SICKLE CELL DISEASE (SCD)
1. Description
| Topic | Information |
|---|---|
| Definition | Sickle cell disease is an inherited genetic disease affecting haemoglobin. It includes HbSC, HbS beta thalassemia, and HbSS. |
| Most severe form | Sickle Cell Anaemia (SCA) occurs in individuals who inherit two copies of Hb S (HbSS). |
| Onset | Symptoms usually appear after 6 months of life. |
| Hallmark | Recurrent painful crises due to vaso-occlusion. Ranges from minor to life-threatening. |
| Importance | Prompt management reduces morbidity, mortality, and complications. |
2. Signs and Symptoms
| Signs & Symptoms |
|---|
| Anaemia – persistent Hb 6–8 g/dL |
| Recurrent jaundice |
| Recurrent abdominal pain |
| Swollen joints of hands/feet (dactylitis) |
| Painful limbs |
| Acute neurological symptoms |
| Sudden circulatory collapse (severely pale, in shock) |
| Hepatosplenomegaly |
| Recurrent infections |
| Poor growth |
3. Investigations
| Investigations | Notes |
|---|---|
| Newborn screening | Infants 0–3 months born in Lusaka or Ndola → UTH Children’s Hospital or Arthur Davison for screening. |
| FBC/DC | May show macrocytosis due to reticulocytosis. |
| Reticulocyte count | Typically 5–15%. |
| Peripheral smear | Irreversibly sickled cells, polychromasia, occasional nucleated RBCs, schistocytes, Howell-Jolly bodies, target cells. |
| Sickling test | — |
| Sickle Scan | — |
| Hb electrophoresis/HPLC | For confirmation. |
| Blood grouping & cross-match | If transfusion required. |
| Chemistry profile | High LDH, low haptoglobin, high bilirubin, high AST. |
4. Treatment
4.1 Routine Long-Term Care
| Component | Details |
|---|---|
| Folic Acid | 5 mg once daily orally for all ages. Infants may have tablet crushed. |
4.2 Hydroxyurea
| Aspect | Details |
|---|---|
| Mechanism | Inhibits DNA synthesis; increases HbF; reduces neutrophils; alters adhesion; increases water content; increases cell deformability. |
| Indications | All HbSS or HbS beta⁰ thalassemia ≥ 9 months should be counselled and encouraged to start. |
| Exclusions | Acute liver disease, previous severe toxicity, hypersensitivity, pregnancy, sexually active without contraception. |
| Baseline tests | FBC/DC, reticulocyte count, Hb electrophoresis/HPLC (incl. HbF%, HbS%), chemistry profile, LFTs (AST/ALT), RFTs. |
| Ongoing monitoring | Hb electrophoresis every 6 months. |
| Specialist input | Consult paediatric haematologist before initiation. |
Hydroxyurea Dosing and Monitoring
| Parameter | Instructions |
|---|---|
| Starting dose | 20 mg/kg/day once daily. Max 35 mg/kg/day. |
| Monitoring | FBC + differential + reticulocytes every 4 weeks during adjustment. |
| Dose escalation | Increase by 5 mg/kg/day every 8–12 weeks until ANC is 2,000–4,000/µL or max tolerated dose. |
| Stable dose monitoring | FBC/DC, reticulocytes, platelets every 2–3 months. |
| Adherence | Counsel caregivers NOT to double doses when missed. |
| Time to response | 3–6 months; monitor MCV and HbF. |
| Withhold if (labs) | ANC < 2.0 × 10⁹/L; retic < 80 × 10¹²/L; platelets < 80 × 10⁹/L; Hb < 5 g/dL. |
| Management of toxicity | Stop 5–7 days → repeat FBC → restart same dose if baseline returns. |
| Liquid formulation | Prepared by compounding pharmacy; expires after 2 weeks. |
| Hospitalization | Continue hydroxyurea during illness/hospital stay. |
4.3 Malaria Prophylaxis
| Age | Dose of Deltaprim (pyrimethamine 12.5 mg + dapsone 100 mg) |
|---|---|
| Infancy – 3 years | ¼ tablet once weekly PO |
| 3–10 years | ½ tablet once weekly PO |
| >10 years | 1 tablet once weekly PO |
| Allergy to Deltaprim | Use dapsone once weekly orally |
4.4 Penicillin Prophylaxis
| Age group | Dose |
|---|---|
| 2 months – 3 years | Penicillin V 125 mg BD PO |
| >3 years | Penicillin V 250 mg BD PO |
| Penicillin allergy | Substitute with erythromycin |
| Stopping criteria (≥5 yrs) | No pneumococcal infection history; received PPV23 + appropriate PCV13; no splenectomy |
5. Outpatient Follow-Up Schedule (Exact Text Provided)
Table 62: Outpatient Clinics Follow-Up Schedule
| Age | Visit Frequency | Lab Tests | Additional Information |
|---|---|---|---|
| 0–2 years | 3 months | Hb electrophoresis, blood group, FBC/DC + retic | Under-5 vaccination; antibiotic prophylaxis; spleen palpation; hydroxyurea (start ≥9 months); vitals at each visit |
| 2–5 years | 6 months | FBC/DC + retic; bilirubin, RFTs, LFTs annually; HIV, Hep B; Transcranial Doppler annually | Vaccination check; PPV23 at 24 months; antibiotics; hydroxyurea; vitals |
| 5–12 years | 6 months | FBC/DC + retic; bilirubin, urinalysis, RFTs, LFTs annually; HIV, Hep B; baseline Brain MRI/MRA/MRV at age 8; Transcranial Doppler annually | Hydroxyurea; ophthalmology at 10 yrs; echo if symptomatic; PFTs at 10 yrs (repeat if symptomatic); vitals; linkages |
| 12–16 years | 6 months | FBC/DC + retic; bilirubin, urinalysis, RFTs, LFTs annually; HIV, Hep B | Hydroxyurea; yearly ophthalmology; echo if symptomatic; PFTs; vitals; linkages; transition assessment |
NB: Hb electrophoresis or HPLC should be done after 6–12 months of age if no transfusion in previous 3 months.
A. Uncomplicated Vaso-Occlusive Crisis (VOC)
| Component | Details |
|---|---|
| Description | Acute pain due to ischaemic tissue injury from obstruction of blood flow by sickled RBCs. Pain sites: bone (extremities, hand/foot syndrome, back) and abdomen. Dactylitis common in infants; back/abdominal pain in older children. Swelling may be symmetrical, asymmetrical, or migratory. |
| Triggers | Infection, fever, acidosis, hypoxia, stress, dehydration, sleep apnoea, extreme temperatures |
| Investigations | FBC/DC with reticulocyte count, peripheral smear (sickled cells, RBC fragments, Howell-Jolly bodies), total bilirubin and LDH |
| Treatment | Pain management: Mild – Paracetamol 15 mg/kg + NSAID (e.g., Ibuprofen 10 mg/kg TID max 30 mg/kg/day). Moderate – Add Tramadol 50–100 mg PO 4–6 hrly (>12 yrs, max 400 mg/24h). Severe – IV or oral morphine (IV 0.1 mg/kg 4 hrly, oral 0.2–0.3 mg/kg max 10 mg/dose 4 hrly). Prescribe stool softener if on morphine. Hydration: 50% above maintenance IV fluids (5% DNS), cautious hydration in ACS, severe anemia, stroke, splenic sequestration. Other: Rest, warm massage; avoid cold. Admission if oral analgesics inadequate or if fever/dehydration present. |
B. SCD with Infection/Fever
| Component | Details |
|---|---|
| Description | Functional asplenia leads to immunocompromise. Common pathogens: S. pneumoniae, H. influenzae type b, E. coli, Salmonella, Mycoplasma pneumoniae, Chlamydia pneumoniae, Strep pyogenes, Staph aureus, Neisseria meningitis |
| Investigations | FBC/DC with retic, RDT/malaria slide, group & save, total bilirubin/LDH, urinalysis, blood culture, CXR, U&E, renal/liver function, urine/stool culture, lumbar puncture, osteomyelitis evaluation |
| Treatment | Admit for IV antibiotics if age <1 yr, fever >38°C, ill/toxic, hypoxia <90%, Hb <6, WBC <5k or >30k, platelets <100k. Oxygen if needed. Blood transfusion if Hb <5 g/dL. Hydration. Ceftriaxone or cefotaxime for 7–10 days. Ciprofloxacin if suspected Salmonella osteomyelitis. Add erythromycin 50 mg/kg/day Q6h or azithromycin 10 mg/kg/day if ACS/severe pneumonia. Anti-pyretics as needed. |
C. Emergency Crises Management
| Emergency | Key Features | Investigations | Treatment |
|---|---|---|---|
| Priapism | Sustained painful erection >4 hr, tip soft, onset usually during sleep, pain worsens | FBC/DC, group & crossmatch, urine M/C/S, blood culture if indicated | Rapid triage, IV access, hydration 1.5x maintenance, analgesia escalation, warm shower/voiding, O2 >95%, urology consult if >4 hr persists, transfuse 15 mL/kg if no detumescence in 12 hr, hydroxyurea, consider PDE5 inhibitor (Sildenafil), joint follow-up |
| Acute Splenic Sequestration | Sudden splenomegaly, Hb drop ≥2 g/dL, occurs 6mo–5yrs | FBC/DC, retic, group & crossmatch | Manage shock (NS 10 mL/kg cautiously), urgent transfusion 10 mL/kg PRBC, avoid aggressive palpation, usually resolves 2–5 days, discuss splenectomy with haematologist |
| Acute Chest Syndrome (ACS)/Pneumonia | Fever, cough, chest pain, SOB, hypoxia, CXR infiltrates | FBC/DC, CRP, ABG, group & crossmatch, Hb electrophoresis, LFTs, blood culture, total bilirubin/LDH, CXR | Hydration (2/3 maintenance), antibiotics (cefotaxime/ceftriaxone + erythro/azithro), cautious analgesia, O2 therapy, blood transfusion 10–15 mL/kg PRBC if Hb <5 or drop ≥2 g/dL, monitor closely |
| Stroke | Focal/global neuro signs >24h, peak 2–5 yrs | FBC/DC, glucose, malaria, electrolytes, Hb electrophoresis, group & crossmatch, D-dimer, blood culture, renal/liver function, EEG, urgent CT/MRI/MRA/MRV | ABCs, high-flow O2, monitor GCS, control seizures, manage raised ICP, blood transfusion 10 mL/kg (exchange preferred to target HbS <30%), hydroxyurea, enroll chronic transfusion program, monitor iron overload, rehab post-acute phase |
D. Complications
| Complication | Description | Management |
|---|---|---|
| Sickle Cell Cardiomyopathy | Chronic hyperdynamic state → restrictive cardiomyopathy, diastolic dysfunction, LA dilation, normal systolic, pulmonary hypertension | Asymptomatic – conservative, annual ECHO, avoid routine anti-failure meds, treat high-output failure with transfusion, avoid prolonged loop diuretics |
| Osteomyelitis | Acute/chronic bone infection (lower limbs common), may mimic VOC | Investigations: bone biopsy, FBC/DC, blood/pus culture, CRP/ESR, X-ray, MRI/US. Treatment: IV Cloxacillin (S. aureus), add 3rd gen ceph if gram-neg, Ciprofloxacin if Salmonella, duration 4–6 weeks (IV 1–2 wks, oral 2–4 wks). Supportive: hydration, pain control, rest. Orthopaedic input for chronic cases or surgical intervention. |
E. Perioperative Management
| Phase | Key Points |
|---|---|
| Pre-op | FBC, U&E, creatinine, Hb electrophoresis, antibody screen, group & crossmatch; O2 sat baseline; transfuse to Hb 10 g/dL if needed; echocardiogram if SpO2 <94% or reduced exercise capacity; TCD assessment <16 yrs; pre-warming; starvation instructions |
| Intra-op | Pre-warmed OR; avoid hypoxia; maintain normothermia; careful induction/intubation; monitor vitals/O2/temperature |
| Post-op | Maintain O2 sat >96%, pulmonary clearing program if ≥4 yrs; monitor hydration carefully; analgesia to enable ambulation; infection prophylaxis; early ICU transfer if complications/sepsis |