Oxygen Supplementation During Seizures

Initial Management Algorithm

• The British Thoracic Society recommends administering high-concentration oxygen immediately to patients with acute seizures, targeting an oxygen saturation of 94-98% (or 88-92% if the patient is at risk of hypercapnic respiratory failure) 1
• Start with a reservoir mask at 15 L/min immediately for any patient actively seizing or in the immediate postictal period, regardless of whether an oximetry reading has been obtained yet 1, 2

Titration Based on Oximetry

• For patients without risk factors for hypercapnia, titrate oxygen to maintain SpO2 94-98% once pulse oximetry is reliable 1
• For patients with risk factors for hypercapnia, target SpO2 88-92% once stable 1
• Consider starting with controlled oxygen delivery (Venturi mask) if the patient has known severe COPD, but do not withhold high-flow oxygen during the acute seizure itself 1, 3

Critical Monitoring Requirements

• Obtain continuous pulse oximetry as soon as possible during and after the seizure 3
• Measure arterial blood gas if the patient requires prolonged oxygen administration or has risk factors for hypercapnia 1
• Record oxygen delivery device and flow rate on monitoring charts 2

Common Pitfalls to Avoid

• Never withhold oxygen during an active seizure due to concerns about hypercapnia, as the immediate risk of hypoxic brain injury outweighs CO2 retention concerns 1, 3
• Do not abruptly discontinue oxygen once initiated, as this causes rebound hypoxemia with rapid fall below baseline SpO2 4, 3
• Do not rely solely on clinical appearance to assess oxygenation, as hypoxemia may not be clinically obvious 1