Effect of surfactant lavage in a rabbit model of meconium aspiration syndrome

Abstract

Meconium aspiration syndrome (MAS) is a frequent cause of respiratory distress in neonates. Recent reports have suggested that surfactant dysfunction contributes to the pathophysiology of MAS and surfactant therapy improves oxygenation of infants with MAS. We evaluated the effect of bronchial lavage with surfactant solution in a rabbit model of meconium aspiration. All animals were given 5 mL/kg of a 20% slurry of human meconium into the endotracheal tube and mechanically ventilated. The animals were then divided into saline lavage (n = 5) or surfactant lavage (n = 5). Lavage was performed an hour after meconium instillation. After the lavage the total amount of meconium recovered was measured. Blood gas was monitored during the experiment. The amount of meconium recovered by saline lavage was 14%, and by surfactant lavage was 57%. The surfactant group had a significant improvement in gas exchange, whereas the saline group had no improvement. It was concluded that the lavage with surfactant solution effectively washed out meconium and improved gas exchange in rabbit model of MAS.

Lavage Administration of Dilute Surfactant in a Piglet Model of Meconium Aspiration

“…In prior studies, meconium was simply administered directly into the normal lung of an animal, including piglets, rats, rabbits, and monkeys [6,8,[25][26][27][30][31][32]. Using this technique, both Cochrane et al [10] and 1 Sun et al [9] suggested that the meconium was unevenly distributed in the lung, leaving certain residual lung regions that appeared well expanded and even normal, presumably because they were beyond the reach of the meconium.…”

“…This has been the basis for exogenous surfactant administration in this disorder. Accordingly, animal [6,[25][26][27][30][31][32]38] and human [1,12,17,18,22] studies have addressed the question of exogenous surfactant treatment in MAS. While the results in animal studies were promising, only one randomized trial of bolus exogenous surfactant has been reported in infants with MAS [12].…”

“…In the past 10 years, several investigators [6,11,18,25,27], including our group [2,3] have reported on a new administration technique for surfactant called "lavage administration." Unfortunately, there are significant differences in the administration technique amongst the studies.…”

Treatment of MAS with PPHN using combined therapy: SLL, bolus surfactant and iNO

“…Similar experimental studies on the use of SLL in the treatment of MAS were conducted at different centers by Dargaville et al 9 and Ogawa and co-workers. [10][11][12] The first clinical studies on SLL were conducted by Ogawa 10 and Lam and Yeung. 13 Ogawa administered as a lavage a surfactant solution with a concentration of 12 mg of phospholipids in 1 ml of physiological salt.…”

“…13 Ogawa administered as a lavage a surfactant solution with a concentration of 12 mg of phospholipids in 1 ml of physiological salt. Earlier, Ohama et al 11 attempted to prove that a higher concentration is more effective. The volume of the solution was 5 ml per kg of body weight.…”