Multiple breath washout and oscillometry after allogenic HSCT: a scoping review

Abstract

Pulmonary chronic graft-versus-host disease (cGVHD) is a substantial cause of pulmonary morbidity and mortality post-haematopoietic stem cell transplantation (HSCT). Current spirometry-based monitoring strategies have significant limitations. Understanding the utility of novel peripheral airway function tests – multiple breath washout (MBW) and oscillometry – is critical in efforts to improve detection, facilitate earlier intervention and improve outcomes. In this scoping review, we identified 17 studies investigating MBW or oscillometry, or both, after allogenic HSCT. Despite small study numbers limiting the ability to draw firm conclusions, several themes were evident. Detectable peripheral airway abnormality in MBW occurred in a substantial proportion prior to HSCT. MBW indices post-HSCT were more frequently abnormal than spirometry when reporting group data and among those with extrapulmonary cGVHD and pulmonary cGVHD. Changes in MBW indices over time may be more indicative of pulmonary complications than absolute values at any given time point. Oscillometry indices were often normal at baseline, but more frequently abnormal in those who developed pulmonary cGVHD. Pooling currently available individual participant data across these studies may improve our ability to formally compare their respective sensitivity and specificity at specific time points and assess the trajectory of MBW and oscillometry indices over time.

Risk factors predicting need for the pediatric intensive care unit (PICU) post-hematopoietic cell transplant, PICU utilization, and outcomes following HCT: a single center retrospective analysis

“…Due to the need for patients to be developmentally capable of participating in PFTs, which generally are difficult to perform in children under 6 years of age, alternative measurements are being explored. Some of these include airway oscillometry (which is performed during normal tidal volume breathing, and therefore does not require the same level of participation) and multiple breath washout to determine lung clearance index (a testing modality that requires only tidal breathing), which are being evaluated in TRANSPIRE and are important for future study in this cohort ( 15 , 20 , 21 ). Despite our limited PFT data, there is a paucity of this data published in the HCT population, and having serial PFTs for some HCT patients is a strength of our study.…”