FFinalistSouthampton · 2027
All procedures
GMC #16/Prescribing taught Y1

Prescribe & administer oxygen

Prescribe and administer oxygen safely using an appropriate delivery method; monitor and adjust as needed.

Target · Perform independently0% ready

Do it yourself on a patient, with support available if you need it — the GMC’s highest new-grad level (“indirect supervision”).

Overview

Oxygen is a drug — it must be prescribed with a target saturation range and titrated. The key safety issue is CO₂ retention in some COPD patients.

Key numbers

  • Target SpO₂ 94–98% for most; 88–92% if at risk of hypercapnic respiratory failureBTS 2017
  • Devices: nasal cannulae 1–6 L/min · simple mask 5–10 L/min · non-rebreathe (reservoir) 15 L/min · Venturi = fixed FiO₂BTS 2017

Indications

  • Hypoxaemia (acute illness, peri-arrest, breathlessness)

Contraindications & cautions

  • Target 94–98% for most acutely unwell adults; 88–92% if at risk of hypercapnic respiratory failure (e.g. COPD, obesity hypoventilation) — do not over-oxygenate

Equipment

Delivery device: nasal cannulae (1–4 L/min), simple face mask (5–10 L/min), non-rebreathe mask with reservoir (15 L/min), or Venturi (fixed FiO₂)

Step by step

Prescribe & deliver
  1. 1Assess the patient and SpO₂; in an emergency give high-flow via a non-rebreathe mask at 15 L/min
  2. 2Prescribe the target range and the device on the drug chart
  3. 3For COPD/retainer risk: controlled O₂ via a Venturi (e.g. 24–28%), target 88–92%, check an ABG
Monitor
  1. 1Titrate to keep SpO₂ within the target range
  2. 2Reassess with ABG if hypercapnia is a risk; wean as the patient improves

Complications

  • CO₂ retention/respiratory acidosis in susceptible patients; mucosal drying; absorption atelectasis

OSCE tips

  • “Oxygen is a drug” — prescribe a target range, not just “O₂”.
  • Know the two target ranges (94–98% vs 88–92%).
  • Non-rebreathe 15 L/min for the acutely hypoxic; Venturi for controlled delivery.

Read

BTS guideline for oxygen use in adults (2017)British Thoracic Society

Sources & credits

Authored to UK finals standard and verified against UK guidance (BTS 2017) and Geeky Medics OSCE guides. Southampton teaching materials © University of Southampton. Always follow current local policy.