Acute Chest Syndrome in Sickle Cell Disease

The Acute Chest Syndrome will unfortunately occur in up to 50% of patients with sickle cell disease. It is defined by:

• Fever
• Chest pain
• New pulmonary infiltrate
• Tachypnea, wheezing, or a cough

Underlying etiologies include Infection (community acquired pneumonia), viral infection, pulmonary infarction, fat embolism, but mostly this is idiopathic (over 40%). The infarction stems from RBC's sickling and clogging up the pulmonary microvasculature.

Treatment of this condition is pretty much supportive and includes:

• Maintaining a PaO2 between 70 to 100 mmHg
• Attaining and maintaining Euvolemia - crystalloids are best
  
• Pain management - typically will require opioid analgesics
• Coverage for community acquired pneumonia

Other things to consider:

• Exchange transfusion - if there are progressive pulmonary infiltrates or severe dyspnea that is not responding to the above therapy.

One last word: patients should be vaccinated against encapsulated organisms (Pneumococcus, Meningococcus, H. Flu), and consideration should be given to placing patients on Hydroxyurea for the prevention of subsequent sickle cell crises.

Links:

• a good review of hydroxyurea here.
• the original article of hydroxyurea's effects from NEJM here.