Na et al. Ann. Intensive Care (2018) 8:31 https://doi.org/10.1186/s13613-018-0375-9

Open Access

RESEARCH

The effect of multidisciplinary extracorporeal membrane oxygenation team on clinical outcomes in patients with severe acute respiratory failure Soo Jin Na1, Chi Ryang Chung1, Hee Jung Choi2, Yang Hyun Cho3, Kiick Sung3, Jeong Hoon Yang1,4, Gee Young Suh1,5 and Kyeongman Jeon1,5* 

Abstract  Background:  The Extracorporeal Life Support Organization (ELSO) has suggested that extracorporeal membrane oxygenation (ECMO) patients should be managed by a multidisciplinary team. However, there are limited data on the impact of ECMO team on the outcomes of patients with severe acute respiratory failure. Methods:  All consecutive patients with severe acute respiratory failure who underwent ECMO for respiratory support from January 2012 through December 2016 were divided into the pre-ECMO team period (before January 2014, n = 70) and the post-ECMO team period (after January 2014, n = 46). Clinical characteristics and outcomes were compared between the two groups. Results:  The mortality rates in the intensive care unit (72.9 vs. 50.0%, P = 0.012) and hospital (75.7 vs. 52.2%, P = 0.009) were significantly decreased in the post-ECMO team period compared to the pre-ECMO team period. The median duration of ECMO support was not different between the two periods. However, the proportion of patients successfully weaned off ECMO was higher in the post-ECMO team period (42.9 vs. 65.2%, P = 0.018). During ECMO support, the incidence of cannula problems (32.9 vs. 15.2%, P = 0.034) and cardiovascular events (88.6 vs. 65.2%, P = 0.002) was reduced after implementation of the ECMO team. The 1-year mortality was significantly different between the pre-ECMO team and post-ECMO team periods (37.8 vs. 14.3%, P = 0.005). Conclusion:  After implementing a multidisciplinary ECMO team, survival rate in patients treated with ECMO for severe acute respiratory failure was significantly improved. Keywords:  Extracorporeal membrane oxygenation, Patient care team, Respiratory insufficiency, Critical care outcomes, Mortality Introduction Recent studies showing the favorable results of extracorporeal membrane oxygenation (ECMO) have highlighted the role of ECMO in treating severe acute respiratory failure [1–4]. In addition, the number of patients *Correspondence: [email protected] 1 Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon‑ro, Gangnam‑gu, Seoul 06351, Republic of Korea Full list of author information is available at the end of the article

receiving ECMO support in clinical practice is growing [4]. Despite the technical advances and generalization of the technique, ECMO is still a complex and costly treatment with potential adverse effects, and the clinical outcomes associated with its use are significantly different depending on the infrastructure of the providing center [5]. Therefore, the Extracorporeal Life Support Organization (ELSO) has published guidelines regarding the ideal institutional requirements for effective use of ECMO [6, 7]. In these guidelines, qualified ECMO physicians are

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Na et al. Ann. Intensive Care (2018) 8:31

referred to as one of the most important components of the successful implementation of ECMO, and their various responsibilities are emphasized, from initiation of ECMO to clinical follow-up [6, 7]. Some adjunctive therapies, such as use of neuromuscular blocking agents [8] and prone positioning [9], have been shown to reduce mortality in patients with severe acute respiratory failure, and these treatments before ECMO are also associated with outcomes seen after ECMO for respiratory failure [10, 11]. Therefore, decision making about the proper indications and timing of ECMO is a challenging problem for physicians who manage patients with severe acute respiratory failure. In addition, the medical management and nursing care of patients with severe respiratory failure receiving ECMO support are complex and can be challenging; therefore, the multidisciplinary ECMO team is recommended to be incorporated into ECMO program [7]. However, there are limited data on the impact of ECMO team on the outcomes of patients with severe acute respiratory failure. The objective of this study was to investigate the association between implementation of a multidisciplinary ECMO team and clinical outcomes in adult patients with severe respiratory failure receiving ECMO support.

Methods Study design

We conducted a retrospective cohort study between January 2012 and December 2016 at Samsung Medical Center (a 1979-bed tertiary referral hospital with tertiary-level intensive care units) in Seoul, South Korea. All patients 18  years of age or older for whom ECMO support was required for severe acute respiratory failure were enrolled in the study. A total of 136 ECMO runs in 133 patients were identified during this period. Twenty patients who were transported to our facility after initiation of ECMO in other hospitals were excluded because the decision regarding whether or not the patient was a suitable candidate for ECMO and initial management were not made by our ECMO team. The remaining 116 eligible ECMO runs were divided into the pre-ECMO team period (before January 2014, n = 70) and the postECMO team period (after January 2014, n = 46), according to the date of ECMO initiation (Fig. 1). The institutional review board of the Samsung Medical Center approved this study and waived the requirement for informed consent because of the observational nature of the study. In addition, patients’ information was anonymized and deidentified prior to analysis.

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Fig. 1  Patient distribution between the two periods

ECMO team and management of ECMO

In our institution, ECMO support has been available since 2004. In the first few years, veno-arterial ECMO was primarily used in patients with cardiac failure, with veno-venous ECMO used for less than five cases per year. The incidence of ECMO runs has gradually increased, with more than 100 cases currently performed annually. The application of veno-venous ECMO for severe respiratory failure has also grown and currently represents up to 20–30% of all ECMO runs. Before 2014, there were standard criteria for indications and contraindications of ECMO (Additional file 1), but decisions about initiation and decannulation were mostly left to the physicians that oversaw patients. Cannula- or circuit-related issues were treated through elective consultation with cardiothoracic surgeons who had experience with ECMO. In 2014, our hospital adopted a multidisciplinary ECMO team consisting of cardiovascular surgeons, cardiologists, critical care physicians, and an ECMO specialist who is a cardiovascular perfusionist trained to manage the ECMO system and clinical needs of the patients on ECMO under supervision of ECMOtrained physicians. This ECMO team was responsible for every issue related to ECMO in the hospital. Protocols for indications and contraindications, management of patients and equipment, and weaning of patients from ECMO were revised. In addition, the ECMO team was charged with educating all medical personnel including bedside nurses caring for patients on ECMO at our institution. When a patient was deemed eligible for ECMO, the final decision to initiate ECMO was made by the treating intensivist and ECMO team, consisting of two more critical care physicians who are board certified in pulmonary and critical care medicine and cardiovascular surgeon, after a comprehensive assessment based on our protocol outlining the indications and contraindications. The primary cannulation strategy for adult respiratory

Na et al. Ann. Intensive Care (2018) 8:31

ECMO was the veno-venous mode. The veno–venoarterial mode was considered if the patient needed additional support due to hemodynamic failure. Cannulation was performed by the attending cardiothoracic surgeons using either the percutaneous method with the Seldinger technique or the surgical method at the bedside or in the operating room. Cannulation sites and cannula sizes were selected at the discretion of the cardiothoracic surgeons. Usually, a 20–28-Fr cannula was used for venous drainage via the common femoral vein, and a 14–18- or 20–24-Fr cannula was used for venous return via the internal jugular or the common femoral vein, respectively. The Prolonged Life Support System (Quadrox PLS, Maquet Inc., Rastatt, Germany) and the Capiox Emergency Bypass System (Capiox EBS; Terumo, Inc., Tokyo, Japan) were used. Pump blood flow and sweep gas flow rates were adjusted to maintain a target oxygen saturation and carbon dioxide removal rate. The mechanical ventilation (MV) strategy during ECMO was adapted from the study protocol of the CESAR trial [1], providing assisted pressure-controlled ventilation while limiting the peak inspiratory pressure to 25 cmH2O and applying positive end-expiratory airway pressure of 10  cmH2O, and respiratory rate of 10 breaths/min, on inspired oxygen fraction of 30%. Once the patients were stabilized and lightly sedated, spontaneous ventilation with pressure support mode was considered. In all patients, arterial catheterization was performed for continuous hemodynamic monitoring. Our ECMO team performed daily rounds and assessed the state of the ECMO circuit, development of ECMO-associated complications, and the possibility of weaning. An ECMO-trained physician provided 24-h oncall coverage, and an ECMO specialist participated in all intra-hospital transport of patients on ECMO. If a patient was considered ready to be weaned off ECMO support, decisions regarding decannulation were assessed through a protocolized weaning trial. Cannulae were removed at the bedside by cardiothoracic surgeons. Data collection and clinical outcomes

The clinical and laboratory data from patients who were treated with ECMO have been prospectively registered in the ECMO database of our hospital since 2012. For this study, these data were supplemented with a retrospective review of all hospital medical records. Demographic data, including age, sex, comorbidity, immune state, history of cardiac arrest, diagnosis, acute physiology and chronic health evaluation (APACHE) II score, and sequential organ failure assessment (SOFA) score, were recorded at admission to the intensive care unit (ICU). Presence of an artificial airway, use of MV, ventilator setting immediately before ECMO initiation, use

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of rescue and adjunctive treatment before ECMO, worst values from arterial blood gas and lactate tests within 6  h before ECMO initiation, respiratory extracorporeal membrane oxygenation survival prediction (RESP) score [11], predicting death for severe ARDS on VV-ECMO (PRESERVE) score [10], ECMO mode, and cannulation site were recorded on the first day of ECMO support. The primary outcome in this study was in-hospital mortality. Secondary outcomes were ICU mortality, rate of weaning from ECMO, duration of ECMO support, adverse events during ECMO, rate of weaning from MV, duration of MV before weaning, ICU and hospital lengths of stay, and 1-year mortality after ECMO initiation. Adverse events during ECMO were defined as follows: cannula-related (vessel perforation with hemorrhage, arterial cannulation, malposition requiring repositioning, or accidental decannulation), other ECMO-related, hematological (gastrointestinal bleeding, cannula site bleeding, surgical site bleeding, plasma hemoglobin level > 50 mg/dL, or disseminated intravascular coagulation), neurological (brain death, seizure, cerebral infarction, or brain hemorrhage), cardiovascular (inotrope or vasopressor use, myocardial stunning, arrhythmia, cardiac tamponade, or cardiac arrest), pulmonary (pneumothorax or pulmonary hemorrhage), renal (serum creatinine level > 1.5 mg/dL or continuous renal replacement therapy), and infection (white blood cell count  0.999

 Asthma/COPD

12 (17.1)

2 (4.4)

0.039

 Liver cirrhosis

3 (4.3)

3 (6.5)

0.680

 Malignancy

0.052

  Solid tumor

18 (25.7)a

6 (13.0)b

  Hematologic malignancy

11 (15.7)c

5 (10.9)d

 Immunocompromised state

23 (32.9)

17 (37.0)

0.650

 Cardiac arrest before ECMO

8 (11.4)

10 (21.7)

0.134

32 (45.7)

12 (26.1)

0.033

2 (2.9)

8 (17.4)

0.014

15 (21.4)

5 (10.9)

0.141

 Trauma/burn

2 (2.9)

4 (8.7)

0.212

 Asphyxia

1 (1.4)

1 (2.2)

>0.999

18 (25.7)

16 (34.8)

0.294

Primary diagnosis  Bacterial pneumonia  Viral pneumonia  Interstitial lung disease

 Othere Severity score on the first day in the ICU

18 (15–25)

25 (21–32)