Reds Lung Fluid Monitoring For Assessing Lung Disease In Patients With Covid-19 Infection

BACKGROUND: Clinical manifestation of COVID-19 infection vary from asymptomatic to severe ARDS pneumonia. Chest CT is highly sensitive in detecting lung injury due to COVID-19, but is not routinely used for serial monitoring. ReDS™ is an FDA-approved, non-invasive measurement tool for monitoring lung fluid content in HF patients (normal values ranging 20-35%). ReDS has proven to have excellent correlation with CT in quantification of lung fluid and may have the potential to assess the severity of lung injury in patients infected with the SARS-CoV-2 virus. METHODS: Cone Health is a six-hospital system in central NC. In March 2020, the previous Women's Hospital site was converted into a 120-bed (24 ICU/96 Medical) COVID hospital. In this prospective, feasibility, pilot study we used the ReDS Clip to evaluate whether it was possible to measure bilateral lung fluid status on a daily basis in qualifying patients with COVID-19 lung infection. Secondary endpoints included correlations between the daily ReDS measurements and standard markers of clinical status. Patients were excluded if they had an implantable cardiac device, did not meet BMI criteria, were in the ICU prior to enrollment or had physical/cognitive limitations that precluded obtaining accurate readings. RESULTS: In May - June 2020, 83 patients who met the inclusion criteria were enrolled. The mean age was 56yr, 60% male. Medication regimen included 100% vitamin C and zinc, 72% steroids, 34% remdesivir, 39% tocilizmab. No patients received hydroxycholoroquine. Over the 2month study period, 78% (65/83 patients) were able to receive daily ReDS measurements. Four patients missed 1 or 2 readings during hospitalization due to oxygen saturations dropping or too weak for minimal movements in bed to place the ReDS Device. Eight patients refused to continue study after 1 reading due to weakness or shortness of breath. ReDS readings were held during ICU stay. Six patients (7.2%) were moved to ICU, of which two patients died (33%). For the studied chohort, six patients (7.2%) died during evaluation. Only 2 patients had a documented history of heart failure. For the entire cohort, the average ReDS reading was 37%. Patients with higher supplemental oxygen demand (O2 > 5 L/min or need for BIPAP) had higher ReDS readings than patients with low oxygen demands, ReDS 43% vs ReDS 35%. Patients who were referred to ICU had higher ReDS readings than patients who were discharged home, ReDS 47% vs ReDS 37%. CONCLUSION: In this single-center feasibility study, ReDS lung fluid was able to be measured on a daily basis in 78% of the hospitalized study cohort. ReDS measurements correlated with then need for higher levels of O(2) supplementation and worsening clinical status in patients with COVID-19 lung infection. More research is warranted to determine if daily monitoring with this technology can assist in early prediction of disease trajectory.