PHYSIOLOGICAL-RESPONSE AND LUNG DISTRIBUTION OF LAVAGE VERSUS BOLUS EXOSURF(R) IN PIGLETS WITH ACUTE LUNG INJURY

Despite evidence of surfactant dysfunction in the acute respiratory di stress syndrome (ARDS), treatment with exogenous surfactant remains ex perimental. Uneven pulmonary distribution is one factor that may limit response. We investigated whether exogenous surfactant administered b y lavage, consisting of a 35 ml/kg volume instilled by gravity and fol lowed immediately by passive drainage (LAVAGE), would result in better lung distribution and physiologic response than with surfactant admin istered as a 5 ml/kg bolus (BOLUS). Exosurf(R), an artificial surfacta nt, was administered after acute lung injury induced by saline lung la vage in neonatal piglets. In the LAVAGE group (n = 9), 10.1 +/- 0.4 ml /kg of surfactant was retained, corresponding to a phospholipid dose o f 136 +/- 5 mg/kg. In the BOLUS group (n = 9), the dose administered w as 203 mg/kg phospholipid. Piglets in the LAVAGE group demonstrated gr eater improvement in pulmonary function, including Pa-O2, Pa-CO2, vent ilation efficiency index, functional residual capacity (FRC), and pres sure-volume curves than piglets in the BOLUS group. Some differences w ere found in lung distribution of surfactant. We conclude that Exosurf is more effective when administered by lavage in this lung injury mod el. We speculate that the lavage method of administration holds promis e as an alternative method of surfactant administration in patients wi th ARDS.