Neonatal respiratory distress syndrome (RDS).
Surfactant administration: indications, types of surfactant, timing, and route of administration.
Pulmonary surfactant is a phospholipid-protein complex that decreases surface tension at the air-liquid interface of the alveolus, thus maintaining alveolar expansion at end expiration. This complex is comprised of phospholipid, primarily phosphatidylcholine, and surfactant-associated proteins that facilitate the surface tension lowering properties (surfactant proteins B and C [SP-B, SP-C]) and provide immunologic functions (surfactant proteins A and D).
Clinical use of exogenous surfactant products began with the FDA approval in 1990 in the United States after many international trials. Since that earliest approval for Exosurf, a synthetic phospholipid preparation, several additional preparations have been approved for clinical use worldwide. All trials have shown consistent results: decrease in the risk of death from RDS and a decrease in the incidence of pneumothorax. These trials have investigated the early and later use of surfactant, the type of surfactant, and the dosing regimen. However, as neonatal and obstetrical practice has changed, with up to 90% of women with threatened preterm labor receiving antenatal corticosteroids and the increasingly prevalent use of noninvasive ventilation, new questions are arising that have not been answered by large multicenter, randomized clinical trials. In this guideline we attempt to answer some of these questions based on available literature and clinical experience.
To formulate recommendations for the various aspects of surfactant administration, one must consider the conditions under which the evidence was gathered and the constant advances made in medicine. Over the past 25 years since surfactant first received FDA approval and became more widely available, perinatal practices have evolved significantly. The most significant change in antenatal management was the accepted use of antenatal steroids for fetuses 24–34 weeks: any woman qualifying for tocolytics is also a candidate for corticosteroids. As corticosteroids have been shown to decrease the risk of RDS by accelerating fetal lung maturation, short-term respiratory outcomes have improved. Many of the initial randomized controlled trials (RCTs) involving surfactant administration (prophylactic vs late selective/rescue treatment) were performed prior to this widespread use of corticosteroids.
Resuscitation guidelines have also changed within this time period with emphasis in establishing functional residual capacity (FRC), the use of noninvasive ventilation, and gentler ventilation strategies. In combination with the use of antenatal steroids, these approaches have led to more success in avoiding intubation.
One must also consider the environment where the resuscitation is taking place and the availability of resources. Most studies are conducted at Level III(+) NICUs where other modes of noninvasive ventilation are readily available, as are support staff who are comfortable with these techniques. In non-tertiary or quaternary facilities, these resources are often not available. Also, the patient population is ...