Sickle cell crises of the lung

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)
• study evidence showed that 50% of patients with sickle cell crises in the lung, had a pain event in the two weeks preceding the event (3)
• around half of all SCD patients will experience at least one episode of ACS during their lives (4)
• 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) (2)
• is a combination of pulmonary infarction, infection, and fat embolism (3)
• caused by sickling and ischaemia in deep tissues of the chest wall (3)
• a review describes typical features as fever, acute respiratory signs and symptoms, such as cough, wheezing, dyspnoea, crepitations or chest pain, and consolidation on chest radiograph (3)
• 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) (4)

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 (4)

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) Charles K S, Friday M, Rochford E. Acute painful crisis in adults with sickle cell disease BMJ 2024; 386 :e075099 doi:10.1136/bmj-2023-075099
• (4) Sickle Cell Society 2008. Standards for the clinical care of adults with sickle cell disease in the UK