Lung deposition of nebulized surfactant in newborn piglets: Nasal CPAP vs Nasal IPPV.

Abstract

Nasal continuous positive airway pressure support (nCPAP) is the standard of care for prematurely born infants at risk of neonatal respiratory distress syndrome (nRDS). However, nasal intermittent positive pressure ventilation (NIPPV) may be an alternative to nCPAP in babies requiring surfactant, and in conjunction with surfactant nebulization, it could theoretically reduce the need for invasive mechanical ventilation. We compared lung deposition of nebulized poractant in newborn piglets supported by nCPAP or NIPPV. Twenty-five sedated newborn piglets (1.2-2.2 kg) received either nCPAP (3 cmH2 O, n = 12) or NIPPV (3 cmH2 O positive end expiratory pressure+3 cmH2 O inspiratory pressure, n = 13) via custom-made nasal prongs (FiO2 0.4, Servo-i ventilator). Piglets received 200 mg kg-1 of technetium-99m-surfactant mixture continuously nebulized with a customized eFlow-Neos investigational vibrating-membrane nebulizer system. Blood gases were taken immediately before, during, and after nebulization. The deposition was estimated by gamma scintigraphy. Mean surfactant deposition in the lungs was 15.9 ± 11.9% [8.3, 23.5] (mean ± SD [95% CI]) in the nCPAP group and 21.6 ± 10% [15.6, 27.6] in the NIPPV group (P = .20). Respiratory rates were similar in both groups. Minute volume was 489 ± 203 [360, 617] in the nCPAP group and 780 ± 239 [636, 924] mL kg-1 min-1 in the NIPPV group (P = .009). Blood gases were comparable in both groups. Irrespective of the noninvasive ventilatory support mode used, relatively high lung deposition rates of surfactant were achieved with nebulization. The amounts of deposited surfactant might suffice to elicit a pulmonary function improvement in the context of nRDS.