- Home
- Critical Care & Anaesthetics
- Oxygen & the airway
Oxygen & the airway
Prescribe oxygen to a target — and open the airway before anything else. Oxygen is a drug: give it to a target saturation using the right device, and know which patients need a lower target. If the airway is threatened, simple manoeuvres and adjuncts buy time while expert help arrives. Built for revision, not live patient decisions.
Settle them, and check the basics
airway firstRed flags — what each should make you think
Pulse oximeters can be wrong. They overestimate saturation in some people with darker skin, read falsely normal in carbon monoxide poisoning, and struggle with poor perfusion. If the patient looks worse than the number, get a blood gas.
Airway — basic steps
- 👀Look, listen, feel
- ↑Head tilt / chin lift
- 🧹Suction
- OPAOropharyngeal airway
- NPANasopharyngeal airway
- ☎Call anaesthetics early
Understand oxygen therapy
BTS guidelineTarget saturations (BTS)
- Most acutely ill patients — 94–98%
- At risk of hypercapnic respiratory failure (COPD, morbid obesity, neuromuscular disease, chest wall deformity, cystic fibrosis, bronchiectasis) — 88–92% until a gas confirms
- Critical illness (shock, sepsis, major trauma, cardiac arrest, anaphylaxis) — start with 15 L/min via reservoir mask, then titrate
- Don't give oxygen to non-hypoxic patients routinely (e.g. MI, stroke with normal saturations)
Devices
- Nasal cannulae — 1–4 L/min; comfortable, low-moderate oxygen
- Simple face mask — 5–10 L/min
- Venturi masks — fixed concentrations (24%, 28%, 35%, 40%, 60%); ideal when precise FiO₂ matters (COPD)
- Non-rebreather (reservoir) mask — 15 L/min; high concentration in emergencies
- High-flow nasal oxygen — heated humidified, up to 60 L/min, FiO₂ up to 1.0
- CPAP / NIV — for type 1 failure (CPAP) or hypercapnic failure (NIV)
Work A–E — assess and act as you go
The diagnoses you must not miss
tap to open eachWhat points toward it, what would rule it in, and how to manage it.
Snoring, gurgling, stridor, or no air movement with see-saw breathing.
Clinical.
Manoeuvres, suction, adjuncts, call anaesthetics; choking algorithm if foreign body.
At-risk patient on high-concentration oxygen, becoming drowsy.
ABG.
Don't stop oxygen suddenly; titrate to 88–92% (Venturi), consider NIV.
Rising RR, worsening SpO₂ or gas despite support, exhaustion.
Clinical, ABG.
Early ITU/anaesthetic review — don't delay intubation.
Headache, nausea, confusion, smoke/faulty boiler exposure, others in the house affected.
COHb on blood gas (co-oximetry).
High-flow 100% oxygen via reservoir mask; discuss with TOXBASE re hyperbaric therapy.
Hypoxia, hypotension, absent breath sounds, ventilated patient.
Clinical.
Decompress. See the pneumothorax page.
Investigate — what to order, when, and what it tells you
test with a question in mindABG
CXR
Prescription
How the plan comes together
disposition · handoverward
Stable on low-flow oxygen with a prescribed target; plan to wean.
critical care
Rising oxygen needs, high-flow/CPAP/NIV failing, threatened airway, or hypercapnic failure needing support.
Hand over: oxygen device and flow, target, gas results, airway concerns.
Airway first, oxygen to a target, the right device for the job, and a gas when the numbers don't fit the patient. Call anaesthetics early when the airway is at risk. Nicely done getting here.
Clerking template
copy or downloadOxygen & the airway — documentation structure
A structure and prompt list to help you document and think systematically. It is not a completeness check and cannot guarantee nothing is missed — use your trust's own proforma, your seniors, and your clinical judgement.
Test yourself
active recallCover the answer, say it out loud, then reveal. Retrieval beats re-reading.
0 / 11 knownFrequently asked questions
quick answersWhat are the red flags for oxygen and the airway?
- Snoring, gurgling, stridor — think partial airway obstruction
- See-saw breathing, silence — think complete obstruction
- SpO₂ falling despite high-flow oxygen — think respiratory failure — escalate
- COPD/obesity/neuromuscular on high-flow O₂ — think hypercapnia risk
- Drowsy with high CO₂ — think hypercapnic failure
- Normal SpO₂ but headache, smoke exposure — think CO poisoning
What is the initial management of oxygen and the airway?
- Look, listen, feel — noises, chest movement, see-saw breathing
- Head tilt / chin lift — jaw thrust if C-spine injury possible
- Suction — under direct vision
- Oropharyngeal airway — unconscious with no gag; size incisors to angle of jaw
- Nasopharyngeal airway — tolerated with a gag; caution in suspected base of skull fracture
- Call anaesthetics early — iGel/SGA, intubation
Always alongside senior support and your local guideline.
What diagnoses must you not miss in oxygen and the airway?
- Airway obstruction — noisy or silent
- Hypercapnic respiratory failure from oxygen — drowsy · rising CO₂
- Failing on high-flow / CPAP — needs intubation
- Carbon monoxide poisoning — SpO₂ falsely normal
- Tension pneumothorax — hypoxia + shock
Open each one in the must-not-miss section for what points toward it, how to rule it in, and how to manage it.
What investigations should a junior doctor order for oxygen and the airway?
- ABG — PaO₂, PaCO₂, pH, lactate, COHb, MetHb.
- CXR — Cause of hypoxia.
- Prescription — Prescribed with a target range and device.
Admit or discharge: how is the plan decided for oxygen and the airway?
- Ward — Stable on low-flow oxygen with a prescribed target; plan to wean.
- Critical care — Rising oxygen needs, high-flow/CPAP/NIV failing, threatened airway, or hypercapnic failure needing support.
Is there a clerking template for oxygen and the airway?
Yes — there is a free clerking template for oxygen and the airway on this page, structured as presenting complaint, red flags asked, history, examination (A–E), investigations, differentials, plan and escalation. You can copy it or download it as a Word document. Jump to the template.
Keep going
one more?More from Critical Care & Anaesthetics