Study:Early Use of Surfactant, NCPAP Improves Outcomes in Infant RDS

  1. Early Use of Surfactant, NCPAP Improves Outcomes in Infant Respiratory Distress Syndrome

    June 4, 2004-Early treatment with surfactant and nasal continuous positive airway pressure (NCPAP) improves outcomes for infant respiratory distress syndrome (iRDS), according to the results of a prospective randomized study published in the June issue of Pediatrics. (Pediatrics. 2004;113:e560-e563)
    "The cornerstones of treatment of iRDS are artificial respiratory support and surfactant treatment," write Carlo Dani, MD, from Careggi University Hospital of Florence in Italy, and colleagues. "Among respiratory support techniques, NCPAP and mechanical ventilation (MV) are known for their effectiveness in reducing the mortality and morbidity rates associated with iRDS. Moreover, early application of NCPAP and early treatment with surfactant are effective in decreasing the need for MV, with its related adverse effects."

    Of 40 eligible infants less than 30 weeks' gestation, 13 infants not meeting study criteria were excluded. All enrolled patients were intubated for surfactant treatment, then 13 infants were randomized to the SURF-NCPAP group (surfactant plus NCPAP), and 14 infants were randomized to the SURF-MV group (surfactant plus MV).

    Infants in the SURF-NCPAP group were extubated as soon as the respiratory rate, heart rate, and arterial hemoglobin oxygen saturation were satisfactory. Infants in the SURF-MV group were extubated after a loading dose of caffeine (20 mg/kg), when the fraction of inspired oxygen (FIO2) was 0.40 or less, mean arterial pressure was 6 cm H2O or less, PO2 was 50 or more, and PCO2 was less than 65 mm Hg. Extubation of infants undergoing MV was mandatory within two hours after they reached extubation criteria.

    At seven days of life, none of the infants in the SURF-NCPAP group and six infants (43%) in the SURF-MV group were still using MV. The SURF-NCPAP group also fared better than the SURF-MV in terms of duration of oxygen therapy, NCPAP, and MV, the need for a second dose of surfactant, and the length of stay in the intensive care unit.

    "The immediate reinstitution of NCPAP after surfactant administration for infants with infant respiratory distress syndrome is safe and beneficial, as indicated by the lesser need for MV and the briefer requirement for respiratory supports, compared with the institution of MV after surfactant treatment," the authors write. "Moreover, this strategy contributed to reducing the need for surfactant treatment and reducing the time and costs involved in keeping the infants in the neonatal intensive care unit."

    Clinical Context

    Artificial respiratory support and surfactant are the cornerstones of treatment for iRDS. Both NCPAP and MV have been shown to reduce mortality and morbidity in preterm infants with iRDS. Although up to 70% of low birth weight (LBW) infants reportedly undergo MV, Avery and colleagues reported in a study in the January 1987 issue of Pediatrics that best survival rates and lowest incidence of bronchopulmonary dysplasia (BPD) were associated with early NCPAP and tolerance of high PCO2. Verder and colleagues, in addition showed that a single dose of surfactant with early NCPAP reduced the subsequent need for MV in a study published in the February 1999 issue of Pediatrics.

    Potential complications related to iRDS in preterm infants include BPD, infection, pneumothorax, patent ductus arteriosis (PDA), intraventricular hemorrhage (IVH), retinopathy of prematurity (ROP), necrotizing enterocolitis, prolonged hospital stay, and death. Benefits of NCPAP include creating a constant airway-opening pressure to decrease the work of breathing, establishing and maintaining functional residual capacity, stabilizing air space, and promoting the release of surfactant stores. Avoiding endotracheal intubation with the use of NCPAP improves mucociliary transport and humidification of inspired air and decreases the risk of airway damage and secondary infection.

    The authors sought to establish the benefits of immediate SURF-NCPAP compared with SURF-MV in reducing the need for MV in a nonblinded study of 27 preterm (less than 30 weeks' gestation) infants with iRDS.

    Study Highlights

    • Inclusion criteria were iRDS at 0 to 6 hours of age, prematurity (less than 30 weeks), FIO2 of 30% or more to maintain arterial O2 saturation of more than 88% and PO2 of more than 50 mm Hg. The clinical diagnosis of iRDS was confirmed by chest radiograph.
    • Exclusion criteria were major congenital anomalies, IVH of more than grade 2, or requirement for MV within 6 hours of birth.
    • 13 consenting (parental) consecutive patients were enrolled in the SURF-NCPAP and 14 in the SURF-MV group and randomization was by sealed envelopes.
    • Enrolled patients were intubated for surfactant administration, which was given in 2 boluses of 100 mg/kg each. Patients in the SURF-NCPAP group were extubated as soon as vital signs and O2 saturation were satisfactory while patients in the SURF-MV group were extubated after a loading dose of caffeine and satisfactory O2 saturation.
    • A second dose of surfactant was allowed 12 hours later.
    • Criteria for discontinuing NCPAP were similar for both groups.
    • Each infant was assessed for gestational age, birth weight, Apgar score at 5 minutes, Clinical Risk Index for Babies (CRIB), arterial/alveolar oxygen tension ratio before and 6 hours after surfactant dose, need for a second dose of surfactant, maternal diseases, and prenatal corticosteroid treatment.
    • Primary outcome was need for MV at 7 days.
    • Secondary outcomes were duration of O2 treatment, need for second dose of surfactant, need for MV, death before discharge and incidences of BPD, pneumothorax, patent ductus arteriosis, IVH, ROP, necrotizing enterocolitis, and length of stay in intensive care (NICU) and the hospital.
    • The study was powered at 80% to detect a 50% reduction in need for MV at an α of .05, which required 24 infants in each group. The study was prematurely terminated with a total of 27 infants because the primary endpoint was reached at a statistically significant level.
    • The 2 groups were similar for birth weight (1100 g), gestational age (29 weeks), sex (40% male), rate of cesarean section (80%), Apgar score at 5 minutes (7.4 - 8.0), CRIB score (1.9 - 2.6), FIO2 at study entry (0.33), and main maternal pregnancy disease (50% gestosis, 40% idiopathic preterm delivery).
    • At 7 days, no patient in the SURF-NCPAP group was intubated, but 43% of patients in the SURF-MV group were intubated and ventilated.
    • 6 hours after surfactant administration, arterial/alveolar oxygen tension was similar in the 2 groups.
    • In the SURF-NCPAP group, 2 patients (15%) required MV for 2.0 1.4 days and none required a second surfactant dose, while in the SURF-MV group, 4 patients required MV for 5.6 3.1 days, and 7 (50%) required a second dose of surfactant.
    • The duration of oxygen therapy (P = .03), NCPAP (P = .009), and MV (P = .03) and the incidence of second dose of surfactant (P = .006) were significantly greater in the SURF-MV group.
    • Incidence of secondary pathological conditions and length of hospital stay were similar for both groups.
    • Length of stay in the NICU was significantly shorter for the SURF-NCPAP group (21.7 10.1 vs. 29.9 8.0 days; P = .03).
    Pearls for Practice

    • The immediate institution of NCPAP after surfactant administration for preterm infants with iRDS is safe and beneficial in reducing the need for MV at seven days.
    • NCPAP compared with MV with surfactant reduces length of NICU stay for preterm infants with iRDS.
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