Changes in the threshold of fetal lung maturity testing and neonatal outcome of infants delivered electively before 39 weeks gestation: implications and cost-effectiveness.

OBJECTIVE: To compare the neonatal outcome of infants delivered before 39 weeks' gestation following documentation of fetal lung maturity before and after the lamellar body count (LBC) threshold was increased from 30,000 to 50,000 LB/ul. We discuss the algorithm employed for testing fetal lung maturity, the cost of testing and potential savings. MATERIAL AND METHODS: We studied the outcome of infants delivered electively before 39 weeks' gestation after fetal lung maturity was documented by amniotic fluid analysis. We compared the outcome of neonates born before and after the LBC threshold was increased. RESULTS: Our cohort included 527 neonates who were divided into two groups: 264 who underwent fetal lung maturity studies before the change in LBC threshold and 263 who underwent testing after the change. In the first group, 158 neonates met the criteria of LBC >30,000 LB/ul and were delivered without further testing. The second group included 154 neonates who were mature by LBC >50,000 LB/ul and were delivered. Seven of the neonates born in the first group required admission to the neonatal intensive care unit (NICU), whereas in the second group only two neonates required admission (P = 0.02). Additionally, 16 neonates in the first group required respiratory assistance compared with six in the second group (P = 0.04). The overall neonatal complication rate was significantly higher in the first group (P = 0.001). CONCLUSION: Changing the LBC threshold resulted in a significant decrease in neonatal morbidity. Employing the algorithm, we described for testing fetal lung maturity is cost effective, and more importantly, represents sound evidence-based medical management.

Transient neonatal diabetes mellitus or an exaggerated steroid response? A case study.

Hyperglycemia is a common finding in the extremely premature neonate, especially during the first several days of life. Premature neonates have difficulty maintaining normal blood glucose levels in spite of normal or below-normal glucose infusion rates. Some infants experience intermittent episodes of hyperglycemia throughout the course of hospitalization that typically can be related to infection, medications, overinfusion of glucose, or episodes of stress. Transient neonatal diabetes mellitus (TNDM) is an uncommon diagnosis that is utilized when other reasons for the hyperglycemia cannot be determined. The article presents a case study describing an episode of hyperglycemia that could have been TNDM or an exaggerated response to the use of dexamethasone.

A multicenter randomized masked comparison trial of synthetic surfactant versus calf lung surfactant extract in the prevention of neonatal respiratory distress syndrome.

OBJECTIVE: To compare the efficacy and safety of a synthetic surfactant (Exosurf Neonatal, Burroughs Wellcome Co) and a surfactant extract of calf lung lavage (Infasurf, IND #27,169, ONY, Inc) in the prevention of neonatal respiratory distress syndrome (RDS). DESIGN AND SETTING: Ten-center randomized masked comparison trial. PATIENTS: Premature infants (n = 871) <29 weeks gestational age by best obstetric estimate. INTERVENTIONS: Infants were randomly assigned to a course of treatment with Exosurf Neonatal (n = 438) or Infasurf (n = 433) at birth, and if still intubated, at 12 and 24 hours of age. Crossover treatment was allowed within 72 hours of age if severe respiratory failure (defined as two consecutive a/A PO2 ratios

A multicenter randomized, masked comparison trial of natural versus synthetic surfactant for the treatment of respiratory distress syndrome.

OBJECTIVE: To compare the efficacy and safety of two surfactant preparations in the treatment of respiratory distress syndrome (RDS). METHODS: We conducted a randomized, masked comparison trial at 21 centers. Infants with RDS who were undergoing mechanical ventilation were eligible for treatment with two doses of either a synthetic (Exosurf) or natural (Infasurf) surfactant if the ratio of arterial to alveolar partial pressure of oxygen was less than or equal to 0.22. Crossover treatment was allowed within 96 hours of age if severe respiratory failure (defined as two consecutive arterial/alveolar oxygen tension ratios < or = 0.10) persisted after two doses of the randomly assigned surfactant. Four primary outcome measures of efficacy (the incidence of pulmonary air leak (< or = 7 days); the severity of RDS; the incidence of death from RDS; and the incidence of survival without bronchopulmonary dysplasia (BPD) at 28 days after birth) were compared by means of linear regression techniques. RESULTS: The primary analysis of efficacy was performed in 1033 eligible infants and an analysis of safety outcomes in the 1126 infants who received study surfactant. Preentry demographic characteristics and respiratory status were similar for the two treatment groups, except for a small but significant difference in mean gestational age (0.5 week) that favored the infasurf treatment group. Pulmonary air leak (< or = 7 days) occurred in 21% of Exosurf- and 11% of infasurf-treated infants (adjusted relative risk, 0.53; 95% confidence interval, 0.40 to 0.71; p < or = 0.0001). During the 72 hours after the initial surfactant treatment, the average fraction of inspired oxygen (+/-SEM) was 0.47 +/- 0.01 for Exosurf- and 0.39 +/- 0.01 for infasurf-treated infants (difference, 0.08; 95% confidence interval, 0.06 to 0.10; p < 0.0001); the average mean airway pressure (+/-SEM) was 8.6 +/- 0.1 cm H2O; for Exosurf- and 7.2 +/- 0.1 cm H2O for Infasurf-treated infants (difference, 1.4 cm H2O; 95% confidence interval, 1.0 to 1.8 cm H2O; p < 0.0001). The incidences of RDS-related death, total respiratory death, death to discharge, and survival without bronchopulmonary dysplasia at 28 days after birth did not differ. The number of days of more than 30% inspired oxygen and of assisted ventilation, but not the duration of hospitalization, were significantly lower in Infasurf-treated infants. CONCLUSION: Compared with Exosurf, Infasurf provided more effective therapy for RDS as assessed by significant reductions in the severity of respiratory disease and in the incidence of air leak complications.