Factors Influencing Nasal Irrigation Efficacy in Infants: An Exploratory 3D Model Study.

Background: Nasal irrigation is widely practiced in infants, but its execution varies greatly. Although a consensus on how to perform this procedure has been published, supporting experimental evidence is lacking. In vitro investigations using anatomical models are a promising first step toward clinical research. Quantitative, exploratory data on pediatric nasal irrigation, obtained from a pragmatic irrigation setup, are needed.

Methods: A previously validated upper airway model of a 10-month-old infant was used and filled with mucus-mimicking hydrogel at two different concentrations. The upper airway clearance efficacy (UAC%) of nasal irrigation (i.e., the extent of airway clearance) was tested by varying different parameters: head position and the nostril selected for irrigation (side-lying via the supra- or infra-lateral nostril, or sitting), irrigation pattern (unilateral or bilateral irrigation), irrigation volume (5, 10, 15, or 20 mL), and hydrogel concentration (1 or 1.5%).

Results: Increasing nasal irrigation volume significantly improved UAC% with each 5 mL increment: mean (SD) UAC% was 75.10 (8.06), 84.00 (7.79), 89.94 (5.86), and 93.15 (4.63) % for 5, 10, 15, and 20 mL/nostril, respectively. Performing unilateral nasal irrigation through the supra-lateral nostril led to a greater UAC% compared to infra-lateral nostril irrigation (mean UAC% (SD) was 83.02 (7.32) and 75.30 (9.29) %, respectively; p < 0.001). The other parameters did not significantly impact the UAC%.

Conclusion: The irrigation volume and the nostril selected for unilateral nasal irrigation significantly impacted upper airway clearance during in vitro nasal irrigation. Future studies should investigate whether large irrigation volumes improve clinical outcomes in infants.

Level of evidence: NA, in vitro study.