Polyethylene Glycol Addition Does Not Improve Exogenous Surfactant Function in an Experimental Model of Meconium Aspiration Syndrome

Abstract

Meconium (MEC) is a potent inactivator of pulmonary surfactant. The authors studied the effects of polyethylene glycol addition to the exogenous surfactant over the lung mechanics and volumes. Human meconium was administrated to newborn rabbits. Animals were ventilated for 20 minutes and dynamic compliance, ventilatory pressure, and tidal volume were recorded. Animals were randomized into 3 study groups: MEC group (without surfactant therapy); S100 group (100 mg/kg surfactant); and PEG group (100 mg/kg porcine surfactant plus 5% PEG). After ventilation, a pulmonary pressure-volume curve was built. Histological analysis was carried out to calculate the mean alveolar size (Lm) and the distortion index (DI). Both groups treated with surfactant showed higher values of dynamic pulmonary compliance and lower ventilatory pressure, compared with the MEC group (P < .05). S100 group had a larger maximum lung volume, V(30), compared with the MEC group (P < .05). Lm and DI values were smaller in the groups treated with surfactant than in the MEC group (P < .05). No differences were observed between the S100 and PEG groups. Animals treated with surfactant showed significant improvement in pulmonary function as compared to nontreated animals. PEG added to exogenous surfactant did not improve lung mechanics or volumes.

A multicenter, randomized, double-blind trial of a new porcine surfactant in premature infants with respiratory distress syndrome

“…( 11 , 12 ) The results of these studies demonstrated that the animals treated with the surfactant produced by Instituto Butantan showed significant improvement of their pulmonary mechanics, pulmonary volumes, and histopathological patterns of alveolar aeration. ( 11 , 12 ) Based on these studies, we hypothesized that the surfactant produced by Instituto Butantan is as efficient and safe as the surfactants commercially available in Brazil for the treatment of neonatal RDS.…”

“…O novo surfactante também foi utilizado para o tratamento da síndrome de aspiração meconial em modelo animal. ( 11 , 12 ) Os resultados desses estudos demonstraram que os animais tratados com o surfactante produzido pelo Instituto Butantan apresentaram melhora significativa da mecânica pulmonar, dos volumes pulmonares e dos padrões histopatológicos de aeração alveolar. ( 11 , 12 ) Com base nesses estudos, foi aventada a hipótese de que o surfactante produzido pelo Instituto Butantan é tão eficaz e seguro quanto os surfactantes disponíveis comercialmente no Brasil para o tratamento da SDR neonatal.…”