Novel Use of Home Pulse Oximetry Monitoring in COVID-19 Patients Discharged From the Emergency Department Identifies Need for Hospitalization

Objectives: Our objective was to evaluate patient-reported oxygen saturation (SpO₂) using pulse oximetry as a home monitoring tool for patients with initially nonsevere COVID-19 to identify need for hospitalization. Methods: Patients were enrolled at the emergency department (ED) and outpatient testing centers. Each patient was given a home pulse oximeter and instructed to record their SpO₂ every 8 hours. Patients were instructed to return to the ED for sustained home SpO₂ < 92% or if they felt they needed emergent medical attention. Relative risk was used to assess the relation between hospitalization and home SpO₂ < 92% in COVID-19–positive patients. Results: We enrolled 209 patients with suspected COVID-19, of whom 77 patients tested positive for COVID-19 and were included. Subsequent hospitalization occurred in 22 of 77 (29%) patients. Resting home SpO₂ < 92% was associated with an increased likelihood of hospitalization compared to SpO₂ ≥ 92% (relative risk = 7.0, 95% confidence interval = 3.4 to 14.5, p < 0.0001). Home SpO₂ < 92% was also associated with increased risk of intensive care unit admission, acute respiratory distress syndrome, and septic shock. In our cohort, 50% of patients who ended up hospitalized only returned to the ED for incidental finding of low home SpO₂ without worsening of symptoms. One-third (33%) of nonhospitalized patients stated that they would have returned to the ED if they did not have a pulse oximeter to reassure them at home. Conclusions: This study found that home pulse oximetry monitoring identifies need for hospitalization in initially nonsevere COVID-19 patients when a cutoff of SpO₂ 92% is used. Half of patients who ended up hospitalized had SpO₂ < 92% without worsening symptoms. Home SpO₂ monitoring also reduces unnecessary ED revisits.