Effects on Lung Function of Small-Volume Conventional Ventilation and High-Frequency Oscillatory Ventilation in a Model of Meconium Aspiration Syndrome

Abstract

For treatment of severe neonatal meconium aspiration syndrome (MAS), lung-protective mechanical ventilation is essential. This study compared short-term effects of small-volume conventional mechanical ventilation and high-frequency oscillatory ventilation on lung function in experimentally-induced MAS. In conventionally-ventilated rabbits, MAS was induced by intratracheal instillation of meconium suspension (4 ml/kg, 25 mg/ml). Then, animals were ventilated conventionally with small-volume (f-50/min; VT-6 ml/kg) or with high frequency ventilation (f-10/s) for 4 h, with the evaluation of blood gases, ventilatory pressures, and pulmonary shunts. After sacrifice, left lung was saline-lavaged and cells in bronchoalveolar lavage fluid (BALF) were determined. Right lung was used for the estimation of lung edema formation (wet/dry weight ratio). Thiobarbituric acid-reactive substances (TBARS), oxidative damage markers, were detected in lung tissue and plasma. Meconium instillation worsened gas exchange, and induced inflammation and lung edema. Within 4 h of ventilation, high frequency ventilation improved arterial pH and CO2 elimination compared with conventional ventilation. However, no other significant differences in oxygenation, ventilatory pressures, shunts, BALF cell counts, TBARS concentrations, or edema formation were observed between the two kinds of ventilation. We conclude that high frequency ventilation has only a slight advantage over small-volume conventional ventilation in the model of meconium aspiration syndrome in that it improves CO2 elimination.

Different ventilation modes combined with ambroxol in the treatment of respiratory distress syndrome in premature infants

“…It is associated with various side effects, including injury to the airways and lung parenchyma due to its invasive nature (9). These side effects led to the invention of modern mechanical ventilation methods including high frequency oscillatory ventilation (HFOV), which can be set to trigger or to coincide with the baby's inspiratory efforts (10,11). Recent studies have confirmed the efficacy of modern ventilators as compared to conventional ventilators (12,13).…”

Experimental Models of Acute Lung Injury in the Newborns

“…2-4 kg) to those in the neonates. From this reason, utilization of several-weeks-old or adult animals (particularly piglets and rabbits) can be advantageous if various modes of artificial ventilation are performed (Wiswell et al 1994, Renesme et al 2013, Mikusiakova et al 2015 or if treatments are intratracheally delivered (exogenous surfactant, inhaled NO, corticosteroids etc.) (Lam et al 2000, Shekerdemian et al 2004, Mokra et al 2007, Colvero et al 2008, Calkovska et al 2008, Mikolka et al 2013.…”