Sickle cell crisis

Background

Precipitating Factors

Clinical Features

Algorithm for the Evaluation and Management of Sickle Cell Crises

Vaso-Occlusive Crisis[1]

See Vaso-occlusive pain crisis

Bony infarction

  • More debilitating and refractory pain than past episodes
  • Localized bone tenderness, elevated WBC

Dactylitis

  • Tender, swollen hands/feet
  • May have low-grade fever
  • Occurs in <2yr old, extremely rare >5yr old

Avascular necrosis of femoral head

  • Occurs in 30% of patients by age 30yr
  • Patients present with afebrile, inguinal pain with weight-bearing

Respiratory distress and Chest pain

Abdominal Pain

  • Pain crisis
    • 3rd most common site of pain crisis
    • Sudden onset of poorly localized abdominal pain
      • May have tenderness, guarding; should not have rigidity/rebound
  • Gallbladder disease (stones) is common; may occur as early as 2-4yr old
    • RUQ pain, jaundice/bilirubin higher than baseline, anorexia, tender hepatomegaly, fever
  • Acute hepatic sequestration
    • Labs are variable
    • US or CT shows diffuse hepatomegaly
  • Bacterial gastroenteritis

Infection

  • Across all ages, infection is leading cause of death
  • Children aged 6mo to 3yr at greatest risk for sepsis
  • Parvovirus B19
    • Can cause several different syndromes:
      • 1. Erythema infectiosum ("slapped cheeks" rash)
      • 2. Gloves and socks syndrome
        • Well-demarcated, painful, erythema of hands and feet
          • Evolves into petechiae, purpura, vesicles, skin sloughing
      • 3. Arthropathy - symmetric or asymmetric, knees and ankles
      • 4. Aplastic crisis
        • Reticulocyte count drops 5d post-exposure, followed by hemoglobin drop
        • Can cause serious anemia which lasts for 2wk

Musculoskeletal Infection

  • Patients with SCD have increased rates of bone and joint infection
    • Difficult to distinguish from bony infarcts
      • High fever is more typical of infection
      • Limited range of motion is much more typical of infection
      • Left shift is unique to infection
      • ESR is unreliable
      • May require bone scan or MRI to definitely distinguish infection from infarct

Splenic Sequestration

  • Major cause of mortality in <5yr old
  • Labs: hemoglobin drop, no change in bili, normal to increased retic count
    • 2 types: major and minor
      • Major
        • Rapid drop of hb (>3pt)
        • Pallor, LUQ pain, splenomegaly
        • Can progress within hours to altered mental status, hypotension, cardiovascular collapse
      • Minor
        • More insidious, smaller drop in hemoglobin

Neurologic Disease

  • CVA is 250x more common in children with SCD
    • 10% of children suffer clinically overt stroke
    • 20% found to have silent CVA on imaging
  • Increased rate of cerebral aneurysm and ICH

GU

  • Priapism
    • Occurs in 25% by age 20
  • Papillary necrosis

Differential Diagnosis

Sickle cell crisis

Evaluation

Work-up

Based on clinical presentation, but may include:

  • CBC (assess for significant anemia)
  • Reticulocyte count (<0.5% suggests aplastic crisis - rare in adults), calculating reticulocyte index
    • Laboratory value is a percentage, and absolute count corrects for level of anemia
    • Absolute retic count = % retics x (pt Hct / normal Hct)
    • Retic index = absolute retic count / maturation factor[2]
      • ≥35%, maturation factor 1.0
      • 25 to <35%, maturation factor 1.5
      • 20 to <25%, maturation factor 2.0
      • <20%, maturation factor 2.5
    • Reticulocyte index ≥2 means adequate reponse
    • Reticulocyte index <2 suggests hypoproliferation
  • Metabolic panel, lipase (if abdominal pain)
  • CXR (if cough, shortness of breath, or fever)
  • ECG
  • VBG
  • Urinalysis
  • Pregnancy test
  • CT Brain (if symptoms of CVA)
    • Note that if patient is anemic, CT non-contrast is unreliable in ruling out hemorrhagic stroke, subarachnoid hemorrhage[3]
    • Will need CTA, MRI, and/or MRA

Evaluation

  • Generally a clinical diagnosis
  • Certain syndromes require imaging/labs for confirmation (see below)

Management

  • Only use supplemental oxygen for patients who are hypoxic (<92%)
  • Reserve IVF bolus for patients who are hypovolemic
    • Over hydration may cause atelectasis which may precipitate Acute Chest Syndrome and hyperCl acidosis which could lead to further sickling \
    • Make sure to use hypotonic fluids: 1/2NS, D5-1/2NS

Anemia

Vaso-occlusive pain crisis

Acute Chest Syndrome

Priapism

  • Hydration
  • Transfusion and/or exchange transfusion
  • Urology consult
  • If persists for >4-6hr:
    • Aspiration of corpora
    • Irrigate and infuse 1:1,000,000 epinephrine solution

Neurologic Disease

  • t-PA is not recommended
  • Exchange transfusion urgently (within 8 hours) to decrease hemoglobinS below 30%
  • Hydration

Splenic Sequestration

Fever

  • Any fever of ≥38.5C requires empiric antibiotics (regardless of well appearance or any localized infection found)
  • Ceftriaxone 50mg/kg (maximum single dose 2g)

Disposition

Consider admission to the hospital

Consider discharge

  • Pain is under control and patient can take oral fluids and medications
  • Ensure appropriate oral analgesics are available
  • Provide home care instructions
  • Ensure resource for follow-up

See Also

References

  1. Lovett P. et al. Sickle cell disease in the emergency department. Emerg Med Clin North Am. 2014 Aug;32(3):629-47
  2. Poorana PP and Subhashree AR. Role of Absolute Reticulocyte Count in Evaluation of Pancytopenia-A Hospital Based Study. J Clin Diagn Res. 2014 Aug; 8(8): FC01–FC03.
  3. Lyon M et al. Approach to the diagnosis and treatment of acute subarachnoid hemorrhage in a patient with sickle cell disease. Am J Emerg Med. 2015 Mar;33(3):481.e3-4.