Synopsis
Start, optimise and monitor acute NIV safely in patients with a reversible ventilatory failure, with a clear ceiling, failure criteria and route to invasive ventilation when needed.
- For acute COPD, consider NIV when pH remains below 7.35 with PaCO2 above 6.5 kPa and tachypnoea after about 1 hour of optimal medical treatment.
- NICE calls NIV the treatment of choice for persistent hypercapnic ventilatory failure during a COPD exacerbation despite optimal medical therapy.
- Start acute NIV within 60 minutes of the qualifying blood-gas result and, for patients presenting with AHRF, within 120 minutes of hospital arrival where possible.
Key red flags
Persistent pH below 7.35 and PaCO2 above 6.5 kPa with tachypnoea after controlled oxygen, bronchodilators, steroids and cause treatment.
Investigation priorities
Confirm acute hypercapnic failure and establish severity.
Management branches
Suspected COPD-related acute hypercapnic respiratory failure.
- Give controlled oxygen to 88–92%, nebulised bronchodilators, systemic steroid and antibiotics when indicated; stop/reverse respiratory depressants and manage secretions.
- Obtain/repeat ABG after initial treatment. If pH remains below 7.35 with PaCO2 above 6.5 kPa and tachypnoea, decide on NIV promptly.
Key medicines
Salbutamol nebuliser2.5 mg nebulised, increasing to 5 mg in severe bronchospasm and repeating according to response; use compressed air to drive in hypercapnia risk while oxygen is delivered separately to target.
Ipratropium bromide nebuliser500 micrograms nebulised, commonly every 4–6 hours during a severe COPD exacerbation, alongside short-acting beta2 agonist.