Sickle Cell Disease

SubsetsSickle Cell Trait:

HbSA (± 10% population) Heterozygocity for HbS (sickle cell trait): usually asymptomatic, lower parasitemia, higher Hb

Sickle Cell Disease:

HbSS (<1% population) Homozygocity for HbS or HbS+C/β: change in Hb structure, sickling if deoxygenated

Making the Diagnosis

• There is a wide spectrum of severity
• Suspect if patient is chronically anaemic and/or received a previous transfusion (>2 months of age)
• Suspect in children who have suffered from one or more of the presentations or complications listed below
• "Sickle cell test"
• sickledex or shaketest (>12 months) available at main lab
• Hb-electrophoresis: quantifies fraction of Hb-types. Often available at sickle clinic.

Important points in history

• Transfusions
• Painful crises
• Infections
• Episodes of Jaundice
• Family history (autosomal recessive disease)
• Provoking events: De-oxygenation:
• Infection
• General anaesthesia & surgery
• Dehydration
• Hypo- and hyperthermia
• Extreme physical exercise
• Altitude
• Smoking/ smoky rooms

Important points on examination

• Vital signs (including blood pressure and oxygen saturations)
• Pallor/ Jaundice
• Chest, heart
• (Hepato-) splenomegaly (or absence)
• Bone tenderness, deformities and frontal bossing

Investigations

• PCV and MPS
• FBC + red cell morphology to look for characteristic sickle cells
• Reticulocytes
• Blood culture if febrile
• Further tests guided by complaints (e.g. X-ray/ abdominal ultrasound/ CT-scan/ LP)

Treatment (general)Anaemia

• Severe (PCV<12%) Anaemia
• Moderate (PCV>12%) see Prevention in Anaemia chapter
• If shocked consider splenic sequestration (Give 10ml/ kg Normal Saline Shock protocol)
• Suspect Parvovirus B19 infection if aplastic
• Transfuse in acute chest syndrome or stroke

Painful & vaso-occlusive crises

• Oxygen: Oxygen stops the sickling of RBC's. All children presenting with a Sickle Cell Crisis should be started on Oxygen, even if saturations are normal
• Fluids:
• Per 24 hrs give 1.5 x maintenance fluid IV
• e.g. 24kg
• 1.5 x (10x 100ml + 10x 50ml + 4x 20ml)
• = 1.5 x 1580ml
• = 2370 ml/ 24 hours
• Encourage lots of oral hydration

Analgesia - Regular Medicine, not PRN

(Pain Management )

• Severe: Morphine + Paracetamol + Ibuprofen or Diclofenac
• Moderate: Codeine + Paracetamol + Ibuprofen or Diclofenac
• Mild: Paracetamol/Ibuprofen
• ONLY IF no morphine available, give Pethidine as an alternative

Infections and Fever (functional asplenia from 6 months)

• Sepsis (usually S. pneumo): Ceftriaxone
• Meningitis (usually S. pneumo): Ceftriaxone x 2 weeks
• Acute Chest Syndrome: Ceftriaxone
• Salmonella Osteomyelitis: Ceftriaxone (IV antibiotics for 2 weeks) then consider change to oral antibiotics (Ciprofloxacin). Aim for total duration of antibiotics 4-6 weeks
• Always check for Malaria parasites

Others

• Cholelithiasis / Cholecystitis (>10yrs): AXR, abdominal ultrasound & surgical referral
• Iron overload secondary to Transfusion (less if not transfused)
• Stunted growth & Delayed maturation

Specific Management Discharge & Long-term follow-up

Send to sickle cell clinic.

In QECH it takes place Tuesdays at 13:30 in Paediatrics Under 5 for:

• Malaria prophylaxis
• Sulphadoxine-Pyrimethamine (SP - Fansidar) once a month
• < 2years: 1/4 tablet
• 2 - 5 years: 1/2 tablet
• 5 - 10 years: 1 tablet
• 10 - 15 years: 2 tablets
• >15 years: 3 tablets
• OR Chloroquine 5 mg/kg once a week
• Folic Acid (1-5 mg daily)
• Benzathine-Penicillin (>6 months): Monthly IM <30kg: 600 000 IU; >30kg: 1 200 000 IU
• Pneumococcal vaccine (2 and 5 yrs) - if available
• Consider Hydroxyurea for those with frequent painful crises (discuss with senior)
• myelosuppressive agent - the only effective drug proven to
• reduces frequency of painful episodes
• raises level of HbF and haemoglobin level
• usually decreases the rate of painful episodes by 50 %
• also decreases the rate of acute chest syndrome episodes and blood transfusions by ~50 % (in adults)
• Initial dose 10 - 15 mg/kg/day OD
• Side effects includes neutropenia, bone marrow suppression, elevation of hepatic enzymes, anorexia, nausea, vomiting and infertility!
• Do Not Give Ferrous-Sulphate
• Instruct mothers and patients to
• ensure early (hyper) hydration & Paracetamol
• keep them warm and to promptly seek medical attention if:
• Severe pain, not controlled with Paracetamol and Ibuprofen
• Fast breathing
• Looking much more pale than usual
• High temperature
• Vomiting and Diarrhoea
• or anything else they are worried about