"You're on mute!" Does pediatric CF home spirometry require physiologist supervision?

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic has accelerated the move towards home spirometry monitoring, including in children. The aim of this study is to determine whether the remote supervision of spirometry by a physiologist improves the technical quality and failure rate of the maneuvers. METHOD: Children with cystic fibrosis who had been provided with NuvoAir home spirometers were randomly allocated to either supervised or unsupervised home spirometry following a detailed training session. Home spirometry was performed every 2 weeks for 12 weeks. Tests were assigned a quality factor (QF) using our laboratory grading system as per American Thoracic Society/European Respiratory Society standards, with tests marked from A to D, or Fail. In our laboratory, we aim for QF A in all spirometry tests, but report results of QF B or C with a cautionary note. QF A was, therefore, the primary outcome, and QF A-C, the secondary outcome. RESULTS: Sixty-one patients were enrolled; 166 measurements were obtained in the supervised group, and 153 in the unsupervised group. Significantly more measurements achieved QF A in the supervised compared to unsupervised group (89% vs. 74%; p = <0.001), while proportions reaching Grade A-C were similar (99% vs. 95%; p = 0.1). All significant declines in spirometry results had a clinical rather than technical reason. Family/patient feedback for both arms was very positive. CONCLUSION: These results suggest that home spirometry in children should ideally be remotely supervised by a physiologist, but acceptable results can be obtained if resources do not allow this, provided that training is delivered and results monitored according to our protocol.

The Young Everest Study: preliminary report of changes in sleep and cerebral blood flow velocity during slow ascent to altitude in unacclimatised children.

BACKGROUND: Cerebral blood flow velocity (CBFV) and sleep physiology in healthy children exposed to hypoxia and hypocarbia are under-researched. AIM: To investigate associations between sleep variables, daytime end-tidal carbon dioxide (EtCO2) and CBFV in children during high-altitude ascent. METHODS: Vital signs, overnight cardiorespiratory sleep studies and transcranial Doppler were undertaken in nine children (aged 6-13 years) at low altitude (130 m), and then at moderate (1300 m) and high (3500 m) altitude during a 5-day ascent. RESULTS: Daytime (130 m: 98%; 3500 m: 90%, p=0.004) and mean (130 m: 97%, 1300 m: 94%, 3500: 87%, p=0.0005) and minimum (130 m: 92%, 1300 m: 84%, 3500 m: 79%, p=0.0005) overnight pulse oximetry oxyhaemoglobin saturation decreased, and the number of central apnoeas increased at altitude (130 m: 0.2/h, 1300 m: 1.2/h, 3500 m: 3.5/h, p=0.2), correlating inversely with EtCO2 (R(2) 130 m: 0.78; 3500 m: 0.45). Periodic breathing occurred for median (IQR) 0.0 (0; 0.3)% (130 m) and 0.2 (0; 1.2)% (3500 m) of total sleep time. At 3500 m compared with 130 m, there were increases in middle (MCA) (mean (SD) left 29.2 (42.3)%, p=0.053; right 9.9 (12)%, p=0.037) and anterior cerebral (ACA) (left 65.2 (69)%, p=0.024; right 109 (179)%; p=0.025) but not posterior or basilar CBFV. The right MCA CBFV increase at 3500 m was predicted by baseline CBFV and change in daytime SpO2 and EtCO2 at 3500 m (R(2) 0.92); these associations were not seen on the left. CONCLUSIONS: This preliminary report suggests that sleep physiology is disturbed in children even with slow ascent to altitude. The regional variations in CBFV and their association with hypoxia and hypocapnia require further investigation.

Treatment of mucopolysaccharidosis type II (Hunter syndrome) with idursulfase: the relevance of clinical trial end points.

The current treatment of mucopolysaccharidosis type II (MPS II, Hunter syndrome) is enzyme replacement therapy with recombinant idursulfase (Elaprase®). The efficacy of ERT was established based primarily on reduction in urine glycosaminoglycans:creatinine (GAG:Cr) ratio and improvement in a composite score of predicted forced vital capacity (FVC% predicted) and 6-min walk-test distance (6MWT). We retrospectively reviewed these parameters in 11 boys with MPS II treated with idursulfase between April 2007 (or the time of diagnosis) and February 2010. Some results were inconsistent with published trial data, and there was only a small number of analyzable results obtained for the FVC% predicted and 6MWT. A major drawback was the high prevalence of neurological involvement and young age of patients in the study cohort compared with the clinical trials. This study emphasizes the limitations of the current tools utilized to monitor ERT efficacy and MPS II disease burden in clinical practice.