Indications
- • Hypoxaemia (SpO₂ <94%, or <88% in chronic CO₂ retainers)
- • Critical illness pre-assessment
- • Peri-arrest / arrest
- • Acute breathlessness while investigating
Contraindications
- ⚠ No absolute CI; titrate carefully in COPD / chronic type 2 respiratory failure
Equipment
- • Nasal cannula (1–4 L/min, FiO₂ 24–36%)
- • Simple face mask (5–10 L/min)
- • Venturi mask (24–60% fixed FiO₂)
- • Non-rebreather mask with reservoir (15 L/min, FiO₂ ~85%)
- • Humidified high-flow nasal O₂ if available
Technique
- • Confirm need: SpO₂ + clinical state
- • Target SpO₂ 94–98% (88–92% if at risk of hypercapnia)
- • Start: cannula 2 L/min or simple mask 5 L/min for moderate hypoxia
- • Severe/critical: NRB 15 L/min while assessing
- • COPD / suspected T2RF: 24–28% Venturi, ABG within 30 min
- • Reassess every 15 min, wean as tolerated
Complications
- ⚠ CO₂ retention in chronic T2RF
- ⚠ Drying of mucosa (humidify if >24 h)
- ⚠ Absorption atelectasis
- ⚠ Fire risk near naked flame
Aftercare
- • Document FiO₂ + delivery device on every observation
- • Wean and stop when SpO₂ stable on room air
- • Repeat ABG after any change in COPD
Clinical pearls
- • O₂ is a drug — prescribe target SpO₂ range
- • Always reassess after 15 min: if not improving, escalate before increasing FiO₂
- • NRB ≠ NIV; if work of breathing rising, escalate
Perform under supervision until competent. Follow local SOPs and consent policy.
