Small-dose perfluorocarbon reduces the recruitment pressure needed to open surfactant-deficient atelectatic lungs

Background: This study was undertaken to investigate the effect of a small dose of perfluorocarbon on the recruitment pressure needed to open atelectatic lung areas. Methods: In 12 Yorkshire pigs (body weight, 9 kg), lung injury was induced by whole lung lavage. After 1 h of conventional ventilation, an open lung maneuver was performed to obtain P_ao₂ values equal to the pre-lavage P_ao₂ values (±10%). After 1 h of ventilation at the lowest possible airway pressure that stabilized the recruited lung volume, the animals were disconnected from the ventilator to allow the lung to collapse. Six animals received a 5 ml/kg intratracheal dose of perfluorocarbon and a second open lung maneuver was performed. Six animals served as controls and received no perfluorocarbon but also underwent a second open lung maneuver. Results: In both groups, an open lung maneuver resulted in a significant increase in oxygenation. The peak pressures needed to open the lung after 1 h of mechanical ventilation in the perfluorocarbon and control groups were 43.8 ± 8.4 cmH₂O and 46.6 ± 4 cmH₂O, respectively. The addition of perfluorocarbon significantly reduced the opening pressure to 34.5 ± 6.3 cmH₂O (P < 0.01), whereas the opening pressure in the control group, 45.0 ± 0.2 cmH₂O, did not change. Conclusion: The instillation of a small amount of perfluorocarbon significantly reduces the opening pressures needed to recruit atelectatic lung areas.