Crit Care Med 40 (4): 1113 - 1121, 2012. doi: 10.1097/CCM.0b013e3182374a67 Prognosis for Acute Exposure to Irritant Gas Most people recover fully, but some have persistent lung injury with reversible airway obstruction (reactive airways dysfunction syndrome) or restrictive abnormalities and pulmonary fibrosis; smokers may be at greater risk.