NATURAL SURFACTANT (SF) VS. BRIEF LIQUID VENTILATION (LV) RESCUE THERAPY IN VERY IMMATURE LAMBS

Abstract

In immature lambs prophylactic LV provides better gas exchange than gas ventilation (GV). In 2 groups of age-matched lambs (gest=lll±1d), after GV for first 45min of life, lambs were rescued: G-I(n=6) with 200mg/Kg of 14C-DPPC label SF (Curosurf) and G-II(n=6) with brief (5min) LV with oxygenated liquid perfluocarbon. Results are compared to previous studies in lambs with LV (G-III;n=7) and GV (G-IV;n=9) since birth (J.Appl. Physiol. 72:1024; 1992). Oxygenation improved after therapy in both rescue groups, not reaching G-III levels. In G-II paO2 decrease by 2.5h, and in G-I remained unchanged while PIP and PEEP need to be increased to values above those of G-III. In both G-I and II pulmonary compliance similarly increased after rescure and compared to untreated lambs, been less than in G-III. Labeled SF was distributed with >65% of lung sections with an amount within 20% of mean. Bleeding through tracheal tube was seen in 5/8 lambs in G-I immediately after treatment and was not seen in other groups. Gross and microscopic examination of lungs demonstrated evidence of hemmorhage and uneven inflation in all groups but G-III. Even in very immature lambs, both rescue strategies transiently improve gas exchange and pulmonary function; although exposure of immature lung to GV after rescue, impedes a sustained effect of both rescue modalities, been total LV since birth a better alternative.