Variable ventilation enhances ventilation without exacerbating injury in preterm lambs with respiratory distress syndrome

Clare A Berry, Bela Suki, Graeme Polglase, Jane Pillow

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)


Background:Compared to constant respiratory rate (RR) and tidal volume (V(T)) during controlled mechanical ventilation (CV), variable ventilation (VV) using the same breath-to-breath minute volume but variable V(T) and respiratory rates enhances ventilation efficiency in preterm lambs. We hypothesized that if V(T) was adjusted to target permissive hypercarbia, VV would result in more efficient gas exchange without increasing inflammatory and injurious responses in the lung.Methods:129 day gestation preterm lambs were anesthetized, tracheotomized and randomized to either CV (n=8) or VV (n=8) using the same initial average V(T) and respiratory rate. Lung mechanics and gas exchange were measured intermittently and average V(T) was adjusted to target partial pressure of arterial carbon dioxide (PaCO(2)) of 40-50 mmHg for 3 h. Lung injury and inflammation was assessed from bronchoalveolar lavage fluid, lung tissue and peripheral blood.Results:VV achieved permissive hypercarbia using a lower average V(T), peak inspiratory pressure and elastance (increased compliance) compared to CV. Oxygenation and markers of lung tissue inflammation or injury were not different apart from a lower wet:dry tissue ratio in the VV lungs.Conclusions:VV improves ventilation efficiency and in vivo lung compliance in the ovine preterm lung without increasing lung inflammation or lung injury.
Original languageEnglish
Pages (from-to)384 - 392
Number of pages9
JournalPediatric Research
Issue number4
Publication statusPublished - 2012

Cite this