A 5 yo 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. 

BP 108/62, HR 152, T 99.2F, R40, SpO2 88%RA

Appears uncomfortable, lungs clear to auscultation

An xray is done.  What's the diagnosis?  Scroll down for answer.

*Note the opacification in the posterior costophrenic sulcus on the lateral film concerning for pneumonia

Answer:  Acute Chest Syndrome

Definition: new infiltrate on chest x-ray with 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

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 start with 20ml/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
• beta2 adrenergic agonsists 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; Accessed June 30, 2020. https://accessemergencymedicine-mhmedical-com.ezproxy.rowan.edu/content....