 In a randomized study of children 2 years old following cardiac surgery, patients given dornase, another mucolytic agent, had a significantly decreased duration of mechanical ventilation versus those given saline placebo 52 hrs vs. 82 hrs. HTS may be even more effective, as mechanically ventilated newborns with persistent atelectasis had more improvement in radiographic findings and oxygen saturation when randomized to receive hypertonic saline compared to those randomized to receive dornase. This may be because dornase may only be effective in patients with leukocytes or bacterial present in tracheal aspirates, while HTS may be effective in all ventilated patients. Further study of the impact of prophylactic mucolytic therapy on the duration of mechanical ventilation in children is warranted. 