Inflammatory markers in meconium induced lung injury in neonates and effect of steroids on their levels: A randomized controlled trial

Acute Neonatal Respiratory Failure

Acute respiratory failure requiring assisted ventilation is one of the most common reasons for admission to the neonatal intensive care unit. Respiratory failure is the inability to maintain either normal delivery of oxygen to the tissues or normal removal of carbon dioxide from the tissues. It occurs when there is an imbalance between the respiratory workload and ventilatory strength and endurance. Definitions are somewhat arbitrary but suggested laboratory criteria for respiratory failure include two or more of the following: PaCO₂ > 60 mmHg, PaO₂ < 50 mmHg or O₂ saturation <80 % with an FiO₂ of 1.0 and pH < 7.25 (Wen et al. 2004).

Respiratory support in meconium aspiration syndrome: a practical guide

Meconium aspiration syndrome (MAS) is a complex respiratory disease of the term and near-term neonate. Inhalation of meconium causes airway obstruction, atelectasis, epithelial injury, surfactant inhibition, and pulmonary hypertension, the chief clinical manifestations of which are hypoxaemia and poor lung compliance. Supplemental oxygen is the mainstay of therapy for MAS, with around one-third of infants requiring intubation and mechanical ventilation. For those ventilated, high ventilator pressures, as well as a relatively long inspiratory time and slow ventilator rate, may be necessary to achieve adequate oxygenation. High-frequency ventilation may offer a benefit in infants with refractory hypoxaemia and/or gas trapping. Inhaled nitric oxide is effective in those with pulmonary hypertension, and other adjunctive therapies, including surfactant administration and lung lavage, should be considered in selected cases. With judicious use of available modes of ventilation and adjunctive therapies, infants with even the most severe MAS can usually be supported through the disease, with an acceptably low risk of short- and long-term morbidities.

Glucocorticoids in the treatment of neonatal meconium aspiration syndrome

Meconium aspiration syndrome is a serious neonatal disease with complex pathophysiology. With respect to the contribution of meconium-induced lung edema, inflammation and vasoconstriction on the course of the disease, glucocorticoids are increasingly used in the treatment of MAS despite the fact that principal questions on the choice of GCs derivative, mode of delivery and dosing have not been answered yet. To bring a complex insight into the topic, this article reviews the pathomechanisms of MAS, mechanisms of action of GCs, as well as the advantages and disadvantages of GCs administration in experimental models and newborns with MAS.

Meconium Aspiration Syndrome: An Insight

Meconium aspiration syndrome (MAS) is respiratory distress in a newborn baby caused by the presence of meconium in the tracheobronchial airways. The aspiration of meconium stained amniotic fluid by the fetus can happen during antepartum or intrapartum periods and can result in airway obstruction, interference with alveolar gas exchange, chemical pneumonitis as well as surfactant dysfunction. These pulmonary effects cause gross ventilation-perfusion mismatching. To complicate matters further, many infants with MAS have primary or secondary persistent pulmonary hypertension of the newborn as a result of chronic in utero stress and thickening of the pulmonary vessels. Although meconium is sterile, its presence in the air passages can predispose the infant to pulmonary infection. MAS is essentially a clinical diagnosis and should always be suspected in a child with respiratory distress and meconium-stained amniotic fluid at delivery. Though a known entity for a long time, its management still remains contentious. Intubation and direct tracheal suction is performed when meconium is observed in the amniotic fluid and the infant is not vigorous. Subsequent management involves ventilation, surfactant instillation and lavage, inhaled nitric oxide and high frequency ventilation. The role of steroids continues to be controversial.

Adjunctive pharmacotherapy in neonates with respiratory failure

Whereas oxygen, continuous positive airway pressure (CPAP) and mechanical ventilation are the mainstays of treatment of pulmonary conditions in newborns, there are a number of adjunctive therapies that may improve the pulmonary function of these infants. These include the use of bronchodilators and diuretics given either systemically or through the inhaled route, mucolytic agents, and anti-inflammatory agents. This chapter gives an overview of the use of the most-studied agents including aerosolized bronchodilators, systemic and inhaled diuretics, and systemic and inhaled corticosteroids in the treatment and prevention of, where appropriate, respiratory distress syndrome, bronchopulmonary dysplasia, and meconium aspiration syndrome. Evidence on the use of mucolytic agents including acetylcysteine and deoxyribonuclease, and the anti-inflammatory agents including the macrolide antibiotics, cromolyn, pentoxyfylline, and recombinant human Clara cell protein are also reviewed.