What are the common acute crises in sickle cell disease?

Common Acute Crises in Sickle Cell Disease

The most common acute crises in sickle cell disease are vaso-occlusive crisis (painful crisis), acute chest syndrome, splenic sequestration, transient aplastic crisis, stroke, and priapism—each requiring specific recognition and management to prevent mortality. 1, 2

Vaso-Occlusive Crisis (Painful Crisis)

• This is the most common acute complication, occurring in 91.6% of crisis presentations, characterized by severe acute pain from microvascular occlusion and tissue ischemia 3, 4
• Presents with severe pain in bones, joints, chest, or abdomen requiring rapid triage and aggressive parenteral analgesia with opioids (morphine) via scheduled dosing or patient-controlled analgesia 1
• Management requires adequate hydration (avoiding excessive fluids), oxygen monitoring, incentive spirometry to prevent acute chest syndrome, and close cardiorespiratory monitoring 1, 5
• Critical pitfall: Delayed or inadequate pain control increases risk of progression to acute chest syndrome 1

Acute Chest Syndrome

• This is the most common cause of ICU admission and death in adults with sickle cell disease 4
• Defined by new segmental infiltrate on chest radiograph (may not be visible initially) plus lower respiratory tract symptoms, chest pain, and/or hypoxemia 1
• Can present acutely or develop after initial presentation for pain crisis, with or without fever 1
• Causative factors include infection (viral, bacterial, Mycoplasma, Chlamydia), pulmonary infarction, pulmonary fat embolism, and hypoventilation from inadequately treated pain 1
• Patients may deteriorate rapidly to pulmonary failure and death, requiring aggressive treatment with oxygen, incentive spirometry, analgesics, antibiotics, and often simple or exchange transfusions 1
• Children with reactive airway disease have increased incidence 1

Splenic Sequestration

• Characterized by rapidly enlarging spleen and hemoglobin decrease >2 g/dL below baseline, with mild to moderate thrombocytopenia 1
• Severe cases rapidly progress to hypovolemic shock and death 1, 4
• Most common in children with HbSS <5 years and adolescents with HbSC, but can occur at any age 1
• Requires prompt recognition and careful red blood cell transfusions in 3-5 mg/kg aliquots with posttransfusion hemoglobin checks before next dose 1
• Critical pitfall: Avoid acute overtransfusion to hemoglobin >10 g/dL, as sequestered red cells may be acutely released from the spleen causing hyperviscosity 1
• Parents of young children must be taught daily spleen palpation to recognize early enlargement 1
• Surgical splenectomy recommended after life-threatening or recurrent episodes 1

Transient Aplastic Crisis

• Characterized by exacerbation of baseline anemia with substantially decreased reticulocyte count (typically <1%) 1
• Most commonly caused by acute parvovirus B19 infection, usually without characteristic rash 1
• Requires comparison of CBC and reticulocyte counts with baseline values for recognition 1
• Red blood cell transfusions often needed 1
• Parvovirus is highly contagious—isolate suspected cases from pregnant healthcare professionals and others with chronic hemolysis 1
• Siblings and household contacts with SCD are at risk for concurrent or subsequent aplastic crisis and require hemoglobin and reticulocyte count monitoring 1

Stroke

• Any acute neurologic symptom other than transient mild headache requires urgent evaluation 1
• Common presentations include hemiparesis, aphasia/dysphasia, seizures, monoparesis, severe headache, cranial nerve palsy, stupor, and coma 1
• Initial evaluation includes CBC, reticulocyte count, blood type and crossmatch, and noncontrast CT or MRI to exclude hemorrhage 1
• Acute treatment requires partial exchange transfusion or erythrocytapheresis to reduce HbS to <30% and raise hemoglobin to 10 g/dL 1
• Patients with SCD have increased stroke risk compared to general population 1, 4

Priapism

• Prolonged painful erection commonly occurring in children and adolescents, often starting during early morning hours 1
• Two forms exist: stuttering episodes lasting <4 hours (often recurrent) and severe acute ischemic episodes lasting ≥4 hours 1
• Treated as painful event with hydration and analgesia at home unless duration exceeds 4 hours 1
• Critical threshold: Episodes lasting >4 hours risk irreversible tissue damage and require urgent medical attention 1

Key Management Principles Across All Crises

• Rapid triage and assessment are essential when home management fails 1
• Maintain adequate (not excessive) hydration across all crisis types 1
• Monitor oxygenation and cardiorespiratory status closely, especially with opioid administration 1, 5
• Use incentive spirometry to encourage deep inspiratory effort and prevent acute chest syndrome 1
• Close observation for development of complications, particularly acute chest syndrome evolving from vaso-occlusive crisis 1