Serum activities of phospholipase A in acute posttraumatic pulmonary insufficiency

The time courses of serum phospholipase A (PLA) and arterioalveolar oxygen differences (AaDO2) were compared in a group of 30 patients with severe multiple injuries. Evaluation of 391 measuring points revealed that high PLA (above 50 U/l) was associated with increased AaDO2 (above 150 mm Hg). Twelve patients who died having the symptoms of acute respiratory distress syndrome (ARDS) exhibited high serum PLA levels with individual peak values between 65 and 363 U/l (normal range 0-10 U/l). Analysis of individual time courses showed some striking parallelism between PLA and AaDO2. In five cases, however, AaDO2 increases preceded those of PLA by 1 to 4 days, while in one patient, impairment of the pulmonary function and subsequent recovery followed the corresponding PLA values with a 5-day delay. Our study supports present theories assuming some association between lung failure and the release of PLA into the circulation. Regarding the obvious time dissociation between both events, the nature of this relationship seems, however, to be complex so that pathophysiological conclusions should be drawn with caution.