(667) APRV as a Recruitment Maneuver in Mechanically Ventilated Children With Restrictive Lung Disease

Introduction: Restrictive lung diseases (RLD) are a heterogeneous group of pulmonary disorders characterized by diminished total lung capacity. The most common causes in pediatrics are extrinsic causes such as neuromuscular diseases, neuromuscular scoliosis associated with cerebral palsy, and obesity. This population is prone to acute on chronic respiratory failure prompting the need for invasive mechanical ventilation. Airway pressure release ventilation (APRV) is a mode of invasive mechanical ventilation by which continuous positive airway pressure is maintained in the airways, with only short spontaneous ventilation releases throughout the respiratory cycle, allowing for recruitment of areas of atelectasis. To our knowledge, the use of APRV as a recruitment maneuver in mechanically ventilated children with RLD has not been described in the literature.

Methods: This study is a retrospective single center case series describing the use of APRV as a ventilation mode in pediatric patients with RLD, involving 12 patient encounters. We will show that use of APRV in mechanically ventilated children with RLD is safe and effective in reducing atelectasis and improving gas exchange. The primary outcome is the decrease in atelectasis when measuring lung field surface area percentage both prior to, and after initiation of APRV for recruitment purposes. The secondary outcome is the improvement in gas exchange as demonstrated by the PaO2/FiO2 ratio (P:F) and Oxygenation Index (OI). We will also show a lack of clinically significant hypercarbia precluding use of APRV.

Results: Our preliminary results show a statistically significant increase in total lung surface area (p = 0.022 at 12-24 hours), and clinically significant decrease in atelectatic surface area of the lung (p= 0.122 at 12-24 hours). Microatelectasis may explain the improvement in total lung surface area while the atelectatic lung area was not statistically changed. In addition, there was a statistically significant improvement in oxygenation, as measured in the P:F and OI, when these markers are compared to initiation and 12-24 hours of APRV (p < 0.005), without development of significant hypercarbia.

Conclusions: Preliminary results suggest APRV is safe and effective in recruitment of atelectasis in children with RLD.