Peripheral oxygen saturation levels as a guide to avoid hyperoxia: an observational study

Area of Science:

• Critical Care Medicine
• Emergency Medicine
• Respiratory Physiology

Background:

• Iatrogenic hyperoxia is linked to adverse outcomes in critically ill patients.
• Guidelines recommend titrating oxygen to physiological levels.
• Prehospital oxygen titration often relies on peripheral oxygen saturation (SpO2) due to unavailability of partial arterial oxygen (PaO2) values.

Purpose of the Study:

• To investigate the efficacy of SpO2-guided oxygen titration in preventing hyperoxia.
• To assess hyperoxia rates in patients receiving oxygen in the emergency department.
• To analyze SpO2-guided titration effectiveness across different patient subgroups.

Main Methods:

• Retrospective observational cohort study (September 2020 - March 2023).
• Inclusion of patients receiving oxygen upon emergency department presentation.
• Analysis of blood gas samples, triage data, SpO2 values, and P/F ratios.

Main Results:

• 17.1% of 1042 patients experienced hyperoxia (PaO2 > 13.5 kPa).
• Among 170 patients with available SpO2, 40% had readings above target ranges.
• Many patients receiving low-flow oxygen (nasal cannula) without ventilation compromise developed hyperoxia (84.4% had P/F ratios > 300).

Conclusions:

• SpO2-guided oxygen titration results in significant hyperoxemia.
• Caution is advised when administering low-flow oxygen to patients without clear respiratory compromise.
• These patients are at high risk for developing occult hyperoxia.