Quantifying the ventilatory control contribution to sleep apnoea using polysomnography

Terrill, Philip I., Edwards, Bradley A., Nemati, Shamim, Butler, James P., Owens, Robert L., Eckert, Danny J., White, David P., Malhotra, Atul, Wellman, Andrew and Sands, Scott A. (2014) Quantifying the ventilatory control contribution to sleep apnoea using polysomnography. European Respiratory Journal, 45 2: 408-418. doi:10.1183/09031936.00062914

Author Terrill, Philip I.
Edwards, Bradley A.
Nemati, Shamim
Butler, James P.
Owens, Robert L.
Eckert, Danny J.
White, David P.
Malhotra, Atul
Wellman, Andrew
Sands, Scott A.
Title Quantifying the ventilatory control contribution to sleep apnoea using polysomnography
Journal name European Respiratory Journal   Check publisher's open access policy
ISSN 1399-3003
Publication date 2014-10-16
Year available 2014
Sub-type Article (original research)
DOI 10.1183/09031936.00062914
Open Access Status
Volume 45
Issue 2
Start page 408
End page 418
Total pages 11
Place of publication Lausanne, Switzerland
Publisher European Respiratory Society
Collection year 2015
Language eng
Formatted abstract
Elevated loop gain, consequent to hypersensitive ventilatory control, is a primary nonanatomical cause of obstructive sleep apnoea (OSA) but it is not possible to quantify this in the clinic. Here we provide a novel method to estimate loop gain in OSA patients using routine clinical polysomnography alone. We use the concept that spontaneous ventilatory fluctuations due to apnoeas/hypopnoeas (disturbance) result in opposing changes in ventilatory drive (response) as determined by loop gain (response/disturbance). Fitting a simple ventilatory control model (including chemical and arousal contributions to ventilatory drive) to the ventilatory pattern of OSA reveals the underlying loop gain.

Following mathematical-model validation, we critically tested our method in patients with OSA by comparison with a standard (continuous positive airway pressure (CPAP) drop method), and by assessing its ability to detect the known reduction in loop gain with oxygen and acetazolamide.

Our method quantified loop gain from baseline polysomnography (correlation versus CPAP-estimated loop gain: n = 28; r = 0.63, p<0.001), detected the known reduction in loop gain with oxygen (n = 11; mean±SEM change in loop gain (ΔLG) −0.23±0.08, p = 0.02) and acetazolamide (n = 11; ΔLG −0.20±0.06, p = 0.005), and predicted the OSA response to loop gain-lowering therapy.

We validated a means to quantify the ventilatory control contribution to OSA pathogenesis using clinical polysomnography, enabling identification of likely responders to therapies targeting ventilatory control.
Keyword Sleep apnoea
Elevated loop gain
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published online before print October 16, 2014

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2015 Collection
School of Information Technology and Electrical Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 7 times in Thomson Reuters Web of Science Article | Citations
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Created: Fri, 17 Oct 2014, 17:51:43 EST by Dr Philip Terrill on behalf of School of Information Technol and Elec Engineering