Effect of oxygen in obstructive sleep apnea: Role of loop gain

Wellman, Andrew; Malhotra, Atul; Jordan, Amy S.; Stevenson, Karen; Gautam, Shiva; White, David P.

doi:10.1016/j.resp.2008.05.019

Cited by 215 publications

(165 citation statements)

References 32 publications

Supporting

Mentioning

152

Contrasting

Unclassified

Order By: Relevance

“…In a recent meta-analysis of the effects of oxygen therapy in over 300 OSA patients, Mehta et al 30 demonstrated that oxygen reduced the AHI by 20% (18% to 28% interquartile range). Similarly, our previous work 22 demonstrated that oxygen therapy reduced the AHI by 33%, with 2 of 12 patients (17%) being considered responders using the definition used in the current study. Furthermore, we have shown 23 that the hypnotic eszopiclone reduced the AHI by a similar magnitude as oxygen (22%), with 2 of 17 patients (12%) considered responders.…”

Section: Combining Oxygen and A Hypnotic Has An Additive Effect In Resupporting

confidence: 79%

“…22,26 Furthermore, we observed a significant correlation between the reduction in loop gain and the reduction in OSA severity, suggesting that those who had the greatest decrease in loop gain benefit substantially from combination therapy. This finding supports a causal role for loop gain in OSA pathogenesis and suggests that maximally lowering loop gain will likely resolve OSA in patients with relatively "good" passive anatomy/collapsibility and a small physiological "gap."…”

Section: Altering Loop Gainmentioning

confidence: 65%

“…For instance, the non-anatomical traits can be targeted with oxygen or acetazolamide to reduce loop gain 21,22 or hypnotics to raise the arousal threshold. 23,24 Such monotherapies typically result in an improvement but rarely a complete resolution of OSA, because (1) the anatomical deficiency is too severe (i.e., a highly collapsible airway), (2) the effects of these therapies on individual traits are not large enough, or (3) more likely, manipulation of a single trait is not adequate to overcome the multifactorial nature of this disorder.…”

Section: Significancementioning

confidence: 99%

“…Doses were chosen based on our previously published data examining the effect of these individual therapies. 22,23,26 During the placebo arm, subjects took a placebo at bedtime and were placed on room air while they slept. Participants then had approximately a 1-w washout period prior to crossover to the other arm of the study, whereby the clinical and research PSGs were repeated.…”

Section: Experimental Designmentioning

confidence: 99%

See 3 more Smart Citations

The Combination of Supplemental Oxygen and a Hypnotic Markedly Improves Obstructive Sleep Apnea in Patients with a Mild to Moderate Upper Airway Collapsibility

Edwards

Sands

Owens

et al. 2016

Sleep

Self Cite

103

View full text Add to dashboard Cite

Study Objectives: Obstructive sleep apnea (OSA) results from the interaction of several physiological traits; specifically a compromised upper airway anatomy and muscle function, and two key non-anatomical deficits: elevated loop gain and a low arousal threshold. Although continuous positive airway pressure (CPAP) is an efficacious treatment, it is often poorly tolerated. An alternative approach could involve administering therapies targeting the nonanatomic causes. However, therapies (oxygen or hypnotics) targeting these traits in isolation typically improve, but rarely resolve OSA. Therefore, our aim was to determine how the combination of oxygen and eszopiclone alters the phenotypic traits and OSA severity and to assess the baseline phenotypic characteristics of responders/nonresponders to combination therapy. Methods: In a single-blinded randomized crossover study, 20 OSA patients received combination therapy (3 mg eszopiclone and 40% oxygen) versus placebo/sham air, with 1 w between conditions. Under each condition, we assessed the effects on OSA severity (clinical polysomnography) and the phenotypic traits causing OSA using CPAP manipulations (research polysomnography). Results: Combination therapy reduced the apnea-hypopnea index (51.9 ± 6.2 vs. 29.5 ± 5.3 events/h; P < 0.001), lowered both the ventilation associated with arousal (5.7 ± 0.3 vs. 5.2 ± 0.3 L/min; P = 0.05) and loop gain (3.3 ± 0.5 vs. 2.2 ± 0.3; P = 0.025). Responders to therapy (apnea-hypopnea index reduced by > 50% to below 15 events/h; n = 9/20) had less severe OSA (P = 0.001), a less collapsible upper airway (P = 0.01) and greater upper airway muscle effectiveness (P = 0.002). Conclusions:The combination of lowering loop gain and raising the arousal threshold is an effective therapy in patients whose anatomy is not severely compromised. Our work demonstrates that combining therapies that target multiple traits can resolve OSA in selected individuals.

show abstract

Section: Combining Oxygen and A Hypnotic Has An Additive Effect In Resupporting

confidence: 79%

Section: Altering Loop Gainmentioning

confidence: 65%

Section: Significancementioning

confidence: 99%

Section: Experimental Designmentioning

confidence: 99%

See 2 more Smart Citations

The Combination of Supplemental Oxygen and a Hypnotic Markedly Improves Obstructive Sleep Apnea in Patients with a Mild to Moderate Upper Airway Collapsibility

Edwards

Sands

Owens

et al. 2016

Sleep

Self Cite

103

View full text Add to dashboard Cite

show abstract

“…Their concept of OSA phenotyping raises the opportunity for alternatives to continuous positive airway pressure (CPAP) in reducing AHI in selected patients, such as oxygen supply and/or acetazolamide lowering the loop gain and hypnotics elevating the arousal threshold. [20][21][22] We did not directly compare our approach to measures and interventions available only in a physiologic laboratory nor have we estimated these specific phenotypes, but instead demonstrate how signals usually available in clinical polysomnography can be informative. Although the treatment effects were not examined in our current study, one might predict that those who showed greater change in ventilation and in PaCO 2 back and forth between sleep and wakefulness, and showed NREM-predominant apneic events might be able to be treated effectively with oxygen supplement therapy and/or hypnotic agents.…”

Section: Discussionmentioning

confidence: 99%

Nonrapid Eye Movement-Predominant Obstructive Sleep Apnea: Detection and Mechanism

Yamauchi

Fujita

Kumamoto

et al. 2015

Journal of Clinical Sleep Medicine

View full text Add to dashboard Cite

Study Objectives: Obstructive sleep apnea (OSA) can be severe and present in higher numbers during rapid eye movement (REM) than nonrapid eye movement (NREM) sleep; however, OSA occurs in NREM sleep and can be predominant. In general, ventilation decreases an average 10% to 15% during transition from wakefulness to sleep, and there is variability in just how much ventilation decreases. As dynamic changes in ventilation contribute to irregular breathing and breathing during NREM sleep is mainly under chemical control, our hypothesis is that patients with a more pronounced reduction in ventilation during the transition from wakefulness to NREM sleep will have NREM-predominant rather than REM-predominant OSA. Methods: A retrospective analysis of 451 consecutive patients (apnea-hypopnea index [AHI] > 5) undergoing diagnostic polysomnography was performed, and breath-tobreath analysis of the respiratory cycle duration, tidal volume, and estimated minute ventilation before and after sleep onset were examined. Values were calculated using respiratory inductance plethysmography. The correlation between the percent change in estimated minute ventilation during wakesleep transitions and the percentage of apnea-hypopneas in NREM sleep (%AHI in NREM; defi ned as (AHI-NREM) / [(AHI-NREM) + (AHI-REM)] × 100) was the primary outcome. Results: The decrease in estimated minute ventilation during wake-sleep transitions was 15.0 ± 16.6% (mean ± standard deviation), due to a decrease in relative tidal volume. This decrease in estimated minute ventilation was signifi cantly correlated with %AHI in NREM (r = −0.222, p < 0.01). 1,2 In general, upper airway obstruction and hypopnea is in REM sleep when upper airway muscle tonus is decreased as compared to nonrapid eye movement (NREM) sleep. However, OSA occurring predominantly in NREM sleep or equally in a numeric manner in both REM and NREM sleep is also encountered in clinical practice; neither prevalence nor mechanisms driving the relative distribution of REM and NREM events have been considered in any detail. In NREM sleep, detailed physiologic studies detect dynamic changes in ventilatory control during state transitions, which are considered to induce irregular breathing, and lead to obstructive apnea and/or hypopnea. [3][4][5][6][7] Detailed studies in REM sleep are absent, leaving an opportunity for the clinical polysomnogram to inform not only REM-predominant OSA but the possibility of NREM predominant OSA as well. ConclusionsVentilation decreases an average of 10% to 15% during the transition from wakefulness to sleep due mainly to a decrease in tidal volume; however, the literature reports substantial

show abstract

International Consensus Statement on Obstructive Sleep Apnea

Chang

Goldberg

Alt

et al. 2023

Int Forum Allergy Rhinol

Self Cite

View full text Add to dashboard Cite

Background: Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA). Methods: Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidencebased review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus. Results: The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated. Conclusion:This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

show abstract

Effect of oxygen in obstructive sleep apnea: Role of loop gain

Cited by 215 publications

References 32 publications

The Combination of Supplemental Oxygen and a Hypnotic Markedly Improves Obstructive Sleep Apnea in Patients with a Mild to Moderate Upper Airway Collapsibility

The Combination of Supplemental Oxygen and a Hypnotic Markedly Improves Obstructive Sleep Apnea in Patients with a Mild to Moderate Upper Airway Collapsibility

Nonrapid Eye Movement-Predominant Obstructive Sleep Apnea: Detection and Mechanism

International Consensus Statement on Obstructive Sleep Apnea

Contact Info

Product

Resources

About