Sickle cell crisis

Precipitating Factors

1. For vaso-occlusion:
   1. Stress
   2. Cold weather
   3. Dehydration
   4. Hypoxia
   5. Infection
   6. Acidosis
   7. Alcohol intoxication
   8. Pregnancy
   9. Exertional stress
2. For aplastic crisis:
   1. Parvovirus B19 infection
   2. Folic acid deficiency
3. For acute chest syndrome:
   1. Fat embolus
   2. Infection
   3. Pain crisis
   4. Asthma

Work-Up

1. CBC
   1. Assess change in anemia
2. Chemistry / LFT / lipase
   1. If abd pain, may develop cholecystitis, mesenteric ischemia, or perforation
3. Retic count (if aplastic crisis considered - rare in adults)
   1. Should be >0.5%
4. CXR
   1. If cough, SOB, or febrile
5. O2
   1. If hypoxic; otherwise may inhibit erythopoesis
6. ECG
7. T&S/T&C
8. BCx2
9. VBG
10. UA
11. Urine pregnancy
12. Head CT/MRI
    1. If symptoms of stroke

Clinical Manifestations

Vaso-occlusive Crisis

• Pain
  • Most common manifestation of SCA (79-91% of ED visits)
  • Lower back, long bones most commonly affected
  • Because anemia can precipitate a crisis, must check for acute Hb drop
• Bony infarction
  • More debilitating and refractory pain than past episodes
  • Localized bone tenderness, elevated WBC
    • Fat embolism can be complication
• 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
  • Pts p/w afebrile, inguinal pain with weight-bearing

Infection

• Pts w/ 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

Abdominal Pain

• Differential Diagnosis
  • 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, anorexia, tender hepatomegaly, fever
    • Bilirubin level higher than usual (>4mg/dL)
  • Acute hepatic sequestration
    • Labs are variable
    • US or CT shows diffuse hepatomegaly

Respiratory Distress and Chest Pain

• DDX
• Acute chest crisis
  • Due to pulmonary ischemia and infarction; complication of PNA
  • Pleuritic chest pain, cough, fever, dyspnea, hypoxia, rales
  • CXR findings may be minimal; should not dissuade treatment
  • A/w neurologic sequelae
• PNA
  • Caused by chlamydia, mycoplasma, viral, strep pneumo, staph, H. Flu
  • Only need blood cx in pts ill enough to require ventilator
  • Asthma
    • Common in pts with SCD
    • Increases likelihood of chest syndrome by 4-6x
• Pulmonary Hypertension
  • Develops in 15-35% of children with SCD
    • Chest pain, DOE, hypoxia, right-sided heart failure, syncope, PE

Infection

• Across all ages, infection is leading cause of death
  • Increased prevalence of meningitis, PNA, arthritis, osteo
• 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 nto petechiae, purpura, vesicles, skin sloughing
    • 3. Arthropathy - symmetric or asymmetric, knees and ankles
    • 4. Aplastic crisis
      • Reticulocyte count drops 5d postexposure, followed by Hb drop
      • Can cause serious anemia which lasts for 2wk

Splenic Sequestration

• Major cause of mortality in <5yr old
• Labs: Hb drop, no change in bili, normal to incr retic count
  • 2 types: major and minor
    • Major
      • Rapid drop of hb (>3pt)
      • Pallor, LUQ pain, splenomegaly
      • Can progress w/in hours to AMS, hypotension, CV collapse
    • Minor
      • More insidious, smaller drop in Hb

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
  • Hematuria w/o casts or pyuria

Treatment

Anemia

• Transfusion
  • Indications:
    • Aplastic crisis
    • Sequestration crisis
    • Hb <6 w/ inappropriately low retic count
    • Hb <10 w/ acute crisis
  • Transfuse 10 mL/kg over 2hr period

Vaso-occlusive pain crisis

1. Analgesia
2. Gentle hydration
   1. 1.5 times maintenance w/ D5 1/2NS
   2. Only use NS boluses for acute dehydration or hypovolemic shock
3. O2 is not useful in the nonhypoxic patient

Acute Chest Syndrome

• See Acute Chest Syndrome

Priapism

1. Hydration
2. Transfsuion and/or exchange transfusion
3. Urology consult
4. If persists for >4-6hr:
   1. Aspiration of corpora
   2. Irrigate and infuse 1:1,000,000 epi solution

Neurologic Disease

1. t-PA is not recommended
2. Urgent exchange transfusion to decrease HbS below 30%

Splenic Sequestration

1. Volume resuscitation
2. Simple transfusion vs exchange transfusion

Disposition

1. Consider admission to the hospital if:
   1. Acute chest syndrome is suspected
   2. Sepsis, osteomyelitis, or other serious infection is suspected
   3. Priapism, aplastic crisis, hypoxia
   4. WBC >30K
   5. Plt <100K
   6. Pain is not under control after 2-3 rounds of analgesics in ED
   7. <1yr old
2. Consider discharge if:
   1. Pain is under control and patient can take oral fluids and medications
   2. Ensure appropriate oral analgesics are available
   3. Provide home care instructions
   4. Ensure resource for follow-up

See Also

Acute Chest Syndrome

Source

Tintinalli