Continuous vital sign monitoring catches COVID-19 deterioration early

A wearable chest patch device can continuously monitor vital signs in patients with the coronavirus disease 2019 (COVID-19), facilitating the early detection of cardiovascular deterioration, according to a recent study.

“Operationally, the small wearable, wireless remote patient monitoring device continuously and automatically collected and transferred the data, in real-time, to the medical staff. This reduced the direct contact between medical staff and patients without compromising the medical care provided, an important feature highly required during a pandemic,” the researchers said.

The present retrospective, multicentre, observational cohort study included 429 COVID-19 patients who were continuously monitored through the noninvasive, wireless, photoplethysmography-based chest patches. Physiological parameters such as heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure, and blood oxygen saturation (SpO₂) were measured every 15 minutes.

Measurements included in the analysis were collected over an average of 75.26 hours corresponding to a total of 245.67±226.39 observations per patient. Baseline mean was 82±10 bpm for HR, 95±2 percent for SpO₂, 129±17 mm Hg for SBP, 74±11 mm Hg for DBP, 70±12 for stroke volume (SV), 5.7±1.3 l/min for cardiac output (CO), 1,368±296 dynes·s^–1·cm–⁵ for systemic vascular resistance (SVR), and 35.7±3.6 ^oC for body temperature. [J Clin Med 2021;10:4218]

A total of 130 patients provided complete vital sign information over 5 days of continuous monitoring. Consistently, the researchers observed that within the first 24 hours, body temperature, respiratory rate, and SVR significantly increased, accompanied by drops in SpO₂, DBP, CO, and cardiac index (p<0.01 for all). Of note, these changes occurred at roughly the same time.

Repeated-measures analysis of variance was then performed to assess differences in physiological changes according to sex. For instance, while both men and women saw increases in body temperature during the first day of monitoring, values were significantly greater among men (p<0.001). From the second to the fifth days, women showed a significant decrease in body temperature (p<0.001).

In addition, evolution of HR was markedly different between sexes. In men HR dropped significantly during the first 48 hours of monitoring, while it showed an upward trend in women (p<0.01 for both). Such opposite trends in HR changes remained until day 5.

Aside from sex differences, notable effects of age and body mass index (BMI) were also observed. For example, younger patients had more stable SpO₂ readings throughout hospitalization, while a more dynamic pattern was observed for other age groups. Patients with normal weight, on the other hand, saw sharper first-day drops in SBP relative to overweight and obese counterparts.

“Frequent monitoring approach using a remote patient monitoring system and advanced bioinformatic tools shows early cardiovascular changes among hospitalized COVID-19 patients. These changes appear in parallel to changes in respiratory parameters, further emphasizing the cardiorespiratory effects of COVID-19 over time, with differential physiological responses noted between sex, BMI, and age groups.”

The present findings “may serve to improve early detection of clinical deterioration of COVID-19 patients, especially important in times of overwhelmed health care systems, helping to reduce direct contact between health care providers and COVID-19 patients without compromising medical care,” they added.