Background: Adherence to airway clearance therapy (ACT) in pediatric cystic fibrosis (CF) patients is reported to be below 50% and inability to sustain daily care is linked to poor health outcomes^7,8,9. Through a collaboration between a CF care center and several schools, we hypothesized that ACT completed at school by pediatric CF patients will improve lung function while decreasing pulmonary exacerbations (PEx), days of antibiotics (abx) and hospitalizations.

Methods: This was a retrospective case-control study at a single CF care center consisting of 50 CF patients age < 18 at time when data was recorded (2012-2020). The case group used high-frequency chest wall oscillation or positive expiratory pressure devices at school for at least 1 year after self-reported or physician identified inadequate use at home. Lung function and measures of healthcare utilization were collected.

Results: In the case group (n = 14), paired t-tests showed that after initiation of ACT at school, there were significant reductions in PEx requiring IV or PO abx (P = 0.010), total days of abx (P = 0.032), and visits to the CF care center (P = 0.037). There was no change in these outcomes in the matched control group (n = 36).

Conclusions: This is the first known study to highlight an initiative between a CF care center and schools which utilized airway clearance devices at school to ensure pediatric CF patients completed ACT. Through increased adherence, this relationship was associated with improved health outcomes. Use of alternative strategies may help patients with CF sustain adequate airway clearance.

Background: Exercise intolerance is present even in the early stages of pulmonary arterial hypertension (PAH) and is associated with poorer prognosis. Respiratory muscle dysfunction is common and may contribute to exercise limitation. We sought to investigate the effects of inspiratory muscle training (IMT) to improve exercise capacity in PAH.

Methods: Adults with PAH were prospectively recruited and randomly assigned to either IMT or a control group. At baseline and after 8 weeks, assessment of respiratory muscle function, pulmonary function, neurohormonal activation, 6-minute walk distance and cardiopulmonary exercise testing variables were conducted. Inspiratory muscle strength was assessed by maximal static inspiratory pressure (PImax). The IMT group performed two cycles of 30 breaths at 30-40% of their PImax 5 days a week for 8 weeks.

Results: Twelve (12) PAH patients (60±14 years, 10 females) were recruited and randomised (six in the IMT group and six in the control group). After 8 weeks, the IMT group improved PImax by 31 cmH₂O compared with 10 cmH₂O in controls, p=0.02. Following IMT, 6-minute walk distance improved by 24.5 m in the IMT group and declined by 12 m in the controls (mean difference 36.5 m, 95% CI 3.5-69.5, p=0.03). There was no difference in peak oxygen uptake between-groups (mean difference 0.4 mL/kg/min, 95% CI -2.6 to 3.4, p=0.77). There was no difference in the mean change between-groups in neurohormonal activation or pulmonary function.

Conclusion: In this pilot randomised controlled study, IMT improved PImax and 6-minute walk distance in PAH patients.

Background: Respiratory training using Threshold Inspiratory Muscle Trainer (IMT) has not been examined adequately in multiple sclerosis (MS). The primary objective in this study of persons with advanced MS was to investigate the training effect of IMT. The secondary objective was to evaluate the retention of IMT benefits.

Methods: This study was a repeated measures within-subject design (before-after trial).. Participants were recruited from a long-term care facility specialized in progressive neurologic conditions. Thirty-six non-ambulatory persons with advanced MS volunteered. Inspiratory muscle exercise using the threshold IMT were performed daily for 10 weeks at 3 sets of 15 repetitions per day. Resistance was progressed weekly based on perceived rate of exertion and symptoms. Primary outcome measures were maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) that were measured at baseline, after 5 and 10 weeks of IMT exercises (training period), and at 4 and 8 weeks after the IMT training ended (retention). Linear mixed-effect regression models with time (i.e. weeks from baseline) as the fixed factor and participants as the random effect factor were applied separately to test each hypothesis. Effect size was calculated using partial eta square (η2p). Two-tailed significance level was p < 0.05.

Results: Participants were 60.5 ± 8.6 years old. Expanded Disability Status Scale was 8.5 ± 0.4. Baseline MIP were 25.9 ± 16.4 cmH2O (33.2% %± 19.8% of predicted values) and MEP were 23.5 ± 15.7 cmH2O (25.8% %± 14.4% of predicted values). Compared to the baseline, MIP increased significantly to 30.1 ± 17.9 cmH2O (38.9% %± 22.4% of predicted values) and 30.6 ± 17.6 cmH2O (39.6% %± 22.3% of predicted values) after 5 (p < 0.05) and 10 weeks (p < 0.05) of IMT exercises. MIP improvements were retained in an 8-week washout period. MEP did not differ significantly by time.

Conclusion: In persons with advanced MS, 10-week IMT training increased inspiratory muscle strength. This study is the first to demonstrate the retention of benefits following daily IMT exercises at 8 weeks after training ended.