Increased R rs resulting from airway narrowing due to sludging, excessive mucus secretion, edema, and possible bronchoconstriction has been described in mechanically ventilated infants with RSV LRTD [19] [20] [21] [22] [23] . Measures to alleviate increased R rs such as nebulisation of bronchodilators or nitric oxide have yielded inconclusive results [20, 22, 24, 25] . However, these studies are methodologically different compared with ours. For instance, we excluded patients with chronic lung disease or congenital heart disease.