Lamellar body count and stable microbubble test on gastric aspirates from preterm infants for the diagnosis of respiratory distress syndrome.
BACKGROUND
Lamellar body count (LBC) in amniotic fluid is being used to identify infants at risk of respiratory distress syndrome (RDS) who would benefit from surfactant prophylaxis or very early therapy. The test in gastric aspirates of newborns has not been properly explored.


OBJECTIVE
The main objective of this research was to evaluate the performance of LBC alone or in combination with the stable microbubble test (SMT), done on gastric aspirates from preterm babies to predict RDS.


METHODS
A total of 34 preterm infants with RDS and 29 without RDS, with a gestational age between 24 and 34 weeks, were included in the study. Gastric fluid was collected in the delivery room. A diluent (dithiothreitol) allowed all samples to be processed, even the thickest and non-homogeneous ones, without centrifugation. The SMT was done for comparison.


RESULTS
The best cut-off value was <42,000 lamellar bodies/microl to predict RDS, with a sensitivity of 92% (95% CI 73-100%) and specificity of 86% (95% CI 77-95%). The area under the receiver-operating characteristic curve was 0.928 (95% CI 0.86-0.99). SMT showed similar results. LBC and SMT together in series (positive result if both tests were positive) showed a sensitivity of 100% and a specificity of 86%.


CONCLUSIONS
LBC on gastric aspirates diluted in a solution of dithiothreitol can be rapidly and easily performed, and may be used alone or in combination with SMT as a predictor of RDS, allowing selective prophylaxis or very early treatment only in surfactant-deficient newborns.
Department of Pediatrics, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil.
Inah Westphal Batista da Silva
IW
Daniel
Humberto Holmer
HH
Fiori
Jefferson Pedro
JP
Piva
Terezinha Paz
TP
Munhoz
André Valiente
AV
Nectoux
Renato Machado
RM
Fiori
D001724:Birth Weight; D005750:Gastric Juice / Q000737:chemistry*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008168:Lung / Q000196:embryology / Q000378:metabolism; D045423:Microbubbles; D010743:Phospholipids / Q000032:analysis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011663:Pulmonary Surfactants / Q000032:analysis*; D012372:ROC Curve; D012127:Respiratory Distress Syndrome, Newborn / Q000175:diagnosis* / Q000503:physiopathology
D010743:Phospholipids; D011663:Pulmonary Surfactants