NEW YORK (Reuters Health) – In adults with acute respiratory failure, extracorporeal membrane oxygenation (ECMO) reduces mortality compared with conventional ventilation support, a study from the UK suggests.

In a randomized multicenter trial reported in the September 16 online issue of The Lancet, survival in the absence of severe disability at 6 months was greater in the ECMO group. And while costs were higher, the authors report, “referral for ECMO is likely to prove more efficient than conventional management.”

Dr. Giles J. Peek, at Glenfield Hospital in Leicester, and colleagues explain that conventional management by intermittent positive-pressure ventilation “can cause very high airway pressures and oxygen concentrations. The combination of barotrauma, volutrauma, biotrauma, and toxic effects of oxygen exacerbates lung injury from the primary illness.”

ECMO, on the other hand, “uses cardiopulmonary bypass technology to provide gas exchange so that ventilator settings can be reduced.”

Their trial, conducted between 2001 and 2006, included 180 patients 18 to 65 years of age with severe but potentially reversible respiratory failure and a Murray score of 3.0 or higher, or uncompensated hypercapnia with a pH of less than 7.20. Analysis was by intent to treat.

Of 90 patients randomly allocated to consideration for ECMO, 5 died either before or during transport to the facility where ECMO was available. A further 17 were treated with gentle ventilation, of whom 14 survived. ECMO was used in 68 patients, of whom 43 (63%) survived.

At 6 months, there were 57 survivors (63%) without severe disability in the group given consideration for ECMO vs 41 (46%) in the 90 assigned to conventional management (relative risk, 0.69, p=0.03). Three patients had withdrawn from the conventional management group before the 6-month endpoint, the authors note.

Also, time from randomization to death was substantially shorter among patients receiving conventional treatment.

The cost of treatment in the ECMO group was twice as high as in the conventional management group (roughly 74,000 GBP vs 33,000 GBP). However, Dr. Peek and associates note, “the lifetime predicted cost-utility of about 19,000 GBP per quality adjusted life year is… well within the range regarded as cost effective.”

In a statement, Dr. Peek noted that H1N1 influenza “causes a viral pneumonia which can result in severe respiratory failure in young adults” and added that physicians “have already used ECMO during the first wave of the pandemic with good effect and we are expecting ECMO to prove an invaluable weapon in the fight against the winter resurgence of the infection, as has already been seen during the Australasian winter.”

In a linked editorial, Dr. Joseph B. Zwischenberger, from the University of Kentucky College of Medicine, Lexington, and Dr. James E. Lynch at the University of Texas Medical Branch, Galveston, congratulate the researchers on completing “such a complex and large trial,” noting that the results “will likely provide ammunition for both those in favor and those against the use of ECMO in the adult population.”

Reference:
Lancet 2009.