Final answer:
The diagnosis is likely meconium aspiration syndrome (MAS) with secondary pneumonia in a 41-week AGA infant with meconium-stained amniotic fluid. The next best steps involve airway management and antibiotic administration. Complications can include pulmonary hypertension and heightened susceptibility to pulmonary infections.
Step-by-step explanation:
A 41-week AGA infant was born after rupture of membranes (ROM), which yielded greenish-brown fluid indicative of meconium-stained amniotic fluid. The chest X-ray (CXR) showing patchy infiltrate is suggestive of pneumonia. The likely diagnosis is meconium aspiration syndrome (MAS), complicated by pneumonia.
The next best step would include managing the respiratory distress, which may involve suctioning the airway, providing respiratory support, and administering antibiotics due to the high risk for pulmonary infection. Treatment should start with ensuring a clear airway and may involve mechanical ventilation if necessary.
Complications of MAS include pulmonary hypertension, persistent pulmonary hypertension of the newborn (PPHN), and secondary bacterial infections. These can arise due to meconium obstructing the airways, interfering with surfactant function, and inducing inflammation in the lungs, making the newborn more susceptible to infections like pneumonia.
In cases like John's, where a gram-negative rod was identified, appropriate antibiotic treatment, such as clarithromycin and if needed, addition of levofloxacin, can be used to target the specific infection, as seen with Legionella pneumophila.