7.5 Haematology & Sickle Cell Disease
Key Takeaways
Jamaica's Ministry of Health and Wellness estimates sickle cell disease affects about 1 in 150 births and about 10% of the population carries the trait.
When both parents have sickle cell trait, each pregnancy carries a 25% chance of a child with sickle cell disease.
Painful crisis care is prompt opioid analgesia, hydration, warmth and oxygen if hypoxaemic; cold packs and pethidine are avoided.
Acute chest syndrome is a new lung infiltrate with chest pain, fever or hypoxia and is a sickle cell emergency.
Children with sickle cell disease receive penicillin prophylaxis and vaccines because functional asplenia makes fever of 38.5 °C or above an emergency.
Haematology and Sickle Cell Disease
The CARICOM Blueprint lists sickle cell anaemia among congenital and genetic problems of the youngest age group, and anaemias among metabolic and nutritional problems. Jamaica's Ministry of Health and Wellness estimates that sickle cell disease affects about 1 in 150 births, and that about 10% of the population carries the sickle cell trait. Every Caribbean RN will care for people with sickle cell disease in clinics, emergency rooms, paediatric wards and maternity units.
Genetics in One Table
Sickle haemoglobin (HbS) results from a single amino-acid change in the beta-globin chain. Inheritance is autosomal recessive.
| Genotype | Name | Usual picture |
|---|---|---|
| HbAA | Normal | No disease |
| HbAS | Sickle cell trait (carrier) | Usually no symptoms; may pass HbS on. Rarely, problems with severe dehydration or extreme exertion |
| HbSS | Sickle cell anaemia | The most severe form: chronic haemolysis and crises |
| HbSC, HbS-beta-thalassaemia | Compound sickle cell disease | Variable. HbSC is often milder but carries more retinopathy |
If both parents carry the trait (AS × AS), each pregnancy has:
- a 25% chance of a child with sickle cell disease;
- a 50% chance of a carrier; and
- a 25% chance of an unaffected non-carrier.
The odds apply to each pregnancy separately. Having one affected child does not protect the next. Genetic counselling and newborn screening let penicillin prophylaxis and parental education start early.
Pathophysiology and Triggers
When deoxygenated, HbS polymerises and the red cell becomes rigid and sickle-shaped. Sickled cells block small vessels (vaso-occlusion), causing ischaemic pain and organ damage, and are destroyed early (chronic haemolytic anaemia, jaundice, gallstones). Triggers include:
- dehydration;
- hypoxia;
- infection and fever;
- cold exposure (including swimming in cold water);
- acidosis;
- emotional stress;
- strenuous exertion; and
- high altitude or unpressurised flight.
Teach clients to avoid these triggers. It is the cornerstone of prevention.
Complications to Recognise
| Complication | What you see | Nursing priority |
|---|---|---|
| Vaso-occlusive (painful) crisis | Severe pain in bones, back, chest or abdomen. In infants, dactylitis (painful swollen hands and feet) | Rapid analgesia, hydration, warmth, monitoring for acute chest syndrome |
| Acute chest syndrome | New infiltrate on chest X-ray with chest pain, fever, cough, tachypnoea or hypoxia | Emergency: oxygen, antibiotics, analgesia, incentive spirometry, possible transfusion |
| Acute splenic sequestration | In young children: sudden pallor, a rapidly enlarging spleen, a falling haemoglobin and shock | Emergency transfusion. Teach parents to palpate the spleen and seek help |
| Aplastic crisis | Sudden severe anaemia with low reticulocytes, often after parvovirus B19 | Transfusion; isolate from pregnant staff and clients at risk |
| Stroke | Hemiparesis, speech loss, seizures, often in children | Emergency care; children may be screened with transcranial Doppler |
| Overwhelming infection | Fever in a child whose spleen no longer works (functional asplenia) | Fever of 38.5 °C or above is an emergency: urgent assessment and antibiotics |
| Priapism | Painful, sustained erection | Urgent medical review |
| Chronic problems | Leg ulcers (often around the ankles), avascular necrosis of the hip, gallstones, kidney damage (inability to concentrate urine, so clients dehydrate easily), retinopathy | Long-term follow-up and education |
Managing a Painful Crisis
- Assess pain promptly with a validated scale and believe the client's report. Give the first analgesic dose quickly. UK guidance sets a target of within 30 minutes of arrival.
- Titrate opioids (for example, morphine) for severe pain and reassess often. Patient-controlled analgesia may be used. Avoid pethidine (meperidine), because its metabolite can cause seizures.
- Hydrate orally or intravenously, but watch for fluid overload.
- Give oxygen if the client is hypoxaemic.
- Keep the client warm. Do not apply ice or cold packs, because cold promotes sickling.
- Encourage incentive spirometry to prevent acute chest syndrome, especially in chest, back or abdominal pain.
- Look for and treat infection, and monitor for chest syndrome, sequestration and neurological change.
The stigma that labels people with sickle cell disease as "drug seeking" delays analgesia and is a recognised quality-of-care problem. Advocate for timely pain relief.
Long-Term Care and Health Promotion
- Penicillin prophylaxis in early childhood (usually from a few months of age until about 5 years) and full pneumococcal and other vaccinations, because functional asplenia raises the risk of infection.
- Folic acid to support red cell production.
- Hydroxyurea (hydroxycarbamide) raises fetal haemoglobin and reduces crises. Monitor blood counts, and teach effective contraception because the drug is teratogenic.
- Transfusion programmes where indicated, such as stroke prevention.
- Pregnancy in sickle cell disease is high risk and needs specialist antenatal care.
- Schooling and work: provide access to water, toilet breaks and warmth, and avoid extreme exertion.
Other Haematology Topics
Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency
G6PD deficiency is X-linked, so it mainly affects males. Oxidant stress causes haemolysis, triggered by fava beans, certain drugs (for example primaquine, dapsone and some sulfonamides), infection, or naphthalene mothballs. It can cause neonatal jaundice. Teach clients to avoid triggers.
Thalassaemia Trait
It causes microcytic anaemia that does not respond to iron. Do not give long courses of iron for microcytosis without confirming iron deficiency.
Haemophilia
Haemophilia is X-linked (factor VIII or IX deficiency). It causes bleeding into joints and muscles. Avoid IM injections and NSAIDs, apply pressure to puncture sites, and replace factor as prescribed.
Iron-Deficiency Anaemia
Iron-deficiency anaemia is the most common anaemia (Section 3.2).
Leukaemia
Look for pallor, bruising or bleeding, fever and infections, and bone pain from marrow failure. Nursing care follows the neutropenic and bleeding precautions in Section 7.6.
Both parents have sickle cell trait (HbAS). What is the chance that their next child will have sickle cell anaemia (HbSS)?
100%, because both parents carry the gene
25% in every pregnancy
Zero, because they already have one affected child
50% in every pregnancy
A 19-year-old with HbSS arrives at the emergency room with severe leg and back pain rated 9/10. Which nursing action is the priority?
Give intramuscular pethidine as needed for breakthrough pain
Apply ice packs to the painful areas to reduce swelling and numb the pain
Wait for the laboratory results before giving any analgesia
Give prescribed opioid analgesia promptly and start fluids while assessing
A 2-year-old with sickle cell anaemia is brought in pale and lethargic. The mother says the child's "belly got big today". The spleen is markedly enlarged and the haemoglobin has fallen sharply. Which complication should the nurse suspect?
Acute splenic sequestration
Dactylitis (hand-foot syndrome)
Acute chest syndrome
Aplastic crisis from parvovirus B19
A client with HbSS has a pain crisis in the chest and back. Which nursing measure most directly helps prevent acute chest syndrome?
Keeping the client flat and still in bed for 48 hours
Restricting oral fluids to 1 litre a day to prevent fluid overload
Hourly incentive spirometry while awake, with good analgesia
Applying cold compresses to the chest to reduce inflammation
Sections you finish are checked off in the contents.