Question 1

When should I use Scale 2 for SpO₂?

Accepted Answer

Scale 2 (the 'hypercapnic' scale) should be used for patients with known or suspected hypercapnic respiratory failure — typically those with chronic type 2 respiratory failure from COPD, obesity hypoventilation syndrome, or neuromuscular disease. Scale 2 allows a target SpO₂ of 88–92%. Do not use Scale 2 for acute respiratory failure without hypercapnia.

Question 2

Can NEWS2 be used in patients on high-flow nasal oxygen or non-invasive ventilation?

Accepted Answer

NEWS2 scores 2 points for any oxygen therapy, regardless of the delivery method or FiO₂. This is a limitation — a patient on high-flow oxygen or NIV gets the same oxygen score as a patient on 1 L/min via nasal cannula. Document respiratory support separately and interpret the score in this context.

Question 3

Should I use NEWS2 for paediatric or pregnant patients?

Accepted Answer

No — NEWS2 thresholds were derived from general adult medical populations. For paediatric patients, use the Paediatric Early Warning Score (PEWS). For pregnant patients, use a specific obstetric early warning score such as MEOWS or MEWC.

Question 4

What if I cannot obtain a SpO₂ reading?

Accepted Answer

If SpO₂ cannot be obtained (e.g., due to poor perfusion or patient movement), document this and calculate the NEWS2 score from the remaining parameters. Consider performing an arterial blood gas to obtain SaO₂. The missing parameter should be highlighted for review.