Surfactant lavage decreases systemic interleukin-1β production in meconium aspiration syndrome

Background: Surfactant lavage has been used to remove meconium debris in meconium aspiration syndrome (MAS), but the influence of surfactant lavage on pro-inflammatory cytokines and cellular apoptosis is unclear. The aim of this study was to investigate the response of pro-inflammatory cytokine and the influence on alveolar cellular apoptosis using therapeutic bronchoalveolar lavage with diluted surfactant to treat MAS. Methods: Twelve newborn piglets were anesthetized, intubated via tracheostomy, and artificially ventilated. MAS was induced by intratracheal instillation of 3-5 mL/kg of 20% human meconium. The piglets were then randomly assigned to a surfactant lavage group (n = 6) or a control group (n = 6). Piglets in the lavage group received bronchoalveolar lavage with 30 mL/kg diluted surfactant (5 mg/mL) in two aliquots. Cardiopulmonary parameters were monitored continuously. Serum was obtained hourly to measure concentrations of pro-inflammatory cytokines, including interleukin (IL)-Iβ, IL-6, and tumor necrosis factor α. Lung tissue was histologically examined after experiments, and terminal deoxynucleotidyl transferase-mediated nick-end labeling assay for apoptotic cell death was also performed. Results: The animals in the lavage group displayed significantly better gas exchange and lower serum concentrations of IL-1β than the animals in the control group (P <0.05). The number of apoptotic cells in lung tissues was significantly lower in the lavage group than the control group, and also in the nondependent than the dependent site. Conclusion: Therapeutic surfactant lavage improves oxygenation, decreases production of systemic pro-inflammatory cytokine IL-1β, and alleviates the severity of lung cell apoptosis in newborn piglets with experimentally-induced MAS.