Upper Airway Obstruction in Snoring and Upper Airway Resistance Syndrome

RationaleUpper airway resistance is critical to the pathophysiology of obstructive sleep apnea (OSA). We have previously characterized a subset of patients with OSA who have evidence of reversible upper airways resistance as measured by spirometry. Specifically, these patients have an increased FEF50/FIF50 ratio which decreases with administration of a short acting bronchodilator. On average these patients had a lower BMI (average 27) compared to OSA patients as a whole suggesting the possibility of unique upper airway pathophysiology among this group. In the current study, we identify additional patients with OSA who have reversible upper airways obstruction on spirometry and characterize their compliance with CPAP therapy as compared to a traditional OSA population.MethodsWe retrospectively evaluated patients who had a sleep screen suggestive of OSA in the last 2 years. Patients who also had spirometry in the previous 5 years were identified for further analysis. Those patients with either normal spirometry or fixed obstructive defects who had a decrease in the FEF50/FIF50 ratio after administration of a short acting inhaled beta agonist (albuterol) were then characterized. We then measured objective CPAP adherence using data downloaded from the positive airway pressure device with adherence defined as CPAP use >4 hrs more than 70% of nights over a 30 day period.ResultsWe identified 70 patients with positive sleep screens who also had spirometry demonstrating normal of fixed lower expiratory obstruction with evidence of upper airways obstruction as demonstrated by a decreased FEF50/FIF50 ratio. Of these, 45 had a decrease in the FEF50/FIF50 ratio of more than 20% following administration of inhaled albuterol. Overall, CPAP adherence between those with reversible upper airways obstruction and those without was similar (23/45=51% vs 14/26=54%). However, subgroup analysis revealed a lower adherence rate among non-obese patients (BMI<30) with reversible airways obstruction (6/16=36%).ConclusionThe identification of a subset of patients with OSA who have evidence of decreased upper airway resistance in response to inhaled bronchodilator suggests unique pathology in this group. Decreased adherence to traditional OSA therapy with CPAP among these patients is additional evidence of differential pathophysiology requiring novel treatments. Specifically, treatment with a long acting beta agonist (LABA) prior to sleep may reduce upper airway obstruction and be better tolerated than CPAP.

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Silent Upper Airway Resistance Syndrome: Prevalence in a Mixed Military Population

Yearbook of Pulmonary Disease ◽

10.1016/s8756-3452(08)70179-8 ◽

2006 ◽

Vol 2006 ◽

pp. 219-220

Author(s):

B.A. Phillips

Keyword(s):

Airway Resistance ◽

Upper Airway ◽

Military Population ◽

Upper Airway Resistance Syndrome ◽

Upper Airway Resistance

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Upper Airway Resistance Syndrome: a Combined ENT and Dental Approach

Current Otorhinolaryngology Reports ◽

10.1007/s40136-021-00354-6 ◽

2021 ◽

Author(s):

Kenny P. Pang ◽

Edward B. Pang

Keyword(s):

Airway Resistance ◽

Upper Airway ◽

Upper Airway Resistance Syndrome ◽

Upper Airway Resistance

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391 Upper Airway Resistance Syndrome is associated with high Cyclic Alternating Pattern

SLEEP ◽

10.1093/sleep/zsab072.390 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A155-A156

Author(s):

Luciana Godoy ◽

Letícia Soster ◽

Clarissa Bueno ◽

Sonia Togeiro ◽

Dalva Poyares ◽

...

Keyword(s):

Airway Resistance ◽

Upper Airway ◽

Sleep Fragmentation ◽

Control Group ◽

Flow Limitation ◽

Upper Airway Resistance Syndrome ◽

Arousal Index ◽

Upper Airway Resistance ◽

Cyclic Alternating Pattern ◽

Cap Rate

Abstract Introduction Upper Airway Resistance Syndrome (UARS) is suspected in individuals with excessive daytime sleepiness, fatigue, and sleep fragmentation associated with increased respiratory effort. UARS can negatively impact daytime function. Conventional polysomnography parameters do not demonstrate significant abnormalities in UARS patients but increase in RERAs and arousal index. Cyclic alternating pattern (CAP) is a periodic electroencephalogram activity of non-REM sleep that expresses a condition of sleep instability. The objective of the study was to compare CAP components between UARS patients and health individuals. Methods Fifteen subjects with UARS and 15 age- and sex- matched controls had their sleep study blinded analyzed. UARS criteria were the presence of sleepiness (Epworth Sleepiness Scale – ESS - ≥ 10) and/or fatigue (Modified Fatigue Impact Scale ≥ 38) associated with an apnea/hypopnea index (AHI) ≤ 5 and a respiratory disturbance index (RDI) > 5 events/hour of sleep, and/or flow limitation in more than 30% of total sleep time. Control group criteria were AHI < 5 events/hour, RDI ≤ 5 events/hour and < 30% of TST with flow limitation and ESS < 10, without sleep, clinical, neurological, or psychiatric disorder. CAP electroencephalogram of both groups was analyzed. Results We found higher CAP rate (p = 0.05) and CAP index in N1 stage (p < 0.001) and in N3 stage (p < 0.001) in UARS patients compared to control group. Considering only CAP phase A1 analysis, UARS patients presented higher CAP rate (p = 0.05) and CAP index in N1 stage (p < 0.001) as well as CAP index in N3 stage (p < 0.001) compared to control group. Considering only CAP phase A2 analysis, UARS patients also presented higher number of CAP in N1 stage (p = 0.05). There was no significant difference for CAP phase A3 between groups. Conclusion Although UARS is associated with high arousal index, we found increase in CAP phase A1 and A2, which do not include necessarily AASM arousals, suggesting not only sleep fragmentation but also sleep instability. Support (if any) Associação Fundo de Incentivo à Pesquisa (AFIP) and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).

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