Treatment of Meconium Aspiration Syndrome
All infants at risk for MAS who show signs of respiratory distress should be admitted into the neonatal intensive care units. Close monitoring is important since they can deteriorate very quickly. Maintenance of adequate oxygenation, optimal blood pressure, correction of acidosis, hypoglycaemia and other metabolic disorders is the mainstay of treatment.
Therapeutic interventions in severe MAS include airway suctioning, oxygen delivery, or ventilatory support.
Suction - the National Institute for Health and Care Excellence (NICE) does not recommend routinely suctioning the nasopharynx and oropharynx prior to birth of the shoulder and trunk. However, it advises that the upper airways may be suctioned after the shoulders are delivered, if thick or tenacious meconium is present in the oropharynx. If the baby has depressed vital signs after delivery, laryngoscopy and suction under direct vision should be carried out by a healthcare professional trained in advanced neonatal life support.
Oxygen should be given to keep oxygen saturations at 95-98%. Ventilation may be necessary. Pneumothoraces will need chest drain insertion.
High-frequency oscillation ventilation may be given in some cases.
Giving prophylactic antibiotics to neonates born through meconium-stained amniotic fluid has not been shown to reduce the incidence of MAS (or other complications).
Surfactant - meconium flowing into the lung deactivates the activity of surfactant, causes a rise in surface tension and presages the onset of respiratory distress. Surfactant replacement can be beneficial for babies with MAS, as it can rapidly improve oxygenation.
Surfactant replacement by bolus or slow infusion in infants with severe MAS has also been shown to reduce the need for extracorporeal membrane oxygenation.
The development of active synthetic surfactants is very complicated.
Anti-inflammatory drugs may be given to diminish the adverse action of products of meconium-induced inflammation on both endogenous and exogenously delivered surfactant.
Inhaled nitric oxide can be useful in the management of pulmonary hypertension associated with MAS.It is thought to act by relaxing smooth muscles in the pulmonary vessels, causing vasodilatation, as well as promoting bronchodilation.
Enteral sildenafil may be used for the treatment of persistent pulmonary hypertension resulting from MAS.
Extracorporeal membrane oxygenation (ECMO) may be needed in those babies who deteriorate.
Steroids - inhaled or systemic - have been used to good effect in some studies. Budesonide has been shown to improve the effects of exogenous surfactant in experimental MAS.