The Effectiveness of Continuous Respiratory Rate Monitoring in Predicting Hypoxic and Pyrexic Events

Title: The Effectiveness of Continuous Respiratory Rate Monitoring in Predicting Hypoxic and Pyrexic Events
Author(s): T. A. McCartan A. P. Worrall R. Ó Conluain F. Alaya C. Mulvey E. MacHale V. Brennan L. Lombard J. Walsh M. Murray R. W. Costello G. Greene
Institution: INCA Group, Royal College of Surgeons in Ireland
Poster: Click to view poster
Category: COVID-19
Abstract: Respiratory rate (RR) is a highly useful index of lung function, however objective measurements thereof are rarely taken. In this retrospective cohort study, we compare the distribution of electronically and visually measured RR and test whether continuous electronic RR monitoring can predict oncoming deteriorations in infectious respiratory disease.

34 COVID-19 patients in Beaumont Hospital were analysed, with 3445 observations of visual RR, SpO2 and temperature and 729117 of electronic RR collected. Cox Proportional Hazards Models determined predictive ability for oncoming hypoxic and pyrexic episodes.

Visually measured RR demonstrates bias, toward lower values clustering at 18 and 20 breaths per minute, while electronic RR has a positively skewed gamma distribution (see Figure 1). Raised RR 12 hours prior resulted in a hazard ratio of 1.8 (1.05 to 3.07) for hypoxia and 9.7 (3.8 to 25) for pyrexia. An RR of ≥25 had a sensitivity of 98.4% and a specificity of 91.9% for detecting pyrexia 12 hours in advance.

Electronic, continuous RR removes bias, is a stronger marker of oncoming hypoxia than visual RR and is highly predictive of oncoming pyrexia 12 hours in advance. This could provide an early window to escalate care prior to deterioration, preventing morbidity and mortality.