[Prognosis following extubation in severe ARDS]

Abstract

The heterogeneity of patient characteristics and the impossibility of ever including all ARDS survivors in follow-up pulmonary function studies over an extended period of time makes statements on the outcome in ARDS patients rather questionable and difficult to compare. Our conclusions are drawn from our own experience in eleven patients who survived a very serious ARDS and from recently published data. In the immediate course of ARDS all patients show restrictive ventilatory impairment and gas exchange abnormalities on exercise, often even at rest. Rarely, hypercapnic hypoxemia is seen. In the months following extubation lung function gradually improves, though sometimes this is delayed and often involves some degree of residual impairment. Pulmonary function may continue to recover for several years. A disproportionate improvement in lung volumes and gas exchanging function is not uncommon, as is the absence of clinical symptoms in the presence of residual pulmonary dysfunction. The very acute first days of ARDS onset are of little prognostic value as to incomplete repair, in contrast to the good correlation between time of mechanical ventilation or amount of oxygen needed and remaining functional deficit. There is good evidence that the recovery pattern is not influenced by the illness underlying ARDS. At present the repair mechanisms are scarcely influenced by therapeutic measures.