Lactate and Echocardiography Before Veno-Venous Extracorporeal Membrane Oxygenation Support

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.

Value, time and outcomes of elevated lactate levels in adult patients on extracorporeal membrane oxygenation

INTRODUCTION

Lactate levels have been recognized as a reliable tool for monitoring critically ill patients requiring venoarterial extracorporeal membrane oxygenation (VA ECMO) or venovenous extracorporeal membrane oxygenation (VV ECMO) but the reasons behind the overproduction of lactate are different and the influance for survival remains controversial. We analyzed the lactate values and lactate clearance in adult patients in these two forms of extracorporeal support.

METHODS

Patient demographics, ECMO duration, 30-day mortality, lactate values and lactate clearance at 24, 48 and 72 h from ECMO initiation of patients supported with VV and VA ECMO at Silesian Centre for Heart Deasese, between January 2011 and April 2020 were retrospectively analyzed. The changes in lactate levels were analyzed using the non-parametric U Mann-Whitney tests and Chi-square test. The ROC curves were draw and the area under the curve was calculated.

RESULTS

The study comprised 91 adult patients, Mortality in the first 30 days from initiation of VV and VA ECMO was 39% and 66%, respectively. Lactate levels were significantly higher in non-survivors that received VV and VA ECMO (p < .001), while lactate clearance was similar (p = .256 and p = 1.000, respectively). Survival curves for patients with elevated (>2.0 mmol/L) vs normal (≤2.0 mmol/L) lactate levels at 72 h were significantly different for VV ECMO (p = .007) and VA ECMO (p = .037) but in both groups of ECMO, lactate levels above 2.0 mmol/L at 72 h from ECMO initiation predicted 30 day-mortality.

CONCLUSION

This results emphasized the importance of lactate levels below 2.0 mmol/L at 72 h from both VV and VA ECMO initiation.

The Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal Compared With Conventional Lung Protective Ventilation on Cardiac Function

OBJECTIVES

Lower tidal volume ventilation (targeting 3 mL/kg predicted body weight, PBW) facilitated by extracorporeal carbon dioxide removal (ECCO2R) has been investigated as a potential therapy for acute hypoxemic respiratory failure (AHRF) in the pRotective vEntilation with veno-venouS lung assisT in respiratory failure (REST) trial. We investigated the effect of this strategy on cardiac function, and in particular the right ventricle.

DESIGN

Substudy of the REST trial.

SETTING

Nine U.K. ICUs.

PATIENTS

Patients with AHRF (Pao2/Fio2 < 150 mm Hg [20 kPa]).

INTERVENTION

Transthoracic echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements were collected at baseline and postrandomization in patients randomized to ECCO2R or usual care.

MEASUREMENTS

The primary outcome measures were a difference in tricuspid annular plane systolic excursion (TAPSE) on postrandomization echocardiogram and difference in NT-proBNP postrandomization.

RESULTS

There were 21 patients included in the echocardiography cohort (ECCO2R, n = 13; usual care, n = 8). Patient characteristics were similar in both groups at baseline. Median (interquartile range) tidal volumes were lower in the ECCO2R group compared with the usual care group postrandomization; 3.6 (3.1-4.2) mL/kg PBW versus 5.2 (4.9-5.7) mL/kg PBW, respectively (p = 0.01). There was no difference in the primary outcome measure of mean (sd) TAPSE in the ECCO2R and usual care groups postrandomization; 21.3 (5.4) mm versus 20.1 (3.2) mm, respectively (p = 0.60). There were 75 patients included in the NT-proBNP cohort (ECCO2R, n = 36; usual care, n = 39). Patient characteristics were similar in both groups at baseline. Median (interquartile range [IQR]) tidal volumes were lower in the ECCO2R group than the usual care group postrandomization; 3.8 (3.3-4.2) mL/kg PBW versus 6.7 (5.8-8.1) mL/kg PBW, respectively (p < 0.0001). There was no difference in median (IQR) NT-proBNP postrandomization; 1121 (241-5370) pg/mL versus 1393 (723-4332) pg/mL in the ECCO2R and usual care groups, respectively (p = 0.30).

CONCLUSIONS

In patients with AHRF, a reduction in tidal volume facilitated by ECCO2R, did not modify cardiac function.

Oncostatin M for characterizing the inflammatory burden and outcome of V-V ECMO in ARDS patients

BACKGROUND

Assessing the outcome of Veno-Venous Extracorporeal Membrane Oxygenation (V-V ECMO) support remains challenging as plasma lactate (pLA), the widely used tool for this purpose, has been shown unreliable. We hypothesized that plasma oncostatin M (pOSM), a sensitive marker of leukocyte activation in infection and inflammation, could address this deficiency.

METHODS

Plasma OSM levels were measured by ELISA in 30 Acute Respiratory Distress Syndrome (ARDS) patients, prior to cannulation (baseline) and decannulation.

RESULTS

Based on the absolute pOSM levels at presentation, patients were separated into two groups, A and B. Patients in group A had low pOSM levels (Mean ± SD; Median, 1.1 ± 3.8; 0 pg/mL), whereas group B had high pOSM levels (1548 ± 1999; 767 pg/mL) [t-test: p < 0.01]. The percentage of pOSM levels at decannulation relative to baseline OSM levels was significantly higher in those who died (116.8 ± 68.0; 85.3%) than those who survived (47.6 ± 25.5; 48.9%) [t-test: p = 0.02; Mann-Whitney U Test: p = 0.01]. Conversely, no significant difference was observed in the percentage of pLA levels between those who died (142.9 ± 179.9; 89.8%) and those who survived (79.3 ± 34.3; 81.8%) [t-test: p = 0.31; Mann-Whitney U Test: p = 0.63].

CONCLUSION

These early findings suggested critical value of absolute and relative pOSM to characterize the inflammatory burden of ARDS patients and the outcome of their V-V ECMO support.

Advanced Metrics and Early Predictors of Cardiogenic Shock

Cardiogenic shock (CS) can be defined as a range of illnesses that describes a state where cardiac output, which is the blood volume ejected from the left ventricle every minute that leads to tissue perfusion of nutrients, is insufficient in providing adequate oxygenation to the systemic circulation. The incidence of CS on admission has increased in recent years, with the six- and 12-month mortality rates remaining unchanged. The purpose of this literature review is to bring forth several parameters that have been utilized in the past 10 years to predict CS mortality. Further studies to implement these parameters in management algorithms, along with early screenings and advanced treatment options such as mechanical cardiac assist devices, can improve the mortality associated with CS. This literature-based review was conducted by evaluating current research focusing on the clinical presentation of CS and predictors of CS. PubMed served as the primary database for article retrieval due to access. Two searches were conducted: One for clinical presentations and advanced metrics for CS and another for early predictors for CS. Thirteen articles regarding clinical presentation and seven articles regarding early predictors were selected. Three tools/scores and five laboratory tests were identified that allowed clinicians to prognosticate outcomes in patients suffering from CS based on clinical and laboratory presentations. Examining these predictors will allow earlier intervention in the development of CS and potentially help lower the mortality rate of CS. The eventual creation of a scoring system that incorporates multiple metrics discussed in this review can provide the most accurate prognosis of CS, which can lead to more targeted interventions.

Right ventricular dysfunction in patients with acute respiratory distress syndrome receiving venovenous extracorporeal membrane oxygenation

Acute respiratory distress syndrome is characterized by non-cardiogenic pulmonary edema, decreased pulmonary compliance, and abnormalities in gas exchange, especially hypoxemia. Patients with acute respiratory distress syndrome (ARDS) who receive support with venovenous (V-V) extracorporeal membrane oxygenation (ECMO) usually have severe lung disease. Many patients with ARDS have associated pulmonary vascular injury which can result in elevated pulmonary vascular resistance and right heart dysfunction. Since V-V ECMO relies upon preserved cardiac function, right heart failure has important implications for patient evaluation, management, and outcomes. Worsening right heart function complicates ARDS and disease processes. Given the increasing use of ECMO to support patients with ARDS, an understanding of right ventricular-ECMO and cardiopulmonary interactions is essential for the clinician. A narrative review of the manifestations of right heart dysfunction, as well as diagnosis and management strategies for the patient with ARDS on ECMO, is provided.

Right Ventricular Injury Increases Mortality in Patients With Acute Respiratory Distress Syndrome on Veno-Venous Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

Right ventricular injury (RVI) in the context of acute respiratory distress syndrome (ARDS) is well recognized as an important determinant risk factor of mortality. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is part of the algorithm for the management of patients with severe ARDS and severely impaired gas exchange. Although VV-ECMO may theoretically protect the RV it is uncertain to what degree RVI persists despite VV-ECMO support, and whether it continues to influence mortality after ECMO initiation. The aim of this systematic review and meta-analysis was to investigate the impact of RVI on mortality in this context, testing the hypothesis that RVI worsens mortality in this cohort. We performed a systematic search that identified seven studies commenting on RVI and mortality in patients with ARDS receiving VV-ECMO. The presence of RVI was associated with greater mortality overall (odds ratios [OR]: 2.72; 95% confidence intervals [CI]: 1.52-4.85; p < 0.00) and across three subgroups (RV dilatational measures: OR: 3.51; 95% CI: 1.51-8.14; p < 0.01, RV functional measures: OR: 1.84; 95% CI: 0.99-3.42; p = 0.05, RV measurements post-ECMO initiation: OR: 1.94; 95% CI: 1.01-3.72; p < 0.05). Prospective studies are needed to investigate the causal relationship between RVI and mortality in this patient group and the best management strategies to reduce mortality.

Veno-venous extracorporeal membrane oxygenation (vv-ECMO) for severe respiratory failure in adult cancer patients: a retrospective multicenter analysis

Purpose

The question of whether cancer patients with severe respiratory failure benefit from veno-venous extracorporeal membrane oxygenation (vv-ECMO) remains unanswered. We, therefore, analyzed clinical characteristics and outcomes of a large cohort of cancer patients treated with vv-ECMO with the aim to identify prognostic factors.

Methods

297 cancer patients from 19 German and Austrian hospitals who underwent vv-ECMO between 2009 and 2019 were retrospectively analyzed. A multivariable cox proportional hazards analysis for overall survival was performed. In addition, a propensity score-matched analysis and a latent class analysis were conducted.

Results

Patients had a median age of 56 (IQR 44–65) years and 214 (72%) were males. 159 (54%) had a solid tumor and 138 (47%) a hematologic malignancy. The 60-day overall survival rate was 26.8% (95% CI 22.1–32.4%). Low platelet count (HR 0.997, 95% CI 0.996–0.999; p = 0.0001 per 1000 platelets/µl), elevated lactate levels (HR 1.048, 95% CI 1.012–1.084; p = 0.0077), and disease status (progressive disease [HR 1.871, 95% CI 1.081–3.238; p = 0.0253], newly diagnosed [HR 1.571, 95% CI 1.044–2.364; p = 0.0304]) were independent adverse prognostic factors for overall survival. A propensity score-matched analysis with patients who did not receive ECMO treatment showed no significant survival advantage for treatment with ECMO.

Conclusion

The overall survival of cancer patients who require vv-ECMO is poor. This study shows that the value of vv-ECMO in cancer patients with respiratory failure is still unclear and further research is needed. The risk factors identified in the present analysis may help to better select patients who may benefit from vv-ECMO.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06635-y.

Development and validation of a nomogram model for early postoperative hyperlactatemia in patients undergoing cardiac surgery

Background

Postoperative hyperlactatemia (POHL) is common in patients undergoing cardiac surgery, associated with adverse outcomes. The aim of this study was to identify predictors for POHL after cardiac surgery and to develop and validate a predictive model.

Methods

Adult patients who underwent open heart surgery at our institution between 2016 and 2019 were retrospectively included. The patients were randomly divided into training and validation groups at a 2:1 ratio. Multivariate logistic regression was performed to identify independent predictors for POHL in the training set. A nomogram was then constructed and was validated in the validation set.

Results

POHL developed in 713 of the 5,323 patients (13.4%). The mortality rate was higher in patients with POHL compared with patients without that (9.5% vs. 2.1%, P<0.001). Age, white blood cell (WBC) count, left ventricular ejection fraction, renal insufficiency, cardiac surgery history, red blood cell (RBC) transfusion, and cardiopulmonary bypass (CPB) time were identified as independent risk factors. The nomogram based on these predictors indicated good discrimination in both the training (c-index: 0.787) and validation (c-index: 0.820) sets. The calibration was reasonable by both visual inspection and goodness-of-fit test. The decision and clinical impact curves demonstrated good clinical utility.

Conclusions

We identified 7 independent risk factors and derived a prediction model for POHL in patients undergoing cardiac surgery. The model may contribute significantly to early risk assessment and clinical intervention.

Mortality of right ventricular dysfunction in patients with acute respiratory distress syndrome subjected to lung protective ventilation: A systematic review and meta-analysis

BACKGROUND

The impact of right ventricular dysfunction(RVD) on the prognosis of acute respiratory distress syndrome(ARDS) patients is controversial.

OBJECTIVES

The objectives of this systematic review and meta-analysis was to investigate whether RVD or pulmonary vascular dysfunction are associated with increased mortality in patients with ARDS.

METHODS

We searched Pubmed, Embase, Cochrane Library, Wanfang Data, CNKI, and the WHO Clinical Trial Registry for studies of RVD or pulmonary vascular dysfunction in patients with ARDS.

RESULTS

The presence of RVD or pulmonary vascular dysfunction in patients with ARDS was associated with an increase in mortality (OR = 1.68, 95% CI = 1.21-2.32, P = 0.069, I² = 40.8%). Subgroup analyses obtained similar results. Funnel plots and the Egger's test indicated no publication bias, and sensitivity analyses determined that the results were stable.

CONCLUSION

The prognosis of patients with ARDS and RVD or pulmonary vascular dysfunction is worse than that of ARDS patients without RVD or pulmonary vascular dysfunction.

Is Extracorporeal Membrane Oxygenation the Standard Care for Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a type of acute respiratory failure syndrome characterised by severe respiratory distress and stubborn hypoxaemia. Patients with ARDS have a prolonged hospital stay and high mortality rate. Over long-term follow-up, ARDS is found to be associated with a high incidence of long-term complications and decreased quality of life. Venovenous extracorporeal membrane oxygenation (vv-ECMO) has been widely used for the treatment of refractory ARDS. However, it is not the standard treatment as recommended by ARDS guidelines.

AIM

The aim of this study was to compare the effects of ECMO (vv-ECMO) and conventional mechanical ventilation (CMV) on the clinical outcomes in patients with ARDS.

METHOD

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, Medline, EMBASE, Web of Science, and PubMed databases up to November 2019. We selected appropriate studies according to our inclusion and exclusion criteria, and extracted and analysed the data using RevMan 5.0 software to evaluate the effectiveness of ECMO systematically.

RESULTS

A total of 18 articles and 2,399 patients were included in this meta-analysis: 898 patients in the ECMO group and 1,501 patients in the CMV group. Treatment with ECMO may be associated with reduced 1-year mortality (95% confidence interval [CI], 0.27-0.83; p=0.009) and 60-day mortality (95% CI, 0.37-0.86; p=0.008), but increased Intensive Care Unit mortality (95% CI, 1.26-2.36; p=0.0007) of patients with ARDS. Extracorporeal membrane oxygenation may not be related to 30-day mortality or complications such as nosocomial pneumonia, haemorrhagic stroke, or continuous renal replacement therapy in patients with ARDS. However, some results showed heterogeneity, such as bleeding complications and in-hospital mortality. Subgroup analysis showed that ECMO treatment might increase ICU mortality (p=0.002) and nosocomial pneumonia complications (p=0.03) in patients with H1N1 ARDS.

CONCLUSIONS

Compared with CMV, ECMO contributed to lower 60-day and 1-year mortality, and increased ICU mortality in patients with ARDS. However, H1N1 ARDS was independently associated with higher ICU mortality and nosocomial pneumonia. The results were not affected by removing retrospective control studies or articles published >20 years ago from the sensitivity analysis. This meta-analysis demonstrates the effectiveness of ECMO and its importance in standard treatment of patients with ARDS.

Impact of Lactate Clearance on Early Outcomes in Pediatric ECMO Patients

Background and Objectives: Pediatric extracorporeal membrane oxygenation (ECMO) support is often the ultimate therapy for neonatal and pediatric patients with congenital heart defects after cardiac surgery. The impact of lactate clearance in pediatric patients during ECMO therapy on outcomes has been analyzed. Materials andMethods: We retrospectively analyzed data from 41 pediatric vaECMO patients between January 2006 and December 2016. Blood lactate and lactate clearance have been recorded prior to ECMO implantation and 3, 6, 9 and 12 h after ECMO start. Receiver operating characteristic (ROC) analysis was used to identify cut-off levels for lactate clearance. Results: Lactate levels prior to ECMO therapy (9.8 mmol/L vs. 13.5 mmol/L; p = 0.07) and peak lactate levels during ECMO support (10.4 mmol/L vs. 14.7 mmol/L; p = 0.07) were similar between survivors and nonsurvivors. Areas under the curve (AUC) of lactate clearance at 3, 9 h and 12 h after ECMO start were significantly predictive for mortality (p = 0.017, p = 0.049 and p = 0.006, respectively). Cut-off values of lactate clearance were 3.8%, 51% and 56%. Duration of ECMO support and respiratory ventilation was significantly longer in survivors than in nonsurvivors (p = 0.01 and p < 0.001, respectively). Conclusions: Dynamic recording of lactate clearance after ECMO start is a valuable tool to assess outcomes and effectiveness of ECMO application. Poor lactate clearance during ECMO therapy in pediatric patients is a significant marker for higher mortality.

Right Ventricular Dysfunction and Mortality After Cannulation for Venovenous Extracorporeal Membrane Oxygenation

Objectives

To assess the prevalence and prognostic value of right ventricular dysfunction as measured by echocardiography in patients treated with venovenous extracorporeal membrane oxygenation.

Design

Retrospective cohort study. The primary endpoint was survival to discharge. Survival to extracorporeal membrane oxygenation decannulation was the secondary endpoint.

Setting

ICU at an academic quaternary medical center.

Subjects

Sixty-four consecutive patients treated with venovenous extracorporeal membrane oxygenation between January 2013 and December 2018 with an echocardiogram performed after cannulation.

Interventions

Transthoracic or transesophageal echocardiography was used to assess several standard right and left ventricular characteristics after cannulation with venovenous extracorporeal membrane oxygenation.

Measurements and Main Results

No single echo variable was predictive of outcomes. Composite markers such as right ventricular dysfunction (right ventricular dilation and abnormal septal motion) or a small dynamic left ventricle (left ventricle internal diastolic diameter < 4.0 cm and left ventricular ejection fraction > 60%) were associated with significantly decreased survival to decannulation (45% vs 83%; p < 0.01) and survival to hospital discharge (32% vs 64%; p = 0.02). Regression models confirmed the absence of both right ventricular dysfunction, and small left ventricle was highly predictive of increased survival to decannulation (odds ratio, 6; 95% CI, 1.87-19.28; p < 0.01) and discharge (odds ratio, 3.86; 95% CI, 1.29-11.55; p = 0.02).

Conclusions

Echocardiographic variables consistent with right ventricular dysfunction or a small dynamic left ventricle were associated with decreased survival to decannulation and hospital discharge. These results enhance prognostic capabilities while implicating right ventricular dysfunction in the high mortality observed in this patient population.

ECMO and Right Ventricular Failure: Review of the Literature

Right ventricular (RV) failure is the inability of the RV to maintain sufficient cardiac output in the setting of adequate preload, due to either intrinsic injury to the RV or increased afterload. Medical treatment of RV failure should include optimizing preload, augmenting contractility with vasopressors and inotropes, and considering inhaled pulmonary vasodilators. However, when medical therapies are insufficient, mechanical circulatory support (MCS) is needed to maintain systemic and RV perfusion. The data on MCS for isolated RV failure are limited, but extracorporeal membrane oxygenation (ECMO) appears to be the most efficient and effective modality. For patients with isolated RV failure from acute hypoxemic respiratory failure, veno-venous (VV) ECMO is an appropriate initial configuration, even if the patient is in shock. With primary RV injury or RV failure with concomitant left ventricle (LV) failure, however, venoarterial (VA) ECMO is indicated. Both modalities provide indirect support to the RV by reducing preload, reducing RV wall tension, and delivering oxygenated blood to the coronary circulation. Peripheral cannulation is required in VV-ECMO and is most commonly used in VA-ECMO, allowing for rapid cannulation even in emergencies. Changes in pulsatility on an arterial catheter waveform can indicate changes in clinical status including changes in myocardial function, inadequate preload, worsening RV failure, and excessive VA-ECMO support leading to an elevated LV afterload. Myocardial function may be improved by titration of inotropes or vasodilators, utilization of an Impella or an intra-aortic balloon counterpulsation support devices, or by changes in VA-ECMO support.

Extracorporeal Membrane Oxygenation in Transport Part 1: Extracorporeal Membrane Oxygenation Configurations and Physiology

Extracorporeal membrane oxygenation (ECMO), a term used to describe oxygenation that occurs outside of the body, is an increasingly common means of supporting the most critically ill patients. Because of the invasiveness and high probability of serious complications during ECMO, ECMO is typically indicated only when there is a high likelihood of death with conventional treatment. With continued improvements in technology and increasing clinical experience, transport clinicians are increasingly likely to be called on to transport patients on ECMO. ECMO can be initiated in 2 distinct forms, venovenous or venoarterial, and can primarily support the respiratory system or the cardiac and respiratory systems concurrently. This review will cover the basic physiology and components of ECMO as well as the preparation for ECMO transport for adults.

[ECMO treatment in acute lung failure : Who profits?]

In intensive care medicine, rapid technical developments that are often beneficial to patients are taking place. On the other hand, there are also voices that generally criticize an increasing "interventionalism". This area of tension includes other important questions regarding usefulness, quality, ethical compliance, scientific evidence, structural capacities and economy. The treatment of acute respiratory distress syndrome (ARDS) using extracorporeal membrane oxygenation (ECMO) is an example of these considerations. Although ECMO has rarely been prospectively evaluated according to scientific criteria, it is still used with an increasing tendency, not least since the documented register survival rates in ECMO patients with severe ARDS are 60%. However, the implementation of this therapy means an immense effort. The necessary centralization and certification for ECMO treatment is currently under intensive discussion. Closely related to this are considerations about which criteria represent good quality in patient care. In order to be able to guarantee high quality, a precise indication is the first step. And here indications and contraindications still need to be defined. It has not yet been sufficiently clarified which prognosis factors need to be taken into account. This article summarizes what is known about ECMO prognosis and indication criteria. In conclusion, parameters are identified that should be developed scientifically in the future.