A 6 year old boy presents with wheezing and a nonproductive cough for 2 hours. He is a refugee, and thus detailed medical records are unavailable. However, his mother mentions that he has experienced recurrent episodes of wheezing from the age of 7 months onwards; for the last 2 years, these have occasionally been accompanied by cyanosis and epistaxis. He has also been persistently anemic from the age of 3 years, which was attributed to a poor diet. His surgical and family histories are unremarkable, while his development is age-appropriate, and all immunizations are up to date. At the emergency department, he was started on oxygen via face mask and back-to-back nebulization with salbutamol and ipratropium bromide. However, his vital parameters have continued to deteriorate. An urgent chest X-ray reveals reticular and nodular opacification of the perihilar and basal regions with sparing of the apices and costophrenic angles. An ECG is normal.
WBC: 12,700/mm3 (5,000-10,500) N: 68% L: 23% Hb: 10.9 g/dL (13.5-16.5) Hct: 32.1% (41.0-50.0) MCV: 78.2 fL (80-100) MCH: 26.5 pg/cell (27-33) MCHC: 33.8 g/dL (33-36) Plt: 270,000/mm3 (150,000-400,000)
The echocardiogram is completely normal.
FiO2: 60% PaO2: 58 mmHg (80-100) PaCO2: 46 mmHg (35-45) pH: 7.34 (7.35-7.45) HCO3: 24 mEq/L (22-26)
The patient is not stable enough to undergo a CT pulmonary angiogram.