Conventional oxygen therapy versus CPAP as a ceiling of care in ward-based patients with COVID-19: a multi-centre cohort evaluation

P Bradley; J Wilson; R Taylor; J Nixon; J Redfern; P Whittemore; M Gaddah; K Kavuri; A Haley; P Denny; C Withers; R C Robey; C Logue; N Dahanayake; D Siaw Hui Min; J Coles; M S Deshmukh; S Ritchie; M Malik; H Abdelaal; K Sivabalah; M D Hartshorne; D Gopikrishna; A Ashish; E Nuttall; A Bentley; T Bongers; T Gatheral; T W Felton; N Chaudhuri; L Pearmain

doi:10.1016/j.eclinm.2021.101122

Conventional oxygen therapy versus CPAP as a ceiling of care in ward-based patients with COVID-19: a multi-centre cohort evaluation

EClinicalMedicine. 2021 Oct:40:101122. doi: 10.1016/j.eclinm.2021.101122. Epub 2021 Sep 8.

Authors

P Bradley^{1

2

3}, J Wilson^{2

4}, R Taylor⁵, J Nixon^{6

3}, J Redfern⁶, P Whittemore⁴, M Gaddah⁷, K Kavuri⁸, A Haley⁷, P Denny⁷, C Withers¹, R C Robey¹, C Logue¹, N Dahanayake⁴, D Siaw Hui Min⁴, J Coles⁴, M S Deshmukh⁴, S Ritchie⁴, M Malik², H Abdelaal², K Sivabalah², M D Hartshorne⁸, D Gopikrishna⁸, A Ashish⁸, E Nuttall⁶, A Bentley^{1

9}, T Bongers², T Gatheral⁷, T W Felton^{1

9}, N Chaudhuri^{1

9}, L Pearmain^{1

3

10

11}

Affiliations

¹ North West Lung Centre, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
² Respiratory department, Blackpool Teaching Hospitals NHS Foundation Trust, Blackpool, UK.
³ NWCORR North West Collaborative Organisation for Respiratory Research.
⁴ Department of infectious diseases and tropical medicine. North Manchester General Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
⁵ Research and Development, Blackpool Teaching Hospitals NHS Foundation Trust, Blackpool, UK.
⁶ Respiratory department, Royal Preston Hospital, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, UK.
⁷ Respiratory department, University Hospitals of Morecambe Bay NHS Foundation Trust, Lancaster, UK.
⁸ Respiratory department, Royal Albert Edward Infirmary, Wrightington, Wigan and Leigh Teaching Hospitals NHS Foundation Trust, Wigan, UK.
⁹ Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester and Manchester University NHS Foundation Trust, Manchester, UK.
¹⁰ Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.
¹¹ Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health and Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.

Abstract

Background: Continuous positive airway pressure (CPAP) therapy is commonly used for respiratory failure due to severe COVID-19 pneumonitis, including in patients deemed not likely to benefit from invasive mechanical ventilation (nIMV). Little evidence exists demonstrating superiority over conventional oxygen therapy, whilst ward-level delivery of CPAP presents practical challenges. We sought to compare clinical outcomes of oxygen therapy versus CPAP therapy in patients with COVID-19 who were nIMV.

Methods: This retrospective multi-centre cohort evaluation included patients diagnosed with COVID-19 who were nIMV, had a treatment escalation plan of ward-level care and clinical frailty scale ≤ 6. Recruitment occurred during the first two waves of the UK COVID-19 pandemic in 2020; from 1^st March to May 31^st, and from 1^st September to 31^st December. Patients given CPAP were compared to patients receiving oxygen therapy that required FiO₂ ≥0_.4 for more than 12 hours at hospitals not providing ward-level CPAP. Logistic regression modelling was performed to compare 30-day mortality between treatment groups, accounting for important confounders and within-hospital clustering.

Findings: Seven hospitals provided data for 479 patients during the UK COVID-19 pandemic in 2020. Overall 30-day mortality was 75.6% in the oxygen group (186/246 patients) and 77.7% in the CPAP group (181/233 patients). A lack of evidence for a treatment effect persisted in the adjusted model (adjusted odds ratio 0.84 95% CI 0.57-1.23, p=0.37). 49.8% of patients receiving CPAP-therapy (118/237) chose to discontinue it.

Interpretation: No survival difference was found between using oxygen alone or CPAP to treat patients with severe COVID-19 who were nIMV. A high patient-initiated discontinuation rate for CPAP suggests a significant treatment burden. Further reflection is warranted on the current treatment guidance and widespread application of CPAP in this setting.

Funding: L Pearmain is supported by the MRC (MR/R00191X/1). TW Felton is supported by the NIHR Manchester Biomedical Research Centre.

Keywords: COVID-19; Ceiling of care; Invasive mechanical ventilation; Non-invasive ventilation; Oxygen; nIMV.

Grants and funding

MR/R00191X/1/MRC_/Medical Research Council/United Kingdom