The objective of the present thesis was to determine the use and optimal settings of MI-E therapy while considering patient satisfaction, efficiency and safety. The specific aims were to determine:
- The prevalence and clinical characteristics of children with neurodisability using long-term MI-E therapy.
- The effect of MI-E treatment settings on expiratory flows and safety.
- The influence of MI-E therapy and treatment settings on patient perspectives.
The prevalence of long-term MI-E use in children with neurodisability and the children's opinion on the MI-E treatment was assessed in a cross-sectional study using national registry data, questionnaires and MI-E device memory SD-card data. A simulator study mimicking an infant with NMD evaluated the effect of various MI-E treatment settings on expiratory flows and safety. Thereafter, in a multi-centre, cross-over, within-subject, double-blinded randomised controlled trial where the children were their own controls, we measured the peak cough flow (PCF) with a pneumotach in the MI-E circuit during three different setting strategies. The strategies included a symmetric high-pressure-, an asymmetric-, and a personalised setting. Any adverse events were recorded. A Visual Analogue Scale (VSA) 0-10 (0=most comfortable) assessed the children's perception of MI-E comfort during the MI-E setting strategies.
The overall prevalence of MI-E users in the Norwegian neuropaediatric population was 6 per 1000. MI-E therapy was used from infancy, with two-thirds having NMD and one-third having CNS-conditions. Concomitant ventilatory support was found in 56% of the children.
A setting strategy using high symmetric pressures resulted in the highest MI-E-assisted PCF; however, all three strategies resulted in a median PCF >160 l/min, a therapeutic threshold >12 years. No serious adverse events were recorded.
The MI-E treatment was generally reported as beneficial, with a median(IQR) VAS for the perceived benefit of MI-E therapy at stable state and respiratory tract infection of 9(6-10) and 10(8.5-10), respectively. After MI-E initiation, children with NMD reported fewer hospitalisations. A personalised or asymmetric setting strategy was rated slightly uncomfortable, VAS 2.9 and 3.2, respectively. More comfortable than a high symmetric pressure approach, scored moderately uncomfortable; VAS 4.7 (p0.001).
MI-E therapy was used from infancy in NMD and CNS-conditions with a prevalence of 6 per 1000 children. The cough flows increased with increasing MI-E pressures; however, a symmetrical high-pressure strategy was reported as less comfortable. The treatment was by large perceived as beneficial and was generally safe.
Several MI-E setting strategies may be applied with sufficient comfort and efficacy.
Mechanical assisted cough
Neurodisability
