1672 NON-ASSOCIATION OF CELL CONTENT WITH RESPIRATORY DISTRESS IN ADULT RABBITS ASPIRATING HUMAN AMNIOTIC FLUID (AF)

Aspiration of uncontaminated AF is considered by some to be one cause of neonatal respiratory distress due to alveolar plugging by its cellular content. We examined the degree of respiratory compromise that occurred in adult rabbits after being administered human AF of varying cell counts. Experimental groups received either 4 or 6 cc/kg of human AF (n=15), saline (n=9), a 10% meconium solution (n=10), or nothing (n=6). Saline was used to provide a control fluid without solid elements while meconium was included to ensure that the experimental model could produce a well-characterized aspiration syndrome. There was one death in the AF group, O in the saline group and 5/10 meconium animals died. The epithelial cell count of the AF samples (n=15, mean= 717 cells/ml3, range=15-2370) was slightly higher than previously reported values (Ob Gyn 49:280). There was no correlatio between the cell count of the AF aspirated and the PO2 at 10, 30, 60 and 90 min and 2, 6 and 24 hrs, nor with lung weight or residual volume. Pressure-volume curves of AF animals were nearly identical with those of controls. Histological finding were similar in the AF and control groups with regard to leukocytes, alveolar macrophages and atelectasis. These findings indicate no correlation between AF cell count and the degree of respiratory compromise and lung pathology in adult rabbits.