Acute respiratory distress syndrome

To the Editor: With respect to the review article on the acute respiratory distress syndrome (ARDS) by Kollef and Schuster (Jan. 5 issue),¹ only two randomized studies of extracorporeal gas exchange have been published,²,³ and neither could establish that this technique improved the outcome in patients with severe ARDS. However, even in the recently published study by Morris et al.,³ the equipment used was not the most up to date. Since hemorrhage was a major complication of extracorporeal gas exchange with high-dose heparin,²,³ the introduction of covalently heparinized systems in conjunction with percutaneously inserted cannulas was a major.