ECMO, cardiac assessment and diagnosis of complications during ECMO therapy, as well as the safety of ultrasound-enhancing agents in this cohort of patients.

2020 EACTS/ELSO/STS/AATS Expert Consensus on Post-cardiotomy Extracorporeal Life Support in Adult Patients

Post-cardiotomy extracorporeal life support (PC-ECLS) in adult patients has been used only rarely but recent data have shown a remarkable increase in its use, almost certainly due to improved technology, ease of management, growing familiarity with its capability and decreased costs. Trends in worldwide in-hospital survival, however, rather than improving, have shown a decline in some experiences, likely due to increased use in more complex, critically ill patients rather than to suboptimal management. Nevertheless, PC-ECLS is proving to be a valuable resource for temporary cardiocirculatory and respiratory support in patients who would otherwise most likely die. Because a comprehensive review of PC-ECLS might be of use for the practitioner, and possibly improve patient management in this setting, the authors have attempted to create a concise, comprehensive and relevant analysis of all aspects related to PC-ECLS, with a particular emphasis on indications, technique, management and avoidance of complications, appraisal of new approaches and ethics, education and training.

The role of extracorporeal membrane oxygenation in critically ill patients with COVID-19: a narrative review

Extracorporeal life support treatments such as extracorporeal membrane oxygenation (ECMO) have been recommended for the treatment of severe acute respiratory distress syndrome (ARDS) patients with coronavirus disease 2019 (COVID-19). To date, many countries, including China, have adopted ECMO as a treatment for severe COVID-19. However, marked differences in patient survival rates have been reported, and the underlying reasons are unclear. This study aimed to summarize the experience of using ECMO to treat severe COVID-19 and provide suggestions for improving ECMO management. The effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the pathophysiology of COVID-19 and the effects of ECMO on the clinical outcomes in patients with severe cases of COVID-19 were reviewed. Recent data from frontline workers involved in the use of ECMO in Wuhan, China, and those experienced in the implementation of artificial heart and lung support strategies were analysed. There is evidence that ECMO may complicate the pathophysiological state in COVID-19 patients. However, many studies have shown that the appropriate application of ECMO improves the prognosis of such patients. To expand our understanding of the benefits of ECMO for critically ill patients with COVID-19, further prospective, multicentre clinical trials are needed.

Veno-arterial extracorporeal membrane oxygenation: Special reference for use in 'post-cardiotomy cardiogenic shock' - A review with an Indian perspective

The ultimate goals of cardiovascular physiology are to ensure adequate end-organ perfusion to satisfy the local metabolic demand, to maintain homeostasis and achieve 'milieu intérieur'. Cardiogenic shock is a state of pump failure which results in tissue hypoperfusion and its associated complications. There are a wide variety of causes which lead to this deranged physiology, and one such important and common scenario is the post-cardiotomy state which is encountered in cardiac surgical units. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is an important modality of managing post-cardiotomy cardiogenic shock with variable outcomes which would otherwise be universally fatal. VA-ECMO is considered as a double-edged sword with the advantages of luxurious perfusion while providing an avenue for the failing heart to recover, but with the problems of anticoagulation, inflammatory and adverse systemic effects. Optimal outcomes after VA-ECMO are heavily reliant on a multitude of factors and require a multi-disciplinary team to handle them. This article aims to provide an insight into the pathophysiology of VA-ECMO, cannulation techniques, commonly encountered problems, monitoring, weaning strategies and ethical considerations along with a literature review of current evidence-based practices.

2020 EACTS/ELSO/STS/AATS expert consensus on post-cardiotomy extracorporeal life support in adult patients

Post-cardiotomy extracorporeal life support (PC-ECLS) in adult patients has been used only rarely but recent data have shown a remarkable increase in its use, almost certainly due to improved technology, ease of management, growing familiarity with its capability and decreased costs. Trends in worldwide in-hospital survival, however, rather than improving, have shown a decline in some experiences, likely due to increased use in more complex, critically ill patients rather than to suboptimal management. Nevertheless, PC-ECLS is proving to be a valuable resource for temporary cardiocirculatory and respiratory support in patients who would otherwise most likely die. Because a comprehensive review of PC-ECLS might be of use for the practitioner, and possibly improve patient management in this setting, the authors have attempted to create a concise, comprehensive and relevant analysis of all aspects related to PC-ECLS, with a particular emphasis on indications, technique, management, and avoidance of complications, appraisal of new approaches and ethics, education, and training.

[Therapy and Outcome of Neonates with Congenital Diaphragmatic Hernia and Congenital Heart Defects]

Die Mortalität von Patienten mit isoliert auftretenden angeborenen Zwerchfellhernien liegt in spezialisierten Zentren bei 20-40%. Wesentliche, das Outcome beeinflussende Faktoren, sind die bestehende Lungenhypoplasie, eine daraus resultierende pulmonale Hypertonie, sowie das Vorliegen weiterer Fehlbildungen. Begleitfehlbildungen wie angeborene Herzfehler treten bei ca. 18% aller Neonaten mit Zwerchfellhernie auf. Schwere angeborene Herzfehler wie das hypoplastische Linksherz Syndrom zeigen sich in ca. 8% der Fälle. In einer retrospektiven Analyse des Patientenkollektivs unserer Klinik zwischen 01/2012 und 12/2018 wurde das prä- und postnatale Management, sowie das Outcome von Neugeborenen mit der Kombination aus angeborenen Herzfehlern und Zwerchfellhernien untersucht. Im Studienzeitraum wurden in unserer Klinik 156 Neugeborene mit Zwerchfellhernie behandelt. Bei 10 Patienten (6,4%) lag zusätzlich ein schwerer, bei 11 Patienten (7,1%) ein moderater Herzfehler vor. 6/21 Patienten verstarben im Verlauf des Krankenhausaufenthaltes, davon 3 am ersten Lebenstag. Es zeigte sich eine deutlich geringere Mortalität bei Patienten mit Zwerchfellhernie und moderatem Herzfehler im Vergleich zu schwerem Herzfehler (9 vs. 50%). Besonders hoch lag die Mortalität bei Kindern mit einem univentrikulären Herzen. Trotz einer deutlich reduzierten Prognose bei der Kombination aus angeborenem Herzfehler und Zwerchfellhernie muss nicht generell mit einer infausten Prognose gerechnet werden. In spezialisierten Zentren kann ein kurativer Ansatz erfolgen.The mortality of patients with isolated congenital diaphragmatic hernia (CDH) in specialized centers is 20-40%. The main factors influencing the outcome are the underlying pulmonary hypoplasia, the resulting pulmonary hypertension and the presence of other malformations. Concomitant malformations such as congenital heart defects occur in around 18% of all neonates with a diaphragmatic hernia. Serious congenital heart defects such as hypoplastic left heart syndrome occur in approximately 8% of cases. In a retrospective analysis of the patient collective of our hospital between 01/2012 and 12/2018, the prenatal and postnatal management as well as the outcome of newborns with a combination of congenital heart defects and diaphragmatic hernias were examined. During the study period, 156 newborns with diaphragmatic hernias were treated at our institution. In 10 patients (6.4%) there was also a severe, and in 11 patients (7.1%) a moderate heart defect. 6/21 patients died during their hospital stay, 3 of them on the first day of life. There was a significantly lower mortality in patients with diaphragmatic hernia and moderate heart defects compared to severe heart defects (9 vs. 50%). The mortality in children with a univentricular heart was particularly high. Despite a significantly reduced prognosis for the combination of congenital heart defects and diaphragmatic hernia, generally a poor prognosis does not have to be expected. A curative approach can be achieved in specialized centers.

A Narrative Review of the 2020 Guidelines for Use of Transesophageal Echocardiography to Assist with Surgical Decision- Making by the Cardiac Anesthesiologist in the Operating Room

Transesophageal echocardiography (TEE) has become an integral part in helping to diagnose, manage, and assess interventions in the cardiac operating room. Multiple guidelines have been created by the American Society of Echocardiography for performing a TEE examination for different cardiac pathologies. The operating room can provide unique challenges when performing a TEE examination, which include hemodynamic instability, time constraints, and use of general anesthesia. The Guideline for the use of TEE to assist in surgical decision- making in the operating room recently was published to provide a starting protocol for conducting a TEE examination for different cardiac surgeries and for using the information obtained to interpret and to communicate findings to the surgical team. This present narrative review focuses and expands upon the relevant portions for the cardiac anesthesiologist.

Assessment of Right Heart Function during Extracorporeal Therapy by Modified Thermodilution in a Porcine Model

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation therapy is a growing treatment modality for acute cardiorespiratory failure. Cardiac output monitoring during veno-arterial extracorporeal membrane oxygenation therapy remains challenging. This study aims to validate a new thermodilution technique during veno-arterial extracorporeal membrane oxygenation therapy using a pig model.

METHODS

Sixteen healthy pigs were centrally cannulated for veno-arterial extracorporeal membrane oxygenation, and precision flow probes for blood flow assessment were placed on the pulmonary artery. After chest closure, cold boluses of 0.9% saline solution were injected into the extracorporeal membrane oxygenation circuit, right atrium, and right ventricle at different extracorporeal membrane oxygenation flows (4, 3, 2, 1 l/min). Rapid response thermistors in the extracorporeal membrane oxygenation circuit and pulmonary artery recorded the temperature change. After calculating catheter constants, the distributions of injection volumes passing each circuit were assessed and enabled calculation of pulmonary blood flow. Analysis of the exponential temperature decay allowed assessment of right ventricular function.

RESULTS

Calculated blood flow correlated well with measured blood flow (r2 = 0.74, P < 0.001). Bias was -6 ml/min [95% CI ± 48 ml/min] with clinically acceptable limits of agreement (668 ml/min [95% CI ± 166 ml/min]). Percentage error varied with extracorporeal membrane oxygenation blood flow reductions, yielding an overall percentage error of 32.1% and a percentage error of 24.3% at low extracorporeal membrane oxygenation blood flows. Right ventricular ejection fraction was 17 [14 to 20.0]%. Extracorporeal membrane oxygenation flow reductions increased end-diastolic and end-systolic volumes with reductions in pulmonary vascular resistance. Central venous pressure and right ventricular ejection fractions remained unchanged. End-diastolic and end-systolic volumes correlated highly (r2 = 0.98, P < 0.001).

CONCLUSIONS

Adapted thermodilution allows reliable assessment of cardiac output and right ventricular behavior. During veno-arterial extracorporeal membrane oxygenation weaning, the right ventricle dilates even with stable function, possibly because of increased venous return.

EDITOR’S PERSPECTIVE