{
  "abstract": "Introduction The National Early Warning Score 2 (NEWS2) assigns 0 points for room air and 2 points for any oxygen therapy. This binary scoring may miss deteriorating patients with an escalating oxygen requirement and otherwise stable observations. Although this limitation was recognised during COVID-19, it remains unexplored in general inpatients.Aims Describe the trajectories of fraction of inspired oxygen (FiO2) and NEWS2 in the 48 hours prior to deterioration in adults on oxygen.Describe the trajectories of vital signs (heart rate, respiratory rate, oxygen saturations, temperature, systolic and diastolic blood pressure) 48 hours before discharge or deterioration.Methods A retrospective cohort study using data from a tertiary NHS foundation trust, composed of four hospitals, including a university teaching hospital. We included adults admitted for > 24 hours with at least one full set of vital signs. We estimated FiO2 via the Bateman equation and conventional prediction rule (see 1). First, we modelled changes in NEWS2 score and FiO2 48 hours prior to unplanned intensive care unit (ICU) admission or death in patients on oxygen. Second, we modelled vital sign changes before discharge or deterioration (unplanned ICU admission or death) in all patients.Results There were 227,812 admissions and 1,532,498 observation sets within 48 hours of discharge or deterioration. 43,662 admissions required oxygen, contributing 178,093 observation sets. 7791 admissions deteriorated.In patients on oxygen before ICU admission, FiO2 began rising ~24 hours prior, whereas NEWS2 score rose 12–16 hours before. In those who died, FiO2 rose more gradually ~16–20 hours before death, with NEWS2 increasing 12–16 hours before death (figure 1).In all patients, all vital signs stabilised before discharge and worsened before deterioration, especially respiratory rate. However, the magnitude of vital sign derangement varied greatly between observations.Abstract S30 Figure 1Trajectories of NEWS2 score (top), FiO2 (estimated via the conventional prediction rule) (middle), and FiO2 (estimated via the Bateman equation) (bottom) in the 48 hours prior to unplanned ICU admission or death, in patients on oxygenConclusions A rise in FiO2 preceded a rise in NEWS2 score by 8–12 hours in patients requiring unplanned ICU admission, and 4–8 hours in those who died. Incorporating FiO2 into NEWS2 may allow for earlier recognition of deterioration.Reference Harrison CH, Tupper P, Gerry S, et al. Oxygen therapy in early warning scores: a systematic review and meta-analysis. Thorax. 2025. doi: 10.1136/thorax-2024–222663",
  "authors": [
    {
      "affiliations": [
        "Critical Care Research Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK"
      ],
      "name": "CH Harrison"
    },
    {
      "affiliations": [
        "Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK"
      ],
      "name": "S Gerry"
    },
    {
      "affiliations": [
        "Critical Care Research Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK"
      ],
      "name": "OC Redfern"
    },
    {
      "affiliations": [
        "Ysbyty Gwynedd, School of Medical Sciences, Bangor University, Bangor, UK"
      ],
      "name": "C Subbe"
    },
    {
      "affiliations": [
        "Critical Care Research Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK",
        "Department of Critical Care, Milton Keynes University Hospital NHS Foundation Trust, Milton Keynes, UK"
      ],
      "name": "JP Bedford"
    },
    {
      "affiliations": [
        "Critical Care Research Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK",
        "Oxford Critical Care, Oxford University Hospitals NHS Foundation Trust, Oxford, UK",
        "National Institute for Health and Care Research (NIHR), Oxford Biomedical Research Centre, Oxford, UK"
      ],
      "name": "PJ Watkinson"
    }
  ],
  "title": "S30 Oxygen requirement rises earlier than the total National Early Warning Score 2 (NEWS2) score prior to deterioration",
  "uid": "65ed1e7f-2929-57cd-9e3d-9fecec113855"
}