ArticleAnnals of the American Thoracic Society2015
Clinical Use of Loop Gain Measures to Determine Continuous Positive Airway Pressure Efficacy in Patients with Complex Sleep Apnea. A Pilot Study.
Article in Annals of the American Thoracic Society, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 33 papers, 1 of them a synthesis that pooled it.
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Who cites it
33 citing papers in PubMed, 1 synthesis or guideline pooled it, 60 citations in OpenAlex.
- Association of alternative polysomnographic features with patient outcomes in obstructive sleep apnea: a systematic review.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2023Pooled it
- Trial
- Trial
- Quantification of ventilatory control in sleep apnea: from physiological insight to computable loop gain.Sleep · 2026Review
- Unraveling sleep apnea dynamics: quantifying loop gain using dynamical modeling of ventilatory control.Sleep · 2026Article
- Expert-level probabilistic breathing event detector informs phenotyping of sleep apnea.Nature communications · 2026Article
- Loop Gain in Obstructive Sleep Apnea: From Physiological Endotype to Clinical Translation.Nature and science of sleep · 2026Review
- Uncontrolled Hypertension from Inappropriate Ventilator Settings in Obstructive Sleep Apnea: A Case Report.Nature and science of sleep · 2026Article
- Obstructive Sleep Apnea Endophenotypes.Sleep science (Sao Paulo, Brazil) · 2025Review
- Treatment-emergent central sleep apnea resolves with lower inspiratory pressure.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2025Article
- Novel physiologic predictors of positive airway pressure effectiveness (NICEPAP) study: rationale, design and methods.Sleep & breathing = Schlaf & Atmung · 2024Observational
- The Present and Future of the Clinical Use of Physiological Traits for the Treatment of Patients with OSA: A Narrative Review.Journal of clinical medicine · 2024Review
- Continuous positive airway pressure and adherence in patients with different endotypes of obstructive sleep apnea.Journal of sleep research · 2024Article
- Article
- The prevalence of treatment-emergent central sleep apnea with mandibular advancement device therapy.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2023Article
- Review
- Enhanced expiratory rebreathing space for high loop gain sleep apnea treatment.Frontiers in sleep · 2023Review
- Sleep apnea endotypes: from the physiological laboratory to scalable polysomnographic measures.Frontiers in sleep · 2023Article
- Point-of-care prediction model of loop gain in patients with obstructive sleep apnea: development and validation.BMC pulmonary medicine · 2022Article
- A longitudinal study of the accuracy of positive airway pressure therapy machine-detected apnea-hypopnea events.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2022Article
Corrections and comments
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Authors and funding
6 authors at 3 institutions in 2 countries.
Funding
Abstract
rationaleMeasures of unstable ventilatory control (loop gain) can be obtained directly from the periodic breathing duty ratio on polysomnography in patients with Cheyne-Stokes respiration/central sleep apnea and can predict the efficacy of continuous positive airway pressure (CPAP) therapy.
objectivesIn this pilot study, we aimed to determine if this measure could also be applied to patients with complex sleep apnea (predominant obstructive sleep apnea, with worsening or emergent central apneas on CPAP). We hypothesized that loop gain was higher in patients whose central events persisted 1 month later despite CPAP treatment versus those whose events resolved over time.
methodsWe calculated the duty ratio of the periodic central apneas remaining on the CPAP titration (or second half of the split night) while patients were on optimal CPAP with the airway open (obstructive apnea index < 1/h). Loop gain was calculated by the formula: LG = 2π/[(2πDR - sin(2πDR)]. Patients were followed on CPAP for 1 month. Post-treatment apnea-hypopnea index and compliance data were recorded from smart cards. MEASUREMENTS AND MAIN
resultsThirty-two patients with complex sleep apnea were identified, and 17 patients had full data sets. Eight patients continued to have a total of more than five events per hour (11.8 ± 0.5/h) (nonresponders). The remaining nine patients had an apnea-hypopnea index less than 5/h (2.2 ± 0.4/h) (responders). Loop gain was higher in the nonresponders versus responders (2.0 ± 0.1 vs. 1.7 ± 0.2, P = 0.026). Loop gain and the residual apnea-hypopnea index 1 month after CPAP were associated (r = 0.48, P = 0.02). CPAP compliance was similar between groups.
conclusionsIn this pilot study, loop gain was higher for patients with complex sleep apnea in whom central apneas persisted after 1 month of CPAP therapy (nonresponders). Loop gain measurement may enable an a priori determination of those who need alternative modes of positive airway pressure.
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