Outcomes and survival prediction models for severe adult acute respiratory distress syndrome treated with extracorporeal membrane oxygenation
Rozencwajg et al. Critical Care
Outcomes and survival prediction models for severe adult acute respiratory distress syndrome treated with extracorporeal membrane oxygenation
Sacha Rozencwajg 0 1 3 4 5
David Pilcher 2 5 6
Alain Combes 0 1 3 4 5
Matthieu Schmidt 0 1 3 4 5
0 Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Medical Intensive Care Unit , 75651 Paris Cedex 13 , France
1 Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS_1166-ICAN, Institute of Cardiometabolism and Nutrition , 75651 Paris Cedex 13 , France
2 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology
3 Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Medical Intensive Care Unit , 75651 Paris Cedex 13 , France
4 Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS_1166-ICAN, Institute of Cardiometabolism and Nutrition , 75651 Paris Cedex 13 , France
5 Preventive Medicine, School of Public Health, Monash University , Melbourne , Australia
6 Intensive Care Department, Alfred Hospital , Melbourne , Australia
Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS) has known a growing interest over the last decades with promising results during the 2009 A(H1N1) influenza epidemic. Targeting populations that can most benefit from this therapy is now of major importance. Survival has steadily improved for a decade, reaching up to 65% at hospital discharge in the most recent cohorts. However, ECMO is still marred by frequent and significant complications such as bleeding and nosocomial infections. In addition, physiological and psychological symptoms are commonly described in long-term follow-up of ECMO-treated ARDS survivors. Because this therapy is costly and exposes patients to significant complications, seven prediction models have been developed recently to help clinicians identify patients most likely to survive once ECMO has been initiated and to facilitate appropriate comparison of risk-adjusted outcomes between centres and over time. Higher age, immunocompromised status, associated extra-pulmonary organ dysfunction, low respiratory compliance and non-influenzae diagnosis seem to be the main determinants of poorer outcome.
Extracorporeal membrane oxygenation; Acute respiratory distress syndrome; Outcome; Predictive survival models; ECMO-related complications
Extracorporeal membrane oxygenation (ECMO) is
considered a therapeutic option for patients with severe
acute respiratory distress syndrome (ARDS) with
refractory hypoxemia or unable to tolerate volume-limited
strategies [1, 2]. Use of ECMO has been growing
exponentially in the last decade , encouraged by promising
results from the multi-centred randomized controlled
trial CESAR  and benefits described during the
influenza A(H1N1) pandemic. In addition, major
progress in technology (e.g. smaller devices, heparin-coated
circuits, biocompatible membranes, dual lumen cannulae)
 and network organization, with referral centres and
mobile ECMO teams available 24/7, have both
contributed to exponentially increase the use of ECMO (Fig. 1).
However, despite these improvements, ECMO is still
marred by a high rate of complications such as bleeding,
thrombosis and nosocomial infection [6–8]. Moreover,
ECMO-treated survivors exhibit significant rates of
longterm neuro-psychological and/or physical impairment .
To date, most of the severe ARDS patients are either
referred to ECMO referral centres [4, 9] or cannulated in
a distant hospital by a mobile ECMO team [4, 10, 11].
Because this therapy is costly and exposes patients to
significant complications, a number of prediction models
have been developed recently to help clinicians identify
patients most likely to survive once ECMO has been
initiated and to facilitate appropriate comparison of
risk-adjusted outcomes between centres and over time.
This review will describe actual short-term and long-term
outcomes of patients with severe ARDS treated with
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Fig. 1 Number of annual adult respiratory cases treated by venovenous ECMO from 1996 to 2015 and the relative hospital survival rate. Adapted
from the ELSO ECLS Registry Report . ECMO extracorporeal membrane oxygenation
ECMO and summarize the characteristics and
performance of published survival prediction models.
Outcomes of severe ARDS patients with and
Outcomes of severe ARDS treated with “conventional”
The past two decades have seen significant progress in
ARDS management. A more accurate definition has been
proposed  and major progress has been achieved in
understanding the ARDS pathophysiology [13–15] and
ventilator-induced lung injury [16, 17]. In addition,
protective-lung mechanical ventilation  and adjuvant
therapies such as prone positioning  and
neuromuscular blockers  have contributed to improvements in
overall ARDS mortality. Despite this, the pooled mortality
of ARDS (covering all levels of ARDS severity) remains
high, even more so in observational studies (48.2%) than
in randomized controlled trials (37.5%) . The mortality
for severe ARDS is higher still, at 50% [12, 22, 23]. In
addition, the burden of ARDS is still perceptible years
after ICU discharge, with notable impairment of quality of
life . Reported long-term sequelae include
ICUacquired weakness, exercise limitation, frozen shoulders,
vocal-cord dysfunction or recurrent reactive airways
disease which may contribute to social isolation,
psychological morbidity and sexual dysfunction . In a large
cohort of 109 patients with ARDS, 51% of patients
reported at least one episode of depression and/or severe
anxiety within 5 years of follow-up . Nevertheless, 77%
of patients returned to work; almost all to their original
work 5 years after ICU discharge.
Outcomes of ARDS treated with venovenous ECMO
Outcomes of patients with ARDS on ECMO have
improved steadily over a decade (Fig. 1) thanks to the
progress of the devices  and better prevention of
ECMO-related complications such as bleeding.
The first large international multicentre database on
ECMO for severe ARDS was provided by Brogan et al.
 using a registry issued from a collaborative
international network (Extracorporeal Life Support
Organization (ESLO)). The data, collected between 1986
and 2006, covered 1473 patients with a median age of
34 years, 78 of whom were treated with venovenous
ECMO (VV-ECMO) with a median time of support of
154 hours. They reported an all-cause mortality of 50%.
Risk factors associated with a poorer outcome were
advanced age, days on mechanical ventilation prior to
ECMO and decreased patient weight. These results were
relatively consistent with the CESAR trial , which
reported 63% survival without severe disability at
6 months. In this trial, conducted between 2001 and
2006 in the United Kingdom, 180 patients with severe
ARDS were either randomized into ECMO (after
transfer to a referral “ECMO centre”) or to conventional
management at the referring hospital. These patients
suffered from severe and potentially reversible ARDS.
Their median age was 40 years (mean APACHE II 20),
with a primary diagnosis of pneumonia in 66%. The
same year, Australia and New Zealand Extracorporeal
Membrane Oxygenation (ANZ ECMO)  reported
excellent results with a cohort of influenza
A(H1N1)-related ARDS patients. They reported 78% of patients
weaned from ECMO and 71% ICU discharge survival
despite extreme severity before cannulation (median
lowest PaO2/FIO2 ratio 56 mmHg, pH 7.2, PaCO2
69 mmHg and modified acute lung injury score of 3.8).
These results should, however, be interpreted with
caution because influenza A(H1N1)-related ARDS has a
better prognosis than other causes of ARDS [27, 28].
More recently, Schmidt et al.  reported the outcome
of 140 patients from three French ICUs. Ninety-five per
cent of patients received VV-ECMO with a median time
between intubation and ECMO cannulation of 5 (1–11)
days. Bacterial pneumonia was the main cause of ARDS
(45%). Influenza A(H1N1)-related ARDS was noted in
26%. Survival rates were respectively 64% and 60% at
ICU discharge and 6 months. A cohort of 2355 patients
extracted from the international ELSO registry  has
also been studied recently. ECMO therapy was initiated
after a median of 57 hours of mechanical ventilation,
with 49% of patients receiving neuromuscular blocker
agents, 20% inhaled nitric oxide and 10% high-frequency
oscillatory ventilation. Fifty-seven per cent of patients
were alive at hospital discharge after a median of
170 hours on ECMO.
The few studies of long-term outcome after ECMO are
described in Table 1. The frequent use for young adults
with no pre-existing co-morbidities should foster
clinicians to measure long-term impact of this therapy. The
long-term effects of ECMO have been evaluated broadly
in three areas: respiratory function; psychological
impairment; and quality of life.
Post-ECMO respiratory impairment can be assessed in
three domains: lung capacity assessed by lung function
tests; parenchymal changes observed on imaging; and
respiratory symptoms. In the CESAR trial , lung
function tests, performed 6 months post ECMO, indicated
relatively preserved lung capacity (forced vital capacity
79.6% predicted, peak expiratory flow rate 54.5%
predicted) and were no different to the conventional
management group. Similarly, Lindén et al.  reported
lung function measured at varying time points at least
1 year post ECMO in a cohort of 21 survivors of
bacterial pneumonia-related ARDS treated with ECMO. They
described slightly impaired lung function with a mildly
obstructive pattern (forced expired volume at 1 second
< 80%). Measurement of SpO2 during exercise tests was
low in 43% patients and a reduced DLCO (70% of
predicted value) was noted in 65%. In addition, radiological
changes compatible with interstitial fibrosis were
reported in 76% of the population. In the study by Li
et al. , 15 patients underwent 1-year follow-up with
repeated computed tomography after severe ARDS
requiring VV-ECMO. Eighty-seven per cent of patients
exhibited similar changes, with more severe damage
distributed in the ventral region. In the context of influenza
A(H1N1)-related ARDS, similar findings were reported
by Luyt et al. . Lung function tests on 67 patients
demonstrated a mild impairment of lung-diffusion
properties (DLCO below the fifth percentile of normal
values) in both ECMO and non-ECMO survivors with
no difference between both groups. No obstructive lung
disease was noted and arterial blood gases at rest and
after exercise were within normal ranges. However, 75%
of patients in the ECMO group suffered from moderate
dyspnoea during strenuous exercise at 1 year .
Lastly, it is notable that most patients in both groups
had returned to work, and one-third practised sport
Health-related quality of life (HRQoL) evaluation
assesses both the physical and psychological impact of
ECMO among survivors. Lindén et al.  first
described HRQoL in their cohort of 21 long-term
survivors of severe ARDS and ECMO, focusing on the
respiratory symptoms, and showed higher scores on the
St George’s Respiratory Questionnaire (SGRQ) than
normal values, indicating subjective respiratory problems
with an impact on daily life. These findings contrast with
the CESAR trial where equivalent SGRQ scores were
reported in both groups. Most of the studies used the
36-Item Short-Form Health Survey (SF-36)  to assess
HRQoL. The physical domain scores of the SF-36
reported mobility limitation or self-care restriction in
about 20–30% of survivors [4, 31, 33], which may mostly
be due to ICU-acquired limb weakness, considered
“slight to moderate” when compared with age-matched
and sex-matched population controls [6, 31].
Psychological impairment may also jeopardize long-term
quality of life of ECMO survivors. Others domains of
the SF-36 evaluate vitality, social functioning and
emotional status. Data regarding psychological impact of
ECMO for ARDS survivors are scarce. However, they
were globally impaired when compared with
agematched and sex-matched population controls [4, 6].
These data were consistent with those of Hodgson et al.
, who reported a 27% decrease in SF-36 mental
component scores in ARDS patients who received ECMO.
Finally, 25–34% of ECMO patients reported long-term
anxiety and depression symptoms, with 15% considered
at risk of post-traumatic stress disorder [4, 6]. These
results were similar to those reported in other post-ICU
In conclusion, HRQoL seems to be significantly
impaired after ECMO for severe ARDS. This must be
interpreted with caution, however, because it may be
attributable to the patient’s ICU length of stay and
underlying disease rather than to ECMO itself. HRQoL
data showing no difference between ECMO and
non-ECMO severe ARDS patients tend to confirm this
The two most important and commonly described
ECMO-related adverse events are bleeding and
Table 1 Studies relating long-term outcomes after ECMO for severe ARDS
Follow-up population 52 21
17 (11–28) months
Factors associated with
death at 6 months
ARDS acute respiratory distress syndrome, ECMO extracorporeal membrane oxygenation, HAD hospital anxiety and depression, HRQoL health-related quality of life, IES Impact of Event Scale, PFT pulmonary function
tests, PTSD post-traumatic stress disorder, SF-36 Medical Outcome Short-Form, SGRQ St George’s Respiratory Questionnaire
26 (12–50) months
9 (8–19) months
Lung function evaluated with PFT, overall health status, HRQoL, depression
and anxiety symptoms
Lung function (PFT), pulmonary symptoms (SGRQ)
Related ECMO complications, survival, discharge destination, return-to-work status
Symptoms and activities since hospital discharge, weight and muscle-strength
testing, lung morphology (CT scan), anxiety and depression (HAD scale), symptoms
of PTSD (IES)
HRQoL (SF-36 score), pulmonary symptoms (SGRQ), anxiety and depression
(HAD scale), symptoms of PTSD (IES)
Bleeding occurs in about 20% of patients on ECMO
with various degrees of severity (i.e. cannula haemorrhage,
spontaneous epistaxis, gastrointestinal or intra-cranial
bleeding, etc.) [37, 38]. The main mechanisms are
anticoagulation, thrombocytopenia and coagulation factor
consumption. ECMO circuits are also responsible for
impaired platelet function  and biological acquired von
Willebrand syndrome (AVWS) [40, 41]. However, a study
by Abrams et al.  reported that severity of critical
illness and platelet count at the time of cannulation, rather
than ECMO duration, were the best predictors for
development of severe thrombocytopenia while receiving
ECMO for respiratory failure. Consumption of red blood
cells has been reported as approximately 1 unit per
ECMO-day while 17% of patients underwent surgery for
bleeding issues . Application of a restrictive
transfusion policy on ECMO is possible by implementing a lower
aim for systemic anticoagulation, a fixed transfusion
threshold of 7 g/dl and auto-transfusion during
Nosocomial infections are also very frequent in ECMO
patients. Their incidence varies widely from 11.7 to 64%
[1, 45, 46], equivalent to 11.9–75.5 infections/1000
ECMO-days. However, these data are lacking in the
specific VV-ECMO population. Among these infections,
the two most common were bloodstream infections and
ventilator-associated pneumonia with a median of 15/
1000 ECMO-days and 4/1000 ECMO-days respectively
when pooling several studies [46–49]. Duration on
ECMO and patient’s severity were independent risk
factors. One should note that the definition of
“ECMOrelated infection” and the diagnostic techniques for
cannula-related infection are not consistent and may
account for differences observed between different studies.
In addition, antibiotic prophylaxis, routine bacterial
surveillance and continuous antibiotics are frequently used in
ECMO centres despite no evidence of their benefit .
Neurological events occurred frequently in patients on
VV-ECMO. Among 135 consecutive patients who had
received VV-ECMO, 18 (15 assessable) developed cerebral
complications on ECMO: cerebral bleeding in 10 patients
(7.5%), ischemic stroke in three patients (2%) or diffuse
microbleeds in two patients (2%). Intracranial bleeding,
the most frequent complication, occurred early and was
associated with higher mortality. Because intracranial
bleeding was independently associated with rapid
hypercapnia decrease, ECMO onset should be avoided in this
situation, but its exact role remains to be determined .
Other ECMO-related complications include thrombosis,
especially deep vein thrombosis in the cannulated vessels
following ECMO. The incidence was estimated at 8.1/
1000 cannula-days and routine venous Doppler
ultrasound following decannulation in the VV-ECMO
population has been advocated . In addition, haemolysis is
commonly observed during VV-ECMO. A recent study of
207 paediatric patients with ECMO reported at least one
episode of haemolysis in 66% patients. Although
haemolysis is frequently considered minor, these patients were
more likely to experience a longer ECMO run and require
more blood products. After controlling for age, weight,
paediatric index of mortality and diagnosis, patients with
severe haemolysis were more likely to die in the ICU and
in hospital (odds ratio (OR) 6.34, 95% confidence interval
(CI) 1.71–23.54; p = 0.006) . In adults, further data are
needed to investigate the causes of haemolysis on ECMO
and to elucidate its influence on morbidity and mortality.
Survival prediction models
Objectives of these scores
Because of the significant numbers of ECMO-related
complications, the high rates of long-term physical and
psychological impairment, and the human and financial
cost, identifying specific populations who could benefit
most from this therapy is crucial. All of these scores
have been derived only from populations already on
ECMO. As such, they should be considered most
appropriate for predicting who will survive once ECMO has
been initiated, comparing outcomes between units and
over time, or helping inform clinicians, family members
and even occasionally patients themselves of likely
outcomes. Without a population of patients who did not
receive ECMO, none of the scores so far described can
be considered directly applicable for choosing which
patients should or should not receive ECMO. However,
given the fact that most of the predictive variables
described have been recorded during the immediate
pre-ECMO period, it is likely that the same factors
which predict survival in populations who are on
ECMO may also be helpful to select patients for
consideration of ECMO.
Survival prediction scores
Over the past 3 years, seven different pre-ECMO
survival prediction scores have been published [6, 27, 28,
53–56]; the characteristics of these scores are
summarized in Table 2 and Fig. 2. The risk factors taken into
account in these models can be divided into four major
determinants: demographic characteristics; organ
dysfunction; characteristics and management of respiratory
failure; and initial diagnosis.
In all models but ECMOnet and the two most recent
published scores [6, 27, 28, 54], age was an independent risk
factor. In the PRESERVE and Roch et al. scores [27, 28],
being younger than 45 years old was associated with a
better prognosis, while a major mortality risk was described
for patients over 60 years of age. Immunocompromised
Table 2 Survival predictive models for patients on VV-ECMO for ARDS
Pappallardo et al. 
Schmidt et al. 
A(H1N1) influenza-related ARDS 60
Roch et al. 
Enger et al. 
ARDS brought to a
Number of Number of Cohort patients centres enrolment Pre-ECMO items
Internal validation’s External validation’s
4. Haematocrit level
5. Mean arterial pressure
5. Days of MV
6. Prone positioning 7. PEEP
8. Plateau pressure
2. Body mass index
4. SOFA score
1. Age 7. Neuromuscular
2. Immunocompromised blockade agents
3. Days of MV 8. Nitric oxide use
4. Diagnosis 9. Bicarbonate infusion
5. Central nervous system 10. Cardiac arrest
dysfunction 11. PaCO2
6. Acute associated 12. Peak inspiratory (non-pulmonary) infection pressure
3. Minute ventilation
2. Underlying lung disease
1. Immunocompromised 2. SOFA score
3. Days of MV
5. Lactate 0.86 0.89 0.74
Fig. 2 Pre-ECMO factors associated with mortality on VV-ECMO according to published predictive survival models. Red pyramid, risk factors; green
pyramid, protective factors: the higher the factor, the heavier impact on mortality according to published predictive survival models. ARDS acute
respiratory distress syndrome, MV mechanical ventilation, Pplat, plateau pressure PEEP positive end-expiratory pressure
status was consistently associated with a poorer outcome
in four out of the seven models [6, 27, 54, 56]. For
instance, chronic immunosuppression was associated with
increased mortality both in Enger et al.’s  score (OR
2.6, 95% CI 1.3–5.2) and the VV-ECMO  mortality
score (OR 2.9, 95% CI 1.1–7.9). Liu et al.  found an
underlying lung disease (i.e. COPD, interstitial lung
disease and lung cancer) to be an independent risk factor
for mortality (OR 12.2, 95% CI 1.2–122.2; p = 0.033). In no
other models were co-morbidities such as chronic organ
dysfunction or diabetes identified as associated with
poorer outcome. However, there were so few patients with
these conditions that it is difficult to raise any conclusion
about their impact on outcome.
Acute organ dysfunction
The number of pre-ECMO organ dysfunctions is
unsurprisingly a significant predictive factor. In the Roch
et al., PRESERVE, Enger et al. and VV-ECMO mortality
scores [27, 28, 54, 56] the SOFA score was used as an
organ failure surrogate, whereas mean arterial pressure,
serum creatinine, bilirubin and haematocrit levels were
used in the ECMOnet score . Lastly, pre-ECMO
central nervous system dysfunction was associated with
a poorer outcome in the RESP score . In recent
retrospective cohorts, SOFA score > 15 was constantly
associated with higher mortality [56–58]. However, it is
worth noting that pre-ECMO neurological status
assessed by the Glasgow Coma Scale score is frequently
difficult to evaluate in these patients due to high-dose
sedative infusion, making reliability of this neurological
SOFA score section questionable .
decade [18–20, 22, 23]. Amongst the patient cohorts from
which scores have been developed, there was evidence of
variation in pre-ECMO management, which influenced
survival. For instance, only 49% of patients received
preECMO neuromuscular blockade in the RESP study 
compared with all patients in Roch et al.’s cohort .
Pre-ECMO nitric oxide and prone positioning were used,
respectively, in 16 and 29% of patients in the ECMOnet
study  vs 90 and 60% in the PRESERVE cohort .
Despite the variation in reported use of pre-ECMO
adjuvant therapies, where these have been reported, the
studies have demonstrated both prone positioning and
provision of neuromuscular blockade to be associated
with improved survival. These findings are consistent with
non-ECMO literature [6, 27]. Duration of mechanical
ventilation pre ECMO over 7 days has been significantly
associated with a poor outcome in the RESP, the
PRESERVE and the VV-ECMO mortality scores [6, 27, 56].
Interestingly, although hypoxemia is a major factor, which
influences the decision to start VV-ECMO, no predictive
score has shown it to be predictive of survival. Potential
reasons for this include a direct effect of ECMO which
reverses the adverse effects of hypoxia, bias induced by lack
of information on “equally hypoxic” patients who do not
receive ECMO or a type II statistical error as a result of
the studies being underpowered to detect a small adverse
effect from hypoxia. On the other hand, pre-ECMO direct
and indirect markers of reduced compliance (e.g. high
PaCO2, high peak inspiratory pressure, plateau
pressure > 30 mmHg or pre-ECMO barotrauma evidence)
were strongly associated with poor outcome in the
PRESERVE, RESP and VV-ECMO mortality scores [6, 27, 56].
Characteristics and management of respiratory failure
Management of mechanical ventilation and adjuvant
therapies for severe ARDS have greatly evolved during the last
Cause of respiratory failure
Aetiology is important in determining the prognosis of
ECMO-treated severe ARDS. Influenza-induced ARDS
was consistently associated with better outcome in the
Roch et al., PRESERVE and RESP scores (70, 83 and 70%
survival, respectively) [6, 27, 28]. The ECMOnet score
, which was derived within this specific population,
exhibited worse discrimination performance when it was
applied in an all-cause ARDS population (area under the
ROC curve of 0.60 in the external cohort validation vs
0.86 in the original cohort). With the exception of the
RESP score , which showed that certain diagnoses
such as “aspiration pneumonitis” had particularly good
survival, patient numbers in most studies have been too
small to detect significant relationships between other
specific diagnoses and outcome.
Prediction model limitations and performance
All scores seem to perform better compared with
classical ICU severity scores [6, 27, 28, 53, 54]. However,
the differences in model composition illustrate
heterogeneity of the ECMO databases in terms of size,
population and data collected.
Some of these scores were specifically focused on
dedicated populations, which limit applicability to other
ARDS diagnosis. For instance, the ECMOnet score was
built on an influenza A(H1N1) ARDS cohort ventilated
for less than 7 days , whereas Roch et al.’s score was
designed for patients transferred to a referral centre for
ECMO . Variation in data collected in the ECMO
databases influences the composition and the
performance of survival prediction models, and we cannot rule
out that other pre-ECMO items not collected in these
databases might also impact on the prognosis. While
pre-ECMO prone positioning and use of neuromuscular
blockage agents are constituent parts of some scores [6, 27],
other studies did not collect these variables [54–56]
or found no statistical association with mortality .
Third, the statistical methodology used to construct
the different scores is heterogeneous. All scores have
used logistic regression techniques but none have
employed mixed or random-effects models. Only two
scores have used bootstrapping [27, 54] and only
three out of seven have been validated externally [6, 27, 53]
(Table 1). Fourth, because patients’ prognosis after ECMO
has markedly improved over the last two decades,
performance of these scores and derived predicted
mortality rates might also change over time. Fifth,
these models have been developed for patients already
on ECMO and not validated for survival prediction in
a general population of severe acute respiratory
failure patients where ECMO has not (yet) been
instituted. The models should therefore not be considered
substitutes for clinical judgment. Lastly, caution
should always be taken when using survival
probabilities derived from these scoring systems to inform
families and relatives on a patient’s prognosis because
ECMO remains associated with devastating
complications such as neurological bleeding which may
occur despite favourable pre-ECMO score-based
Although the use of ECMO for severe refractory ARDS
has markedly increased since 2009, in-hospital mortality
remains high (from 35 to 45%). In addition, despite
major technological improvement of the devices, ECMO
is still associated with numerous therapy-related
complications and significant physical/psychological long-term
impairment. These factors reinforce the need to perform
ECMO in high volume  and expert referral centres
with appropriate and accurate selection of patients who
are mostly to obtain benefit over standard therapies. On
the basis of a large development cohort, external validation
and easily available web calculator (www.respscore.com),
we recommend the RESP score to benchmark outcomes, to
interpret variation in practice and to inform clinicians and
families of likely outcomes for patients treated with ECMO
for severe respiratory failure, and await with interest future
prospective interventional studies to inform clinicians
about when, how and on whom to perform ECMO.
SR and MS were responsible for conception and design of the review. SR,
DP, AC and MS were responsible for writing the manuscript. All authors read
and approved the final manuscript.
SR is a fellow in the Medical ICU of La Pitié Salpetrière Hospital, Paris, France.
DP is a professor in the ICU of the Alfred Hospital, Melbourne, Australia. AC is
a professor and the head of the Medical ICU of La Pitié Salpetrière Hospital
Paris, France. MS is an assistant professor in the Medical ICU of La Pitié
Salpetrière Hospital Paris, France.
SR and DP have no conflicts of interest to declare. AC is the primary
investigator of the EOLIA trial (NCT01470703), a randomized trial of VV-ECMO
supported in part by MAQUET, and has received honoraria for lectures from
MAQUET. MS reports receiving lecture honoraria from Maquet.
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