Surfactant lavage decreases systemic interleukin-1 beta 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)-I beta, IL-6, and tumor necrosis factor alpha. 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-1 beta 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-1 beta, and alleviates the severity of lung cell apoptosis in newborn piglets with experimentally-induced MAS.