Feasibility of lung clearance index in a clinical setting in pre-school children

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology
• Clinical Diagnostics

Background:

• Lung function testing in preschool children is challenging due to difficulties with spirometry and the need for sedation in some infant tests.
• The lung clearance index (LCI), derived from multiple-breath washout (MBW), is sensitive to early lung disease but can be time-consuming.
• A shortened test, LCI₀.₅, was proposed to improve feasibility in young children.

Purpose of the Study:

• To assess the feasibility of performing MBW tests in unsedated preschool children in a clinical setting.
• To determine if the shortened LCI₀.₅ test increases success rates compared to the full LCI.
• To evaluate if LCI is elevated in preschool children with respiratory diseases.

Main Methods:

• 116 preschool children (28 healthy, 88 with respiratory disease; median age 4.0 years) underwent unsedated MBW tests using sulfur hexafluoride tracer gas.
• An adapted photoacoustic gas analyzer was employed for gas measurement.
• Feasibility was defined by successful completion of LCI and LCI₀.₅ measurements.

Main Results:

• Overall test completion rates were 70% for LCI and 72% for LCI₀.₅.
• Test success significantly increased with age, with 70% success in children over 3 years old (p<0.0001).
• LCI was significantly elevated in children with respiratory disease compared to healthy controls.

Conclusions:

• MBW testing is feasible in unsedated preschool children, particularly those older than 3 years.
• LCI is a sensitive indicator of respiratory disease in this age group.
• The shortened LCI₀.₅ did not improve success rates in preschool children.