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

S52 Figure 1Kaplan-Meier curve comparing overall survival in the two treatment groups (conventional oxygen therapy vs continuous positive airway pressure therapy). The null hypothesis of no survival difference is evaluated with a log-rank test (p = 0.92)[Figure omitted. See PDF]DiscussionThis is, as far as we are aware, the first study comparing conventional oxygen therapy with CPAP in cohorts unaffected by physician selection. 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 continued widespread use of CPAP in this patient group.Please refer to page A189 for declarations of interest related to this abstract.

Developing a novel advanced clinical practitioner led severe COVID-19 follow-up service – a picture is not always worth a thousand words

During the COVID-19 pandemic the British Thoracic Society produced national guidance advising for all severe COVID-19 pneumonia (defining our inclusion criteria as clinico-radiological diagnosis, oxygen requirements >35%, continuous positive pressure ventilation or mechanical ventilation) to have 4–6-week follow-up with all COVID-19 patients having imaging at 12 weeks.1 To avoid duplication of work streams, the district general hospital developed a pathway liaising with ICU to ensure follow-up 4–6 weeks post discharge, chest x-ray at 12 weeks and follow-up telephone appointment at six months with the aim of discharging back to the community or referring for further investigations. In total we followed up 272 patients who were referred to our service.In the first wave (April 2020 - July 2020) we followed up 117 patients of whom 99 had a follow-up chest X-ray. Chest x-rays were performed on average 80.4 (43–140) days post discharge. Of these patients, 14% had residual changes, with 86% having a clinic normal chest X-ray, with 33 (28%) requiring referral for further investigation and respiratory physician follow-up due to breathlessness (quantified by Modified Medical Council Research dyspnoea score) identified at follow-up clinic appointments, on average 168.4 (91–209) days post discharge.In the second wave (October 2020 – April 2021) we followed up 155 patients of whom 133 had a chest x-ray and 51 (38%) had residual changes. Chest x-rays were performed on average 88.7 (32–120) days post discharge and follow-up clinic appointments were on average 150.9 (92–172) days post discharge. Only 35 patients have been followed up to date (the remaining having not reached 6-months post discharge). Of these 15 (42.8%) required onwards referral for further investigation.This data shows that we have run a robust follow-up service for severe COVID-19 pneumonia patients. It is important that we think carefully about who is referred for further respiratory investigations as our data shows that chest x-ray resolution does not necessarily correlate with resolution of symptoms, and the implication for NHS services.British Thoracic Society. British Thoracic Society Guidance on Respiratory Follow Up of Patients with a Clinico-Radiological Diagnosis of COVID-19 Pneumonia [V1.2], 2020. https://www.brit-thoracic.org.uk/document-library/quality-improvement/covid-19/resp-follow-up-guidance-post-covid-pneumonia/

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

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 1st March to May 31st, and from 1st September to 31st 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.