Synopsis
Prescribe and deliver controlled oxygen, assess and teach device-specific inhaler technique, and verify safe self-management through demonstration and teach-back.
- Oxygen is a medicine: prescribe target and device except in immediate emergencies, then titrate and record response.
- BTS uses 94–98% for most acutely ill adults and 88–92% pending gases for known COPD or other hypercapnic risk, then individualise.
- Reservoir bags must remain inflated; simple masks have manufacturer minimum flows; Venturi valves require their specified flow.
Key red flags
Low saturation with exhaustion, cyanosis, reduced consciousness or instability needs immediate support and senior help.
Drowsiness or acidosis in an at-risk patient needs urgent gas and ventilatory assessment.
Reasoning priorities
Guide oxygen titration and detect hypoxaemia.
Confirm signal and clinical fit; target depends on hypercapnic risk and prescription.
Worked reasoning
An alert adult with COPD has SpO2 82% on air, respiratory rate 26 and BP 132/78, without shock or exhaustion. The available 28% Venturi valve specifies 4 L/min.
- Call for urgent clinical assessment and check ABCDE. Start the 28% Venturi at its specified 4 L/min immediately, with an initial 88–92% saturation target pending urgent blood gases.
- Check the source, tubing and fit while observing breathing and saturation; in this case SpO2 rises to 90%. Continue the controlled supply and treat the exacerbation. If target is not reached, escalate oxygen delivery and urgent clinical support rather than accepting hypoxaemia.
- The urgent gas shows pH 7.37 and PaCO2 6.5 kPa. With raised carbon dioxide but no acidaemia and a stable clinical response, maintain the 88–92% target and repeat gases after 30–60 minutes. A falling pH, worsening hypercapnia, exhaustion or reduced consciousness requires immediate senior ventilatory assessment.
- Document device, flow, target, gas and response. Reassess sooner for deterioration, maintain adequate supply during transfer and give a named handover. Critical illness would change this initial oxygen strategy and require resuscitation support.