Drug-induced sleep endoscopy improves intervention efficacy among patients treated for obstructive sleep apnea with a mandibular advancement device.

PURPOSE: To compare the short-term treatment effect of a mandibular advancement device (MAD) with and without previous drug-induced sleep endoscopy (DISE) on polysomnography (PSG) and other sleep apnea-related treatment outcomes (Short Form Health Survey [SF-36] and Epworth Sleepiness Scale [ESS]) among adults with mild, moderate, and severe obstructive sleep apnea (OSA). We hypothesized that using DISE would improve the efficacy of MADs on the sleep apnea parameters. METHODS: The study sample consisted of patients with OSA who were unable or unwilling to tolerate a CPAP device, divided into an experimental (with DISE) and a control (without DISE) group. RESULTS: Of 50 patients with OSA, 40 men (80%), mean age was 48.8 ± 12,3 years. The mean apnea-hypopnea index (AHI) score of both groups decreased significantly between baseline and the 8-week follow-up titration PSG with MAD in situ, from 31.7 ± 17.3 (mean ± SD) apnea-hypopnea episodes/h to 7.0 ± 6.4/h (p < 0.0001) in the experimental group, and from 22.5 ± 16.6 episodes/h to 11.4 ± 8.0/h (p < 0.024) in the control group. Capillary oxygen saturation (SpO2) levels did not change significantly between the two timepoints for either group. The SF-36 (p < 0.023) and ESS (p < 0.036) results of both groups improved significantly between baseline and the 8-week follow-up after starting MAD treatment; however, the improvement in quality of life was significantly more pronounced in the experimental group than in the control group (p < 0.0001). CONCLUSION: DISE provides a significant benefit to patients with OSA undergoing MAD treatment. It can be used as a valuable prediction tool in clinical practice for the management of patients with OSA, even those with moderate and severe disease.

Regulation of breathing pattern by IL-10.

Proinflammatory cytokines like interleukin-1ß (IL-1ß) affect the control of breathing. Our aim is to determine the effect of the anti-inflammatory cytokine IL-10 οn the control of breathing. IL-10 knockout mice (IL-10-/-, n = 10) and wild-type mice (IL-10+/+, n = 10) were exposed to the following test gases: hyperoxic hypercapnia 7% CO2-93% O2, normoxic hypercapnia 7% CO2-21% O2, hypoxic hypercapnia 7% CO2-10% O2, and hypoxic normocapnia 3% CO2-10% O2. The ventilatory function was assessed using whole body plethysmography. Recombinant mouse IL-10 (rIL-10; 10 µg/kg) was administered intraperitoneally to wild-type mice (n = 10) 30 min before the onset of gas challenge. IL-10 was administered in neonatal medullary slices (10-30 ng/ml, n = 8). We found that IL-10-/- mice exhibited consistently increased frequency and reduced tidal volume compared with IL-10+/+ mice during room air breathing and in all test gases (by 23.62 to 33.2%, P < 0.05 and -36.23 to -41.69%, P < 0.05, respectively). In all inspired gases, the minute ventilation of IL-10-/- mice was lower than IL-10+/+ (by -15.67 to -22.74%, P < 0.05). The rapid shallow breathing index was higher in IL-10-/- mice compared with IL-10+/+ mice in all inspired gases (by 50.25 to 57.5%, P < 0.05). The intraperitoneal injection of rIL-10 caused reduction of the respiratory rate and augmentation of the tidal volume in room air and also in all inspired gases (by -12.22 to -29.53 and 32.18 to 45.11%, P < 0.05, respectively). IL-10 administration in neonatal rat (n = 8) in vitro rhythmically active medullary slice preparations did not affect either rhythmicity or peak amplitude of hypoglossal nerve discharge. In conclusion, IL-10 may induce a slower and deeper pattern of breathing.

Temporal instability of the post-surgical maxillary sinus microbiota.

BACKGROUND: Chronic rhinosinusitis is an inflammatory disorder in which the role of bacteria remains uncertain. While sinus outflow obstruction is often an initiating event, mucosal inflammation and dysbiosis may persist or develop in sinuses with widely patent surgical openings. Understanding of the relationship between dysbiosis and chronic sinus inflammation is obfuscated by inter-individual microbiota variability and likely intra-individual temporal variation that has yet to be defined. In this study, long-term microbiota stability is investigated within surgically-opened maxillary sinuses of individuals with and without sinus inflammatory disease. METHODS: Maxillary sinus swabs were performed in 35 subjects with longstanding maxillary antrostomies. Subjects with and without active chronic maxillary sinusitis were included. Repeat swabs were obtained from the same sinuses after a prolonged interval (mean 719 ± 383 days). Patients were categorized based on the inflammatory status of the sinus mucosa at times of sample collection, as assessed by nasal endoscopy. Total DNA from swab eluents was extracted, and the microbiota characterized using 16S rRNA gene sequencing followed by taxonomic classification. Prevalence and abundance of genera were determined by analysis of 16S rRNA gene sequences. Taxa were identified that were stably present between two time points in individual subjects. RESULTS: The overall proportion of stable taxa across time points was 24.5 ± 10.6%. This stability index was consistent across patient groups and not correlated with clinical parameters. Highly prevalent taxa, including Staphylococcus, Corynebacterium, Propionibacterium, and Pseudomonas, were often stably present, but varied in relative abundance. Janthinobacterium, Enterobacter, Lactobacillus, and Acinetobacter were prevalent and moderately abundant taxa in healthy sinuses, but not in inflamed sinuses. Moraxella and Haemophilus were present at low prevalence and proportional abundance in chronically or intermittently inflamed sinuses, but not in healthy sinuses. CONCLUSIONS: A relatively small component of the post-antrostomy maxillary sinus microbiota exhibits long-term stability in individual subjects. Stable bacteria include a limited number of highly prevalent and a larger number of lower prevalence taxa, which vary widely in proportional abundance. The concept of individual-specific core sinus microbiota, durable over time and medical therapy, but fluctuating in proportional abundance, has implications for understanding the role of bacteria in CRS pathogenesis.

Nasal steroids in snorers can decrease snoring frequency: a randomized placebo-controlled crossover trial.

Although it is anecdotally known that nasal obstruction is associated with snoring, it remains unknown whether the application of nasal steroids could decrease oral/oro-nasal breathing and increase nasal breathing, and subsequently decrease snoring indices. This study evaluated the effect of nasal budesonide on breathing route pattern and snoring. Twenty-four snorers were enrolled in a randomized, double-blind, crossover trial of 1-week treatment with nasal budesonide compared with 1-week intervention with nasal placebo. At the start and end of each treatment period, patients underwent nasal resistance measurement and overnight polysomnography with concomitant measurement of breathing route pattern and snoring. Twelve patients were randomly assigned to a 1-week treatment with nasal budesonide, followed by 2-week washout period and a 1-week intervention with the nasal placebo; and 12 patients were randomly assigned to a 1-week intervention with nasal placebo, followed by 2-week washout period and a 1-week treatment with nasal budesonide. Nasal budesonide was associated with a decrease in oral/oro-nasal breathing epochs and concomitant increase in nasal breathing epochs, decrease of snoring frequency by [median (interquartile range)] 15.8% (11.2-18.8%), and an increase of rapid eye movement sleep; snoring intensity decreased only in patients with increased baseline nasal resistance by 10.6% (6.8-14.3%). The change in nasal breathing epochs was inversely related to the change in snoring frequency (Rs = 0.503; P < 0.001). Nasal budesonide in snorers can increase nasal breathing epochs, modestly decrease snoring frequency and increase rapid eye movement sleep.

Upper airway collapse during drug induced sleep endoscopy: head rotation in supine position compared with lateral head and trunk position.

Drug induced sedated sleep endoscopy (DISE) is often employed to determine the site, severity and pattern of obstruction in patients with sleep apnea. DISE is usually performed in supine position. We recently showed that the obstruction pattern is different when DISE is performed in lateral position. In this study, we compared the outcomes of DISE performed in supine position with head rotated, with the outcomes of DISE performed with head and trunk in lateral position. The Prospective study design was used in the present study. Sixty patients with OSA (44 male; mean apnea hypopnea index (AHI) 20.8 ± 17.5 events/h) underwent DISE under propofol sedation. Patients were placed in lateral position, and the upper airway collapse was evaluated. The patients were then placed in supine position with the head rotated to the right side. DISE outcomes were scored using the VOTE classification system. In lateral position, nine patients (15.0%) had a complete antero-posterior (A-P) collapse at the level of the velum, nine had a partial A-P collapse. During head rotation and trunk in supine position, at the level of the velum, four patients (6.7%) had a complete A-P collapse, while two patients (3.3%) had a partial A-P collapse. For all other sites, the patterns of collapse were not significantly different between head rotation and lateral position. During DISE, rotation of the head in supine position, and lateral head and trunk position present similar sites, severity and patterns of upper airway collapse, with the exception of collapse at the level of the velum. Here the severity of A-P collapse is less severe during head rotation than in lateral head and trunk position.

The effect of nasal tramazoline with dexamethasone in obstructive sleep apnoea patients.

Although there is a strong correlation between oral/oro-nasal breathing and apnoea/hypopnoea index in patients with obstructive sleep apnoea and normal nasal resistance at wakefulness, it remains unknown whether the pharmacological prevention of potential nasal obstruction during sleep could decrease oral/oro-nasal breathing and increase nasal breathing and subsequently decrease the apnoea/hypopnoea index. This study evaluated the effect of a combination of a nasal decongestant with corticosteroid on breathing route pattern and apnoea/hypopnoea index. 21 patients with obstructive sleep apnoea (mean apnoea/hypopnoea index 31.1 events per hour) and normal nasal resistance at wakefulness were enrolled in a randomised crossover trial of 1 weeks' treatment with nasal tramazoline and dexamethasone compared with 1 weeks' treatment with nasal placebo. At the start and end of each treatment period, patients underwent nasal resistance measurement and overnight polysomnography with attendant measurement of breathing route pattern. Nasal tramazoline with dexamethasone was associated with decrease in oral/oro-nasal breathing epochs and concomitant increase in nasal breathing epochs, and mean decrease of apnoea/hypopnoea index by 21%. The change in nasal breathing epochs was inversely related to the change in apnoea/hypopnoea index (Rs=0.78; p<0.001). In conclusion, nasal tramazoline with dexamethasone in OSA patients with normal nasal resistance at wakefulness can restore the preponderance of nasal breathing epochs and modestly improve apnoea/hypopnoea index.

The sleep position trainer: a new treatment for positional obstructive sleep apnoea.

BACKGROUND: Positional obstructive sleep apnoea (POSA), defined as a supine apnoea-hypopnoea index (AHI) twice or more as compared to the AHI in the other positions, occurs in 56 % of obstructive sleep apnoea patients. Positional therapy (PT) is one of several available treatment options for these patients. So far, PT has been hampered by compliance problems, mainly because of the usage of bulky masses placed in the back. In this article, we present a novel device for treating POSA patients. METHODS: Patients older than 18 years with mild to moderate POSA slept with the Sleep Position Trainer (SPT), strapped to the chest, for a period of 29 ± 2 nights. SPT measures the body position and vibrates when the patient lies in supine position. RESULTS: Thirty-six patients were included; 31 patients (mean age, 48.1 ± 11.0 years; mean body mass index, 27.0 ± 3.7 kg/m(2)) completed the study protocol. The median percentage of supine sleeping time decreased from 49.9 % [20.4-77.3 %] to 0.0 % [range, 0.0-48.7 %] (p < 0.001). The median AHI decreased from 16.4 [6.6-29.9] to 5.2 [0.5-46.5] (p < 0.001). Fifteen patients developed an overall AHI below five. Sleep efficiency did not change significantly. Epworth Sleepiness Scale decreased significantly. Functional Outcomes of Sleep Questionnaire increased significantly. Compliance was found to be 92.7 % [62.0-100.0 %]. CONCLUSIONS: The Sleep Position Trainer applied for 1 month is a highly successful and well-tolerated treatment for POSA patients, which diminishes subjective sleepiness and improves sleep-related quality of life without negatively affecting sleep efficiency. Further research, especially on long-term effectiveness, is ongoing.

Clinical and polysomnographic determinants of snoring.

Snoring is considered one of the hallmarks of sleep-disordered breathing, but its determinants remain obscure in both obstructive sleep apnoea (apnoeic) and non-apnoeic snorers. We aimed to document positional dependency of snoring along with its association with clinical and polysomnographic variables. Seventy-seven apnoeic and 27 non-apnoeic snorers who complained for every-night loud snoring and slept in supine and lateral positions in all sleep stages during overnight polysomnography were included. Snoring (i.e. sound intensity > 40 dB) was quantified by measuring the mean and maximum sound intensity, and snoring frequency. In apnoeic and non-apnoeic snorers, mean snoring intensity and snoring frequency were higher in supine than in lateral positions irrespective of sleep stage, and were also usually higher in N3 in comparison to rapid eye movement and/or N2 sleep stage in any given position. Positional change in snoring intensity as expressed by the ratio of mean intensity in the supine to lateral positions was independently and positively correlated with body mass index, tonsils size and age in the total of patients. Snoring is more prominent in the supine position and in N3 sleep stage in apnoeic and non-apnoeic snorers. Snoring positional dependence is determined by body mass index, tonsils size and age.

The role of sleep endoscopy in oral appliance therapy for obstructive sleep apnea.

OBJECTIVE: Although oral appliance therapy is considered a validated treatment for obstructive sleep apnea, its therapeutic success varies significantly among patients. Drug-induced sleep endoscopy is often employed in order to identify candidates for upper airway surgery; however, it remains unknown whether its findings can be associated with success of oral appliance therapy. This study tested the hypothesis that drug-induced sleep endoscopy variables can predict the outcome of oral appliance therapy in obstructive sleep apnea patients. METHODS: Forty-nine obstructive sleep apnea patients [45 men; mean apnea-hypopnea index 25.3 ± 7.5 events/h; mean body mass index 28.2 ± 3.0 kg/m2] underwent drug-induced sleep endoscopy, followed by a one-month of oral appliance therapy, and subsequently a follow-up polysomnography to assess outcome. RESULTS: Thirty-three patients (67.3%) were responders and sixteen were non-responders (32.6%). Non-responders had a higher occurrence of complete or partial circumferential collapse at velum in comparison with responders. Multivariate logistic regression analysis revealed that, among baseline clinical and polysomnographic characteristics and sleep endoscopy findings, the presence of complete circumferential collapse at velum and increased body mass index were the only independent predictors of oral appliance therapy failure. CONCLUSION: Drug-induced sleep endoscopy can be used to predict a higher likelihood of success to oral appliance therapy in obstructive sleep apnea patients.

Improving outcomes of hypoglossal nerve stimulation therapy: current practice, future directions, and research gaps. Proceedings of the 2019 International Sleep Surgery Society Research Forum.

Hypoglossal nerve stimulation (HGNS) has evolved as a novel and effective therapy for patients with moderate-to-severe obstructive sleep apnea. Despite positive published outcomes of HGNS, there exist uncertainties regarding proper patient selection, surgical technique, and the reporting of outcomes and individual factors that impact therapy effectiveness. According to current guidelines, this therapy is indicated for select patients, and recommendations are based on the Stimulation Therapy for Apnea Reduction or STAR trial. Ongoing research and physician experiences continuously improve methods to optimize the therapy. An understanding of the way in which airway anatomy, obstructive sleep apnea phenotypes, individual health status, psychological conditions, and comorbid sleep disorders influence the effectiveness of HGNS is essential to improve outcomes and expand therapy indications. This article presents discussions on current evidence, future directions, and research gaps for HGNS therapy from the 10th International Surgical Sleep Society expert research panel. CITATION: Suurna MV, Jacobowitz O, Chang J, et al. Improving outcomes of hypoglossal nerve stimulation therapy: current practice, future directions and research gaps. Proceedings of the 2019 International Sleep Surgery Society Research Forum. J Clin Sleep Med. 2021;17(12):2477-2487.

Contralateral Tongue Muscle Activation during Hypoglossal Nerve Stimulation.

OBJECTIVE: The effectiveness of upper airway stimulation via hypoglossal nerve stimulation for obstructive sleep apnea depends upon the pattern of tongue muscle activation produced. This study investigated the nature of contralateral tongue muscle activation by unilateral hypoglossal nerve stimulation using intraoperative nerve integrity monitoring in conjunction with electromyography and explored the relationship between contralateral tongue muscle activation and polysomnographic measures of obstructive sleep apnea severity. STUDY DESIGN: Prospective case series. SETTING: Tertiary care medical center. SUBJECTS AND METHODS: Fifty-one patients underwent unilateral (right) hypoglossal nerve stimulator implantation for obstructive sleep apnea. Neurophysiological data included electromyographic responses in ipsilateral (right) and contralateral (left) genioglossus muscles in response to intraoperative bipolar probe stimulation (0.3 mA) of medial hypoglossal nerve branches. Clinical data included pre- and postoperative apnea-hypopnea indices and oxygen desaturation levels. RESULTS: A subset of patients (20/51, 39%) exhibited electromyographic responses in both the ipsilateral and contralateral genioglossus (bilateral), whereas the remaining patients (31/51, 61%) exhibited electromyographic responses only in the ipsilateral genioglossus (unilateral). The baseline characteristics of bilateral and unilateral responders were similar. Both groups exhibited significant and comparable improvements in apnea-hypopnea index and oxygen desaturations after hypoglossal nerve stimulation. Neither the amplitude nor the latency of contralateral genioglossus responses was predictive of clinical outcomes. CONCLUSION: A subset of patients undergoing unilateral hypoglossal nerve stimulation exhibits activation of contralateral genioglossus muscles. Patients with unilateral and bilateral genioglossus responses exhibit comparable, robust improvements in apnea-hypopnea index and oxygen desaturation levels.

Determinants of subjective sleepiness in suspected obstructive sleep apnoea.

Although daytime sleepiness is commonly associated with obstructive sleep apnoea (OSA), the relationship between OSA severity and subjective sleepiness has been documented elusive. This study aimed to identify clinical and polysomnographic determinants of subjective sleepiness among patients suspected of having OSA. A sleep clinic-based sample of 915 patients was interviewed with a structured questionnaire and underwent diagnostic overnight polysomnography. Subjective sleepiness was quantified by Epworth Sleepiness Scale (ESS). Excessive daytime sleepiness (defined as ESS score > 10) was present in 38.8% of patients. In multiple linear regression analysis, respiratory disturbance index [RDI; used to define (whenever RDI was >5) and quantify OSA], depression and diabetes were the most important determinants of ESS score accounting for 17%, 11% and 6% of its variability respectively. Chronic obstructive pulmonary disease (COPD), stroke, heart disease, alcohol use and body mass index were less important determinants of ESS score explaining 1-3% of its variability. In conclusion, OSA should not be considered the sole potential cause of increased subjective sleepiness in patients suspected of having OSA. Primarily depression and diabetes, but also COPD, stroke, heart disease, alcohol use and increased body mass index may contribute to increased subjective sleepiness.

Ileocolic intussusception due to endometriosis.

Intussusception is a rare cause of bowel obstruction in adults. Clinical manifestations are not specific, making the preoperative diagnosis difficult to establish. We report a case of acute small-bowel obstruction due to ileocolic intussusception. An emergency explorative laparoscopy was performed and revealed a mass in the right colon proximal to the ileocecal valve. Conversion to open laparotomy allowed us to perform a right hemicolectomy. The pathologic examination of the resected sample revealed endometriosis of the terminal ileus.

Analysis of the influence of head rotation during drug-induced sleep endoscopy in obstructive sleep apnea.

OBJECTIVES/HYPOTHESIS: Currently, drug-induced sleep endoscopy (DISE) in obstructive sleep apnea (OSA) is predominantly performed in supine position. When positional therapy (avoidance of supine sleeping position in positional OSA (POSA) is implemented as (part of the) treatment, one should assess levels of obstruction in the other sleeping positions. Therefore, the current study examined the influence of difference head positions during DISE in patients with OSA and POSA. STUDY DESIGN: Consecutive prospective study. METHODS: DISE was performed in patients with an apnea hypopnea index at baseline polysomnography greater than 5 events/h. The upper airway was assessed at velum, oropharynx, tongue base, and epiglottis level in supine position. The patients head were then tilted to the left and the right side and the DISE findings were recorded. RESULTS: One hundred consecutive patients were included. In positional apneics (n = 67), lateral position was associated with decreased frequency of complete anteroposterior collapse at velum (P < 0.01), tongue base (P < 0.01), and epiglottis (P < 0.01) level-and increased frequency of partial anteroposterior collapse at velum (P < 0.01), tongue base (P < 0.01), and epiglottis (P <0.05) level in comparison with supine position. DISE findings showed no difference between the right and left position, whereas findings after head rotation were significantly different in comparison with the supine position. CONCLUSIONS: Head rotation improves upper airway collapse during DISE in supine position. This improvement of upper airway patency is more predominant in POSA patients.

Surgery for obstructive sleep apnea: sleep endoscopy determinants of outcome.

OBJECTIVES/HYPOTHESIS: Although drug-induced sleep endoscopy is often employed to determine the site of obstruction in patients with obstructive sleep apnea (OSA) who will undergo upper airway surgery, it remains unknown whether its findings are associated with surgical outcome. This study tested the hypothesis that drug-induced sleep endoscopy variables can predict the outcome of upper airway surgery in OSA patients. STUDY DESIGN: Case series retrospective analysis. METHODS: Forty-nine OSA patients (41 male; mean apnea-hypopnea index [AHI] 30.9 ± 18.5 events/hour) underwent propofol-induced sleep endoscopy followed by upper airway surgery (palatal surgery, and/or radiofrequency ablation of the tongue base, and/or hyoid suspension) and subsequently a follow-up polysomnography to assess surgical outcome. RESULTS: Twenty-three patients (47%) were responders, and twenty-nine were nonresponders (53%). Nonresponders had a higher occurrence of complete or partial circumferential collapse at velum and complete antero-posterior collapse at tongue base or epiglottis in comparison with responders. Multivariate logistic regression analysis revealed that among baseline clinical and polysomnographic characteristics (e.g., AHI, body mass index) and sleep endoscopy findings, the presence of complete circumferential collapse at velum, and of complete antero-posterior collapse at tongue base were the only independent predictors of upper airway surgery failure. CONCLUSIONS: Drug-induced sleep endoscopy can be used to predict higher likelihood of response to upper airway surgery in OSA.

Average volume-assured pressure support in a 16-year-old girl with congenital central hypoventilation syndrome.

Congenital central hypoventilation syndrome (CCHS) is an uncommon disorder characterized by the absence of adequate autonomic control of respiration, which results in alveolar hypoventilation and decreased sensitivity to hypercarbia and hypoxemia, especially during sleep. Patients with CCHS need lifelong ventilatory support. The treatment options for CCHS include intermittent positive pressure ventilation administered via tracheostomy, noninvasive positive pressure ventilation, negative-pressure ventilation by body chamber or cuirass, and phrenic nerve pacing. However, it may be necessary to alter the mode of ventilation according to age, psychosocial reasons, complications of therapy, and emergence of new modes of ventilation. We present a case of a 16-year-old girl with CCHS who was mechanically ventilated via tracheostomy for 16 years and was successfully transitioned to a new modality of noninvasive ventilation (average volume-assured pressure support [AVAPS]) that automatically adjusts the pressure support level in order to provide a consistent tidal volume.

Exhaled breath markers in patients with obstructive sleep apnoea.

The objectives of the present study were to assess the level of exhaled breath markers indicating airway inflammation and oxidative stress in patients with obstructive sleep apnoea syndrome (OSAS) in comparison with non-apnoeic (obese and non-obese) subjects and investigate whether therapy with continuous positive airway pressure (CPAP) can modify them. The design was a retrospective observational study, set in Evgeneidio Hospital. Twenty-six OSAS patients and nine obese and 10 non-obese non-apnoeic subjects participated in this study. We measured nasal nitric oxide (nNO), exhaled nitric oxide (eNO), exhaled carbon monoxide (eCO) in exhaled breath, and 8-isoprostane, leukotriene B(4) (LTB(4)), nitrates, hydrogen peroxide (H(2)O(2)), and pH in exhaled breath condensate (EBC) before and after 1 month of CPAP therapy. The levels of eNO and eCO were higher in OSAS patients than in control subjects (p < 0.05). Nasal NO was higher in OSAS patients than in obese controls (p < 0.01). The level of H(2)O(2), 8-isoprostane, LTB(4), and nitrates were elevated in OSAS patients in comparison with obese subjects (p < 0.01). Conversely, pH was lower in OSAS patients than in non-apnoeic controls (p < 0.01). One month of CPAP therapy increased pH (p < 0.05) and reduced eNO (p < 0.001) and nNO (p < 0.05). Apnea/hypopnoea index was positively correlated with 8-isoprostane (r = 0.42; p < 0.05), LTB(4) (r = 0.35; p < 0.05), nitrates (r = 0.54; p < 0.001), and H(2)O(2) (r = 0.42; p < 0.05). Airway inflammation and oxidative stress are present in the airway of OSAS patients in contrast to non-apnoeic subjects. Exhaled breath markers are positively correlated with the severity of OSAS. One-month administration of CPAP improved airway inflammation and oxidative stress.