II. Epidemiology

  1. Affects almost all Sickle Cell Anemia patients
  2. May occur as early as age 6 months

III. Pathophysiology

  1. Deoxygenated Hemoglobin polymerizes in triple helix chains
  2. Results in Red Blood Cells assuming sickled shape
  3. Results in Occlusion of small vessels and capillaries with secondary small tissue ischemia and infarctions
    1. Repeat pain crises to the same region is a risk for avascular necrosis

IV. Precipitating Factors

  1. Preceded by infection 25% of the time
    1. Human Parvovirus B19 is a common viral cause
  2. Cold Weather due to reflex vasospasm
  3. Dehydration in warm weather

V. Symptoms

  1. Child under age 18 years
  2. Recurrent painful crises
    1. Often follows a distribution pattern specific to the patient
    2. Sudden onset pain in Abdomen, chest, back and extremities (esp. joints)
    3. Dactylitis (infants)

VI. Labs

  1. No lab abnormality defines VOC (clinical diagnosis)
  2. Profound Anemia
  3. Reticulocyte Count <1%
  4. Consider additional labs in case of suspected infection
    1. Complete Blood Count
    2. Reticulocyte Count
    3. Blood Culture

VII. Differential Diagnosis: Bone Pain

  1. Avascular Necrosis
    1. Avascular Necrosis of the Femoral Head
    2. Avascular Necrosis of the Humeral Head
  2. Osteomyelitis
    1. Infection of infarcted bone, especially long bones
    2. Salmonella is most common organism in Sickle Cell Anemia (S. Aureus represents <25% of cases)

VIII. Precautions

  1. Sickle Cell Crisis is not typically a drug seeking mission
    1. Patients who present with symptoms of Sickle Cell Crisis typically have crisis
    2. Vital Signs (Heart Rate, Blood Pressure) and labs do not differentiate a Sickle Cell Crisis
    3. Believe patients presenting with Sickle Cell Anemia and effectively treat their pain
    4. Rarely, patients without Sickle Cell Anemia present with factitous crisis
      1. However these patients may be identified from the medical record
      2. Review with prescribing providers and consider behavioral health referral
    5. Address Drug Seeking Behavior after the acute pain crisis (treat pain adequately during crisis)
      1. Consider VOC therapy plan (on file in ED or patient carries with them)
  2. Evaluate for other concurrent sickle cell complications (esp. if pain pattern is not typical for specific patient)
    1. Transient Red Cell Aplasia
    2. Cerebrovascular Accident in Sickle Cell Anemia
    3. Sickle Cell Hemolytic Crisis
    4. Acute Chest Syndrome
    5. Sepsis
    6. Septic Joint or Osteomyelitis

IX. Management: Pain control for acute crisis

  1. Requires aggressive Opioid analgesia
    1. Avoid delays in management
      1. Triage patient urgently to a management bed within 30-60 minutes of presentation
      2. Start at outset by titrating to high dose Opioids in first 10 minutes of management
    2. Pain management is based on patient's reported level of pain
    3. Avoid allowing Analgesics to wear off prior to re-dosing
    4. Re-evaluate pain level and sedation every 15-30 minutes
      1. Increase dose by 25% if inadequate pain control
      2. Monitor closely for respiratory depression
    5. Consider Patient Controlled Analgesia (PCA Pump)
    6. Morphine
      1. Initial (child): 0.1 mg/kg up to 5 mg
      2. Re-evaluate and repeat as needed every 20-30 minutes
      3. Consider hospital admission for more than 2 doses required in 1-2 hours
    7. Hydromorphone (Dilaudid)
      1. Initial: 0.01 mg/kg up to 1 mg IV
    8. Fentanyl Intranasal
      1. Dose: 1-2 mcg/kg up to 100 mcg/dose every 15 minutes for up to 2 doses
      2. Consider if IV Access is delayed
  2. Avoid agents with adverse effects
    1. Avoid Meperidine (Demerol)
      1. Meperidine metabolite normeperidine is neurotoxic and associated with increased Seizure risk
      2. Meperidine is associated with euphoria and less effective Analgesic effect
      3. Morphine or Dilaudid are preferred over Meperidine (Demerol)
    2. Avoid NSAIDS
      1. High Incidence of occult renal dysfunction in Sickle Cell Anemia
      2. Serum Creatinine typically underestimates renal dysfunction in Sickle Cell Anemia
      3. In some cases may be used for mild to moderate pain, or adjunctive relief if no contraindications
    3. Avoid parenteral Antihistamines
      1. Associated with euphora
      2. Pruritus may be less common with Dilaudid than Morphine
      3. Pruritus may be treated with Benadryl
  3. Avoid agents not shown to offer benefit
    1. Transfusions are not indicated for management of vaso-occlusive crisis
    2. Magnesium does not appear to reduce pain, reduce Opioid use or reduce lengths of ED stays
      1. Brousseau (2015) Blood 126(14): 1651-7 [PubMed]
    3. Antiplatelet agents (e.g. Prasugrel) does not appear to prevent vaso-occlusive crisis
      1. Heeney (2016) N Engl J Med 374(7): 625-35 [PubMed]

X. Management: Other Measures

  1. Intravenous Fluids
    1. Avoid Fluid Overload (risk of Atelectasis and Acute Chest Syndrome)
    2. Limit total fluid to <1.5x maintenance requirements
    3. On achieving euvolemia, consider maintenance with Hypotonic Saline (D5 1/2NS) which may enter the RBC
  2. Oxygen
    1. Only indicated if Oxygen Saturation <93%
    2. Oxygen may be associated with a higher risk of Bone Marrow suppression and secondary need for Blood Transfusions
  3. Incentive Spirometry
    1. Decreases Atelectasis risk and risk of Acute Chest Syndrome
  4. Adjunctive measures
    1. Local heat (warm compresses) applied to painful area
  5. Disposition
    1. Admission criteria after 3 Opioid doses is likely to be too restrictive and result in over-admitting
    2. Consider longer emergency department course (up to 6 hours) for pain stabilization to determine if admission indicated

XI. Course

  1. Acute Crisis usually resolves spontaneously 7-10 days

XII. References

  1. Claudius, Behar and Sadowitz in Herbert (2018) EM:Rap 18(4): 10-2
  2. Glassberg and Weingart in Herbert (2012) EM: Rap 12(8): 5-6
  3. Lowe and Wang (2018) Crit Dec Emerg Med 32(11): 17-25
  4. Welsh and Welsh (2016) Crit Dec Emerg Med 30(11): 15-23
  5. Preboth (2000) Am Fam Physician 61 [PubMed]
  6. Yawn (2015) Am Fam Physician 92(12): 1069-76 [PubMed]

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