Sickle cell anaemia is a genetic blood disorder inherited in an autosomal recessive pattern. A single amino acid substitution replaces glutamic acid with valine on the beta-globin chain of haemoglobin, forming abnormal haemoglobin S (HbS). When deoxygenated, HbS molecules polymerise into rigid fibres. These stiff polymers distort red blood cells into the characteristic sickle shape. The altered erythrocytes lose their normal flexibility, leading to premature destruction, known as haemolysis, and subsequent chronic anaemia. Furthermore, these sticky, misshapen cells clump together, blocking microvascular blood flow and depriving tissues of adequate oxygen.
Clinical presentations of sickle cell anaemia vary widely depending on the organ systems involved. Chronic haemolysis produces baseline jaundice, fatigue, and pallor. Vaso-occlusive events cause sudden, severe ischaemic pain in the bones, chest, and abdomen. Infants often present with dactylitis, characterised by painful swelling of the hands and feet. Chronic tissue hypoxia also impairs splenic function early in life, leaving patients vulnerable to severe bacterial infections. Leg ulcers, delayed growth, and cholelithiasis frequently develop as secondary consequences of persistent red blood cell breakdown.
Early detection of sickle cell anaemia relies on specific laboratory tests. Newborn screening programs use high-performance liquid chromatography or isoelectric focusing to identify abnormal haemoglobin variants. Haemoglobin electrophoresis remains the definitive confirmatory test, separating different types of haemoglobin based on electrical charge. A complete blood count typically reveals a low haemoglobin level, reticulocytosis reflecting bone marrow compensation, and peripheral blood smears showing sickled cells, target cells, and Howell-Jolly bodies resulting from hyposplenism.
Management of an acute vaso-occlusive crisis focuses on prompt pain relief, hydration, and identifying triggers such as infection, dehydration, or cold exposure. Administer prescribed analgesics, often using patient-controlled analgesia for severe pain. Intravenous or oral hydration reduces blood viscosity and helps clear sickled cells. Supplemental oxygen is given only if the patient is hypoxic, as hyperoxia does not reverse sickling once polymers have formed. Keep the patient warm and avoid tight clothing that could further restrict peripheral circulation.
Hydroxyurea is a cornerstone pharmacological therapy that stimulates foetal haemoglobin production, reducing red blood cell sickling and vaso-occlusive episodes. Prophylactic penicillin is administered to young children to prevent overwhelming pneumococcal sepsis. Blood transfusions increase the oxygen-carrying capacity and reduce the percentage of HbS cells, which is vital during acute crises, stroke prevention, or pre-operative preparation. Chronic transfusions, however, carry the risk of iron overload, requiring concurrent chelation therapy.
Preventing complications requires vigilance against infection, hypoxia, and dehydration. Routine immunisations against pneumococcal disease, meningococcus, and influenza are vital due to functional asplenia. Nurses must teach families to recognize early signs of splenic sequestration, a life-threatening pooling of blood in the spleen that causes rapid enlargement, hypovolaemic shock, and severe anaemia. Similarly, monitoring for neurological deficits helps prevent devastating strokes caused by narrowed cerebral arteries.
Empowering patients and caregivers with practical knowledge reduces the frequency and severity of crises. Education focuses on maintaining adequate hydration, dressing warmly in cold weather, and avoiding extreme physical exhaustion or high altitudes that lower oxygen tension. Families should learn to identify early infection signs, such as fever, and seek immediate medical help. Genetic counselling is also an important component of long-term supportive care, helping individuals understand inheritance patterns and family planning options.