A comparison of surfactant delivery with conventional mechanical ventilation and partial liquid ventilation in meconium aspiration injury

The objective of this study was to compare surfactant (SF) distribution and physiological effects after standard SF delivery during conventional mecha nical ventilation (CMV) with that using partial liquid ventilation (PLV). A model of meconium aspiration syndrome (MAS) was developed using two groups of adult rats (n = 14). After meconium instillation of 2.5 ml kg(-1) (20% v/w),SF/CMV: (n = 7) CMV and SF/PLV: (n = 7) PLV, received C-14- labeled su rfactant (4 ml kg(-1)) delivered intratracheally in four aliquots over 20 m in in both groups. Sequential measurements of arterial blood chemistry and lung mechanics were performed in all animals. At the conclusion of experime nts, lungs were inflated (30 cmH(2)O), dried, sectioned and evaluated for r adioactivity in disintegrations per minute (DPM). Surfactant distribution w as improved (P < 0.01) with PLV as compared to CMV with 48.8.% of the piece s vs. 30.9% of the pieces receiving within 25% of the mean amount of surfac tant, respectively. Further, regional distribution was also significantly m ore uniform with PLV than CMV: left vs right (P<less than>0.01) lung and ve ntral vs. dorsal (P <0.01) regions. Finally, arterial PO2 and ventilation e fficiency index were significantly (P<0.01) greater post-treatment in SF/PL V than SF/CMV. These data demonstrate surfactant delivery with LV, as compa red to CMV alone, to be an improved method of delivering surfactant in MAS and suggest the possible utility of SF/PLV combination therapy for its trea tment of other etiologies of neonatal respiratory distress.