Abstract Mechanical circulatory assistance has become a frequent therapeutic option for patients with advanced heart failure. For patients with acute cardiogenic shock and impaired organ function, ...short-term assistance with venoarterial extracorporeal membrane oxygenation is the leading therapeutic option. It enables a “bridge to decision-making” i.e. withdrawal of the device after myocardial recovery or after recognition of therapeutic futility, or as a bridge-to-transplantation or to long-term mechanical support. For Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) class 2–6 patients, implantation of a long-term ventricular assist-device (VAD) should be considered before progression to multiple organ failure if heart transplantation is not a first-line option. Most patients receive a miniaturized axial or centrifugal fully implantable left VAD as a bridge-to-transplantation or as “destination therapy” in this setting.
Cardiogenic shock can occur due to acute ischaemic or non-ischaemic cardiac events, or from progression of long-standing underlying heart disease. When addressing the cause of underlying disease, the ...management of cardiogenic shock consists of vasopressors and inotropes; however, these agents can increase myocardial oxygen consumption, impair tissue perfusion, and are frequently ineffective. An alternative approach is to temporarily augment cardiac output using mechanical devices. The use of these devices—known as temporary circulatory support systems—has increased substantially in recent years, despite being expensive, resource intensive, associated with major complications, and lacking high-quality evidence to support their use. This Review summarises the physiological basis underlying the use of temporary circulatory support for cardiogenic shock, reviews the evidence informing indications and contraindications, addresses ethical considerations, and highlights the need for further research.
WHO interim guidelines recommend offering extracorporeal membrane oxygenation (ECMO) to eligible patients with acute respiratory distress syndrome (ARDS) related to coronavirus disease 2019 ...(COVID-19). The number of patients with COVID-19 infection who might develop severe ARDS that is refractory to maximal medical management and require this level of support is currently unknown. Available evidence from similar patient populations suggests that carefully selected patients with severe ARDS who do not benefit from conventional treatment might be successfully supported with venovenous ECMO. The need for ECMO is relatively low and its use is mostly restricted to specialised centres globally. Providing complex therapies such as ECMO during outbreaks of emerging infectious diseases has unique challenges. Careful planning, judicious resource allocation, and training of personnel to provide complex therapeutic interventions while adhering to strict infection control measures are all crucial components of an ECMO action plan. ECMO can be initiated in specialist centres, or patients can receive ECMO during transportation from a centre that is not specialised for this procedure to an expert ECMO centre. Ensuring that systems enable safe and coordinated movement of critically ill patients, staff, and equipment is important to improve ECMO access. ECMO preparedness for the COVID-19 pandemic is important in view of the high transmission rate of the virus and respiratory-related mortality.
The use of extracorporeal membrane oxygenation (ECMO) for both respiratory and cardiac failure in adults is evolving rapidly. Advances in technology and accumulating data are spurring greater ...interest and explosive growth in ECMO worldwide. Expanding indications and novel strategies are being used. Yet the use of ECMO outpaces the data. The promise of a major paradigm shift for the treatment of respiratory and cardiac failure is tempered by a need for evidence to support many current and potential future uses. The authors review cannulation strategies, indications, and evidence for ECMO in respiratory and cardiac failure in adults as well as potential applications and the impact they may have on current treatment paradigms.
Bayesian analysis of clinical trial data may provide useful information to aid in study interpretation, especially when trial evidence suggests that the benefits of an intervention are uncertain, ...such as in a trial that evaluated early extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS).
To demonstrate the potential utility of Bayesian analyses by estimating the posterior probability, under various assumptions, that early ECMO was associated with reduced mortality in patients with very severe ARDS in a randomized clinical trial (RCT).
A post hoc Bayesian analysis of data from an RCT (ECMO to Rescue Lung Injury in Severe ARDS EOLIA) that included 249 patients with very severe ARDS who had been randomized to receive early ECMO (n = 124; mortality at 60 days, 35%) vs initial conventional lung-protective ventilation with the option for rescue ECMO (n = 125, mortality at 60 days, 46%). The trial was designed to detect an absolute risk reduction (ARR) of 20%, relative risk (RR) of 0.67. Statistical prior distributions were specified to represent varying levels of preexisting enthusiasm or skepticism for ECMO and by Bayesian meta-analysis of previously published studies (with downweighting to account for differences and quality between studies). The RR, credible interval (CrI), ARR, and probability of clinically important mortality benefit (varying from RR less than 1 to RR less than 0.67 and ARR from 2% or more to 20% or more) were estimated with Bayesian modeling.
Combining a minimally informative prior distribution with the findings of the EOLIA trial, the posterior probability of RR less than 1 for mortality at 60 days after randomization was 96% (RR, 0.78 95% CrI, 0.56-1.04); the posterior probability of RR less than 0.67 was 18%, the probability of ARR of 2% or more was 92%, and the probability of ARR of 20% or more was 2%. With a moderately enthusiastic prior, equivalent to information from a trial of 264 patients with an RR of 0.78, the estimated RR was 0.78 (95% CrI, 0.63-0.96), the probability of RR less than 1 was 99%, the probability of RR less than 0.67 was 8%, the probability of ARR of 2% or more was 97%, and the probability of ARR of 20% or more was 0%. With a strongly skeptical prior, equivalent to information from a trial of 264 patients with an RR of 1.0, the estimated RR was 0.88 (95% CrI, 0.71-1.09), the probability of RR less than 1 was 88%, the probability of RR less than 0.67 was 0%, the probability of ARR of 2% or more was 78%, and the probability of ARR of 20% or more was 0%. If the prior was informed by previous studies, the estimated RR was 0.71 (95% CrI, 0.55-0.94), the probability of RR less than 1 was 99%, the probability of RR less than 0.67 was 48%, the probability of ARR of 2% or more was 98%, and the probability of ARR of 20% or more was 4%.
Post hoc Bayesian analysis of data from a randomized clinical trial of early extracorporeal membrane oxygenation compared with conventional lung-protective ventilation with the option for rescue extracorporeal membrane oxygenation among patients with very severe acute respiratory distress syndrome provides information about the posterior probability of mortality benefit under a broad set of assumptions that may help inform interpretation of the study findings.
Increasing use of extracorporeal membrane oxygenation (ECMO) for acute respiratory failure may increase resource requirements and hospital costs. Better prediction of survival in these patients may ...improve resource use, allow risk-adjusted comparison of center-specific outcomes, and help clinicians to target patients most likely to benefit from ECMO.
To create a model for predicting hospital survival at initiation of ECMO for respiratory failure.
Adult patients with severe acute respiratory failure treated by ECMO from 2000 to 2012 were extracted from the Extracorporeal Life Support Organization (ELSO) international registry. Multivariable logistic regression was used to create the Respiratory ECMO Survival Prediction (RESP) score using bootstrapping methodology with internal and external validation.
Of the 2,355 patients included in the study, 1,338 patients (57%) were discharged alive from hospital. The RESP score was developed using pre-ECMO variables independently associated with hospital survival on logistic regression, which included age, immunocompromised status, duration of mechanical ventilation before ECMO, diagnosis, central nervous system dysfunction, acute associated nonpulmonary infection, neuromuscular blockade agents or nitric oxide use, bicarbonate infusion, cardiac arrest, PaCO2, and peak inspiratory pressure. The receiver operating characteristics curve analysis of the RESP score was c = 0.74 (95% confidence interval, 0.72-0.76). External validation, performed on 140 patients, exhibited excellent discrimination (c = 0.92; 95% confidence interval, 0.89-0.97).
The RESP score is a relevant and validated tool to predict survival for patients receiving ECMO for respiratory failure.
The use of extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure (ARF) in adults is growing rapidly given recent advances in technology, even though there is controversy ...regarding the evidence justifying its use. Because ECMO is a complex, high-risk, and costly modality, at present it should be conducted in centers with sufficient experience, volume, and expertise to ensure it is used safely. This position paper represents the consensus opinion of an international group of physicians and associated health-care workers who have expertise in therapeutic modalities used in the treatment of patients with severe ARF, with a focus on ECMO. The aim of this paper is to provide physicians, ECMO center directors and coordinators, hospital directors, health-care organizations, and regional, national, and international policy makers a description of the optimal approach to organizing ECMO programs for ARF in adult patients. Importantly, this will help ensure that ECMO is delivered safely and proficiently, such that future observational and randomized clinical trials assessing this technique may be performed by experienced centers under homogeneous and optimal conditions. Given the need for further evidence, we encourage restraint in the widespread use of ECMO until we have a better appreciation for both the potential clinical applications and the optimal techniques for performing ECMO.
This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2023. Other selected articles can be found online at ...https://www.biomedcentral.com/collections/annualupdate2023 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .
BACKGROUNDExtracorporeal carbon-dioxide removal (ECCO2R) might allow ultraprotective mechanical ventilation with lower tidal volume (VT) (< 6 ml/kg predicted body weight), plateau pressure (Pplat) (< ...30 cmH2O), and driving pressure to limit ventilator-induced lung injury. This study was undertaken to assess the feasibility and safety of ECCO2R managed with a renal replacement therapy (RRT) platform to enable very low tidal volume ventilation of patients with mild-to-moderate acute respiratory distress syndrome (ARDS).METHODSTwenty patients with mild (n = 8) or moderate (n = 12) ARDS were included. VT was gradually lowered from 6 to 5, 4.5, and 4 ml/kg, and PEEP adjusted to reach 23 ≤ Pplat ≤ 25 cmH2O. Standalone ECCO2R (no hemofilter associated with the RRT platform) was initiated when arterial PaCO2 increased by > 20% from its initial value. Ventilation parameters (VT, respiratory rate, PEEP), respiratory system compliance, Pplat and driving pressure, arterial blood gases, and ECCO2R-system operational characteristics were collected during at least 24 h of very low tidal volume ventilation. Complications, day-28 mortality, need for adjuvant therapies, and data on weaning off ECCO2R and mechanical ventilation were also recorded.RESULTSWhile VT was reduced from 6 to 4 ml/kg and Pplat kept < 25 cmH2O, PEEP was significantly increased from 13.4 ± 3.6 cmH2O at baseline to 15.0 ± 3.4 cmH2O, and the driving pressure was significantly reduced from 13.0 ± 4.8 to 7.9 ± 3.2 cmH2O (both p < 0.05). The PaO2/FiO2 ratio and respiratory-system compliance were not modified after VT reduction. Mild respiratory acidosis occurred, with mean PaCO2 increasing from 43 ± 8 to 53 ± 9 mmHg and mean pH decreasing from 7.39 ± 0.1 to 7.32 ± 0.10 from baseline to 4 ml/kg VT, while the respiratory rate was not altered. Mean extracorporeal blood flow, sweep-gas flow, and CO2 removal were 421 ± 40 ml/min, 10 ± 0.3 L/min, and 51 ± 26 ml/min, respectively. Mean treatment duration was 31 ± 22 h. Day-28 mortality was 15%.CONCLUSIONSA low-flow ECCO2R device managed with an RRT platform easily and safely enabled very low tidal volume ventilation with moderate increase in PaCO2 in patients with mild-to-moderate ARDS.TRIAL REGISTRATIONClinicalTrials.gov, NCT02606240. Registered on 17 November 2015.
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