Hematology Oncology · Year 2 · from Hematology Oncology
Case 1: Sickle Cell Disease with Acute Vaso-Occlusive Crisis
Patient Presentation
Demographics: 24-year-old African American male
Chief Complaint: Severe pain in lower back, legs, and chest for 12 hours
History of Present Illness: The patient has known sickle cell disease (HbSS) diagnosed at birth through newborn screening. He reports sudden onset of severe pain starting in his lower back and spreading to his thighs and chest. He rates the pain 10/10, describing it as similar to previous vaso-occlusive crises. He reports mild shortness of breath. He was recently non-compliant with hydroxyurea. He denies fever initially but developed low-grade temperature overnight. He has had 4 hospitalizations for pain crises in the past year.
Physical Examination:
- Vital signs: BP 125/80, HR 110, RR 24, Temp 38.1C, SpO2 94% on room air
- General: Young man in obvious distress, writhing in pain
- HEENT: Scleral icterus, conjunctival pallor
- Cardiac: Tachycardic, III/VI systolic murmur
- Lungs: Decreased breath sounds at right base, no crackles
- Abdomen: Mild splenomegaly (auto-infarcted but not completely absent)
- Extremities: Tender to palpation over femurs bilaterally
- Skin: Chronic leg ulcer over left medial malleolus
Workup and Results
Complete Blood Count:
- WBC: 18,500/uL (elevated from baseline 12,000)
- Hemoglobin: 7.2 g/dL (baseline 8.5)
- MCV: 85 fL
- Platelets: 425,000/uL
- Reticulocyte count: 12%
Hemoglobin Electrophoresis (prior):
- HbS: 92%
- HbF: 5%
- HbA2: 3%
- HbA: 0% (confirms HbSS disease)
Chemistry:
- LDH: 580 U/L (elevated)
- Total bilirubin: 4.2 mg/dL (elevated)
- Creatinine: 1.4 mg/dL (elevated from baseline 1.0)
Chest X-ray:
- New infiltrate in right lower lobe
Arterial Blood Gas:
- pH 7.38, pCO2 32, pO2 65 on room air
Clinical Image
Peripheral blood smear in sickle cell disease showing characteristic sickle-shaped red blood cells (drepanocytes), target cells, and polychromasia reflecting ongoing hemolysis and reticulocytosis.
Diagnosis
Sickle Cell Vaso-Occlusive Crisis complicated by Acute Chest Syndrome
Acute chest syndrome criteria met:
- New pulmonary infiltrate on chest X-ray
- Respiratory symptoms (dyspnea, hypoxia)
- In setting of sickle cell disease
Treatment Plan
- Pain management (priority):
- IV morphine or hydromorphone patient-controlled analgesia
- Scheduled NSAIDs (ketorolac) if no renal contraindication
- Avoid meperidine (seizure risk with metabolite accumulation)
- Acute chest syndrome management:
- Supplemental oxygen to maintain SpO2 > 92%
- Incentive spirometry every 2 hours while awake
- Empiric antibiotics (ceftriaxone + azithromycin) for atypical coverage
- Simple transfusion to raise hemoglobin to 10 g/dL
- Consider exchange transfusion if worsening
- Supportive care:
- IV fluids (avoid over-hydration which worsens ACS)
- DVT prophylaxis
- Monitor for multiorgan failure
- Long-term management:
- Restart hydroxyurea and emphasize compliance
- Consider chronic transfusion program if frequent ACS
- Evaluate for curative options (stem cell transplant, gene therapy)
Teaching Points
- Acute chest syndrome is the leading cause of death in adult sickle cell patients
- The pathophysiology involves in situ sickling, fat embolism, and infection
- Incentive spirometry prevents atelectasis that triggers sickling
- Exchange transfusion rapidly reduces HbS percentage for severe cases
- Hydroxyurea increases HbF, which does not participate in sickling
- Pain management should be aggressive - undertreated pain is common
- Fever in sickle cell disease requires evaluation for infection due to functional asplenia