Evaluation of a Novel Portable Capnograph (MARIE) in Adult Postoperative Patients

NCT ID: NCT07178236

Last Updated: 2026-01-21

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 40 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-09-22
• Study Completion Date: 2025-12-22

Brief Summary

Postoperative respiratory complications are common and sometimes hard to detect early. Desaturation is a late sign of reduced minute ventilation, especially if the patient is on supplemental oxygen, and measurement of arterial or endtidal CO2 will rapidly detect a reduction in minute ventilation. Capnography offers a non-invasive and continuous measure of end-tidal expiratory pressure of carbon dioxide (EtCO2). Capnography is not a standard in postoperative care but rather quite rare. In the present study we evaluate a novel portable capnography device, MARIE, in postoperative patients.

1. The primary outcome is to describe the correlation of end-tidal CO₂ (EtCO₂) measurements between MARIETM (Oxlantics Medical) and Philips Intelli Vue X3 Microstream.

2. Secondary outcomes include

1. Correlation between PaCO₂ and EtCO₂ measured by MARIE and Philips Intelli Vue X3 Microstream, respectively.

2. Time trajectories of PaCO₂ and EtCO₂ measured using MARIE and Philips Intelli Vue X3 Microstream, respectively

3. The overall agreement between the EtCO2 measured by MARIE and Philips Intelli Vue X3 Microstream and PaCO2

4. Respiratory rate measured by MARIE compared to manual counting and Philips Intelli Vue X3.

5. Comparison of oxygen flow by MARIE and the rotameter.

6. Comfort as reported by patient.

7. Usability as reported by nurse.

8. Reasons for premature termination of MARIE

9. Registration of technical problems, for example unexpected shut downs and blockage by mucus.

MARIE will be applied immediately after tracheal extubation after surgery. CO2 values from MARIE will be compared to EtCO2 and PaCO2 derived from capnography equipment routinely used in the hospital and blood gas analysis, at set intervals in the postoperative ward. Respiratory rate will be compared to our standard care monitors, ie Philips Intelli Vue X3, alongside manual counting. Rate of oxygen delivery, when applicable, will also be compared to the rotameter.

Conditions

Surgery; Anesthesia; Postoperative Care; Respiration Rate Detection; Capnography; Monitoring

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

MARIE

Portable capnograph

Group Type: EXPERIMENTAL

MARIE

Intervention Type: DEVICE

Portable capnoghraphy

Interventions

MARIE

Portable capnoghraphy

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

1. Adult, ≥18 years of age

2. Elective surgery under general anesthesia

3. Planned for over night postoperative care

Exclusion Criteria

1. Tracheostomy

2. Nasal obstruction

3. Rhino- or oral surgery

4. Not able to understand study information or signing consent form

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Malin Jonsson Fagerlund

OTHER

Sponsor Role: lead

Responsible Party

Malin Jonsson Fagerlund

Professor

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Malin Jonsson Fagerlund, Professor

Role: PRINCIPAL_INVESTIGATOR

Karolinska University Hospital & Karolinska Institutet

Locations

Karolinska University Hospital

Stockholm, , Sweden

Countries

Sweden

Other Identifiers

CIV-ID 25-06-053097

Identifier Type: REGISTRY

Identifier Source: secondary_id

NOVOCAP-Postop

Identifier Type: -

Identifier Source: org_study_id