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Updated: Aug 21, 2026

Surfactant Depletion Combined with Injurious Ventilation Results in a Reproducible Model of the Acute Respiratory Distress Syndrome (ARDS)
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Surfactant Depletion Combined with Injurious Ventilation Results in a Reproducible Model of the Acute Respiratory Distress Syndrome (ARDS)

Published on: April 7, 2021

Dysfunction of pulmonary surfactant in chronically ventilated premature infants

Jeffrey D Merrill1, Roberta A Ballard, Avital Cnaan

  • 1Neonatology, Department of Pediatrics, University of Pennsylvania School of Medicine, USA.

Pediatric Research
|October 22, 2004
PubMed

Insights

Most premature infants needing respiratory support develop abnormal surfactant function due to deficiencies in surfactant proteins SP-B and SP-C. This dysfunction is linked to infection and respiratory decline, impacting long-term pulmonary health.

Area of Science:

  • Neonatal Medicine
  • Respiratory Physiology
  • Biochemistry

Background:

  • Premature infants (<30 wk gestation) often require prolonged respiratory support.
  • Bronchopulmonary dysplasia (BPD) is a significant risk in these infants, leading to long-term pulmonary issues or death.
  • Surfactant dysfunction is implicated in respiratory distress.

Purpose of the Study:

  • To investigate surfactant status in premature infants at high risk for BPD.
  • To identify factors associated with abnormal surfactant function in this population.

Main Methods:

  • Prospective analysis of 247 tracheal aspirate samples from 68 infants (23-30 wk gestation) intubated for 7-84 days.
  • Surfactant function assessed using a pulsating bubble surfactometer (minimum surface tension).
  • Surfactant protein (SP) A, B, and C levels measured by immunoassay in surfactant pellets.

Main Results:

  • 75% of infants exhibited abnormal surfactant function (elevated minimum surface tension).
  • Abnormal surfactant function correlated with infection (p=0.01) and respiratory deterioration (p=0.005).
  • Reduced levels of SP-A (50%), SP-B (80%), and SP-C (72%) were found in samples with abnormal surface tension. SP-B and SP-C content strongly correlated with surfactant function (p<0.0001).

Conclusions:

  • Premature infants requiring prolonged respiratory support frequently experience transient surfactant dysfunction.
  • This dysfunction is characterized by deficiencies in surfactant proteins SP-B and SP-C.
  • Surfactant protein deficiencies are linked to clinical events like infection and respiratory decline in high-risk infants.

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