Timing of initial surfactant treatment for infants 23 to 29 weeks' gestation: is routine practice evidence based?

OBJECTIVE: To describe the timing of initial surfactant treatment for high-risk preterm infants in routine practice and compare these findings with evidence from randomized trials and published guidelines.
METHODS: Data from the Vermont Oxford Network Database for infants who were born from 1998 to 2000 and had birth weights 401 to 1500 g and gestational ages of 23 to 29 weeks were analyzed to determine the time after birth at which the initial dose of surfactant was administered. Multivariate models adjusting for clustering of cases within hospitals identified factors associated with surfactant administration and its timing. Evidence on surfactant timing from systematic reviews of randomized trials and from published guidelines was reviewed.
RESULTS: A total of 47 608 eligible infants were cared for at 341 hospitals in North America that participated in the Vermont Oxford Network Database from 1998 to 2000. Seventy-nine percent of infants received surfactant treatment (77.6% in 1998, 79.4% in 1999, and 79.6% in 2000). Factors that increased the likelihood of surfactant treatment were outborn birth, lower gestational age, lower 1-minute Apgar score, male gender, white race, cesarean delivery, multiple birth, or birth later in the study period. The first dose of surfactant was administered at a median time after birth of 50 minutes (60 minutes in 1998, 51 minutes in 1999, and 42 minutes in 2000). Over the 3-year study period, inborn infants received their initial dose of surfactant earlier than outborn infants (median time: 43 minutes vs 79 minutes). Other factors associated with earlier administration of the initial surfactant dose were gestational age, lower 1-minute Apgar score, cesarean delivery, antenatal steroid treatment, multiple birth, and small size for gestational age. In 2000, 27% of infants received surfactant in the delivery room. There was wide variation among hospitals in the proportion of infants who received surfactant treatment in the delivery room (interquartile range: 0%-75%), in the median time of the initial surfactant dose (interquartile range: 20-90 minutes), and in the proportion of infants who received the first dose >2 hours after birth (interquartile range: 7%-34%). Six systematic reviews of randomized trials of surfactant timing were identified. No national guidelines addressing the timing of surfactant therapy were found.
CONCLUSION: Although the time after birth at which the first dose of surfactant is administered to infants 23 to 29 weeks' gestation decreased from 1998 to 2000, in 2000 many infants still received delayed treatment, and delivery room surfactant administration was not routinely practiced at most units. We conclude that there is a gap between evidence from randomized controlled trials that supports prophylactic or early surfactant administration and what is actually done in routine practice at many units.