RT Journal Article
SR Electronic
T1 Post-exertion oxygen saturation as a prognostic factor for adverse outcome in patients attending the emergency department with suspected COVID-19: a substudy of the PRIEST observational cohort study
JF Emergency Medicine Journal
JO Emerg Med J
FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine
SP 88
OP 93
DO 10.1136/emermed-2020-210528
VO 38
IS 2
A1 Goodacre, Steve
A1 Thomas, Ben
A1 Lee, Ellen
A1 Sutton, Laura
A1 Loban, Amanda
A1 Waterhouse, Simon
A1 Simmonds, Richard
A1 Biggs, Katie
A1 Marincowitz, Carl
A1 Schutter, José
A1 Connelly, Sarah
A1 Sheldon, Elena
A1 Hall, Jamie
A1 Young, Emma
A1 Bentley, Andrew
A1 Challen, Kirsty
A1 Fitzsimmons, Chris
A1 Harris, Tim
A1 Lecky, Fiona
A1 Lee, Andrew
A1 Maconochie, Ian
A1 Walter, Darren
YR 2021
UL http://emj.bmj.com/content/38/2/88.abstract
AB Background Measurement of post-exertion oxygen saturation has been proposed to assess illness severity in suspected COVID-19 infection. We aimed to determine the accuracy of post-exertional oxygen saturation for predicting adverse outcome in suspected COVID-19.Methods We undertook a substudy of an observational cohort study across 70 emergency departments during the first wave of the COVID-19 pandemic in the UK. We collected data prospectively, using a standardised assessment form, and retrospectively, using hospital records, from patients with suspected COVID-19, and reviewed hospital records at 30 days for adverse outcome (death or receiving organ support). Patients with post-exertion oxygen saturation recorded were selected for this analysis. We constructed receiver-operating characteristic curves, calculated diagnostic parameters, and developed a multivariable model for predicting adverse outcome.Results We analysed data from 817 patients with post-exertion oxygen saturation recorded after excluding 54 in whom measurement appeared unfeasible. The c-statistic for post-exertion change in oxygen saturation was 0.589 (95% CI 0.465 to 0.713), and the positive and negative likelihood ratios of a 3% or more desaturation were, respectively, 1.78 (1.25 to 2.53) and 0.67 (0.46 to 0.98). Multivariable analysis showed that post-exertion oxygen saturation was not a significant predictor of adverse outcome when baseline clinical assessment was taken into account (p=0.368). Secondary analysis excluding patients in whom post-exertion measurement appeared inappropriate resulted in a c-statistic of 0.699 (0.581 to 0.817), likelihood ratios of 1.98 (1.26 to 3.10) and 0.61 (0.35 to 1.07), and some evidence of additional prognostic value on multivariable analysis (p=0.019).Conclusions Post-exertion oxygen saturation provides modest prognostic information in the assessment of selected patients attending the emergency department with suspected COVID-19.Trial registration number ISRCTN Registry (ISRCTN56149622) http://www.isrctn.com/ISRCTN28342533.