Bedside saline-contrast electrical impedance tomography for diagnosing acute pulmonary embolism

A Multicenter Comparative Study of Saline Contrast Electrical Impedance Tomography Method Versus CTPA in the Diagnosis of Acute Pulmonary Embolism

This study will test whether a bedside saline-contrast electrical impedance tomography (EIT) scan can diagnose acute pulmonary embolism in adults with suspected PE and respiratory failure.

Quick facts

• Study type: Observational
• Enrollment: 343 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Peking Union Medical College Hospital (other)
• Locations: 1 site (Beijing, Beijing Municipality)
• Trial ID: NCT07190079 on ClinicalTrials.gov

What this trial studies

This observational study compares a bedside saline-contrast electrical impedance tomography (EIT) method with standard computed tomography pulmonary angiography (CTPA) for diagnosing acute pulmonary embolism. Patients with suspected or confirmed acute PE and acute respiratory failure will undergo both saline-contrast EIT and CTPA within 24 hours. The EIT procedure uses a short saline bolus injected through central or peripheral venous access while an electrode belt measures impedance changes to map lung perfusion. Study findings will compare EIT and CTPA results for consistency to determine whether EIT reliably detects perfusion defects consistent with PE.

Who should consider this trial

Good fit: Adults over 18 with suspected or confirmed acute pulmonary embolism presenting with acute respiratory failure, who have venous access and can undergo CTPA within 24 hours, are ideal candidates.

Not a fit: Patients who are pregnant or lactating, have pacemakers or chest wall wounds at electrode sites, severe hypernatremia, BMI over 50, are on ECMO, or cannot hold their breath for the required time are unlikely to benefit or may be excluded.

Why it matters

Potential benefit: If successful, this could enable faster bedside detection of PE in unstable patients, reducing the need to move critically ill patients for CT and lowering radiation exposure.

How similar studies have performed: Some small pilot studies have shown that saline-contrast EIT can map pulmonary perfusion, but it remains incompletely validated against CTPA and is not yet widely adopted.

Eligibility criteria

Inclusion Criteria:

1. Patients with clinically suspected or confirmed acute pulmonary embolism (PE) presenting with acute respiratory failure;
2. Availability of CTPA results within 24 hours or scheduled to undergo CTPA within the next 24 hours;
3. Age \>18 years; no gender restrictions;
4. Presence of central venous access (internal jugular or subclavian vein) or peripheral forearm venous access;
5. Willingness to participate with signed informed consent from either the patient or legal guardian.

Exclusion Criteria:

1. Pregnancy or lactation;
2. Relative contraindications to EIT examination (e.g., chest wall wounds at electrode belt placement site, presence of pacemakers);
3. Severe hypernatremia (serum sodium \>155 mmol/L);
4. Inability to maintain expiratory breath-hold for ≥8 seconds;
5. BMI \>50 or severe thoracic deformities;
6. Current extracorporeal membrane oxygenation (ECMO) therapy.

Where this trial is running

Beijing, Beijing Municipality

• Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences — Beijing, Beijing Municipality, China (RECRUITING)

Study contacts

• Study coordinator: Huaiwu He

Conditions: Acute Pulmonary Embolism