Respiratory Failure, Oxygen & Non-Invasive Support
Separate oxygenation failure from ventilatory failure and recognise when support is failing.
Quick revision ↓ Medical Dictionary
01Identify respiratory failure
Assess respiratory rate, work of breathing, consciousness and oxygenation rather than saturation alone. Hypoxaemic failure concerns oxygen transfer; hypercapnic failure concerns inadequate alveolar ventilation. Blood gases help define severity and acid-base effects when clinically indicated.
02Prescribe oxygen thoughtfully
Give urgent oxygen when needed and then titrate to an appropriate prescribed target. Patients at risk of hypercapnic failure often need a controlled target and blood-gas review. Oxygen treats hypoxaemia but does not correct airway obstruction, exhaustion or the underlying disease by itself.
03Treat the cause
Consider pneumonia, pulmonary oedema, bronchospasm, embolism, pneumothorax and neuromuscular weakness according to the presentation. Investigations should support prompt treatment and must not delay action for an immediately life-threatening cause identified clinically.
04Choose non-invasive support
High-flow nasal oxygen and non-invasive ventilation have different roles. NIV may support selected patients with ventilatory failure or cardiogenic pulmonary oedema, but requires cooperation, airway protection and close review. Vomiting, impaired consciousness or instability can make non-invasive support unsafe.
05Recognise failure early
Increasing distress, worsening gas exchange, exhaustion or reduced consciousness require urgent expert reassessment. Agree escalation and treatment limits before starting support where possible. Continuing an ineffective interface can delay a necessary definitive airway and worsen the outcome.
High-Yield Revision
- A normal saturation does not establish adequate ventilation.
- Treat the cause as well as the oxygen level.
- Define escalation before non-invasive support.
Common Pitfalls
- Ignoring rising carbon dioxide because saturation looks satisfactory.
- Persisting with failing support without senior review.
References & Further Reading
Read the relevant guideline sections alongside these original clinical teaching cases. Local pathways, available services and individual patient factors determine care.
Reference review: 29 September 2026. Consult current local protocols for prescribing, procedures and escalation.