A Noninvasive Surfactant Adsorption Test Predicting the Need for Surfactant Therapy in Preterm Infants Treated with Continuous Positive Airway Pressure

J Pediatr. 2017 Mar:182:66-73.e1. doi: 10.1016/j.jpeds.2016.11.057. Epub 2016 Dec 15.

Abstract

Objective: To determine the diagnostic accuracy of the surfactant adsorption test (SAT) as a predictor for the need for surfactant replacement therapy in neonates with respiratory distress syndrome (RDS).

Study design: Amniotic fluid samples were collected from 41 preterm neonates with RDS treated with continuous positive airway pressure (CPAP) and 15 healthy control term neonates. Purified porcine surfactant served as a further control. Lamellar bodies and lung ultrasound score were also measured in a subset of the neonates treated with CPAP. Surfactant was administered according to the European guidelines, and clinical data were collected prospectively. Surfactant activity was measured as adsorption at the air/liquid interface and given in relative fluorescent units (RFU).

Results: Surfactant activity differed among native porcine surfactant (median, 4863 RFU; IQR, 4405-5081 RFU), healthy term neonates (median, 2680 RFU; IQR, 2069-3050 RFU), and preterm neonates with RDS (median, 442 RFU; IQR, 92-920 RFU; P <.0001). The neonates who failed CPAP had lower surfactant activity compared with those who did not fail CPAP (median, 92 RFU; IQR, 0-315 RFU vs 749 RFU; IQR, 360-974 RFU; P = .0002). Differences between groups were more evident beyond 20-30 minutes of fluorescence; the 30-minute time point showed the highest area under the curve (0.84; P <.001) and the best cutoff level (170 RFU; specificity, 72%; sensitivity, 96%) for the prediction of CPAP failure. Surfactant activity at 30 minutes was significantly correlated with lamellar bodies (r = 0.51, P = .006) and lung ultrasound score (r = -0.39, P = .013).

Conclusion: This technique has the potential to be developed into a fast, simple-to-interpret clinical test. The SAT can reliably identify preterm infants with subsequent CPAP failure and shows promise as a screening test for surfactant replacement in preterm neonates.

Keywords: CPAP; NRDS; amniotic fluid; lamellar bodies; pulmonary surfactant; surface tension.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Amniotic Fluid
  • Continuous Positive Airway Pressure / adverse effects
  • Continuous Positive Airway Pressure / methods*
  • Female
  • Humans
  • Infant, Newborn
  • Infant, Premature
  • Male
  • Pilot Projects
  • Prospective Studies
  • Pulmonary Surfactants / therapeutic use*
  • ROC Curve
  • Respiratory Distress Syndrome, Newborn / diagnosis*
  • Respiratory Distress Syndrome, Newborn / therapy
  • Surface-Active Agents

Substances

  • Pulmonary Surfactants
  • Surface-Active Agents