Remote dielectric sensing for detecting pulmonary edema in the emergency department

Remote dielectric sensing to detect pulmonary congestion in acute dyspnoeic patients: Reproducibility and the effect of pulmonary comorbidities

BACKGROUND

Remote Dielectric Sensing (ReDS) is a fast and non-invasive method that estimates lung fluid. We previously described moderate accuracies for ReDS to detect acute heart failure in consecutive patients. We hypothesise that unprecise ReDS values may stem from concomitant pulmonary diseases.

PURPOSE

To examine the ReDS reproducibility and the effect of pulmonary comorbidities on ReDS values in acute dyspnoeic patients.

METHODS

This prospective observational study included 97 consecutive patients ≥50 years with acute dyspnoea. Upon admission, patients underwent low-dose chest computed tomography (CT), echocardiography and ReDS examination. ReDS is by default performed on the right hemithorax in sitting position. For reproducibility comparisons, we conducted additional ReDS measurements two centimetres above and below the default placement, and in sitting and supine position. Two blinded radiologists evaluated the CT scans for pulmonary congestion and pulmonary diseases.

RESULTS

Comparing three ReDS measurements on the right hemithorax revealed coefficients of variations of 9.6 %, 8.2 %, and 8.3 %. For sitting versus supine comparison, the coefficient of variation was 9.5 % for the default ReDS placement. Patients with CT-verified pulmonary congestion had a coefficient of variation of 5.9 % in sitting versus supine comparison, while those without had 10.3 %. In multivariable regression, lower ReDS values were observed in patients with pneumonia (-1.81, p = 0.215, N = 51), emphysema (-5.44, p = 0.001, N = 26), and higher in fibrosis (5.58, p = 0.032, N = 8) and congestion (5.79, p = 0.002, N = 17), compared to those without.

CONCLUSION

ReDS values of lung fluid content and reproducibility were affected by pulmonary diseases. ReDS showed consistent reproducibility for patients with CT-verified pulmonary congestion.

Initial Experience of Noninvasive Quantification of Pulmonary Congestion Utilizing the Remote Dielectric Sensing System in Pediatric Patients with Heart Failure

Background/Objectives: Remote dielectric sensing (ReDS) is a recently developed, noninvasive, electromagnetic energy-based technology designed to quantify pulmonary congestion without requiring expert techniques in adult patients with heart failure. However, its applicability in pediatric patients remains unknown. Methods: ReDS values and chest X-rays were simultaneously obtained from pediatric patients with a history of Fontan surgery at an outpatient clinic. The Congestion Severity Index (CSI) was calculated from chest X-rays to analyze its correlation with ReDS values. Results: A total of 21 pediatric patients (median age: 17 years; median height: 152.7 cm; median weight: 48.6 kg; 12 male patients) were included. ReDS values were successfully measured in all participants without any measurement failure. A mild correlation was observed between ReDS values and CSIs (r = 0.47, p = 0.030). In patients with ReDS values exceeding 35% (N = 11), a stronger correlation was noted between ReDS values and CSIs (r = 0.61, p = 0.046). In patients with ReDS values ≤ 35% (N = 10), ReDS values exhibited a wide distribution (25% to 35%) despite low CSI values. Conclusions: The ReDS system demonstrates potential as a feasible technology for the noninvasive quantification of pulmonary congestion in pediatric patients, irrespective of the severity of congestion. Notably, the ReDS system may have the potential to identify subclinical pulmonary congestion in pediatric patients with heart failure.

Noninvasive assessment of pulmonary congestion in heart failure: Need of the hour

Early pulmonary congestion detection and surveillance in acute heart failure patients can prevent decompensation, minimize hospitalizations, and improve prognosis. In India, the warm and wet types of HF are still the most common types and residual congestion at discharge is still a significant concern. Thus, there is an urgent need for a reliable and sensitive means of identifying residual and subclinical congestion. Two such monitoring systems are available and approved by US FDA. These include CardioMEMS HF System (Abbott, Sylmar, California) and ReDS System (Sensible Medical Innovations, Ltd., Nanya, Israel). CardioMEMS is a wireless pressure-sensitive implantable device, while ReDS is a wearable noninvasive device for measurement of the lung fluid and hence direct detection of PC. This review discusses the role of noninvasive assessment in PC monitoring in patients with heart failure and its implications from an Indian perspective.

Remote dielectric sensing to detect acute heart failure in patients with dyspnoea: a prospective observational study in the emergency department

Aims

Remote dielectric sensing (ReDS) enables quick estimation of lung fluid content. To examine if ReDS is superior to other methods in detecting acute heart failure.

Methods and results

We included consecutive patients with dyspnoea from the emergency departments at Bispebjerg Hospital, Copenhagen, and performed ReDS, low-dose chest computed tomography (CT), echocardiogram, lung ultrasound, NT-Pro-brain natriuretic peptide (NT-proBNP), and a Boston score evaluation (chest X-ray and clinical signs). ReDS values >35% were used as a cut-off to diagnose pulmonary congestion. Acute heart failure was adjudicated by experts' review of health records but independently of ReDS values. Sub-analyses investigated ReDS in acute heart failure patients with congestion on CT. We included 97 patients within a median of 4.8 h from admittance: 25 patients (26%) were ReDS-positive and 39 (40%) had adjudicated acute heart failure (21 with and 18 without CT congestion). Heart failure patients had median ReDS 33%, left ventricular ejection fraction 48%, and NT-proBNP 2935 ng/L. A positive ReDS detected heart failure with 46% sensitivity, 88% specificity, and 71% accuracy. The AUC for ReDS was like the Boston score (P = 0.88) and the lung ultrasound score (P = 0.74). CT-congested heart failure patients had higher ReDS values than patients without heart failure (median 38 vs. 28%, P < 0.001). Heart failure patients without CT-congestion had ReDS values like patients without heart failure (mean 30 vs. 28%, P = 0.07).

Conclusion

ReDS detects acute heart failure similarly to the Boston score and lung ultrasound score, and ReDS primarily identifies the acute heart failure patients who have congestion on a chest CT.