Acute chest syndrome

Background

Lobes of the lung with related anatomy.
Pulmonary arterial tree anatomy.
  • The leading cause of death in patients with HbSS in the United States
    • HbSS individuals are at higher risk than HbSC, but acute chest may occur in both genotypes
  • Occurs most commonly in the 2-4yr old age group and then declines with age
  • Pathophysiology is due to deoxygenation of Hb, leading to sickling in the pulmonary vasculature, causing vaso-occlusionm, ischemia, and endothelial injury[1]
    • In pediatric population, ACS is more often triggered by asthma or viral/bacterial pulmonary infection, leading to local hypoxia
    • In adult population, ACS is commonly associated with vaso-occlusive pain, which may lead to hypoventilation or long bone fat/marrow emboli
    • However, a specific cause is not identified in a majority of cases

Causes

Clinical Features

Complications

Differential Diagnosis

Sickle cell crisis

Evaluation

Chest X-ray of TRALI (left) compared to the same subject after resolution of symptoms (right).

Work-Up

Imaging

  • New infiltrate seen on chest x-ray
    • Chest x-ray findings may lag behind clinical features
  • Lung ultrasound to CXR or CT finding correlations[2]
    • 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
  • Consider CTPE for persistent hypoxia with unclear cause

Management

  • O2
    • Titrate to pulse oximetry >95%
    • NNoninvasive or invasive positive pressure ventilation may be required in severe cases
  • Hydration
    • Oral hydration preferred
    • IV hydration with hypotonic fluid if patient unable to tolerate PO
      • Consider D5 + 1/2 Normal saline at 1-1.5x maintenance rate
    • While dehydration can predispose sickling, overhydration can cause pulmonary edema that exacerbates sickling
  • Analgesia
    • Opioids often required for adults and sometimes needed for pediatrics
    • However, attempt to prevent oversedation and hypoventilation, atelectasis
  • Incentive Spirometry
  • Bronchodilators
  • Antibiotics
  • Simple Transfusion (leucocyte depleted)
    • Consider transfusion to goal of hemoglobin 11 / hematocrit 30 for:
      • O2 Sat <92% on room air
      • hematocrit/hemoglobin 10-20% below patient's usual values, or continuously dropping hematocrit/hemoglobin
  • 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
    • Can prevent the need for intubation

Disposition

  • Admission
  • Consider consultation to hematologist

See Also

External Links

References

  1. ↑ Friend A, Settelmeyer TP, Girzadas D. Acute Chest Syndrome. [Updated 2023 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441872/
  2. ↑ Razazi et al. Bedside Lung Ultrasound During Acute Chest Syndrome in Sickle Cell Disease. Medicine (Baltimore). 2016 Feb; 95(7): e2553.
This page is issued from WikEM. The text is available under an unknown license unless otherwise noted. Additional terms may apply for the media files.