Related Experiment Video
Updated: May 1, 2026
Breath Collection from Children for Disease Biomarker Discovery
Published on: February 14, 2019
Exhaled breath temperature in children: reproducibility and influencing factors
S Vermeulen1, M Barreto, F La Penna
1Faculty of Medical Sciences, University of Groningen , Groningen , The Netherlands and.
Insights
Exhaled breath temperature measurements are reproducible in children, influenced by age and humidity. Normalized values may help assess inhaled corticosteroid therapy effectiveness in asthma.
Area of Science:
- Pediatric Pulmonology
- Respiratory Physiology
- Biomedical Engineering
Background:
- Asthma management in children requires accurate monitoring.
- Exhaled breath temperature (EBT) is a potential non-invasive biomarker.
- Understanding EBT reproducibility and influencing factors is crucial for clinical application.
Purpose of the Study:
- To assess the reproducibility of EBT using the tidal breathing technique in children.
- To identify factors influencing EBT measurements.
- To compare EBT between healthy children and those with asthma.
Main Methods:
- EBT, fractional exhaled nitric oxide, and spirometry were measured in 124 children (63 healthy, 61 asthmatic).
- Parental questionnaires gathered respiratory history and medication use.
- Environmental factors (ear temperature, ambient temperature, humidity) were recorded.
Main Results:
- EBT measurements demonstrated high reproducibility.
- EBT increased with age and relative-ambient humidity.
- Adjusted EBT was higher in asthmatic children (1.1°C difference).
- Normalized EBT was lower in asthmatic patients on inhaled corticosteroids.
Conclusions:
- EBT measurements are reproducible but affected by various factors.
- Normalized EBT shows potential for assessing inhaled corticosteroid therapy in pediatric asthma.
- Further research is needed to optimize EBT's clinical utility in children.
Objective:
This study will investigate the reproducibility and influencing factors of exhaled breath temperature measured with the tidal breathing technique in asthmatic patients and healthy children.
Methods:
Exhaled breath temperature, fractional exhaled nitric oxide, and spirometry were assessed in 124 children (63 healthy and 61 asthmatic), aged 11.2 ± 2.5 year, M/F 73/51. A modified version of the American Thoracic Society questionnaire on the child's present and past respiratory history was obtained from parents. Parents were also asked to provide detailed information on their child's medication use during the previous 4 weeks. Ear temperature, ambient temperature, and relative-ambient humidity were also recorded.
Results:
Exhaled breath temperature measurements were highly reproducible; the second measurement was higher than the first measurement, consistent with a test-retest situation. In 13 subjects, between-session within-day reproducibility of exhaled breath temperature was still high. Exhaled breath temperature increased with age and relative-ambient humidity. Exhaled breath temperature was comparable in healthy and asthmatic children; when adjusted for potential confounders (i.e. ambient conditions and subject characteristics), thermal values of asthmatic patients exceeded those of the healthy children by 1.1 °C. Normalized exhaled breath temperature, by subtracting ambient temperature, was lower in asthmatic patients treated with inhaled corticosteroids than in those who were corticosteroid-naive.
Conclusion:
Measurements of exhaled breath temperature are highly reproducible, yet influenced by several factors. Corrected values, i.e. normalized exhaled breath temperature, could help us to assess the effect of therapy with inhaled corticosteroids. More studies are needed to improve the usefulness of the exhaled breath temperature measured with the tidal breathing technique in children.
Related Concept Videos
01:14Temperature Measurement Sites
Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
01:14Assessing Body Temperature - Oral
Step 1:
Start by practicing proper hand hygiene to prevent the spread of microorganisms.
Step 2:
Take the thermometer out of the charging unit, switch it on, and wait for the ready sign.
Step 3:
Gently slide the probe cover until a click is heard. This simple action prevents cross-contamination and ensures the correct placement of the probe cover.
Step 4:
Instruct the patient to open their mouth and place...
01:27Assessing Body Temperature - Rectal
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
01:20Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation:
01:28Factors Affecting Body Temperature
Factors may include:
01:14Assessing Body Temperature - Tympanic membrane
Step 1: Begin by practicing good hand hygiene to prevent the transmission of microorganisms.
Step 2: Turn on the thermometer and wait until the ready sign appears on the screen to ensure accurate measurement.
Step 3: Slide the probe cover in place to prevent cross-contamination.
Step 4: Instruct the patient to tilt their head to the side for comfort and check for cerumen...