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

Brit Hov; Tiina Andersen; Michel Toussaint; Ingvild B Mikalsen; Maria Vollsæter; Cathrine Brunborg; Mathea Hovde; Vegard Hovland

doi:10.1183/23120541.00274-2023

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

ERJ Open Res. 2024 Jan 8;10(1):00274-2023. doi: 10.1183/23120541.00274-2023. eCollection 2024 Jan.

Authors

Brit Hov^{1

2}, Tiina Andersen^{3

4}, Michel Toussaint⁵, Ingvild B Mikalsen^{6

7}, Maria Vollsæter^{7

8}, Cathrine Brunborg⁹, Mathea Hovde¹⁰, Vegard Hovland¹

Affiliations

¹ Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway.
² Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
³ Norwegian Advisory Unit on Long-term Mechanical Ventilation, Thoracic Department, Haukeland University Hospital, Bergen, Norway.
⁴ The Faculty of Health and Social Sciences, Western Norway University of Applied Science, Bergen, Norway.
⁵ Centre de Référence Neuromusculaire, Department of Neurology, CUB Hôpital Erasme, Hôpital Universitaire de Bruxelles, Université libre de Bruxelles, Brussels, Belgium.
⁶ Department of Paediatric Medicine, Stavanger University Hospital, Stavanger, Norway.
⁷ Department of Clinical Science, University of Bergen,Bergen, Norway.
⁸ Department of Paediatrics, Haukeland University Hospital, Bergen, Norway.
⁹ Oslo Centre for Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway.
¹⁰ Clinic of Rehabilitation, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.

Abstract

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.