All issues > Volume 35(10); 1992

Original Article

J Korean Pediatr Soc. 1992;35(10):1361-1368. Published online October 15, 1992.

Diagnostic Accuracy of Stable Microbubble Rating Test for the Early Detection of Neonatal Respiratory Distress Syndrome

Jung-Sam JS Jun¹, Chy-Hyung CH Park¹, Jong-Woo JW Bae¹, Chang-Il CI Ahn¹

¹Department of Pediatrics, Kyung Hee University, College of Medicine, Seoul, Korea

Abstract

Respiratory distress syndrome(RDS) of preterm infants remains a significant cause of morbidity and mortality despite improvements in neonatal intensive care and artificial ventiratory techniques. After identification of the deficiency of pulmonary surfactant is major pathophysiologic basis in RDS, artificial surfactant replacement therapy in RDS was first successfully tested on RDS infants by Fujiwara and co-workers in 1980. Therefore, exogenous surfactant replacement produced excellent results in improved clinical and respiratory status during the acute stage and decreased incidence of late complications and mortality. According to cmparison of administration timing between early (within 6 hours after birth) and late (after 6 hours) group, early replacement therapy is more effective in improving of clinical course and progrosis. Because of that, early, just after birth, recognition and detection of RDS is also important procedure. There are many investigations and methods for the detection of RDS in pre-natal or post-natal period. Among them, Stable microbubble rating (RDS) test was first reported by Pattle and coworkers in 1979. To determine the maturity of the lungs and detect the neonatal RDS predictively, the author conducted test of SMR method on gastric aspirates immediately after birth by using modified Pattle's method. A total 305 neonates was examined (gestational period; 26∼44 weeks), SMR less than 15 ㎛ in diameter were counted under a 10 power objective of microscope. The SMR are; strong(more than 20/mm2), medium(10∼20/mm2) and weak (less than 10/mm2). Among the 305 neonates, 19 cases of RDS were noticed. Of the 19 infants with RDS, SMR results were 14 cases of weak, 3 cases of medium and 2 cases of strong. Of the 286 infants with non-RDS, 4 cases of weak, 9 cases of medium and 273 cases of strong, sensitivity and specificity were 89.5%, 95.5% respectively with low false positivity and false negativity. We also studied the comparison of variable factors (eg, premature rupture of membrane, neonatal asphyxia, blood or meconium contamination on gastric aspirates) which were effecting the results of SMR, but there were no significant difference of the results of SMR between one group which had aboved factors and which another group had not aboved factors. Change of SMR results according to the timing after birth were checked. The author checked serial SMR test at birth, 2, 4, 6 hours after birth on same neonates under the condition of nothing per os. There were no significant difference of SMR results within 6 hours duration after the birth. In conclusion, the diagnostic accuracy of SMR test was higher and this test is a simple and good method for early detection and prediction of RDS. In the furture, we expected that prophylactic surfactant replacement therapy, immediated after the birth, will be more popular in the field of care of neonatal RDS. So, we recommened the use of this method for early detection and serving optimal care neonates with RDS.

Keywords :Respiratory distress syndrome (RDS), Stable microbubble rating test