Sickle cell disease (acute chest syndrome)

Acute chest syndrome (ACS) in sickle cell disease is a leading thoracic complication - as well as leading cause of mortality - in those affected by sickle cell disease. The diagnosis is made on the combination of new pulmonary opacity on chest x-ray with at least one new clinical symptom or sign.

For a general discussion of sickle cell disease, please refer to sickle cell disease.

Clinical presentation

Patients may present with acute fever, cough, wheezing, tachypnea and/or chest pain on a background of established sickle cell disease.

Pathology

There is no single underlying etiology to acute chest syndrome but rather a variety of infectious and noninfectious causes, including :

• pneumonia
• pulmonary infarction
• fat embolism
• rib or sternal infarct causing atelectasis (from splinting)

Radiographic features

Plain radiograph

Typically seen as segmental or subsegmental atelectasis/consolidation with a lower lobe predilection, and/or pleural effusion.

A chest radiograph may also show other sequelae from sickle cell disease such as bone infarcts, rib enlargement and cardiomegaly (from anemia).

Ultrasound

Point-of-care lung ultrasonography in the acute chest syndrome may reveal one of the following patterns;

• alveolar consolidation
  • the most common abnormality found, with a posterobasal regional predilection
  • air bronchograms may be visualized
• anterior subpleural consolidations
  • presence of small (≤1 cm) crescentic hypoechoic collections disrupting the pleural line (C-lines thought to represent lung infarction )
  • often associated with adjacent pleural thickening and loss of lung sliding
• lung rockets
  • three or more B-lines per sonographic field, typically 3 cm apart (B3 lines) - defines the sonographic interstitial syndrome
  • bilateral diffuse anterolateral interstitial syndrome may be observed
• pleural effusions 

CT

May show a mosaic perfusion pattern that could be associated with a pleural effusion. The radiographic signs above may also be seen on CT.

Differential diagnosis

General imaging differential considerations include:

• aspiration pneumonia

See also

• sickle cell disease (general article)
  • chronic lung disease in sickle cell disease
  • skeletal manifestations of sickle cell disease
  • abdominal manifestations of sickle cell disease
  • cerebral manifestations of sickle cell disease

Siehe auch:

• Sichelzellenanämie
• Aspirationspneumonie
• muskuloskelettale Manifestationen bei Sichelzellanämie
• Sichelzellenanämie (abdominelle Manifestationen)
• sickle cell crisis
• Sichelzellenanämie (zerebrale Manifestationen)
• Sichelzellenanämie (chronische Lungenerkrankung)