Proof-of-concept Study on Dyspnea Analysis Via GapCO2 (MicroDys)

How to Differentiate Congestive and Non-congestive Dyspnea in the Emergency Department? Proof-of-concept Study on Microperfusion Analysis Via GapCO2

Patients presenting to the emergency department with acute dyspnea undergo arterial blood gas measurement and monitoring of transcutaneous capnography using the TCM5 monitor. The aim of this study is to determine whether GapCO2, the difference between transcutaneous and arterial pCO2 (PaCO2 - PtcCO2), is correlated with the congestive or non-congestive origin of dyspnea.

Study Overview

• Status: Recruiting
• Conditions: Dyspnea; Acute Dyspnea

Detailed Description

Upon arrival at the emergency department, patients are placed in the vital emergency reception area for monitoring. An emergency physician will review the selection criteria and offer the patient participation. The information sheet will be provided to the patient along with a copy of the non-opposition form in case of patient agreement.

Before the introduction of any treatment, a TC 92 sensor is placed on the earlobe (or on the forehead if the earlobe is inaccessible), connected to a Radiometer TCM5 monitor, measuring SpO2 (Massimo technology), perfusion index, and transcutaneous capnography (PtcCO2).

After a 5-minute equilibration period, measurements were taken throughout the duration of patient management. Standard diagnostic and therapeutic management will be provided according to the attending physician's prescription. The attending physician won't consider PtcCO2 (nor GapCO2) measurements in patient management.

At the time of data analysis, an adjudication committee comprising 2 emergency physicians from the inclusion service but not involved in patient care will review the complete medical records of patients to determine whether dyspnea was of congestive or non-congestive origin.

• Study Type: Observational
• Enrollment (Estimated): 45

Contacts and Locations

• Study Contact: Name: Judith GORLICKI, MD; Phone Number: +33 (0)1 48 95 57 85; Email: judith.gorlicki@aph.fr
• Study Contact Backup: Name: Frédéric ADNET, MD-PhD; Phone Number: +33 (0)1 48 95 57 85; Email: frederic.adnet@aphp.fr

Study Locations

• France
  • Bobigny, France, 93000
    • Recruiting
    • Emergency Department Hospital Avicenne
    • Contact: Judith GORLICKI; Phone Number: +33 (0)1 48 95 57 85; Email: judith.gorlicki@aphp.Fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patient presenting to the emergency department of the inclusion center for acute dyspea

Description

Inclusion Criteria:

• Age ≥ 18 years
• Patient presenting with acute dyspnea defined by a sensation of respiratory discomfort with at least one of the following criteria: RR ≥ 22 and/or SpO2 < 95%
• Arterial blood gas sampling performed as part of care
• Inclusion less than 1 hour after arrival time to the emergency department
• Non-opposition to participation in the study

Exclusion Criteria:

• Temperature greater than or equal to 37.5°C
• Patient who has already received a diuretic or vasodilator treatment in the emergency department or by a prehospital medical team
• Systolic blood pressure less than or equal to 100 mmHg and/or signs of peripheral hypoperfusion
• Inability to express refusal to participate in the study

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
GapCO2	PaCO2 measured via arterial blood gas analysis - PtcCO2 measured via TCM5 monitor, at 37°C	Within 1 hour after enrolment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic performance of GapCO2 at 37°C		Within 1 hour after enrolment
Proportion of patients who underwent GapCO2 measurement among those who presented to the emergency department for dyspnea on the days of inclusion	Feasibility of measuring GapCO2 in the emergency department	up to 28 days

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Investigators: Principal Investigator: Judith GORLICKI, MD, Assistance Publique - Hôpitaux de Paris

Study record dates

Study Major Dates

• Study Start (Actual): January 26, 2025
• Primary Completion (Estimated): March 26, 2026
• Study Completion (Estimated): April 26, 2026

Study Registration Dates

• First Submitted: June 21, 2024
• First Submitted That Met QC Criteria: August 14, 2024
• First Posted (Actual): August 16, 2024

Study Record Updates

• Last Update Posted (Actual): February 10, 2026
• Last Update Submitted That Met QC Criteria: February 6, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Dyspnea; Emergency department; Congestion; Proof-of-concept study; Acute dyspnea; GapCO2
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Emergencies; Dyspnea
• Other Study ID Numbers: APHP221251; 2022-A01957-36 (Other Identifier: IDRCB ANSM)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No