Is the "instant flow" option on the NIOX analyser needed?

Area of Science:

• Respiratory Medicine
• Pediatric Pulmonology
• Biomedical Engineering

Background:

• Elevated levels of gaseous nitric oxide in exhaled breath are characteristic of asthma.
• Fraction of nitric oxide in exhaled breath (FE(NO)) measurements are vital for asthma diagnosis and management.
• The NIOX chemiluminescence analyser is a common tool for FE(NO) assessment.

Purpose of the Study:

• To investigate the effect of the Instant Flow (IF) restriction feature on the NIOX analyser.
• To determine if IF restriction influences the accuracy of FE(NO) measurements.
• To assess the impact of IF restriction on the success rate of obtaining FE(NO) measurements in children.

Main Methods:

• A study was conducted on 38 children with a median age of 10 years.
• FE(NO) measurements were taken from the same individuals with and without the IF restriction enabled on the NIOX analyser.
• Statistical analysis was performed to compare FE(NO) values and success rates between the two conditions (p=0.002 for success rate).

Main Results:

• FE(NO) values obtained with and without IF restriction were not significantly different within individuals.
• The success rate for obtaining FE(NO) measurements was higher when IF was not restricted (57%).
• Conversely, the success rate was lower when IF was restricted (41%), indicating a significant negative impact.

Conclusions:

• The Instant Flow (IF) restriction feature on the NIOX analyser does not alter the measured FE(NO) values.
• The IF restriction significantly decreases the likelihood of successfully obtaining FE(NO) measurements in pediatric subjects.
• Current findings do not support the use of IF restriction on the NIOX analyser for FE(NO) measurements in children.