Correct!
4. Poor inspiratory effort
Poor inspiratory effort often makes the lung bases appear to have an infiltrate. Although her heart silhouette approaches 50% of the chest diameter on PA film, this is hard to interpret for a less than full breath. With a full expansion, the silhouette would be less than 50% of the chest diameter. Her lungs are clearly not hyperexpanded.
A couple hours later, she becomes increasingly obtunded and is hypotensive.
She is transferred to the MICU and emergently intubated. Her pre-intubation ABG showed hypoventilation with pH 7.19, pCO2 59 mm Hg, pO2 210 mm Hg on 4 Lpm oxygen.
What further testing is indicated?