Respiratory Distress Syndrome-Reply

In Reply.—Drs Carey and Fabri have proposed that if in our recent study the single patient with the noticeably elevated preoperative shunt were excluded from consideration, postoperative shunting would actually have been less in patients transfused through standard filters than in those transfused through Dacron wool micropore filters. Using the same logic, one might as easily argue for the exclusion of the single patient in whom shunt rose when Dacron wool filters were used, thus making our data even more important.

In our most recently published experiments with animals,¹ a strong correlation (r =.85) was noted between absolute percent change in Qs/Qt and the "quantity" of microaggregates administered. A similar correlation, albeit not as great (r =.68), is illustrated in Fig 2 of our present human study. The data illustrated in our article clearly show an increase in Qs/Qt in patients after transfusion when more than 20%