A Study of Relation between Stable Microbubble Rating and Surfactant Derivatives (Surfacten : Phospholipid :, Exosurf :Dipalmitoyl-Phosphatidyl Choline) Concentration in Vitro

Oh, Myung Ho; Kim, Kee Hyuck; Sim, Jae Gun; Kim, Min Hee

Abstract

PURPOSE
With the recent advent of surfactant replacement therapy, there is an increasing need for a rapid and reliable test to predict respiratory distress syndrome (RDS) immediately before or at birth. There are many investigations and methods for the detection of RDS in prenatal or postnatal period. The stable microbubble rating test (SMR-test) developed by pattle et al. is rapid and simple test performed on amniotic fluid and gastric aspirates which reflects the adequacy of pulmonary surfactant with higher diagnostic accuracy. To determine the relation of the SMR and surfactant derivatives [Surfacten : phospholipid (PL), Exosurf : dipalmitoyl-phosphatidyl choline (DPPC) concentration in vitro, author performed SMR test according to 15 groups of surfactant derivatives concentration by using modified Pattle's method.
METHODS
Surfacten & Exosurf were diluted each concentration (0, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100microgram/ml) by dilutional fluid. We enveloped test tube by paraffin paper for protection of evaporation. When we performed SMR test, we shaked test tube vigorously by Vlotex shaker. We performed SMR test according to 15 groups of Surfactant concentration by using modified Pattle's method.
RESULTS
1) The number of SMR according to 15 groups of surfactant derivatives concentration were 2, 1/mm2 in 4.2microgram/ml of PL and 3.1microgram/ml of DPPC, 279, 1104/mm2 in 83.3microgram/ml of PL and 61.8microgram/ml DPPC. 2) The regression curve of SMR and surfactant derivatives concentration showed statistically significant relation (p<0.005).
CONCLUSION
The SMR test was a good method in estimation of surfactant concentration in vitro and also in diagnosis of RDS recognized as a surfactant deficiency.