Effect of liquid ventilation on preterm lamb tracheal mechanics

Liquid ventilation with fluorocarbon has been demonstrated as a viable mode of ventilatory support to preterm or distressed lambs. The effect of liquid ventilation and its high inflation pressures in proximal airways was evaluated on the mechanical behavior of the preterm trachea. 7 preterm lambs (134 +/- 1.5 SE days of gestation; 90% term) were ventilated with fluorocarbon (Rimar) for 58.6 +/- 8 min. The tracheae were dissected and the ventilated, distal segments were compared to nonventilated proximal segments. Pressure-volume curves were determined by plethysmography and specific tracheal compliance was computed. Tracheal dimensions increased 13.6 and 25.6% in diameter and volume (p less than 0.05), respectively, and the compliance decreased 29.9% (p less than 0.05). The magnitude of these changes is comparable to that observed during gaseous ventilation of term animals.