The effectiveness of continuous respiratory rate monitoring in predicting hypoxic and pyrexic events: a retrospective cohort study

Abstract

Respiratory rate (RR) is routinely used to monitor patients with infectious, cardiac and respiratory diseases and is a component of early warning scores used to predict patient deterioration. However, it is often measured visually with considerable bias and inaccuracy. Objectives: Firstly, to compare distribution and accuracy of electronically measured RR (EMRR) and visually measured RR (VMRR). Secondly, to determine whether, and how far in advance, continuous electronic RR monitoring can predict oncoming hypoxic and pyrexic episodes in infectious respiratory disease. Approach: A retrospective cohort study analysing the difference between EMRR and VMRR was conducted using patient data from a large tertiary hospital. Cox proportional hazards models were used to determine whether continuous, EMRR measurements could predict oncoming hypoxic (SpO2 <92%) and pyrexic (temperature >38 °C) episodes. Main Results: Data were gathered from 34 COVID-19 patients, from which a total of 3445 observations of VMRR (independent of Hawthorne effect), peripheral oxygen saturation and temperature and 729117 observations of EMRR were collected. VMRR had peaks in distribution at 18 and 20 breaths per minute. 70.9% of patients would have had a change of treatment during their admission based on the UK's National Early Warning System if EMRR was used in place of VMRR. An elevated EMRR was predictive of hypoxic (hazard ratio: 1.8 (1.05 to 3.07)) and pyrexic (hazard ratio: 9.7 (3.8 to 25)) episodes over the following 12 hours. Significance: Continuous EMRR values are systematically different VMRR values, and results suggest it is a better indicator of true RR as it has lower kurtosis, has higher variance, a lack of peaks at expected values (18 and 20) and it measures a physiological component of breathing directly (abdominal movement). Results suggest EMRR is a strong marker of oncoming hypoxia and is highly predictive of oncoming pyrexic events in the following 12 hours. In many diseases, this could provide an early window to escalate care prior to deterioration, potentially preventing morbidity and mortality.

Continuous Monitoring of Respiratory Rate with Wearable Sensor in Patients Admitted to Hospital with Pneumonia Compared with Intermittent Nurse-Led Monitoring in the United Kingdom: A Cost-Utility Analysis

“…This is also aligned with a study that used RespiraSense in a group of patients with infectious respiratory disease in a tertiary hospital in Dublin (Ireland). The study showed that an increased RR had a hazard ratio of 1.8 (95% confidence interval 1.05–3.70) for desaturation in the next 12 h [ 15 ]. Because of the limited clinal data for effectiveness of ARRM (and RespiraSense) compared with IM, an effectiveness threshold analysis was performed to understand the robustness of results based on variation in the effect size.…”

“…RespiraSense™ is a non-invasive, wireless, body worn, motion-tolerant, and continuous respiratory rate monitor [ 14 ]. It measures the mechanics of breathing by analysing the movements of the chest and abdomen using proprietary piezo film sensors [ 15 ].…”

The United Kingdom’s National Early Warning Score: should everyone use it? A narrative review

“…Respiratory rate may be the vital sign that most accurately predicts outcome [ 57 ], yet manual values are often inaccurate [ 58 ] and correlate poorly with machine-measured values [ 59 ]. Although machine-measured values should be the best predictors of deterioration and mortality [ 59 , 60 ], others have found that manual recordings may be better because they are biased by a nurse’s more accurate intuitive judgment of how sick the patient is [ 61 ]. The assessment of mental status required by NEWS may also be inadequate and more thorough screening for delirium has been suggested [ 62 ].…”

Community Virtual Ward (CVW+cRR) Proofof-Concept Examining the Feasibility and Functionality of Partnership-Based Alternate Care Pathway for COPD Patients- Empowering Patients to Become Partners in their Disease Management

“…Internationally CVW+cRR has become an alternative way of providing care to high-risk patients using a combination of specialist care and telehealth, employing "systems, staffing, and daily routines of a hospital ward…" in a community-based care model [9,10]. However, as we attempted to answer the challenge statement -"How might we empower people with exacerbating COPD to become a partner in the management of their health and ensure that they receive the right care at the right time as close to home as possible?"…”

“…Published evidence demonstrates that cRR was able to predict patients who became de-saturated (SpO 2 <92%) and those who developed a fever (38 0 Celsius) 12 hours earlier when rates stayed elevated above 24 breaths per minute for 30 minutes or longer [10].…”