Acute chest syndrome

Background

• A leading cause of hospitalization and death in adults with sickle cell disease
• Occurs most commonly in the 2-4yr old age group and then declines with age
• Due to pulmonary ischemia and infarction; complication of pneumonia

Causes

• Pulmonary infection
  • C. pneumoniae and mycoplasma are most common organisms
  • May also be caused by viruses, H. flu, klebsiella, staph
• Fat emboli
  • Lodge in pulmonary vasculature → additional ischemia
• Rib infarction
• Overly aggressive IV hydration
• Vaso-occlusive pain crisis
• Asthma

Clinical Features

• Fever >38.5
• Cough
• Wheezing
• Tachypnea
• Chest pain

Complications

• Pulmonary Embolism (bone marrow, fat or thrombotic)
• Pneumonia
• CVA
• Sepsis

Differential Diagnosis

• Pneumonia
• Asthma
• Pulmonary hypertension

Sickle cell crisis

• Vaso-occlusive pain crisis
• Bony infarction
• Dactylitis
• Avascular necrosis of femoral head
• Acute chest syndrome
• Asthma
• Pulmonary hypertension
• Gallbladder disease
• Acute hepatic sequestration
• Infection
  • Meningitis
  • Pneumonia
  • Septic joint
  • Osteomyelitis
• Parvovirus B19
• Splenic sequestration
• CVA
• Cerebral aneurysm and ICH
• Priapism
• Papillary necrosis

Evaluation

Work-Up

• CBC
• Retic count
• VBG / ABG
• Blood culture /sputum cultures
• CXR

Evaluation

• New infiltrate on CXR with at least one of the following:
  • Fever >38.5
  • Cough
  • Wheezing
  • Tachypnea
  • New hypoxemia
  • Chest pain
• Note: CXR findings may lag behind the clinical features
• Lung ultrasound to CXR or CT finding correlations
  • Consolidation seen as hyperechoic punctiform air bronchograms
  • Ground-glass opacities seen as coalescent B lines
  • Pleural effusion, defined as large if interpleural distance > 25 mm

Management

1. O2
   • Titrate to pulse oximetry >92%
2. Incentive Spirometer
3. Hydration
   • Oral hydration preferred
   • IV hydration with hypotonic fluid if patient unable to tolerate PO
4. Analgesia
   • Pulmonary toilet is important but avoid excessive sedation
5. Bronchodilators
6. Antibiotics
   • 3rd generation cephalosporin + macrolide
7. Transfusion (leucocyte depleted)
   • Consider transfusion to goal of hemoglobin 11 / hematocrit 30 for:
     • O2 Sat <92% on room air
     • hematocrit 10-20% below patient's usual hematocrit or dropping hematocrit
8. Exchange transfusion
   • Consider for:
     • Progression of acute chest syndrome despite simple transfusion
     • Severe hypoxemia
     • Multi-lobar disease
     • Previous history of severe acute chest syndrome or cardiopulmonary disease

See Also

• Sickle Cell Crisis

Video

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