Table 2 Trial escalation of respiratory therapy protocol

All patients on oxygen therapy (HFNT or standard therapy) should have regular pulse oximetry measurements. The frequency of oximetry measurements will depend on the stability of the patient. Critically ill patients should have their oxygen saturations monitored continuously and recorded every few minutes whereas patients with mild breathlessness will need less frequent monitoring. Oxygen therapy should be increased if the saturation is < 93% and decreased if the saturation is > 95% (and eventually discontinued as the patient recovers).

Any sudden fall in oxygen saturation should lead to clinical evaluation of the patient and in most cases, measurement of blood gases. All peri-arrest and critically ill patients should be given 100% oxygen (15 l/min reservoir mask) whilst awaiting immediate medical review.

Escalation of respiratory therapy may be indicated if:

- Saturations < 93%

- RR > 20 breaths/min

- PaCO₂ > 7 kPa

Plan A

 Assess patient, consider chest x-ray

 Increase FiO2 in increments of 10% up to a maximum of 60%.

 If patient is receiving high-flow nasal therapy, consider increasing flow up to max 60 l/min

Plan B

 Assess patient, consider chest X-ray and arterial blood gas

 Consider transfer to level 2 or level 3 care environment (HDU or ICU)

 Increase FiO₂ in increments of 10% up to a maximum of 100%

 Consider CPAP (mask or nasal mask or hood), start at 5 cm H₂O

 Consider non-invasive ventilation (NIV) or BiPAP

Plan C

 Assess patient, consider chest X-ray and arterial blood gas

 Consider invasive mechanical ventilation (requires tracheal intubation)

Clinicians can move between plans A, B and C depending on the patient’s condition and not necessarily in that order.