A nursing and allied health concept defining a care activity, clinical process, or operational practice used in healthcare delivery. It applies when clinical prerequisites are met and produces defined effects on safety, quality, and patient outcomes. It does not ensure outcomes without appropriate training, monitoring, and escalation when risks are identified. It materially affects recovery and experience by supporting timely assessment, safe interventions, and coordinated care. The concept is generally stable, though clinical evidence and practice standards evolve over time.

Principle

Increase the fraction of inspired oxygen (FiO2) to improve arterial oxygen content and tissue oxygen delivery while minimising toxicity and preserving patient comfort and airway function.

Demonstration

A nurse sets a nasal cannula at 2 L/min for a postoperative patient with SpO2 89%, titrating flow to maintain SpO2 ≥ 92% while monitoring respiratory rate and signs of CO2 retention.

Misapplication

Delivering high-flow oxygen indiscriminately to all breathless patients without assessing baseline SpO2, ventilatory drive, or risk of hypercapnia can delay appropriate ventilation support and cause oxygen toxicity.

Consequence

When applied correctly, oxygen therapy reduces hypoxaemic organ injury, improves symptom relief and may reduce perioperative or acute morbidity; incorrect use can cause absorption atelectasis, suppression of hypoxic drive in susceptible patients, or delayed escalation of respiratory support.

Reversal

Withdrawing supplemental oxygen or returning to room air in a hypoxaemic patient causes falling arterial oxygen saturation and can precipitate organ hypoxia if applied prematurely.

Boundary

Includes low-flow and high-flow nasal devices, masks, and mechanical ventilation oxygen delivery; excludes treatments aimed at altering ventilation (e.g., bronchodilators) unless they directly change oxygen delivery, and does not cover hyperbaric oxygen therapy unless specified.

Semantic Tension

Tension exists between treating hypoxaemia aggressively to avoid tissue hypoxia and avoiding excessive FiO2 that risks hypercapnia or oxidative injury, particularly in COPD or hypercapnic respiratory failure.

Synthesis

Oxygen therapy is a targeted intervention to correct or prevent clinically significant hypoxaemia by titrating supplemental oxygen to physiologic goals, balancing improved oxygen delivery against risks of over-oxygenation and delayed ventilatory support.