meconium aspiration syndrome
Respiratory distress in newborns caused by inhalation of meconium-stained amniotic fluid.
Full Definition
Meconium aspiration syndrome (MAS) is a serious respiratory condition affecting newborns who inhale meconium-stained amniotic fluid during delivery or immediately after birth. Meconium, the first intestinal discharge of newborns, is typically passed in utero during fetal stress or post-term pregnancies. When aspirated, meconium causes mechanical obstruction of airways, chemical pneumonitis, and can lead to air leak syndromes such as pneumothorax. The condition is characterized by respiratory distress, hypoxemia, and characteristic chest radiograph findings showing patchy infiltrates and hyperinflation. Treatment involves respiratory support, surfactant therapy in some cases, and occasionally extracorporeal membrane oxygenation (ECMO) for severe cases.
Usage
Usage note: Distinguish from meconium ileus, which is a gastrointestinal condition.
In Context
- "The chest radiograph showed bilateral patchy infiltrates consistent with meconium aspiration syndrome." — Radiology report
- "The neonate required intubation and high-frequency ventilation for severe meconium aspiration syndrome." — Clinical documentation