Perfluorocarbon-associated gas exchange improves pulmonary mechanics, oxygenation, ventilation, and allows nitric oxide delivery in the hypoplastic lung congenital diaphragmatic hernia lamb model.

OBJECTIVES

To determine the efficacy of perfluorocarbon-associated gas exchange and the effects of inhaled nitric oxide during perfluorocarbon-associated gas exchange in the congenital diaphragmatic hernia lamb model.

DESIGN

Prospective, nonrandomized, controlled, nonhuman trial.

SETTING

Animal research facility.

SUBJECTS

Fetal lambs of 16 time-dated pregnant ewes, at 80 days gestation (term 140 to 145 days).

MEASUREMENTS AND MAIN RESULTS

The congenital diaphragmatic hernia lamb model was created in 16 animals. Twelve animals survived to be studied. All animals were mechanically ventilated for 4 hrs with a time-cycled, pressure-limited ventilator. Perfluorocarbon-associated gas exchange was started after 15 mins of ventilation (n = 6). Blood gases were analyzed at 30 mins and then hourly. The perfluorocarbon-associated gas exchange animals had dynamic compliance and tidal volumes measured. After 1 hr, inhaled nitric oxide (80 parts per million) was delivered to the perfluorocarbon-associated gas exchange animals for 10 mins. All blood gas parameters, including pH (6.72 +/- 0.06 vs. 7.14 +/- 0.07), PCO2 (186 +/- 12 vs. 70.5 +/- 16.7 torr [24.8 +/- 1.6 vs. 9.5 +/- 2.1 kPa]), and PO2 (48 +/- 17 vs. 156 +/- 48 torr [6.4 +/- 2.3 vs. 20.8 +/- 6.4 kPa]) were significantly improved in the perfluorocarbon-associated gas exchange-treated group at 4 hrs (p < .005). Dynamic compliance (0.13 +/- 0.02 vs. 0.32 +/- 0.06 mL/cm H2O/kg) and tidal volume (3.5 +/- 0.35 vs. 7.22 +/- 0.61 mL/kg) were also significantly (p < .001) increased in the perfluorocarbon-associated gas exchange group. In the perfluorocarbon-associated gas exchange animals, nitric oxide caused a significant (p < .05) increase in oxygenation and a reduction in pulmonary hypertension. This effect was reversed by stopping the inhaled nitric oxide.

CONCLUSIONS

Perfluorocarbon-associated gas exchange significantly improved gas exchange, dynamic compliance, and tidal volumes. Furthermore, inhaled nitric oxide can be effectively delivered during perfluorocarbon-associated gas exchange to reduce pulmonary hypertension and enhance oxygenation.