Physiological, Biochemical, and Biophysical Characterization of the Lung-Lavaged Spontaneously-Breathing Rabbit as a Model for Respiratory Distress Syndrome

PLoS One. 2017 Jan 6;12(1):e0169190. doi: 10.1371/journal.pone.0169190. eCollection 2017.

Abstract

Nasal continuous positive airway pressure (nCPAP) is a widely accepted technique of non-invasive respiratory support in spontaneously-breathing premature infants with respiratory distress syndrome (RDS). Surfactant administration techniques compatible with nCPAP ventilation strategy are actively investigated. Our aim is to set up and validate a respiratory distress animal model that can be managed on nCPAP suitable for surfactant administration techniques studies. Surfactant depletion was induced by bronchoalveolar lavages (BALs) on 18 adult rabbits. Full depletion was assessed by surfactant component analysis on the BALs samples. Animals were randomized into two groups: Control group (nCPAP only) and InSurE group, consisting of a bolus of surfactant (Poractant alfa, 200 mg/kg) followed by nCPAP. Arterial blood gases were monitored until animal sacrifice, 3 hours post treatment. Lung mechanics were evaluated just before and after BALs, at the time of treatment, and at the end of the procedure. Surfactant phospholipids and protein analysis as well as surface tension measurements on sequential BALs confirmed the efficacy of the surfactant depletion procedure. The InSurE group showed a significant improvement of blood oxygenation and lung mechanics. On the contrary, no signs of recovery were appreciated in animals treated with just nCPAP. The surfactant-depleted adult rabbit RDS model proved to be a valuable and efficient preclinical tool for mimicking the clinical scenario of preterm infants affected by mild/moderate RDS who spontaneously breathe and do not require mechanical ventilation. This population is of particular interest as potential target for the non-invasive administration of surfactant.

MeSH terms

  • Animals
  • Blood Gas Analysis
  • Chromatography, Liquid
  • Continuous Positive Airway Pressure
  • Disease Models, Animal*
  • Mass Spectrometry
  • Models, Theoretical
  • Phospholipids / blood
  • Pulmonary Surfactants / administration & dosage
  • Rabbits
  • Random Allocation
  • Respiratory Distress Syndrome, Newborn / physiopathology*
  • Surface-Active Agents

Substances

  • Phospholipids
  • Pulmonary Surfactants
  • Surface-Active Agents

Grants and funding

The present study was supported by Chiesi Farmaceutici S.p.A. The funder provided support in the form of salaries for authors [FR, CC, BR, LL, FB, SC, GV, BP, FS], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.