Complications

An important complication of painful sickling crisis is avascular necrosis of the relevant bone, which is probably most important when it occurs in the femoral head (1):

• however, avascular necrosis of any long bone may result in deformity

NICE state (2):

Possible acute complications:

• be aware of the possibility of acute chest syndrome in patients with an acute painful sickle cell episode if any of the following are present at any time from presentation to discharge:
  • • abnormal respiratory signs and/or symptoms
    • chest pain
    • fever
    • signs and symptoms of hypoxia:
      － oxygen saturation of 95% or below or
    • an escalating oxygen requirement
  • be aware that some pulse oximeters can underestimate or overestimate
    oxygen saturation levels, especially if the saturation level is borderline
    • overestimation has been reported in people with dark skin

Other possible complications seen with an acute painful sickle cell episode, at any time from presentation to discharge, include:

• acute stroke
• aplastic crisis
• infections
• osteomyelitis
• splenic sequestration
• bone marrow embolism (fat embolism syndrome)

Reference

1. Martí-Carvajal AJ, Solà I, Agreda-Pérez LH. Treatment for avascular necrosis of bone in people with sickle cell disease. Cochrane Database Syst Rev. 2019 Dec 5;(12):CD004344.
2. NICE (June 2012). Sickle cell disease: managing acute painful episodes in hospital; Updated September 2026.