Recognition of Impending Respiratory Failure

First Things First (assess & treat for the following):

  • Definition
    • Respiratory failure: inadequate oxygenation and/or ventilation OR failure to protect airway
    • Respiratory failure can be physiologic or mechanical
      • Physiologic: infection, mental status, systemic acid–base disturbance, acute coronary syndromes, etc.
      • Mechanical failure: anatomic obstruction or disruption preventing adequate gas exchange (eg, angioedema, tracheal transection, neck hematoma) OR failure of respiratory musculature (eg, neuromuscular disease, spinal trauma)
    • Oxygenation: measured by SaO2 or PaO2
    • Ventilation: measured by PaCO2
    • ABG is test of choice; VBG correlates, but higher PCO2 threshold value
    • Airway protection: gag reflex is not helpful—clinical assessment is paramount; gag reflex does not accurately predict ability to protect airway
    • Despite potential appearance otherwise, trauma patients with GCS < 8 should be considered to have impeding respiratory failure
  • Treat hypoxemia aggressively and early
    • Rule out acute cardiac failure as cause
    • Rule out toxidrome by history
      • Toxicology-focused labs generally not helpful in identifying life-threatening toxidrome with respiratory failure
  • Identification
    • Recognition of impending respiratory failure is a CLINICAL assessment
    • Not done on the basis of laboratory or radiographic findings
  • Findings that mandate airway management
    • Significant hypoxia that does not improve with non-invasive O2 supplementation
    • Expanding neck mass
    • GCS 8 or less in acute trauma
    • Inability to protect airway
    • Anticipated worsening of clinical condition

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Last updated: April 29, 2010