Using End-Tidal CO₂ to Help Diagnose and Monitor Pulmonary Embolism

NCT07241130 | Completed

• 1 other identifier: B.30.2.ATA.0.01.00/427
• Study Type: observational
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

Pulmonary embolism (PE) can reduce blood flow in the lungs and impair gas exchange, leading to lower end-tidal carbon dioxide (EtCO₂) levels. This prospective observational study aims to evaluate whether EtCO₂ can help identify high-risk and intermediate-high-risk patients and monitor early treatment response, especially during thrombolytic therapy. A total of 120 participants were included: high-risk PE, intermediate-high-risk PE patients who received thrombolysis, intermediate-high-risk PE patients treated only with anticoagulation, and healthy controls. The study measured EtCO₂ along with oxygen saturation, heart rate, respiratory rate, perfusion index, and radiological obstruction scores. By comparing these parameters at diagnosis and during the first 24 hours, the study seeks to determine whether EtCO₂ can serve as a simple, noninvasive marker of disease severity and early hemodynamic improvement in patients with acute PE.

Conditions

Pulmonary Embolism Acute

Outcome Measures

Primary Outcomes (1)

• End-Tidal Carbon Dioxide (EtCO₂) Level at Diagnosis

  EtCO₂ level measured in mmHg using nasal capnography at the time of diagnosis to assess its ability to identify high-risk and intermediate-high-risk pulmonary embolism and to predict the need for thrombolytic therapy.

  At baseline (within first 1 hour of diagnosis)

Study Arms (4)

Group 1: High-Risk Pulmonary Embolism (Thrombolysis)

Patients presenting with shock or persistent hypotension and receiving systemic thrombolytic therapy.

Other: thrombolytic therapy

Group 2: Intermediate-High-Risk Pulmonary Embolism (Thrombolysis)

Hemodynamically stable patients with RV dysfunction and elevated biomarkers who required thrombolysis.

Other: thrombolytic therapy

Group 3: Intermediate-High-Risk Pulmonary Embolism (Non-Thrombolysis)

Patients meeting intermediate-high-risk criteria but treated with anticoagulation only.

Group 4: Healthy Controls

Individuals without cardiopulmonary disease and with normal clinical and laboratory findings.

Interventions

thrombolytic therapy OTHER

Participants received standard clinical management according to current pulmonary embolism guidelines. No intervention was assigned by the investigators.

Group 1: High-Risk Pulmonary Embolism (Thrombolysis); Group 2: Intermediate-High-Risk Pulmonary Embolism (Thrombolysis)

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

This study included adult patients diagnosed with acute pulmonary embolism who were classified as high-risk or intermediate-high-risk based on hemodynamic status, right ventricular dysfunction, and cardiac biomarker elevation. Participants were consecutively enrolled at a tertiary university medical center. The study also included a healthy control group composed of adults without cardiopulmonary disease or significant medical comorbidities. A total of 120 individuals were studied across four cohorts representing different clinical risk categories and routine treatment pathways.

You may qualify if:

• Adults aged 18 years or older Diagnosis of acute pulmonary embolism confirmed by CT pulmonary angiography (for PE groups) Classified as high-risk or intermediate-high-risk pulmonary embolism according to ESC/ERS 2019 guidelines Ability to provide informed consent For healthy control group: no history of cardiopulmonary disease, coagulation disorders, or acute medical illness

You may not qualify if:

• Known chronic respiratory diseases significantly affecting EtCO₂ measurement (e.g., advanced COPD, severe asthma, chronic respiratory failure) Active infection, sepsis, or acute complications of malignancy Prior thrombolytic therapy for pulmonary embolism Anatomical or technical limitations preventing reliable nasal capnography Pregnancy Individuals younger than 18 years Inability or refusal to provide informed consent

Sponsors & Collaborators

• Ataturk University: lead

Study Sites (1)

Ataturk University

Erzurum, 25200, Turkey (Türkiye)

Location

MeSH Terms

Interventions

Thrombolytic Therapy

Intervention Hierarchy (Ancestors)

Drug Therapy; Therapeutics

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor of Pulmonary Medicine

Study Record Dates

• First Submitted: November 17, 2025
• First Posted: November 21, 2025
• Study Start: February 1, 2025
• Primary Completion: July 30, 2025
• Study Completion: July 30, 2025
• Last Updated: December 22, 2025

Record last verified: 2025-12

Locations

TU (1)