High positive end-expiratory pressure during high-frequency jet ventilation improves oxygenation and ventilation in preterm XXXX .

@entity32 @entity742 @entity26 @entity651 @entity2507
Increasing positive end-expiratory pressure (PEEP) is advocated to recruit alveoli during high-frequency jet ventilation (HFJV), but its effect on cardiopulmonary physiology and @entity651 is poorly documented. We hypothesized that high PEEP would recruit alveoli and @entity651 but compromise pulmonary blood flow (PBF). Preterm @entity742 of anesthetized ewes were instrumented, intubated, and delivered by cesarean section after instillation of surfactant. HFJV was commenced with a PEEP of 5 cm @entity2507 . @entity742 were allocated randomly at delivery to remain on constant PEEP (PEEPconst, n = 6) or to recruitment via stepwise adjustments in PEEP (PEEPadj, n = 6) to 12 cm @entity2507 then back to 8 cm @entity2507 over the initial 60 min. PBF was measured continuously while ventilatory parameters and arterial blood gases were measured at intervals. At postmortem, in situ pressure-volume deflation curves were recorded, and bronchoalveolar lavage fluid and lung tissue were obtained to assess @entity32 . PEEPadj @entity742 had lower pressure amplitude, fractional inspired @entity26 concentration, oxygenation index, and PBF and more compliant lungs. Inflammatory markers were lower in the PEEPadj group. Adjusted PEEP during HFJV improves oxygenation and lung compliance and reduces ventilator requirements despite reducing pulmonary perfusion.
