Extra-Corporeal Membrane Oxygenation

Original Editor - Saud Alghamdi Top Contributors - Saud Alghamdi and Ewa Jaraczewska
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Introduction[edit | edit source]

In 2022, it is estimated that nearly 200,000 patients received Extra-Corporeal Membrane Oxygenation (ECMO).[1] ECMO is a technique that oxygenates the blood outside the body. It’s typically used when conventional ventilation is unable to oxygenate the blood adequately.[2]

It is important to understand that ECMO is a supportive therapy, not a disease-modifying treatment.[3] Similar to a ventilator or a dialysis machine, ECMO doesn't cure the underlying disease but takes over a vital function (oxygenation or blood circulation) when the body's organs are unable to do so adequately.

ECMO is a highly specialised technique that requires the input of intensive care specialists, cardiothoracic surgeons as well as ECMO-trained nurses and perfusion scientists.[2]

How Does ECMO Work[edit | edit source]

ECMO is a technique that oxygenates the blood outside the body. It’s typically used when conventional ventilation is unable to oxygenate the blood adequately.[2]

In ECMO, the blood is drained from the vascular system, circulated outside the body by a mechanical pump and then reinfused into the circulation. While the blood is outside the body, hemoglobins become fully saturated with oxygen and carbon dioxide (CO2) is removed from them. [4]

Types of ECMO[edit | edit source]

There are two types of ECMO. Veno-arterial (VA) ECMO can be used for heart and lung support, while veno-venous (VV) ECMO is used for lung support only.[5]

VA-ECMO[edit | edit source]

VA-ECMO drains the blood from the venous system, reinfuses it into the arterial system and provides complete cardiopulmonary support. [5]

VV-ECMO[edit | edit source]

VV-ECMO drains the blood from the venous system, reinfuses it into the venous system and provides gas exchange. Unlike VA-ECMO, VV-ECMO does not provide direct cardiac support.[5]

Is Physiotherapy Safe for Patients on ECMO?[edit | edit source]

A 2019 systematic review found that physiotherapy interventions including early ambulation for patients on ECMO is considered safe due to the absence of severe adverse events and the small number of mild adverse events. [6] Of the 259 patients who underwent physiotherapy interventions, only 4 patients presented with adverse events. One study reported two complications from femoro-femoral cannulation with one patient presenting with severe leg swelling and another with an obstructive thrombus in the return cannula. One study reported a cannula fracture during physiotherapy mobilisation and one study reported a decrease in peripheral oxygen saturation that was sufficiently compensated for by increased blood flow during ECMO. [6]

Implications for Clinical Practice for Physiotherapists[edit | edit source]

Implementing physiotherapy interventions for ECMO patients should be a highly personalised approach. The selection of appropriate exercises should be individualised for each patient according to their consciousness level, functional status and disease severity.[7] Furthermore, the functional level of ICU patients is strongly determined by their pre-ICU admission functionality. Therefore, physiotherapists should aim to obtain a baseline functional assessment to assist them in providing optimal care.

Physiotherapy Management / Interventions[edit | edit source]

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Exercise[edit | edit source]

Based on the available evidence from two recent systematic reviews, active physiotherapy is not only safe but should be a priority. The 2019 systematic review outlined that the physiotherapy interventions included active-assisted exercises, sitting, standing, passive mobilization, resistance exercises, positioning in bed, stretching and functional electrical stimulation (FES) of the lower limb muscles combined with cycling. Additionally, in 11 out of 19 studies (93 patients out of 259 total patients), patients on ECMO were mobilised and their physiotherapy intervention involved walking.[6]

This was later supported in 2022 by another systematic review whereby cycling and strength training appeared to be the most commonly used types of exercises.[7] Additionally, there was a mention of neuromuscular electrical stimulation (NMES). NMES has been shown to, increase muscle thickness, improves microcirculation, increase oxygen consumption and reperfusion, and prevent patients from muscle atrophy. [7] However, with that said, there is only one study that investigated the application of NMES in patients on ECMO, four ECMO patients were put on 30 minutes session of NMES followed by a sham NMES session after. NMES was well tolerated by the patients and showed promising results. However, due to the extremely limited data on NMES as an alternative to exercise in ECMO patients, more randomised controlled trials are needed.

Prone Positioning[edit | edit source]

Prone Positioning (PP) is a strategy to improve the outcomes of ARDS patients. However, due to organizational issues and a lack of experience and appropriate medical literature, PP is generally not applied to ECMO patients.[8] In fact, a 2021 study suggested that PP was only used in 15% of ECMO patients. [9] Recently there has been an increase in reports showing that PP in ECMO patients is associated with a reduction of hospital mortality. [10] [11] These findings were later supported by a 2022 systematic review and meta-analysis where it showed that PP in ECMO patients was associated with significant improvements in survival rates compared to supine positioning of ECMO patients. [8]

Contraindications of Prone Positioning[edit | edit source]
  • Unstable spinal fractures (An absolute contraindication). [9]
  • Hemodynamic instability. [9]
  • Unstable large bone or pelvic fracture.[9]
  • Open abdominal wounds.[9]
  • Increased intracranial pressure, or a risk of intracranial hypertension without adequate intracranial pressure monitoring.[9]

Verticalisation Therapy[edit | edit source]

The evidence regarding the implementation of verticalisation therapy (VT) in ECMO patients is very limited. To date, we are only aware of 1 case study from 2023 that have specifically looked at VT as treatment option to enhance survivability rates in ECMO patients.[12] In this study, the patient was able to sustain an oxygen saturation above 90% for approximately up to 3 hours after each VT session without any changes to the ventilator or ECMO settings. [12]

PP has been associated with adverse events in ECMO patients, most notably pressure ulcers and inadvertent decannulation. [12] Whilst the incidence of such adverse events are low, PP for ECMO patients is a challenging procedure that may be associated with more complications when performed in ECMO centres without specialist expertise and training. [10] VT when available may be a better choice of positioning as not only is it associated with better oxygenation, but can also be a stepping stone for better functionality later on as it promotes early weightbearing.


References[edit | edit source]

  1. ECLS ELSOEA. ELSO International Summary of Statistics | ECMO | ECLS [Internet]. Copyright (C) 2023 by Extracorporeal Life Support Organization - ECMO and ECLS. Available from: https://www.elso.org/registry/internationalsummaryandreports/internationalsummary.aspx
  2. 2.0 2.1 2.2 ECMO | Extracorporeal Membrane Oxygenation (ECMO) [Internet]. Royal Papworth Hospital. Available from: https://royalpapworth.nhs.uk/our-services/theatres-and-critical-care/ecmo#:~:text=ECMO%20is%20a%20highly%20specialised,trained%20nurses%20and%20perfusion%20scientists.
  3. Horan M. Extracorporeal membrane oxygenation and mechanical support for the circulation, Anaesthesia & Intensive Care Medicine 2023; 24(11):711-719.
  4. Makdisi G, Wang IW. Extra Corporeal Membrane Oxygenation (ECMO) review of a lifesaving technology. J Thorac Dis. 2015 Jul;7(7):E166-76.
  5. 5.0 5.1 5.2 Cui Y, Zhang Y, Dou J, Shi J, Zhao Z, Zhang Z, et al. Venovenous vs. Venoarterial Extracorporeal Membrane Oxygenation in Infection-Associated Severe Pediatric Acute Respiratory Distress Syndrome: A Prospective Multicenter Cohort Study. Frontiers in Pediatrics [Internet]. 2022 Mar 18;10.
  6. 6.0 6.1 6.2 Da Cunha Ferreira D, Marcolino MAZ, Macagnan FE, Della Meã Plentz R, Kessler A. Safety and potential benefits of physical therapy in adult patients on extracorporeal membrane oxygenation support: a systematic review. Revista Brasileira De Terapia Intensiva [Internet]. 2019 Jan 1;31(2).
  7. 7.0 7.1 7.2 Kourek C, Nanas S, Κοτανίδου Α, Raidou V, Dimopoulou M, Adamopoulos S, et al. Modalities of Exercise Training in Patients with Extracorporeal Membrane Oxygenation Support. Journal of Cardiovascular Development and Disease [Internet]. 2022 Jan 20;9(2):34.
  8. 8.0 8.1 (8) Papazian L, Schmidt M, Hajage D, Combes A, Petit M, Lebreton G, et al. Effect of prone positioning on survival in adult patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a systematic review and meta-analysis. Intensive Care Medicine [Internet]. 2022 Jan 17;48(3):270–80.
  9. 9.0 9.1 9.2 9.3 9.4 9.5 Roca O, Pacheco A, García-De-Acilu M. To prone or not to prone ARDS patients on ECMO. Critical Care [Internet]. 2021 Aug 31;25(1).
  10. 10.0 10.1 Giani M, Martucci G, Madotto F, Belliato M, Fanelli V, Garofalo E, et al. Prone Positioning during Venovenous Extracorporeal Membrane Oxygenation in Acute Respiratory Distress Syndrome. A Multicenter Cohort Study and Propensity-matched Analysis. Annals of the American Thoracic Society [Internet]. 2021 Mar 1;18(3):495–501.
  11. Petit M, Fétita C, Gaudemer A, Tréluyer L, Lebreton G, Franchineau G, et al. Prone-Positioning for severe acute respiratory distress syndrome requiring extracorporeal membrane oxygenation. Critical Care Medicine [Internet]. 2021 Jul 14;50(2):264–74.
  12. 12.0 12.1 12.2 Shayan S, DeLeon AM, McGregor R, Mader TH, Garino M, Mehta CK. Verticalization therapy for acute respiratory distress syndrome patients receiving Veno-Venous extracorporeal membrane oxygenation. Cureus [Internet]. 2023 Jun 7;