What should I do when a patient is desaturating?

Management of Patient Desaturation

When a patient is desaturating, immediately provide supplemental oxygen while simultaneously assessing and addressing the underlying cause using a systematic ABCDE approach.

Initial Actions

• Immediately provide supplemental oxygen to maintain SpO₂ >92% while preparing for definitive management 1, 2
• Position the patient appropriately - consider head-up position (35°) to reduce airway swelling 2 or reverse Trendelenburg position if spinal injury is suspected 1
• Perform a rapid ABCDE assessment to identify the cause of desaturation 3:
  • Airway: Check for patency and obstruction
  • Breathing: Assess respiratory rate, effort, and breath sounds
  • Circulation: Check pulse, blood pressure, and perfusion
  • Disability: Assess level of consciousness
  • Exposure: Look for other contributing factors

Airway Management

• If airway is compromised, consider:

  • Simple airway maneuvers (jaw thrust, chin lift) 1
  • Airway adjuncts (oropharyngeal or nasopharyngeal airway) 1
  • Supraglottic airway device if needed 1
  • Endotracheal intubation for definitive airway control 1

• For intubation in a desaturating patient:

  • Pre-oxygenate thoroughly before intubation attempts 1
  • Consider using high-flow nasal oxygen (HFNO) or non-invasive positive pressure ventilation (NIPPV) for pre-oxygenation in patients with severe hypoxemia 1
  • Limit intubation attempts to three to avoid prolonged periods without ventilation 1
  • Have a backup plan for failed intubation 1
  • Consider rapid sequence induction (RSI) with appropriate medications 1

Special Considerations for High-Risk Patients

• Obesity: Obese patients are at higher risk for rapid desaturation due to reduced functional residual capacity 1

  • Position in ramped position to improve intubation success rates 1
  • Consider CPAP/NIV or HFNO for pre-oxygenation 1
  • Be prepared for rapid progression to front-of-neck airway access if intubation fails 1

• Sleep-disordered breathing/OSA: Patients with OSA are at increased risk for desaturation and respiratory complications 1

  • Consider CPAP if the patient is known to use it at home 1
  • Be cautious with sedative medications which may worsen respiratory depression 1

• Interstitial lung disease: Patients may develop ambulatory desaturation 1

  • Monitor for desaturation with activity 1
  • Consider supplemental oxygen for activities 1

Monitoring During Resuscitation

• Continuous pulse oximetry is essential to detect early decreases in oxygen saturation 1
• Consider capnography to detect hypoventilation before desaturation occurs 1
• Monitor for signs of inadequate oxygen delivery: tachycardia, hypotension, altered mental status 4
• For patients receiving procedural sedation, monitor oxygen saturation closely as desaturation can occur without clinical signs 1, 5

Specific Interventions Based on Cause

• Hypoventilation: Support ventilation with bag-mask ventilation or mechanical ventilation 1
• V/Q mismatch: Provide supplemental oxygen, consider PEEP/CPAP 4
• Diffusion limitation: Provide high-concentration oxygen, consider inhaled nitric oxide if pulmonary hypertension is present 6
• Low cardiac output: Optimize preload, consider inotropes if needed 4
• Anemia: Consider transfusion if hemoglobin is significantly low 4

Common Pitfalls and Caveats

• Pulse oximetry may be inaccurate below 80% saturation 1
• Supplemental oxygen may mask hypoventilation by delaying the onset of hypoxemia 1
• Transient desaturations may occur without clinical consequence, but persistent desaturation requires intervention 1
• Patients with central obesity are at higher risk for desaturation than those with peripheral fat distribution 1
• Older patients (>55 years) are at higher risk for desaturation during procedures 1
• Rapid recognition of desaturation is critical, as delays in intervention can lead to cardiac arrest 7
• Abrupt discontinuation of inhaled nitric oxide can lead to rebound pulmonary hypertension and worsening oxygenation 6

Remember that the most consistent predictor of desaturation during procedures is age greater than 55 years, and higher pre-procedure oxygen saturation is protective against desaturation during intubation 1, 7.