Interventional procedure consultation document

Extracorporeal membrane oxygenation for severe acute respiratory failure in adults

Treating severe acute respiratory failure using an artificial ‘lung’ to oxygenate the blood outside the body

Extracorporeal membrane oxygenation (ECMO) is a temporary life support technique, used to treat respiratory failure (where the lungs do not work effectively) in critically ill patients. The aim is to increase oxygen levels in the blood. During the procedure, a tube carries blood from the right side of the heart then pumps it through an artificial lung where it picks up oxygen. This oxygen-rich blood is then passed back into the person’s blood system.

The National Institute for Health and Clinical Excellence (NICE) is examining extracorporeal membrane oxygenation for severe acute respiratory failure in adults and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about extracorporeal membrane oxygenation for severe acute respiratory failure in adults.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

NICE is committed to promoting through its guidance race and disability equality and equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and give suggestions for how it might be improved. NICE reserves the right to summarise and edit comments received during consultations, or not to publish them at all, where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 23 November 2010

Target date for publication of guidance: February 2011

1   Provisional recommendations

1.1  Evidence on the safety of extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure in adults is adequate but shows that there is a risk of serious side effects. Evidence on its efficacy is inadequate to draw firm conclusions: data from the recent CESAR (Conventional ventilation or extracorporeal membrane oxygenation for severe adult respiratory failure) trial were difficult to interpret because different management strategies were applied among many different hospitals in the control group and a single centre was used for the ECMO treatment group. Therefore this procedure should only be used with special arrangements for clinical governance, consent and research.

1.2  Clinicians wishing to undertake ECMO for severe acute respiratory failure in adults should take the following actions.

• Inform the clinical governance leads in their Trusts.
• Whenever possible, ensure that patients and their families or carers understand the uncertainty about the procedure’s efficacy and its risks and provide them with clear written information. In addition, the use of NICE’s information for patients (‘Understanding NICE guidance’) is recommended (available from www.nice.org.uk/IPGXXXpublicinfo). [[details to be completed at publication]]

1.3  Extracorporeal membrane oxygenation for severe acute respiratory failure in adults should only be carried out by clinical teams with specific training and expertise in the procedure.

1.4  Clinicians are encouraged to submit data on all adults undergoing ECMO for severe acute respiratory failure to the international Extracorporeal Life Support Organization register (www.elso.med.umich.edu).

1.5  NICE encourages further research into the use of innovative technologies for the management of severe acute respiratory failure, and may review this guidance on publication of further evidence.

2   The procedure

2.1   Indications and current treatments

2.1.1  Extracorporeal membrane oxygenation is a supportive therapy for adults with severe acute respiratory failure from a potentially reversible cause. Extracorporeal membrane systems mimic gas exchange in the lungs by eliminating some carbon dioxide from the blood and adding oxygen.

2.1.2  There are many causes of severe acute respiratory failure, including acute respiratory distress syndrome (ARDS, which may in turn be caused by a range of underlying conditions), pneumonia, and chest trauma.

2.1.3  Conventional treatment involves maximum medical support, including mechanical ventilation (for example, intermittent positive‑pressure ventilation). Arteriovenous extracorporeal membrane carbon dioxide removal, also known as pumpless extracorporeal lung assist, can also be used to support gas exchange.

2.2   Outline of the procedure

2.2.1  Extracorporeal membrane oxygenation for severe acute respiratory failure in adults aims to reduce ventilator-induced lung injuries and improve patient outcomes.

2.2.2  There are two main types of ECMO: venovenous ECMO (for respiratory support) and venoarterial ECMO (for cardiac and mixed cardiac and respiratory support). In venovenous ECMO, 2 or 3 single-lumen catheters are used, typically placed via the jugular and femoral veins; alternatively a double-lumen cannula is placed into the right side of the circulation via the jugular vein. Desaturated blood is withdrawn from the superior and inferior venae cavae and pumped through an oxygenator, where gas exchange of oxygen and carbon dioxide takes place. The oxygenated blood is then returned to the venous system. In venoarterial ECMO, blood is usually withdrawn via the jugular or femoral vein and the oxygenated blood is returned to the arterial system, normally via the femoral artery. In both systems patients are given a continuous infusion of an anticoagulant, usually heparin, to prevent blood clotting in the external system.

Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.

2.3   Efficacy

2.3.1  A randomised controlled trial (RCT) of 180 patients treated by ECMO or conventional management reported death or severe disability in 37% (33/90) and 53% (46/87; there was no information about 3 patients) respectively at 6-month follow-up (relative risk [RR] 0.69, 95% confidence interval [CI] 0.05 to 0.97).

2.3.2  A non-randomised comparative study of 245 patients treated by ECMO or conventional treatment reported survival to hospital discharge in 55% (34/62) and 61% (absolute figures not stated) of patients respectively (p = not significant). A non-randomised comparative study of 150 patients treated by ECMO or conventional treatment reported survival rates of 53% (17/32) and 71% (84/118) respectively (p = 0.06).

2.3.3  Case series of 1473 and 255 patients reported survival to discharge in 50% (741/1473) and 52% (132/255) of patients respectively.

2.3.4  The RCT of 180 patients treated by ECMO or conventional management reported similar levels of overall health status scores in both groups at 6 months (67.9 versus 65.9; measured on a visual analogue scale from 0 to 100, where a higher score indicates a better health status).

2.3.5  The Specialist Advisers listed key efficacy outcomes as successful weaning from ECMO, successful weaning from ventilation, improved survival and quality of life.

2.4   Safety

2.4.1  The non-randomised comparative study of 245 patients and the case series of 255 patients both reported that 5% of patients (3/62 in the comparative study, no actual figures were given for the case series) developed disseminated intravascular coagulation.

2.4.2  Vessel perforation during cannulation contributed to the death of 1 patient out of 68 treated by ECMO in the RCT of 180 patients.

2.4.3  Difficulties and/or injuries during cannulation were reported in 8% (5/62) of patients in the non-randomised comparative study of 245 patients; 1 patient required surgical intervention to repair an injury to the carotid artery.

2.4.4  The non-randomised comparative study of 245 patients and case series of 1473 and 255 patients reported rupture of the ECMO tubing system in 5% (3/62), 4% (64/1473) and 3% (actual numbers not stated) of patients respectively. Of the patients in the non‑randomised comparative study, brain death was diagnosed in 1 patient after resuscitation and reinstitution of ECMO.

2.4.5  A non-randomised study of 201 patients and the case series of 1473 patients reported haemorrhage in 54% (37/68) and 42% (613/1473) of patients respectively.

2.4.6  The Specialist Advisers listed anecdotal adverse events as air embolism, thromboembolic events, sepsis, multi-organ failure and mechanical failure.

3   Further information

3.1  This procedure is a review of IPG39 published in 2004.

3.2  For related NICE guidance see www.nice.org.uk

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

October 2010

_{Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.}

 _{It is the responsibility of consultees to accurately cite academic work in order that they can be validated.}