Pneumologie 2020; 74(S 01): 11
DOI: 10.1055/s-0039-3403078
Freie Vorträge (FV04) – Sektion Schlafmedizin
Freie Vorträge der Sektion Schlafmedizin
Georg Thieme Verlag KG Stuttgart · New York

Daytime respiratory muscle function correlates of nocturnal ventilatory failure and dyspnoea in patients with slowly progressive neuromuscular disorders

J Spießhöfer
1   Respiratory Physiology Laboratory, Department of Neurology with Institute for Translational Neurology, University Hospital Muenster, Germany
,
HJ Kabitz
2   Medizinische Klinik II, Department of Pneumology, Cardiology and Intensive Care Medicine, Klinikum Konstanz, Germany
,
WJ Randerath
3   Klinik für Pneumologie und Allergologie, Zentrum für Schlaf- und Beatmungsmedizin, Krankenhaus Bethanien GmbH
,
SD Herkenrath
4   Institut für Pneumologie an der Universität zu Köln; Klinik für Lungen- und Bronchialerkrankungen, Krankenhaus Bethanien gGmbH
,
M Boentert
5   Department für Neurologie, Klinik für Schlafmedizin und Neuromuskuläre Erkrankungen, Universitätsklinikum Münster
› Author Affiliations
Further Information

Publication History

Publication Date:
28 February 2020 (online)

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Background and objective: Little is known about the pathophysiology of nocturnal ventilatory failure and dyspnoea in slowly progressive neuromuscular disorders (NMD). Therefore, this study explored daytime respiratory muscle function correlates of nocturnal ventilatory failure and dyspnoea in patients with slowly progressive NMD.

Methods: 45 patients with genetically proven slowly progressive NMD (21 myotonic dystrophy type I or II, 14 late-onset pompe disease, 10 facioscapulohumeral dystrophy; 25 men, 20 women; 50 ± 15 years) underwent clinical examination, spirometric lung function testing, manometry (maximal inspiratory -MIP- and expiratory pressure -MEP-), and diaphragm ultrasound. Overnight transcutaneous capnometry (tcCO2) was performed for determination of nocturnal ventilatory failure while dyspnoea was quantified by MRC breathlessness scale.

Results: 7 patients showed nocturnal ventilatory failure (peak tcCO2 ≥ 49 mmHg) at night. Daytime respiratory muscle function correlates of this comprised clinical arm involvement (2.7 ± 1.5 vs. 1.6 ± 1.0 on the functional grading scale for arms, p = 0.01), a trend towards reduced forced vital capacity (FVC, %predicted) (53.2 ± 28.9 vs. 64.9 ± 21.2%, p = 0.084) and a trend towards reduced diaphragm velocity during Voluntary sniff (VS) (3.6 ± 1.8 vs. 5.8 ± 2.5 cm/sec, p = 0.106). ROC analysis revealed that specifity of clinical arm involvement was 69.4% at a value of 1.5. 11 patients complained significant dyspnoea (MRC ≥ 3). Correlates of this comprised a trend towards reduced MIP (37.9 ± 14.4 vs. 52.5 ± 25.7, p = 0.099), reduced diaphragm velocity during VS (4.2 ± 2.3 vs. 6.3 ± 2.3 cm/sec, p = 0.034), reduced maximum diaphragm excursion amplitude (3.8 ± 1.3 vs. 5.5 ± 2.0 cm, p = 0.032) and a trend towards reduced diaphragm thickening ratio (1.70 ± 0.22 vs. 2.00 ± 0.50, p = 0.062).

Conclusions: In slowly progressive NMD nocturnal hypoventilation (NH) is linked to diaphragm dysfunction with restrictive lung function impairment and functional arm disability is a clinical characteristic that identifies patients with NMD at increased risk for NH. The sensation of dyspnoea is closely related to diaphragm function in these patients.