IMPACT OF TWO PRE-HAEMOPOIETIC STEM CELL TRANSPLANTATION LUNG FUNCTION TESTS ON BASELINE MEASUREMENT QUALITY IN PAEDIATRIC PATIENTS

Abstract

Introduction/Aim: Pulmonary complications are common and a major cause of morbidity and mortality in patients undergoing HSCT. Accurate baseline lung function tests (LFTs) are essential for detecting posttransplantation deterioration. However, many children undergoing HSCT have no prior experience with LFTs, potentially affecting test quality. This study aims to evaluate whether two separate LFT visits before HSCT leads to improved test quality and more reliable baseline measurements. Method: In July 2023, a protocol requiring two pre-HSCT LFT visits was implemented at the Queensland Children's Hospital. This retrospective analysis includes spirometry (≥5 years), body plethysmography (Pleth) and diffusing capacity (DLCOc; both ≥8 years, corrected for haemoglobin). Subjects were excluded if unwell during or between visits (based on scientist comments and electronic medical records). Two independent respiratory scientists rated test quality using the ATS/ERS 2019 grading system.1 Paired t-tests and chi-squared analyses were used to compare results between first and second visits. Results: Ten subjects (mean age: 11.7 (5.5;5.4-17.3) years, 40% female) completed two LFT visits without intervening illness. The first and second visit occurred a median of 29 and 18 days before HSCT, respectively. Eight (80%) were naïve to LFTs at first visit. Improvements in feasibility were observed for both spirometry and Pleth. Mean (SD) differences in FEV1, TLC and DLCOc were 0.02 (0.21), 0.05 (0.28) and 0.55 (0.75), respectively with the difference approaching statistical significance for DLCOc (p = 0.07). Conclusion: Preliminary results suggest that scheduling two pre-HSCT LFT visits may improve test feasibility and potentially enhance baseline lung function results. Ongoing research will further investigate which patient characteristics benefit most from a second visit.