Perinatal Factors Influencing Clinical Response to Surfactant Replacement Therapy in Neonates with Respiratory Distress Syndrome

ABSTRACT

PURPOSE: Surfactant replacement therapy significantly decreases neonatal complications and mortality in neonates with respiratory distress syndrome (RDS), but clinical responses to the treatment is not consistent. An analysis of the perinatal factors influencing the clinical response to the therapy is important for early detection of high risk and prognosis. The purpose of this study is to analyze the clinical responses to the therapy and to assess the perinatal factors influencing the clinical response. METHODS: From April 1992 to Dec. 1995, 80 infants were enrolled in this study. Medical records were reviewed, and the clinical response to the therapy was defined by a change in the ventilatory index (VI). The perinatal factors were compared according to the clinical response. RESULTS: "Good" response was found in 58 infants (72.5%), "poor" in 14 infants (17.5%), and eight infants (10%) had a "relapse". The factor affecting the response to the therapy in the comparison among the three groups was pretreatment VI, reflecting the severity of the underlying disease. In the comparison between the initial response group and initial non-responders, pretreatment FiO2, pretreatment arterial pH, a/APO2, and VI were significantly different. With control of compounding variables, only pretreatment VI was a significant independent risk factor of the "poor" response. CONCLUSION: The clinical response to surfactant replacement therapy is only influenced by the severity of RDS. According to the results, we speculate that the dosage of surfactant in high pretreatment VI is needed to be increased, and further studies are required to determine the adequate dosage of surfactant in high risk infants.