Evaluation of specificity and sensitivity of gastric aspirate shake test to predict surfactant deficiency in Iranian premature infants

Abstract

Introduction: Respiratory failure secondary to pulmonary surfactant deficiency is an important cause of severe respiratory distress in term and preterm infants. The aim of this study was to evaluate the specificity and sensitivity of gastric aspirate shake test (GAST) to predict surfactant deficiency in newly born premature infants in Arash Hospital (Iran) during 2012-13.

Methods: In this case-control study, the case group comprised 69 premature infants (gestational age<37 weeks) who were admitted to the neonatal intensive care unit due to respiratory distress. The control group included 50 healthy infants .GAST test was done. The subjects were finally categorized as healthy or surfactant-deficient based on clinical and radiological assessments.

Results: Using statistical methods the sensitivity, specificity, and positive and negative predictive values of GAST were 60%, 75%, 15%, and 52%, respectively. There was a significant difference between respiratory distress syndrome (RDS) scores and receiving surfactant in neonates with gestational age below 34 weeks. Moreover, there were significant differences between GAST results and both radiological findings of RDS and receiving oxygen in premature infants (gestational age<34 weeks). Negative GAST results were more prevalent in neonates who were born to mothers with hypothyroidism, preeclampsia, diabetes mellitus, and premature rupture of membranes. However, this difference was not significant.

Conclusion: According to our findings, the application of GAST on gastric aspirate secretions is not a useful method to predict surfactant deficiency. Therefore, decisions for RDS management must be made based on clinical and radiological findings.

Keywords: Gastric aspirate shake test; Newborn; Preterm; Surfactant.