Paul D Robinson1, Sooky Lum2, Courtney Moore3, Kate M Hardaker4, Nick Benseler3, Paul Aurora5, Peter Cooper6, Dominic Fitzgerald4, Renee Jensen7, Reginald McDonald8, Hiran Selvadurai4, Felix Ratjen7, Sanja Stanojevic7. 1. Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, Australia; Discipline of Paediatrics and Child Health, University of Sydney, Westmead, Australia. Electronic address: paul.robinson1@health.nsw.gov.au. 2. Respiratory, Critical Care & Anaesthesia section, UCL, Institute of Child Health, London, United Kingdom. 3. Division of Respiratory Medicine, Hospital for Sick Children, Toronto, Canada. 4. Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, Australia; Discipline of Paediatrics and Child Health, University of Sydney, Westmead, Australia. 5. Respiratory, Critical Care & Anaesthesia section, UCL, Institute of Child Health, London, United Kingdom; Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom. 6. Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, Australia. 7. Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom; Physiology and Experimental Medicine, Research Institute, Hospital for Sick Children, Toronto, Canada. 8. Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom.
Abstract
BACKGROUND: Different interfaces (mouthpiece/nose clip vs. facemask) are used during multiple breath washout (MBW) tests in young children. METHODS: We investigated the effect of interface choice and breathing modalities on MBW outcomes in healthy adults and preschool children. RESULTS: In adults (n = 26) facemask breathing significantly increased LCI, compared to mouthpiece use (mean difference (95% CI) 0.4 (0.2; 0.6)), with results generalizable across sites and different equipment. Exclusively nasal breathing within the facemask increased LCI, as compared to oral breathing. In preschoolers (2-6 years, n = 46), no significant inter-test difference was observed across interfaces for LCI or FRC. Feasibility and breathing stability were significantly greater with facemask (incorporating dead space volume minimization), vs. mouthpiece. This was more pronounced in subjects <4 years of age. CONCLUSION: Both nasal vs. oral breathing and mouthpiece vs. facemask affect LCI measurements in adults. This effect was minimal in preschool children, where switching between interfaces is most likely to occur.
BACKGROUND: Different interfaces (mouthpiece/nose clip vs. facemask) are used during multiple breath washout (MBW) tests in young children. METHODS: We investigated the effect of interface choice and breathing modalities on MBW outcomes in healthy adults and preschool children. RESULTS: In adults (n = 26) facemask breathing significantly increased LCI, compared to mouthpiece use (mean difference (95% CI) 0.4 (0.2; 0.6)), with results generalizable across sites and different equipment. Exclusively nasal breathing within the facemask increased LCI, as compared to oral breathing. In preschoolers (2-6 years, n = 46), no significant inter-test difference was observed across interfaces for LCI or FRC. Feasibility and breathing stability were significantly greater with facemask (incorporating dead space volume minimization), vs. mouthpiece. This was more pronounced in subjects <4 years of age. CONCLUSION: Both nasal vs. oral breathing and mouthpiece vs. facemask affect LCI measurements in adults. This effect was minimal in preschool children, where switching between interfaces is most likely to occur.