NEWS2 system requires modification to identify deteriorating patients with COVID-19

Editor – The UK National Early Warning Score 2 (NEWS2) was developed as a track-and-trigger system to ensure a nationally uniform, evidence-based approach to early identification of the deteriorating patient in the UK. It allows monitoring of patients' vital signs and succinct reporting to clinical decision makers, facilitating early intervention in deteriorating patients.¹

Patients with severe COVID-19 develop hypoxic respiratory failure reminiscent of acute respiratory distress syndrome (ARDS).² ARDS severity is measured by the Berlin criteria, where degree of severity is defined as deteriorating arterial oxygen partial pressure (PaO₂) to fractional inspired oxygen (FiO₂) ratios.³ The current NEWS2 system in use in NHS hospitals treats oxygen delivery as a yes/no binary score without demonstrating a graded increase from increasing oxygen demand.¹

Consider the following two scenarios:

• Patient A is a COVID-19 patient on 1 L nasal cannula to maintain O₂ saturations >92%, a respiratory rate (RR) of 20 breath per minute and a heart rate (HR) of 100 beats per minute. This patient scores 3 on NEWS2.

• Patient B is a COVID-19 patient on continuous positive airway pressure (CPAP) on 60% FiO₂, 15 cmH₂0 to maintain O₂ saturations of 92%, with RR of 20 breath per minute and HR of 100 beats per minute. This patient also scores 3 using NEWS2 despite the vast difference in clinical status.

While the Royal College of Physicians (RCP) has recognised this issue, stating that ‘ANY increase in oxygen requirements should trigger an escalation call to a competent clinical decision maker’, this statement does not differentiate acuity of a required clinical review between patients A and B should their oxygen demand increase.⁴ Patient safety may be at risk when healthcare staff with only basic training are monitoring observations on the ward unaware of this problem. The window of time for recognition and escalation would be shortened if the oxygen delivery systems could be scored in an escalating ladder (see supplementary material S1).

Given the limitations of denoting oxygen on NEWS2 highlighted by guidance issued by the RCP, NEWS2 would benefit from a re-evaluation and updated scoring system in the interests of patient safety in anticipation of future waves during the COVID-19 pandemic.

Supplementary material

S1 – Proposed oxygen delivery scoring system.