Severe acute respiratory failure in adults causes high mortality despite improvements
in ventilation techniques and other treatments (eg, steroids, prone positioning, bronchoscopy,
and inhaled nitric oxide). We aimed to delineate the safety, clinical efficacy, and
cost-effectiveness of extracorporeal membrane oxygenation (ECMO) compared with conventional
ventilation support.
In this UK-based multicentre trial, we used an independent central randomisation service
to randomly assign 180 adults in a 1:1 ratio to receive continued conventional management
or referral to consideration for treatment by ECMO. Eligible patients were aged 18-65
years and had severe (Murray score >3.0 or pH <7.20) but potentially reversible respiratory
failure. Exclusion criteria were: high pressure (>30 cm H(2)O of peak inspiratory
pressure) or high FiO(2) (>0.8) ventilation for more than 7 days; intracranial bleeding;
any other contraindication to limited heparinisation; or any contraindication to continuation
of active treatment. The primary outcome was death or severe disability at 6 months
after randomisation or before discharge from hospital. Primary analysis was by intention
to treat. Only researchers who did the 6-month follow-up were masked to treatment
assignment. Data about resource use and economic outcomes (quality-adjusted life-years)
were collected. Studies of the key cost generating events were undertaken, and we
did analyses of cost-utility at 6 months after randomisation and modelled lifetime
cost-utility. This study is registered, number ISRCTN47279827.
766 patients were screened; 180 were enrolled and randomly allocated to consideration
for treatment by ECMO (n=90 patients) or to receive conventional management (n=90).
68 (75%) patients actually received ECMO; 63% (57/90) of patients allocated to consideration
for treatment by ECMO survived to 6 months without disability compared with 47% (41/87)
of those allocated to conventional management (relative risk 0.69; 95% CI 0.05-0.97,
p=0.03). Referral to consideration for treatment by ECMO led to a gain of 0.03 quality-adjusted
life-years (QALYs) at 6-month follow-up [corrected]. A lifetime model predicted the
cost per QALY of ECMO to be pound19 252 (95% CI 7622-59 200) at a discount rate of
3.5%.
We recommend transferring of adult patients with severe but potentially reversible
respiratory failure, whose Murray score exceeds 3.0 or who have a pH of less than
7.20 on optimum conventional management, to a centre with an ECMO-based management
protocol to significantly improve survival without severe disability. This strategy
is also likely to be cost effective in settings with similar services to those in
the UK.
UK NHS Health Technology Assessment, English National Specialist Commissioning Advisory
Group, Scottish Department of Health, and Welsh Department of Health.