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 / stat hemaglobin
   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
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 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 diseasestones are 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
    • Symptomatic anemia
      • Due to aplastic crisis, sequestration
    • Hb <6 w/ inappropriately low retic count
    • Hb <10 w/ acute crisis
  • 10 mL/kg over 2hr period
  • If require transfusion but Hb >10 then perform exchange transfusion

Vaso-occlusive pain crisis

• Analgesia
• Gentle hydration
  • 1.5 times maintenance w/ D51/2NS
  • Only use NS boluses for acute dehydration or hypovolemic shock
• O2 is not useful in the nonhypoxic patient

Acute Chest Syndrome and PNA

• Tx w/ abx
  • 3rd generation cephalosporin + macrolide
• Transfusion
  • Indicated if pt deteriorates, PaO2 <70 or SpO2 <10% from baseline
• Steroids are not beneficial

Priapism

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

Neurologic Disease

• t-PA is not recommended
• Urgent exchange transfusion to decrease HbS below 30%

Disposition

1. Admission if:
   1. Acute Chest Syndrome
   2. CVA, priapism, serious infection, aplastic crisis, hypoxia, acidosis
   3. Unable to tolerate PO or inadequate pain control
   4. Consider if pregnant (in crisis), or uncertain dx of SCD
   5. Infection
      1. Discharge if:
         1. Well-appearing, >1yr w/ isolated fever after 4-hr obs
         2. Give dose of CTX before d/c pending cx results
      2. Admit if:
         1. <1yr old or have high-risk criteria:
            1. Temp >40
            2. WBC >30K or <5K
            3. Plt <100K
            4. Hb <5
            5. Infiltrate on chest radiograph
            6. History of pneumococcal sepsis
            7. Ill appearance, poor perfusion, hypotension

See Also

Acute Chest Syndrome

Source

Tintinalli