Mechanically assisted cough strategies: user perspectives and cough flows in children with neurodisability.

Background: Mechanical insufflation-exsufflation (MI-E) is used to augment cough in children with neurodisability. We aimed to determine the user comfort and cough flows during three MI-E strategies, and to predict factors associated with improved comfort and cough flows. Methods: This multicentre, crossover trial was done at four regional hospitals in Norway. Children with neurodisability using MI-E long term via mask were enrolled. In randomised order, they tested three MI-E setting strategies (in-/exsufflation pressure (cmH2O)/in (In)- versus exsufflation (Ex) time): 1) "A-symmetric" (±50/In=Ex); 2) "B-asymmetric" (+25- +30)/-40, In>Ex); and 3) "C-personalised", as set by their therapist. The primary outcomes were user-reported comfort on a visual analogue scale (VAS) (0=maximum comfort) and peak cough flows (PCF) (L·min-1) measured by a pneumotachograph in the MI-E circuit. Results: We recruited 74 children median (IQR) age 8.1 (4.4-13.8) years, range 0.6-17.9, and analysed 218 MI-E sequences. The mean±sd VAS comfort scores were 4.7±2.96, 2.9±2.44 and 3.2±2.46 for strategies A, B and C, respectively (A versus B and C, p<0.001). The mean±sd PCF registered during strategies A, B and C were 203±46.87, 166±46.05 and 171±49.74 L·min-1, respectively (A versus B and C, p<0.001). Using low inspiratory flow predicted improved comfort. Age and unassisted cough flows increased exsufflation flows. Conclusions: An asymmetric or personalised MI-E strategy resulted in better comfort scores, but lower PCF than a symmetric approach utilising high pressures. All three strategies generated cough flows above therapeutic thresholds and were rated as slightly to moderately uncomfortable.

User-perceived impact of long-term mechanical assisted cough in paediatric neurodisability.

AIM: To (1) compare the perceived benefit of long-term mechanical insufflation-exsufflation (MI-E) of children with neuromuscular disorders (NMDs) and central nervous system (CNS) disorders, including health care needs and treatment routines and (2) describe the children's health-related quality of life (HRQoL). METHOD: This cross-sectional study used a questionnaire and memory card data to assess the perceived benefit of MI-E via the Visual Analogue Scale (VAS; 10 maximum), willingness to pause treatment, level of health care needs before and after MI-E initiation, and the children's treatment routines. A DISABKIDS questionnaire assessed HRQoL (100 maximum). RESULTS: Seventy-three children using MI-E participated (42 males, median [interquartile range {IQR}] age 10 years 2 months [6 years 3 months-14 years 1 month]), 47 with NMDs (such as spinal muscular atrophy and Duchenne muscular dystrophy) and 26 with CNS disorders (such as cerebral palsy, encephalitis, neurometabolic and other diseases). The median (IQR) VAS score for the perceived benefit of MI-E therapy at stable state and respiratory tract infection were 9 (6-10) and 10 (8.5-10) respectively. Sixty-two per cent were reluctant or unwilling to pause MI-E therapy, with no NMD versus CNS disorder group difference. After MI-E initiation, fewer physician consultations and hospitalizations were reported by the group with NMDs. The MI-E routine was similar in both groups. The mean (SD) HRQoL score for 26 of 51 eligible children was 71 (16.7). INTERPRETATION: MI-E treatment was generally perceived as beneficial and performed equally in both diagnostic groups. HRQoL was in line with children with a moderate-to-severe chronic condition. WHAT THIS PAPER ADDS: Mechanical insufflation-exsufflation (MI-E) was generally perceived as beneficial by the children and parents. The reported benefit of MI-E was higher among daily than sporadic MI-E users. The MI-E treatment routine did not differ between diagnostic groups. The health-related quality of life in this neuropaediatric population was in line with that of children with other moderate-to-severe chronic conditions.

Prevalence of long-term mechanical insufflation-exsufflation in children with neurological conditions: a population-based study.

AIM: To determine the prevalence of long-term mechanical insufflation-exsufflation (MI-E) and concomitant mechanical ventilation in children with neurological conditions, with reported reasons behind the initiation of treatment. METHOD: This was a population-based, cross-sectional study using Norwegian national registries and a questionnaire. RESULTS: In total, 114 of 19 264 children with a neurological condition had an MI-E device. Seventy-three of 103 eligible children (31 females, 42 males), median (min-max) age of 10 years 1 month (1y 5mo-17y 10mo), reported their MI-E treatment initiation. Overall, 76% reported airway clearance as the main reason to start long-term MI-E. A prophylactic use was mainly reported by children with neuromuscular disorders (NMDs). Prevalence and age at initiation differed by diagnosis. In spinal muscular atrophy and muscular dystrophies, MI-E use was reported in 34% and 7% of children, of whom 83% and 57% respectively received ventilator support. One-third of the MI-E users were children with central nervous system (CNS) conditions, such as cerebral palsy and degenerative disorders, and ventilator support was provided in 31%. The overall use of concomitant ventilatory support among the long-term MI-E users was 56%. INTERPRETATION: The prevalence of MI-E in a neuropaediatric population was 6 per 1000, with two-thirds having NMDs and one-third having conditions of the CNS. The decision to initiate MI-E in children with neurological conditions relies on clinical judgment. WHAT THIS PAPER ADDS: The prevalence and age at initiation of mechanical insufflation/exsufflation (MI-E) differed between diagnoses. MI-E was most commonly used in spinal muscular atrophy, where it generally coincided with ventilatory support. One-third of MI-E devices were given to children with central nervous system conditions, and one-third also received ventilatory support.

The outcome after severe bronchiolitis is related to gender and virus.

The association between bronchiolitis in the first year of life and subsequent asthma, atopy, airway obstruction and bronchial hyper-responsiveness (BHR) is unsettled. Genetic predispositions, pre-morbid lung function, environmental interactions and altered immunological responses are risk factors that have been studied. The aim of this study was to assess lung function, BHR and the occurrence of asthma and atopy 11 yr after hospitalization for bronchiolitis in the first year of life, particularly focusing on the role of gender and virus involved. The study included 121 of 131 (92%) children hospitalized for bronchiolitis, 90 (74%) respiratory syncytial virus (RSV)-positive children and 141 children in an age-matched and unselected control group. At follow-up, current asthma was more common after RSV-negative bronchiolitis compared to controls (35.5% vs. 9.2%; p < 0.001), but not after RSV bronchiolitis (15.6%; p = 0.144). Higher BHR and an obstructive lung function pattern were observed after bronchiolitis, the latter most prominent after RSV-negative bronchiolitis. Higher BHR was confined to boys, but present in both the RSV-positive and RSV-negative groups (p = 0.007 and 0.003, respectively). Asthma after bronchiolitis was not associated with atopy. Atopy was similarly distributed between the RSV-positive and RSV-negative bronchiolitis groups and the control group. This study has shown that gender and type of virus are important factors to consider when addressing later development of asthma, BHR and lung function after hospitalization for bronchiolitis in early life.