Measurement of Expiratory Gas Temperature in Intubated Patients to Estimate Expiratory Absolute Humidity

February 12, 2026 updated by: François Lellouche, Laval University
Adequate humidification is essential for intubated patients because dry medical gases can cause thick secretions and dangerous endotracheal tube blockages. A clear correlation exists between exhaled and inhaled humidity delivered by heat and moisture exchanger. The objective of this study is to measure the temperature of exhaled gases in intubated patients in order to accurately calculate the absolute humidity during the expiratory phase. These data will allow for a more accurate reproduction of real clinical conditions during bench testing and will improve the assessment of heat and moisture exchanger performance device evaluation.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Previous clinical studies suggest that real expiratory humidity in intubated patients is close to 35 mg H₂O/L, with expiratory temperatures around 32-33 °C or slightly lower. However, data are limited, heterogeneous, and often derived from anesthetized patients. Therefore, accurate measurement of expiratory temperature in intensive care patients under normothermia and across varying body temperatures is necessary to define realistic simulation standards and ensure reliable heat and moisture exchanger performance evaluation on a bench. A relationship between expiratory gases temperature and expiratory humidity exist.

Study Type

Observational

Enrollment (Estimated)

70

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Canada
    • Quebec
      • Québec, Quebec, Canada, G1V4G5
        • Insitut universitaire de cardiologie et de pneumologie de Quebec - Universite Laval

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Intubated patient using a heater and moist exchanger

Description

Inclusion Criteria:

  • Adults (≥18 years)
  • Intubated and mechanically ventilated in the intensive care unite
  • Using passive humidification (Heat and Moisture exchanger)

Exclusion Criteria:

  • PEEP set < 12 cmH₂O
  • Inhaled nitric oxide therapy
  • Tracheostomy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Normothermic patient
Normothermic patient under mechanical ventilation with passive humification (heat and moisture exchanger) with body temperature between 36.0 and 38.0 Celsius degrees
Other: Expiratory gases temperature
Measure expiratory gas temperature immediately before the passive humidifier in intubated ICU patients and evaluate the relationship between body temperature and expiratory temperature.
Hypothermic patient
Hypothermic patient under mechanical ventilation with passive humification (heat and moisture exchanger) with body temperature < 36.0 Celsius degrees
Other: Expiratory gases temperature
Measure expiratory gas temperature immediately before the passive humidifier in intubated ICU patients and evaluate the relationship between body temperature and expiratory temperature.
Hyperthermic patient
Hyperthermic patient under mechanical ventilation with passive humification (heat and moisture exchanger) with body temperature > 38.0 Celsius degrees
Other: Expiratory gases temperature
Measure expiratory gas temperature immediately before the passive humidifier in intubated ICU patients and evaluate the relationship between body temperature and expiratory temperature.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Expiratory gas temperature
Time Frame: H0, up to 60 minutes after inclusion
Measure expiratory gas temperature immediately before the passive humidifier
H0, up to 60 minutes after inclusion
Relationship between body temperature and expiratory temperature.
Time Frame: H0, up to 60 minutes after inclusion
Evaluate the relationship between body temperature and expiratory temperature
H0, up to 60 minutes after inclusion

Secondary Outcome Measures

Outcome Measure
Time Frame
Estimate expiratory absolute humidity based on measured temperature
Time Frame: H0, up to 60 minutes after inclusion
H0, up to 60 minutes after inclusion

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Laval University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

April 1, 2026

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

February 12, 2026

First Submitted That Met QC Criteria

February 12, 2026

First Posted (Actual)

February 19, 2026

Study Record Updates

Last Update Posted (Actual)

February 19, 2026

Last Update Submitted That Met QC Criteria

February 12, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 2026-4543

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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