A 5 year old male with a history of sickle cell disease (SCD) complicated by splenic sequestration presents to the ED with complaints of hip and back pain. He has had the pain for days, but now over the last 24 hour has had decreased PO intake associated with nausea, vomiting, and chest pain. Mom reports fever at home and that he appears to be having difficulty breathing. Vitals include BP 108/62, HR 152, T 99.2F, RR 40, SpO2 88% on room air. On exam, he appears uncomfortable and has clear lung sounds. A chest x-ray is performed and shown below. What’s the diagnosis?
Answer: Acute Chest Syndrome – note the opacification of the posterior costophrenic sulcus on the lateral film concerning for pneumonia
Definition: New infiltrate on chest x-ray in addition to fever > 101.3F, cough, wheeze, tachypnea, or chest pain
- Clinical features may present before radiographic changes, and patients may develop acute chest during hospitalization for another SCD complication.
- Chest x-ray has an approximately 85% sensitivity, thus obtain a chest CT if chest-x ray is non-diagnostic with high index of suspicion.
Etiology: Pulmonary infection, fat emboli, vaso-occlusion, over aggressive fluid administration
- Most common organisms are Chlamydia pneumoniae and Mycoplasma (other organisms are Staph aureus, Haemophilus influenza, Klebsiella pneumonia, and respiratory viruses)
- Consider Strep pneumoniae in patients with sickle cell disease not taking prophylactic penicillin
Treatment:
- Oxygen for hypoxia
- Pain control
- IV fluids – correct hypovolemia with isotonic fluid bolus, usually starting with 20 mL/kg if no heart failure; thereafter maintain euvolemia with maintenance oral hydration or IVF (D5NS or D5.45NS)
- Antibiotics to cover atypical organisms and encapsulated organisms
- Beta-2 adrenergic agonists for wheezing
- Exchange transfusion reserved for severe crisis (and PaO2<60 or high hemoglobin)
Pitfall: These patients can decompensate quickly with increasing oxygen requirements and often require critical care!
References:
Long B, Koyfman A. Sickle Cell Disease and Hereditary Hemolytic Anemias. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill
