ICU · Haematology

Acute sickle cell crisis in the ICU

Also known as Sickle cell crisis (SCC) · Vaso-occlusive crisis (VOC) · Acute chest syndrome (ACS) · Sickle cell disease (SCD)

Sickle cell crisis is caused by polymerisation of sickle haemoglobin (HbS) under hypoxia/dehydration/infection → red blood cells sickle → vaso-occlusion → ischaemia, pain, organ damage. The molecular lesion is a single point mutation in the β-globin gene (HBB): GAG→GTG at codon 6, substituting valine for glutamic acid at position 6 of the β-chain. Under deoxygenation HbS polymerises; erythrocytes that contain mostly haemoglobin polymers sickle → haemolysis, endothelial activation, leucocyte adhesion and vaso-occlusion. Types: vaso-occlusive crisis (pain — bones, chest, abdomen), acute chest syndrome (new infiltrate + respiratory symptoms — leading cause of death), splenic sequestration (children), aplastic crisis (parvovirus B19), stroke, priapism. Management: oxygen, IV hydration (isotonic crystalloid at no more than maintenance once euvolemic), rapid parenteral opioids, treat triggers (infection, dehydration). Exchange transfusion for severe complications (stroke, acute chest syndrome). Hydroxyurea, crizanlizumab and voxelotor for prevention/modification. CRISPR gene therapy (Casgevy, exagamglogene autotemcel) FDA/MHRA-approved 2023.

Checked against its sources on 3 Sept 2026