Abstract
Purpose
To analyse the association of body weight with hospital mortality of adult patients supported with veno-venous extracorporeal membrane oxygenation (VV ECMO).
Methods
Retrospective analysis of the international Extracorporeal Life Support Organization (ELSO) registry. Univariate and multivariable logistic regression analyses were used to estimate the odds ratio (OR) of hospital death for each body weight quartile. Adjustment was made for demographic, physiologic and ECMO-related characteristics. We undertook a similar analysis for the subgroup of patients with confirmed H1N1 infection on VV ECMO.
Results
The study group consisted of 1,334 adult patients supported with VV ECMO between 2005 and 2011 with a median (Q1, Q3) body weight of 80 kg (69, 101 kg). Univariate analysis identified increased body weight to be associated with a reduced risk of death. In multivariable analysis, only age greater than 53 years, primary diagnosis other than pneumonia and intubation time longer than 3 days prior to initiation of ECMO were independent risk factors for mortality, whereas the association between high body weight and adjusted risk of death (OR 0.73, 95 % CI 0.52–1.04, P = 0.08) was no longer statistically significant. The body weight of the 196 patients with confirmed H1N1 infection was significantly higher than that of the remaining study group. Body weight was not significantly associated with risk of death for these patients either (univariate OR for Q4 vs. Q1: 0.75, 95 % CI 0.33–1.72, P = 0.49).
Conclusions
Increased body weight was not a risk factor for hospital mortality in adult patients who required support with VV ECMO. High body weight should therefore not be regarded as a contraindication to initiation of VV ECMO in adult patients. Data collection and reporting that include patient height in addition to body weight would facilitate future research into the association of obesity with outcome of ECMO patients.
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Introduction
The prevalence of overweight and obesity has risen over recent decades and is high in most regions of the world [1]. This trend is expected to continue with the majority of adults in the USA, UK and Australia projected to be overweight by 2020 [2]. Obesity has been identified as a risk factor for the development of acute respiratory distress syndrome [3], primary graft dysfunction after lung transplantation [4] and more severe disease in patients with H1N1 pandemic influenza in 2009 [5–9]. As such, obesity is common in critically ill patients with severe respiratory failure requiring support with extracorporeal membrane oxygenation (ECMO) [10–13].
Theoretically, the cardiac output increase associated with high body weight may surpass the oxygenation capacity of the ECMO membrane [14]. As a result, veno-venous ECMO (VV ECMO) may be of limited utility for the management of hypoxia in overweight patients [15]. This theoretical concern has led some organisations to view high body weight as an absolute contraindication for all forms of ECMO [16, 17], thus excluding a large subpopulation from potentially life-saving treatment.
We hypothesized that increased body weight independently increases the risk of death among adult patients on VV ECMO. To test this hypothesis, we interrogated a large international database of patients on extracorporeal life support to investigate the association of body weight with hospital mortality.
Patients and methods
Study population
Since 1986, the ECMO Registry of the Extracorporeal Life Support Organization (ELSO, Ann Arbor, Michigan, USA) has maintained a registry with data of over 2,500 adults with respiratory and cardiac failure on extracorporeal life support contributed by over 170 international centres. Each institution approves data reported to the registry through their local institutional review board. The decision to commence ECMO is made at each centre without standardization and reporting is voluntarily. We queried the ELSO registry for adult patients (age ≥ 18 years) on ECMO from 1 January 2005 to 31 December 2011. We considered that data from prior years was not representative of current practice. Only patients who had venous cannulation i.e. veno-venous (VV), veno-venous double lumen (VVDL) or VVDL with additional venous drainage (VVDL + V) ECMO were included. Cases were excluded if the ECMO configuration involved arterial cannulation such as for veno-arterial, veno-venoarterial, venovenous–venoarterial, venoarterial–venovenous or venoarterial–venous ECMO or if the configuration mode could not be identified. For patients with multiple episodes of ECMO, we limited the analysis to the last ECMO run. Patients were excluded if the body weight was not reported or implausible (i.e. <10 kg). The primary outcome assessed was survival to hospital discharge. This analysis was approved by the ECMO Registry Committee of ELSO.
Study design
We described the association of body weight and death adjusted for the following variables: gender, race, age, primary diagnosis (pneumonia or other), time on mechanical ventilation before institution of ECMO, arterial blood gas data (pH, bicarbonate, pCO2 and pO2) and relevant ventilation parameters (positive end expiratory pressure, peak inspiratory pressure, respiratory rate and FiO2) prior to institution of ECMO, year of ECMO run (before or after H1N1 pandemic), mode of ECMO (VV, VVDL or VVDL + V), pump flow 4 and 24 h after institution of ECMO, time spent on ECMO and number of ECMO runs. Furthermore, we analysed the association of body weight and survival for the subgroup of patients with confirmed H1N1 infection on VV ECMO.
Statistical analysis
Continuous variables were expressed as median (Q1, Q3). Accordingly, the Mann–Whitney U test was used to test two independent variables and the Kruskal–Wallis H test was used to test for more than two independent variables. Discrete data were displayed as number and percentage, and analysed by using the chi-squared test. The main outcome was hospital mortality defined whether patients were dead or alive at hospital discharge. Univariate and multivariable logistic regression analyses were used to estimate odds ratio (OR) and 95 % confidence interval (95 % CI) for each quartile with the lowest quartile used as reference for categorized risk factors. All factors associated with mortality in the univariate analysis were introduced in the multivariable logistic regression. Diagnostic regression analysis was performed to test model assumptions. Collinearity was also investigated. Non-parametric variables then were categorized in quartile groups in final models. The goodness of fit of models was also examined. All statistical analyses were performed by using the R statistical language (R Foundation for Statistical Computing, Vienna, Austria).
Results
A total of 2,017 ECMO runs were reported for the years of 2005–2011 as of mid August 2012. There were 1,502 VV ECMO (VV, VVDL, VVDL + V modes) runs identified in 1,433 patients. The datasets of 1,334 patients with a reported body weight of at least 10 kg were used for further analysis (Fig. 1).
The median (Q1, Q3) body weight of the study group was 80.4 kg (69.3, 101.0 kg, Supplemental Table). The median body weight of survivors and non-survivors was statistically not different (81.0 vs. 80.0 kg, P = 0.06). The distribution of body weight did not change between 2005 and 2011. Body weights in the lower quartiles were seen more frequently in Asians whereas those in the higher quartiles were predominantly seen in the Caucasian and African–American population (Table 1). Patients in the lowest body weight quartile were more commonly female and tended to be younger compared to those in higher quartiles. Patients with body weights in the highest quartile were ventilated with significantly higher PEEP, peak inspiratory pressures and mean airway pressures. The time of mechanical ventilation prior to initiation of VV ECMO tended to be short and resulted generally in uncompensated respiratory acidosis and poor oxygenation. The VVDL + V configuration was more frequently used for patients in the highest body weight quartile who also had higher median ECMO flows in the first 24 h (Table 2). The duration of ECMO support increased with body weight and was statistically significant when the highest and lowest quartiles were compared (OR 1.8, 95 % CI 1.3–2.5). Unadjusted hospital mortality, however, was not statistically different across body weight quartiles (Table 1).
Univariate analysis identified body weight to be inversely associated with risk of death, with patients in the highest body weight quartile having the lowest mortality (Table 3). Other significant factors identified included age, primary diagnosis, blood pressure, duration of mechanical ventilation, respiratory rate, bicarbonate, pH (all prior to institution of ECMO), year, mode and duration of ECMO support (Tables 3, 4). Patients with body weight in the highest decile (121–251 kg) did not have increased risk of death (OR 0.62, 95 % CI 0.38–1.02, P = 0.06) either.
In multivariable analysis, only age, primary diagnosis and intubation time were independent risk factors for mortality (Table 5). Body weight was no longer significantly associated with a reduced adjusted risk of death. The lack of association of body weight with mortality was not altered when H1N1 status was included in multivariate analysis (OR 0.73, CI 95 % 0.51–1.03, P = 0.071).
Of the 1,334 patients in the study group, 196 (14.7 %) had a confirmed H1N1 infection, accounting for 20.0 % of all VV ECMO patients on the ELSO database for the period from 2009 to 2011. The body weight of this subgroup was significantly higher than that of the remaining study group [median (Q1, Q3) kg, 92.4 (80.0–115.7) vs. 80.0 (67.0, 97.0), respectively, P < 0.001]. Body weight was not significantly associated with risk of death for these patients either (univariate OR for Q4 vs. Q1: 0.75, 95 % CI 0.33–1.72, P = 0.49).
Discussion
In this large cohort of adult patients on veno-venous ECMO, high body weight was not associated with an increase in hospital mortality. Indeed, patients with a body weight in the highest quartile showed a trend toward a reduced adjusted risk of death when compared with those who had a body weight in the lowest quartile.
Our main intention was to investigate the validity of body weight as an independent prognostic factor on VV ECMO support. The ELSO database does not include the patient’s height and, as a consequence, the body mass index (BMI) could not be calculated in this study. Therefore, caution is required in the extrapolation of our results to patients who are obese as defined by the BMI.
Amongst ambulatory cohorts, overweight and obesity are well-established risk factors for diabetes, cancer and cardiovascular diseases and related mortality [18]. Counter-intuitively, several meta-analyses have demonstrated that overweight and obesity, in contrast to the deleterious effects in the general population, were associated with similar or even lower mortality rates in critically ill patients [19–23]. This so-called obesity paradox has also been reported for patients undergoing non-bariatric surgery [24] or coronary revascularization [25] and trauma patients [26]. Similarly, obesity has not been associated with higher mortality in mechanical ventilated patients [27, 28] or those with acute lung injury or ARDS [3, 29–31]. It has been speculated that the obesity paradox is caused by a larger nutritional reserve of overweight patients with critical illness [21, 23]. Some studies suggest that adipose tissue releases factors such as leptin and IL-10, which may favourably modulate the inflammatory response [32, 33].
Patients in our analysis, who were supported with VV ECMO between 2005 and 2011, had a median body weight of 80 kg (IQR 69–101 kg). This needs to be compared to the median body weight of only 61 kg (IQR 50–75 kg) of patients on ECMO for severe respiratory failure reported to the ELSO database in the early 1990s [13]. This increase may not only reflect a rising prevalence of overweight in the general population and critical ill patients with respiratory failure, but possibly also a change in the risk assessment of ECMO utilisation over the last two decades despite scarce published evidence. Mongero et al. [34] reported on two patients with a BMI of more than 50 kg/m2 and ARDS who were successfully managed with veno-venous ECMO. Brogan et al. [13], who undertook a multivariable analysis of data on adults with severe respiratory failure supported with various ECMO modes in 2002–2006, reported a statistically significantly higher body weight in survivors. Their study, however, included a large number of patients on other modes than VV ECMO from the early years of the last decade and provided no further details of the association of body weight and death.
About half of the adults requiring ICU admission in the USA for the management of H1N1 pandemic influenza were obese [6, 7, 35, 36]. More than a quarter of patients with confirmed critical illness related to H1N1 admitted to ICUs in Australia and New Zealand had a BMI greater than 35 kg/m2 [37]. The median BMI of those on ECMO support for severe hypoxia related to H1N1 pandemic influenza ranged between 26 and 33 kg/m2 in various international reports [10–12]. Not surprisingly, our analysis found that the body weight of patients with H1N1 infection on VV ECMO was higher than those without confirmed H1N1 infection.
Obesity and morbid obesity were frequently identified as risk factors for death [6, 8, 38–42] in patients hospitalized with confirmed H1N1. In contrast, our analysis shows that hospital mortality was independent of body weight in patients with H1N1 infection who were supported with VV ECMO. Interestingly, Kok et al. [43] reported recently that the mortality rate of patients admitted to Australian ICUs during the first wave of pandemic H1N1 was not increased in the group of obese patients (mean body weight of 116 kg), which was supported with ECMO in 10 % of cases.
Some methodological factors need to be considered for the interpretation of our study results. Selection bias may have influenced the decision to initiate ECMO for obese patients. The severity of respiratory illness in this group may have been less than that perceived because of the difficulty in interpreting chest radiographs or atelectasis related to the body habitus thus lowering the threshold to initiate ECMO. Similarly, selection bias might have favoured only the “fittest” obese patients being selected for initiation of ECMO support, causing an inverse association of body weight and mortality. Furthermore, high body weight could solely be indicative of a large muscle compartment in patients with an athletic body habitus while unintentional weight loss due to smoking and chronic illness may have contributed to increased mortality in patients with low body weight.
We were not able to adjust for some factors that may be associated with mortality that were not reported such as co-morbidities, severity of illness, ECMO centre, tidal volume and plateau pressures of ventilation before ECMO support and procedures of care (e.g. thrombosis prophylaxis or nutrition). We did not adjust for specific diagnostic groups other than the presence or absence of pneumonia as in a majority of cases diagnoses belonged either to a multitude of infrequent miscellaneous categories or remained altogether unclear. Criteria for the institution and mode of ECMO are centre specific and neither standardized nor included in the ELSO database thus potentially limiting the external validity of our analysis. However, we believe that this outcome analysis, which includes data of the largest number of patients supported with VV ECMO published to date, is a fair representation of recent worldwide practice.
In summary, we have shown that increased body weight was not a risk factor for hospital mortality of adult patients who required support with VV ECMO and may even be protective. Even though obesity has been previously identified as a risk factor for death of hospitalised patients with confirmed H1N1 infection, body weight was not independently associated with increased mortality of those on VV ECMO.
In view of our results, high body weight should not be regarded as a contraindication to initiation of VV ECMO in adult patients. We further recommend that data collection and reporting should include patient height in addition to body weight to facilitate future research into the association of obesity with outcome of ECMO patients.
References
Swinburn BA, Sacks G, Hall KD, McPherson K, Finegood DT, Moodie ML et al (2011) The global obesity pandemic: shaped by global drivers and local environments. Lancet 378(9793):804–814
Wang YC, McPherson K, Marsh T, Gortmaker SL, Brown M (2011) Health and economic burden of the projected obesity trends in the USA and the UK. Lancet 378(9793):815–825. Erratum in Lancet 2011 Nov 19; 378(9805):1778
Gong MN, Bajwa EK, Thompson BT, Christiani DC (2010) Body mass index is associated with the development of acute respiratory distress syndrome. Thorax 65(1):44–50
Lederer DJ, Kawut SM, Wickersham N, Winterbottom C, Bhorade S, Palmer SM et al (2011) Lung Transplant Outcomes Group. Obesity and primary graft dysfunction after lung transplantation: the Lung Transplant Outcomes Group Obesity Study. Am J Respir Crit Care Med 184(9):1055–1061
Muscatello DJ, Barr M, Thackway SV, Macintyre CR (2011) Epidemiology of influenza-like illness during pandemic (H1N1) 2009, New South Wales, Australia. Emerg Infect Dis 17(7):1240–1247
Louie JK, Acosta M, Samuel MC, Schechter R, Vugia DJ, Harriman K, California Pandemic (H1N1) Working Group (2011) A novel risk factor for a novel virus: obesity and 2009 pandemic influenza A (H1N1). Clin Infect Dis 52(3):301–312
Jain S, Kamimoto L, Bramley AM et al (2009) Hospitalized patients with 2009 H1N1 influenza in the United States, April–June 2009. N Engl J Med 361:1935–1944
Morgan OW, Bramley A, Fowlkes A, Freedman DS, Taylor TH, Gargiullo P et al (2010) Morbid obesity as a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1) disease. PLoS One 5(3):e9694
Yu H, Feng Z, Uyeki TM, Liao Q, Zhou L, Feng L et al (2011) Risk factors for severe illness with 2009 pandemic influenza A(H1N1) virus infection in China. Clin Infect Dis 52(4):457–465
Australia and New Zealand Extracorporeal Membrane Oxygenation (ANZ ECMO) Influenza Investigators, Davies A, Jones D, Bailey M, Beca J, Bellomo R, Blackwell N et al (2009) Extracorporeal membrane oxygenation for 2009 influenza A(H1N1) acute respiratory distress syndrome. JAMA 302(17):1888–1895
Roch A, Lepaul-Ercole R, Grisoli D, Bessereau J, Brissy O, Castanier M et al (2010) Extracorporeal membrane oxygenation for severe influenza A(H1N1) acute respiratory distress syndrome: a prospective observational comparative study. Intensive Care Med 36(11):1899–1905
Freed DH, Henzler D, White CW, Fowler R, Zarychanski R, Hutchison J, Canadian Critical Care Trials Group (2010) Extracorporeal lung support for patients who had severe respiratory failure secondary to influenza A(H1N1) 2009 infection in Canada. Can J Anaesth 57(3):240–247
Brogan TV, Thiagarajan RR, Rycus PT, Bartlett RH, Bratton SL (2009) Extracorporeal membrane oxygenation in adults with severe respiratory failure: a multi-center database. Intensive Care Med 35(12):2105–2114
Schmidt M, Tachon G, Devilliers C, Muller G, Hekimian G, Bréchot N, Merceron S, Luyt CE, Trouillet JL, Chastre J, Leprince P, Combes A (2013) Blood oxygenation and decarboxylation determinants during venovenous ECMO for respiratory failure in adults. Intensive Care Med 39(5):838–846
Extracorporeal Life Support Organization. Patient specific supplements to the ELSO general guidelines version 1.1 April 2009. http://www.elso.med.umich.edu/Guidelines.html. Accessed 1 Apr 2013
Strickland R, Frantzis P, Buttery J. Royal Adelaide Hospital general ICU ECMO guidelines. October 2009. www.icuadelaide.com.au/files/manual_ecmo.pdf. Accessed 1 Apr 2013
Abbenbroek B, Department of Health, NSW, Australia (2010) Policy directive PD2010_028 influenza pandemic - providing critical care, publication date 20 May 2010. http://www0.health.nsw.gov.au/policies/pd/2010/PD2010_028.html. Accessed 1 Apr 2013
Prospective Studies Collaboration, Whitlock G, Lewington S, Sherliker P, Clarke R, Emberson J, Halsey J et al (2009) Body-mass index and cause-specific mortality in 900,000 adults: collaborative analyses of 57 prospective studies. Lancet 373(9669):1083–1096
Sakr Y, Madl C, Filipescu D, Moreno R, Groeneveld J, Artigas A, Reinhart K, Vincent JL (2008) Obesity is associated with increased morbidity but not mortality in critically ill patients. Intensive Care Med 34(11):1999–2009
Hutagalung R, Marques J, Kobylka K, Zeidan M, Kabisch B, Brunkhorst F, Reinhart K, Sakr Y (2011) The obesity paradox in surgical intensive care unit patients. Intensive Care Med 37(11):1793–1799
Akinnusi ME, Pineda LA, El Solh AA (2008) Effect of obesity on intensive care morbidity and mortality: a meta-analysis. Crit Care Med 36(1):151–158
Hogue CW Jr, Stearns JD, Colantuoni E, Robinson KA, Stierer T, Mitter N et al (2009) The impact of obesity on outcomes after critical illness: a meta-analysis. Intensive Care Med 35(7):1152–1170
Oliveros H, Villamor E (2008) Obesity and mortality in critically ill adults: a systematic review and meta-analysis. Obesity (Silver Spring) 16(3):515–521
Mullen JT, Moorman DW, Davenport DL (2009) The obesity paradox: body mass index and outcomes in patients undergoing nonbariatric general surgery. Ann Surg 250(1):166–172
Oreopoulos A, Padwal R, Norris CM, Mullen JC, Pretorius V, Kalantar-Zadeh K (2008) Effect of obesity on short- and long-term mortality postcoronary revascularization: a meta-analysis. Obesity (Silver Spring) 16(2):442–450
Diaz JJ Jr, Norris PR, Collier BR, Berkes MB, Ozdas A, May AK et al (2009) Morbid obesity is not a risk factor for mortality in critically ill trauma patients. J Trauma 66(1):226–231
O’Brien JM Jr, Philips GS, Ali NA, Aberegg SK, Marsh CB, Lemeshow S (2012) The association between body mass index, processes of care, and outcomes from mechanical ventilation: a prospective cohort study. Crit Care Med 40(5):1456–1463
Frat JP, Gissot V, Ragot S, Desachy A, Runge I, Lebert C et al (2008) Association des Réanimateurs du Centre-Ouest (ARCO) study group. Impact of obesity in mechanically ventilated patients: a prospective study. Intensive Care Med 34(11):1991–1998
O’Brien JM Jr, Phillips GS, Ali NA, Lucarelli M, Marsh CB, Lemeshow S (2006) Body mass index is independently associated with hospital mortality in mechanically ventilated adults with acute lung injury. Crit Care Med 34(3):738–744
Morris AE, Stapleton RD, Rubenfeld GD, Hudson LD, Caldwell E, Steinberg KP (2007) The association between body mass index and clinical outcomes in acute lung injury. Chest 131(2):342–348
Anzueto A, Frutos-Vivar F, Esteban A, Bensalami N, Marks D, Raymondos K, Ventila group et al (2011) Influence of body mass index on outcome of the mechanically ventilated patients. Thorax 66(1):66–73
Stapleton RD, Dixon AE, Parsons PE, Ware LB, Suratt BT, NHLBI Acute Respiratory Distress Syndrome Network (2010) The association between BMI and plasma cytokine levels in patients with acute lung injury. Chest 138(3):568–577
Koch A, Sanson E, Voigt S, Helm A, Trautwein C, Tacke F (2011) Serum adiponectin upon admission to the intensive care unit may predict mortality in critically ill patients. J Crit Care 26(2):166–174
Mongero LB, Beck JR, Charette KA, Stewart A (2006) Respiratory failure of two sp gastric bypass patients and subsequent rescue with extracorporeal membrane oxygenation. Perfusion 21(1):73–76
Riscili BP, Anderson TB, Prescott HC, Exline MC, Sopirala MM, Phillips GS et al (2011) An assessment of H1N1 influenza-associated acute respiratory distress syndrome severity after adjustment for treatment characteristics. PLoS One 6(3):e18166
Bramley AM, Dasgupta S, Skarbinski J, Kamimoto L, Fry AM, Finelli L, The 2009 Pandemic Influenza A(H1N1) Virus Hospitalizations Investigation Team et al (2012) Intensive care unit patients with 2009 pandemic influenza A(H1N1pdm09) virus infection, United States, 2009. Influenza Other Respi Viruses 6(6):e134–e142
ANZIC Influenza Investigators, Webb SA, Pettilä V, Seppelt I, Bellomo R, Bailey M, Cooper DJ, Cretikos M, Davies AR, Finfer S, Harrigan PW, Hart GK, Howe B, Iredell JR, McArthur C, Mitchell I, Morrison S, Nichol AD, Paterson DL, Peake S, Richards B, Stephens D, Turner A, Yung M (2009) Critical care services and 2009 H1N1 influenza in Australia and New Zealand. N Engl J Med 361(20):1925–1934
Myles PR, Semple MG, Lim WS, Openshaw PJ, Gadd EM, Read RC, Influenza Clinical Information Network (FLU-CIN) et al (2012) Predictors of clinical outcome in a national hospitalised cohort across both waves of the influenza A/H1N1 pandemic 2009–2010 in the UK. Thorax 67(8):709–717
Subramony H, Lai FY, Ang LW, Cutter JL, Lim PL, James L (2010) An epidemiological study of 1,348 cases of pandemic H1N1 influenza admitted to Singapore Hospitals from July to September 2009. Ann Acad Med Singapore 39(4):283–288
Fezeu L, Julia C, Henegar A, Bitu J, Hu FB, Grobbee DE et al (2011) Obesity is associated with higher risk of intensive care unit admission and death in influenza A(H1N1) patients: a systematic review and meta-analysis. Obes Rev 12(8):653–659
Ríos FG, Estenssoro E, Villarejo F, Valentini R, Aguilar L, Pezzola D et al (2011) Lung function and organ dysfunctions in 178 patients requiring mechanical ventilation during the 2009 influenza A(H1N1) pandemic. Crit Care 15(4):R201
Van Kerkhove MD, Vandemaele KA, Shinde V, Jaramillo-Gutierrez G, Koukounari A, Donnelly CA et al (2011) WHO working group for risk factors for severe H1N1pdm infection risk factors for severe outcomes following 2009 influenza A (H1N1) infection: a global pooled analysis. PLoS Med 8(7):e1001053
Kok J, Blyth CC, Foo H, Bailey MJ, Pilcher DV, Webb S et al (2013) Viral pneumonitis is increased in obese patients during the first wave of pandemic A(H1N1) 2009 virus. PLoS One 8(2):e55631
Acknowledgments
Source(s) of support in the form of grants, equipment, drugs, or all of these: none. The authors declare that they have no conflict of interest.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Al-Soufi, S., Buscher, H., Nguyen, N.D. et al. Lack of association between body weight and mortality in patients on veno-venous extracorporeal membrane oxygenation. Intensive Care Med 39, 1995–2002 (2013). https://doi.org/10.1007/s00134-013-3028-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00134-013-3028-3