Remote dielectric sensing for detecting pulmonary edema in the emergency department

Dyspnea is a common Emergency Department (ED) complaint of which acute pulmonary edema (APE) is a potentially life-threatening etiology. Remote Dielectric Sensing (ReDS™) is a novel, non-invasive, radar based, rapid, point of care vest testing system used to objectively quantify lung fluid content and may be useful in the early diagnosis of APE.

To determine the accuracy of ReDS to detect pathologic lung fluid in ED undifferentiated dyspneic patients.

We performed a prospective convenience sample observation pilot study enrolling adult ED patients with a chief complaint of "shortness of breath." After informed consent, patients were fitted with the ReDS vest and a reading, blinded to the care team, was recorded. A gold standard diagnosis of pulmonary edema, determined by 2 physicians performing a chart review and blinded to ReDs data, was compared to the ReDS reading.

Overall, 123 patients were included; 59% (n = 73) were male, mean (SD) age 57.2 (±12) years, 46.3% (n = 57) Hispanic, 34.1%(n = 42) African American, 13.0% (n = 16) Caucasian and 5.7% (n = 7) Asian. The gold standard diagnosis showed pulmonary edema in 38 (30.9%) patients, of which 30 were detected by ReDS. At an optimal cutoff (≥ 37%), ReDS had a Sn of 79.5% (CI 63.5% - 90.5%), Sp of 72.6% (CI 61.8% - 81.8%), a PPV of 57.4% and a NPV of 88.4%.

ReDS is moderately sensitive and specific with an accuracy of 74.8% for pulmonary edema.