Lung crisis in sickle cell anaemia

Sickle cell crises in the lung - otherwise referred to as acute chest syndrome (ACS) - are characterised by pleuritic chest pains, fever, abnormal chest examinations and presence of new infiltrations in the chest X ray (1).

• is the second most common cause of hospital admission in SCD patients (2)
• around half of all SCD patients will experience at least one episode of ACS during their lives (3)
• in some areas, the acute chest syndrome is the commonest cause of death in sickle cell anaemia.

They are of mixed pathology; caused by a combination of infection, fat embolism and vaso occlusion of the pulmonary vasculature (2)

• mostly seen during early childhood (usually presents with clinical features that are more typical for pneumonia)
• in later childhood and adulthood, it is more frequent during a painful crises or after anaesthesia (1)

A combination of clinical signs or symptoms of chest consolidation and worsening hypoxia is sufficient for the diagnosis of ACS (since X ray changes often lag behind clinical signs) (3)

Local protocols should be prepared for management of ACS and should include:

• analgesia
• monitoring arterial blood gas measurement
• oxygen and respiratory support - persistent, profound hypoxia is an indication for ventilation.
• incentive spirometry – useful in SCD patients presenting with chest or back pain above the diaphragm to prevent pulmonary complications
• fluid management
• bronchodilator therapy – for patients with evidence of wheeze or reversible airways disease, or a history of asthma
• antibiotic treatment may be indicated
• blood transfusion (3)

Longterm treatment with hydroxycarbamide (former British Approved Name, hydroxyurea) has led to a reduction by 50% in acute chest syndrome in some studies.

Reference:

• (1) NHS Antenatal and Newborn Screening Programmes 2010. Sickle cell disease in childhood: standards and guidelines for clinical care
• (2) Rees DC, Williams TN, Gladwin MT. Sickle-cell disease Lancet. 2010 11;376(9757):2018-31
• (3) Sickle Cell Society 2008. Standards for the clinical care of adults with sickle cell disease in the UK