@article {RingPA393, author = {Astrid Ring and Yagmur Sisman and Frederik Buchvald and Kim Nielsen}, title = {Hypoxic challenge test in patients previous treated for chILD conditions}, volume = {54}, number = {suppl 63}, elocation-id = {PA393}, year = {2019}, doi = {10.1183/13993003.congress-2019.PA393}, publisher = {European Respiratory Society}, abstract = {Aim: To gain knowledge of saturation during Pre-flight hypoxic challenge test (HCT) in patient previously treated for Children{\textasciiacute}s interstitial lung disease (chILD) and to investigate the association between nadir SpO2 and pulmonary function.Method: A cross sectional study in patients previously treated for biopsy verified chILD conditions utilizing HCT as a surrogate assessment of inflight saturation. HCT was performed with the patient seated breathing a gas mixture of 15\% oxygen in nitrogen through a tight-fitting mask. SpO2\<90\% was considered abnormal according to BTS guideline (Thorax 2011; 66:i1-i30). Prior to HCT lung function was measured by spirometry and diffusing capacity for monoxide (DLCO).Results: Thirty-one patients (20 males) with a mean age of 14 years (range 8-27) and biopsy verified chILD were included. Diagnoses were hypersensitivity pneumonitis (n=11), post infectious diffuse lung disease (n=8), neuroendocrine cell hyperplasia of infancy (n=2) and non-specific chILD (n=11). Median(range) zFEV1:-1.4 (-3.7;1.7), zFVC: -0.7 (-2.9;1.9), zTLC: -0.8 (-2.9;2.9, zDLCO: -0.7 (-4.5;2.3) and zDLCO/VA: 0.4 (-2.4;3.0). FEV1, FVC, TLC and DLCO were abnormal (\<-1.64 z-score) in 42\%, 16\%, 29\% and 23\% of patients.Median(range) SpO2 at baseline was 98(93{\textendash}100)\%. Desaturation \<90\% occurred in 35\% of patients (n=11) during HCT with median (range) nadir SpO2: 88(82-89)\%. Nadir SpO2\% during HCT was correlated with baseline SpO2\% (room air), p\<0.01, R2=0.32 but not with zFEV1, zDLCO, zDLCO/VA or zTLC.Conclusion: A substantial proportion of patients previously treated for biopsy verified chILD conditions desaturated during HCT, partly explained by baseline saturation but without any relation to lung function.FootnotesCite this article as: European Respiratory Journal 2019; 54: Suppl. 63, PA393.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/54/suppl_63/PA393}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }