Background and Goal of Study: Diaphragm dysfunction worsens outcomes in mechanically ventilated patients. However, the clinical impact of changes in diaphragm structure and function due to mechanical ventilation (MV) is unknown. The hypothesis was that in children the duration of MV and the duration of stay in the intensive care unit, the frequency of complications depend on the degree of diaphragm atrophy. The aim of the study was to determine whether diaphragm atrophy developing during MV leads to prolonged ventilation. 
Materials and Methods: We investigated data of 54 patients at the age 1 month-1 year admitted in Lviv Regional Children Clinical Hospital "OCHMATDYT", who needed invasive MV and were eligible for measurement of diaphragm function. 4 patients were excluded due to the neuromuscular disease and bronchopulmonary dysplasia, in the 2 patients ultrasound investigation was impossible. 48 patients were included in the study results analysis and all of them had two or more diaphragm thickness measurements. Diaphragm thickness (Tdi) at end of inspiration and diaphragmatic excursion were measured daily by ultrasound in children requiring invasive MV, evaluating an inspiratory effort was assessed by thickening fraction. The primary outcome was time to liberation from ventilation. The secondary outcomes included complications (reintubation, tracheostomy, prolonged ventilation, or death). We use Statistical Package for the Social Sciences and results were presented using adjusted hazard ratio (HR), duration ratio, and odds ratio (OR).
Results and Discussion: Thickness decreased more than 10% in 30 patients (68%) by median day 6 (IQR 5-7). Development of decreased thickness was associated with a lower daily probability of liberation from ventilation (adjusted HR 0.47, 95%CI 0.38-0.62, per 10% decrease), prolonged ICU admission (duration ratio 1.63, 95%CI 1.25-2.44), and a higher risk of complications (OR 2.14, 95%CI 1.21-4.72). Development of increased thickness (n=8, 18%) also predicted prolonged ventilation (duration ratio 1.38, 95%CI 1.00-1.90). Decreasing thickness was related to abnormally low inspiratory effort; increasing thickness was related to excessive effort. Patients with thickening fraction between 15-30% during the first 4 days had the shortest duration of ventilation.
Conclusion(s): Diaphragm atrophy developing during MV strongly impacts clinical outcomes.

04 / Diaphragm ultrasound as a method to predict ventilation outcome in children: the prospective observational cohort study.