Mean Oxygen Desaturation Index Research Articles

The Efficacy of Noninvasive Ventilation in Patients Affected by Rett Syndrome With Hypoventilation

BackgroundRett syndrome is a progressive neurological disorder associated to several comorbidities that contribute significantly to impair lung function. Respiratory morbidity represents a major cause of death in this population. Little is known about the benefit of noninvasive ventilation. MethodsWe retrospectively enrolled patients with Rett syndrome who underwent a pneumological evaluation combined with a cardiorespiratory polygraphy and/or a pulse oximetry and capnography from 2012 to 2022. ResultsMedical records of 11 patients with Rett syndrome, mean age 13 ± 6 years, were evaluated. Most patients presented with both epilepsy and scoliosis. Five patients showed a pathologic sleep study and/or impaired night gas exchange: mean obstructive apnea-hypopnea index was 4 ± 3 events/hour; mean and minimal SpO2 were, respectively, 93% ± 2% and 83% ± 6%, while mean and maximal transcutaneous carbon dioxide monitoring (PtcCO2) were, respectively, 51 ± 5 mm Hg and 55 ± 8 mm Hg; and mean oxygen desaturation index was 13 ± 11 events/hour. These patients started noninvasive ventilation with clinical benefit and improved gas exchange mostly in terms of PtcCO2 (mean PtcCO2 51 ± 5 mm Hg before and 46 ± 6 mm Hg after noninvasive ventilation). ConclusionsNoninvasive ventilation is a suitable option for patients with Rett syndrome.

Cephalometrics in Obstructive Sleep Apnea Patients with Mixed Dentition

Distal occlusion is one of the most common dentoalveolar anomalies and can be the reason for the obstructive sleep apnea (OSA) syndrome development among children. The aim of the study was to investigate the relationship between cephalometric and OSA parameters in the pediatric population. Methods: The cohort study included 39 children with OSA symptoms. Orthodontic examination consisted of a cephalometric analysis of 39 linear and angular variables. Patients underwent a sleep diagnostic study. Statistical analysis was performed using SPSS 19.0.0. Results: Of the general sample, 53.8% were mouth breathers and 46.2% had a mixed type of breathing. Moreover, 30.8% of patients had bruxism. The mean apnea-hypopnea index and oxygen desaturation index were 4.6/h and 3.9/h, respectively. A 1.06 times increase in the SNA index indicated the anterior position of the upper jaw. The MnPLSN° exceeded the norm by 1.3 times, which indicated the posterior position of the lower jaw and vertical type of the growth. An increase in ANSPNSSPT° by 1.1 times indicated an inclination of the upper jaw in the posterior position and a narrowing of the nasal passages. Patients with pediatric OSA had a significantly smaller lower airway space and MPH parameter. Conclusion: Systematic orthodontic monitoring of children with pediatric OSA is important for diagnosis and timely treatment.

Ketogenic Dietary Effects on Sleep, Cognition and Behavior in MCI: Baseline Sleep Results

AbstractBackgroundSleep disturbances in dementia occur often, are reported as neuropsychiatric symptoms, and are associated with higher caregiver burden and institutionalization. In mild cognitive impairment (MCI), sleep changes co‐occur with increasing neuropsychiatric symptoms and cognitive decline. Diet quality, like sleep, is a modifiable risk factor for Alzheimer’s disease. It is unknown how dietary interventions may impact sleep quality. This controlled clinical trial investigates for the first time a modified Mediterranean ketogenic diet (MMKD) compared to a low‐fat American Heart Association diet (AHAD) over 4 months on multiple sleep indices in adults with amnestic MCI. Here we report our baseline sleep findings.MethodThe WatchPAT Central Plus, an FDA approved home sleep test, was used to assess sleep quality. The WatchPAT quantifies numerous measures including total sleep time, pulse and sleep efficiency. Sleep‐disordered breathing is measured via the apnea‐hypopnea index (AHI) and oxygen‐desaturation index (ODI). Time spent in sleep stages is also quantified along with full night oxygen saturation and pulse rate. Independent samples t‐tests compared baseline sleep differences among male and female MCI participants.ResultA total of 64 MCI participants completed the baseline sleep assessments (mean age 70.2±7.0, BMI 27.0±4.3; 64.1% women). Mean sleep duration was 6 hrs46 min and 83.9% sleep efficiency. Mean AHI was 17.3±12.2 and mean ODI was 8.2±7.5 measured as >3% 02 desaturations, indicating on average moderate severity sleep apnea (AHI>15). Overnight sleep percentage by sleep stage (estimated from heart rate and accelerometer) averaged 15.4% in deep sleep and 22.3% in REM sleep. Mean REM latency was 105 minutes. Oxygen saturation averaged 94% and pulse, 61 bpm. Women had higher resting pulse (64.3bpm, p<.001). Sleep measures did not significantly differ by sex.ConclusionThe MCI sample, on average, had moderate severity sleep apnea at baseline, with sleep duration and efficiency slightly below standard recommendations of 7‐8 hours and efficiency > 85%, respectively. Future work will compare longitudinal changes in sleep quality across diet intervention groups. Understanding potential therapeutic effects of the MMKD on sleep quality and cognitive change will be vital in adding to the portfolio of targeted non‐pharmacological interventions for Alzheimer’s disease prevention.

A randomized controlled crossover trial of acute intermittent and continuous hypoxia exposure in mild-moderate obstructive sleep apnea: A feasibility study.

In a prospective, randomized, controlled crossover study, we explored the effects of acute intermittent hypoxia and acute continuous hypoxia on patients with mild-moderate obstructive sleep apnea. Over three single-night sessions, subjects were alternately exposed to normoxia, acute continuous hypoxia and acute intermittent hypoxia before sleep. The apnea-hypopnea index and oxygen desaturation index were used to diagnose obstructive sleep apnea and evaluate efficacy. A responder was defined as a participant with a ≥ 50% reduction in apnea-hypopnea index between normoxia and hypoxia exposure. Sixteen participants with mild-moderate obstructive sleep apnea completed the study. Compared with normoxia, the mean apnea-hypopnea index decreased by 8.9 events per hr (95% confidence interval, 4.2-13.6, p = 0.001) with acute intermittent hypoxia and by 4.1 events per hr (95% confidence interval, 0.5-8.8, p = 0.082) with acute continuous hypoxia, equating to a mean decrease in apnea-hypopnea index of 4.8 events per hr (95% confidence interval, 0.1-9.5, p = 0.046) with acute intermittent hypoxia compared with acute continuous hypoxia. Compared with normoxia, the mean oxygen desaturation index decreased by 9.8 events per hr (95% confidence interval, 4.4-15.1, p = 0.001) with acute intermittent hypoxia but did not significantly decrease with acute continuous hypoxia; the mean oxygen desaturation index decreased by 7.2 events per hr (95% confidence interval, 1.8-12.6, p = 0.010) with acute intermittent hypoxia compared with acute continuous hypoxia. Of the 16 participants, 11 responded to acute intermittent hypoxia and four responded to acute continuous hypoxia (p = 0.032), of whom eight of 11 cases and all four cases had oxygen desaturation indexes <5 events per hr, respectively (p = 0.273). All participants tolerated acute intermittent hypoxia and there were no obvious adverse events during acute intermittent hypoxia exposure. In conclusion, acute intermittent hypoxia exposure improved apnea-hypopnea index and oxygen desaturation index in patients with mild-moderate obstructive sleep apnea, suggesting that further prospective validation of intermittent hypoxia exposure in patients with obstructive sleep apnea is needed to establish its clinical feasibility as a therapeutic modality.

Interleukin 8 in children with obstructive sleep apnea before and after adenotonsillectomy

ObjectiveTo assess serum interleukin 8 (IL-8) levels after adenotonsillectomy in children with symptoms suggestive for OSA.Study designProspective interventional study.SettingsThe study was carried out on 30 children with OSA attending ENT clinic of Suez Canal University Hospital.MethodsIncluding, children with sleep-related chronic intermittent hypoxia (CIH) and OSA symptoms performed an elective adenotonsillectomy, and aged (3–12 years). Excluding, children with acute tonsillitis, cardiorespiratory, craniofacial, or diseases affecting IL-8 level as cystic fibrosis, COVID-19 patients, and hepatitis C, taking drugs affecting IL-8 level as benzodiazepines or glutamine supplementation. Children were subjected to full history, clinical examination and laboratory investigations. Nocturnal pulse oximetry (ChoiceMMed) was performed (48–72 h preoperative and 3–4 weeks postoperative) used to determine the number of 4% dips in saturation from baseline, and the nadir saturation (nSAT). IL-8 was measured 1 month pre-operative and 1 month post-operative by flow cytometry using the Human Inflammatory Cytometric Bead Array kit.ResultsThe mean preoperative IL-8 (237.55 p/ml) and oxygen desaturation index (7.77%)cwere statistically significantly higher than mean postoperative IL-8 (207.98 p/ml) and oxygen desaturation index (2.90). The mean pre-operative SpO2 is 98.27 ranged (96.00–100.0%), while the mean postoperative SpO2 is 98.77 ranged (97.00–100.0%), with no statistically significant difference between them (p = 0.069). Preoperative IL-8 (p/ml), postoperative IL-8 (p/ml), and preoperative SpO2 (%) were found to be negatively correlated with IL-8 change.ConclusionIL-8 level significantly decreased after adenotonsillectomy in children with symptoms suggestive for OSA.

0530 Efficacy of obstructive sleep apnea treatment by a unique oral appliance and effect of concurrent myofunctional and CPAP therapy

Abstract Introduction Current treatment options for obstructive sleep apnea (OSA) include positive airway pressure, oral appliances, and upper airway surgery. The Day and Night Appliance (DNA) is a component of a dentist-guided system (Complete Airway Repositioning and Expansion [CARE], Vivos Therapeutics) that leads to gradual increases in upper airway volume. This study examines the effects of DNA treatment on OSA in patients before and after use of the device; we also examined how DNA treatment was impacted by concurrent myofunctional and CPAP therapy. Methods Data from a prospectively-collected clinical database (Vivos Airway Intelligence Service [AIS]) were reviewed, and 94 adult OSA patients who met DNA use criteria and had pre- and post-treatment sleep studies without the device in place were included. We compared the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) pre- and post-treatment using a paired t-test and fit linear regression models with change in AHI and ODI as dependent variables. Results Mean patient age was 47.8±14.7 years and 44.7% were men. Pre- and post-treatment sleep studies were conducted 15.2±7.0 months apart. 24.5% of patients were treated with DNA and myofunctional therapy (14.1% exclusively myofunctional, 10.4% myofunctional plus another treatment, e.g., tonsillectomy, frenectomy). 17.0% of patients were treated with CPAP (12.8% exclusively CPAP, 4.2% CPAP plus another treatment). For both pre-treatment and post-treatment, mean AHIs were 22.3±19.4 and 12.7±11.2 respectively (p&amp;lt; 0.0001) and mean ODIs were 11.6±13.7 and 7.8±9.1 respectively (p&amp;lt; 0.0001). Excluding patients who had undergone myofunctional therapy and another treatment modality and adjusting for patient age, BMI, and gender, we found myofunctional therapy was associated with a -10.4 change in AHI (p=0.038). However, myofunctional therapy was not associated with a significant change in ODI (p=0.905). Concurrent CPAP use did not have a significant association with change in either AHI (p=0.47) or ODI (p=0.61). Conclusion This study shows that DNA use significantly improved post-treatment OSA severity, and that concurrent myofunctional but not CPAP therapy may result in further OSA improvement. An oral appliance system that provides palatal expansion with consequent improvement in OSA severity but does not require permanent nightly use has advantages over conventional oral appliances; however, further investigation is warranted. Support (if any)

The effect of longitudinal sleep monitoring on clinician agreement in obstructive sleep apnea diagnosis: The ELSA study.

There is strong evidence for clinically relevant night-to-night variability of respiratory events in patients with suspected obstructive sleep apnea. Sleep experts retrospectively evaluated diagnostic data in 56 patients with suspected obstructive sleep apnea. Experts were blinded to the fact that they were diagnosing the same case twice, once based on a short report of a single in-laboratory respiratory polygraphy and once with the additional information of 14 nights of pulse oximetry at home. All experts (n = 22) were highly qualified, 13 experts (59.1%) treated > 100 patients with suspected obstructive sleep apnea per year. In 12 patients, the apnea-hypopnea index in the respiratory polygraphy was < 5 per hr, but the mean oxygen desaturation index of 14 nights of pulse oximetry was ≥ 5 per hr. The additional information of 14 nights of pulse oximetry helped to diagnose obstructive sleep apnea with a 70% consensus in two of those patients (16.7% [95% confidence interval: 4.7/44.8]). In eight patients, experts could not agree to a 70% consensus regarding continuous positive airway pressure therapy recommendation after respiratory polygraphy. The additional information of multiple-night testing led to a consensus in three of those cases (37.5% [95% confidence interval: 14/69]). Change of obstructive sleep apnea diagnosis and continuous positive airway pressure recommendation was significantly negatively associated with the number of treated obstructive sleep apnea patients > 100 per year compared with 0-29 patients per year (Coef. [95% confidence interval] -0.63 [-1.22/-0.04] and -0.61 [-1.07/-0.15], respectively). Experts found already a high level of consensus regarding obstructive sleep apnea diagnosis, severity and continuous positive airway pressure recommendation after a single respiratory polygraphy. However, longitudinal sleep monitoring could help increase consensus in selected patients with diagnostic uncertainty.

Abstract 13798: Obstructive Sleep Apnea Severity and Abnormal Right Ventricular Flow Reserve in Adult OSA Patients Who Received Rubidium-82 Cardiac PET Perfusion Imaging

Background: Obstructive sleep apnea (OSA) is associated with right ventricular (RV) remodeling, RV dysfunction and pulmonary hypertension. Myocardial flow reserve (MFR), the ratio of stress-to-rest myocardial blood flow (MBF), is an index of coronary microvascular health. Recent evidence suggests that severe OSA is associated with abnormal left ventricular MFR (LVFR). However, little is known about MFR in the RV of patients with OSA. In this study we examined the relationship between measures of OSA severity and RV MFR (RVFR) in humans. Methods: We conducted RV MBF assessment in 47 persons with OSA who had a cardiac positron emission tomographic (PET) perfusion scan. All participants had in-laboratory polysomnography. RVFR &lt;2.0 was chosen as threshold for abnormal RVFR to coincide with the 25 th percentile of RVFR in our sample. Abnormal LVFR was also defined as &lt;2.0 based on thresholds from previously determined studies. We compared the mean apnea-hypopnea index (AHI), oxygen desaturation index (ODI) and time spent with &lt;90% oxygen saturation (T90%). Results: The mean age of the participants was 58 years and 63% were female. There was a strong correlation between RVFR and LVFR (Spearman Rho = 0.63, P&lt;0.001). The mean AHI was greater among persons with RVFR &lt;2 compared to those with RVFR≥2 [mean (SE) AHI: 63 (20) v. 32 (5), P=0.042]. This trend was observed with the ODI although it was not statistically significant. Given the RVFR and LVFR were strongly correlated, we created a ratio of RVFR to LVFR to account for the LV MBF. The mean AHI and ODI among persons with RVFR/LVFR &lt;1 was greater than those with ≥1; p = 0.025 and p=0.031 respectively. See the figure for more details. Conclusion In patients with OSA, patients with reduced RVFR had higher AHI and ODI indicating greater severity of OSA. The exact mechanism behind this phenomenon is not known. Future studies should further characterize the relationship between RV myocardial blood flow and OSA.

A novel sleep oximetry scoring tool for pediatric laryngomalacia

ObjectiveDespite being a more accessible and less resource intensive modality than polysomnography, the utility of sleep oximetry (SO) in pediatric laryngomalacia (LM) is not well understood or validated. We aimed to retrospectively evaluate the utility of overnight home based SO in children with LM by developing and internally validating the Modified Laryngomalacia Oximetry Score (MLOS) scoring system to triage severity and guide clinical decision making. MethodsWe evaluated pediatric patients with a diagnosis of LM at our tertiary referral centre. Data from initial and post-treatment SO including mean oxygen saturation (spO2) nadir and mean oxygen desaturation index (ODI) were aggregated. The MLOS ranging from I-VI (inconclusive to severe) was created by two otolaryngologists to incorporate bradycardia associated desaturation events during SO. Corresponding McGill Oximetry Score (MOS) was also determined. Results172 patients were included in final analysis. The average age was 9.2 ± 14.3 months. 98 (57%) of patients were identified as Thompson severity score 1, and 87 (50.6%) of patients underwent supraglottoplasty. The surgical cohort had a significantly higher MLOS and MOS scores of 4 and 2 respectively, and higher mean ODI and spO2 nadir metrics. When evaluating post-supraglottoplasty SO tracings, all parameters improved significantly, including median MLOS score from 4 to 1. Only the mean ODI improved in the non-surgical cohort. Patients with Thompson severity score 2/3 had significantly higher MLOS. ConclusionWe present a simple scoring system based on overnight SO, the MLOS, to help triage severity of pediatric LM and guide decision-making. MLOS is associated with worse clinical severity and a need for surgery, and shows significant improvement after surgery.

A cross-sectional study of obstructive sleep apnea in patients with colorectal cancer.

The association between colorectal cancer (CRC) and obstructive sleep apnoea (OSA) has been attracting increasing attention. several studies had confirmed that OSA increases the risk of CRC onset. However, the findings of studies on the morbidity of OSA in patients with CRC were unclear. Therefore, this study aimed to investigate the morbidity of OSA in patients with CRC as well as the association between the clinicopathological characteristics of OSA and CRC. A total of 414 patients with a pathological diagnosis of CRC from 1 January, 2020 to 30 December, 2020 were included in this study. Demographic characteristics, clinical information, and tumor characteristics of participants were collected; sleep was monitored using a wearable oximeter and via sleep quality questionnaire. The oxygen desaturation index (ODI) was used to classify OSA severity so that the diagnostic criteria for OSA were set based on the ODI as 0-5 (normal) and ≥5 (abnormal). After correcting for confounding factors, a logistic regression analysis was performed to calculate the odds ratio (OR) and 95% confidence interval (CI) for the factors affecting the tumor lymph node stage (N stage). A total of 402 patients with CRC were included in this study, including 225 (55.97%) men and 177 (44.03%) women. The mean ODI value of participants was 3.40±8.17. The morbidity of OSA among the patients with CRC having ODI ≥5 was 16.17%. A comparison between the normal and abnormal ODI value groups revealed that the high proportion of abnormal ODI was related to higher N stage (P<0.05). Logistic regression analysis revealed a correlation of ODI values and age to the N stage. Specifically, CRC patients with an abnormal ODI had a higher risk of lymph node metastasis compared to those with normal ODI (OR =1.915, 95% CI: 1.025 to 3.579). Moreover, patients with CRC aged ≥65 years had a higher risk of lymph node metastasis compared to those aged <65 years (OR =2.190, 95% CI: 1.163 to 4.125). CRC patients with abnormal ODI are susceptible to OSA. Additionally, abnormal ODI and age ≥65 years are relevant factors for the N2 stage.

Clinical polysomnographic methods for estimating pharyngeal collapsibility in obstructive sleep apnea.

Obstructive sleep apnea has major health consequences but is challenging to treat. For many therapies, efficacy is determined by the severity of underlying pharyngeal collapsibility, yet there is no accepted clinical means to measure it. Here, we provide insight into which polysomnographic surrogate measures of collapsibility are valid, applicable across the population, and predictive of therapeutic outcomes. Seven promising polysomnography-derived surrogate collapsibility candidates were evaluated: Vpassive (flow at eupneic ventilatory drive), Vmin (ventilation at nadir drive), event depth (depth of the average respiratory event), oxygen desaturation slope and mean oxygen desaturation (events-related averages), Fhypopneas (fraction of events scored as hypopneas), and apnea index. Evaluation included (1) validation by comparison to physiological gold-standard collapsibility values (critical closing pressure, Pcrit), (2) capacity to detect increased collapsibility with older age, male sex, and obesity in a large community-based cohort (Multi-Ethnic Study of Atherosclerosis, MESA), and (3) prediction of treatment efficacy (oral appliances and pharmacological pharyngeal muscle stimulation using atomoxetine-plus-oxybutynin). Pcrit was significantly correlated with Vmin (r = -0.54), event depth (r = 0.49), Vpassive (r = -0.38), Fhypopneas (r = -0.46), and apnea index (r = -0.46; all p < .01) but not others. All measures detected greater collapsibility with male sex, age, and obesity, except Fhypopneas and apnea index which were not associated with obesity. Fhypopneas and apnea index were associated with oral appliance and atomoxetine-plus-oxybutynin efficacy (both p < .05). Among several candidates, event depth, Fhypopneas, and apnea index were identified as preferred pharyngeal collapsibility surrogates for use in the clinical arena.

No-cutting remodelling intra-pharyngeal surgery can avoid CPAP in selected OSA patients: myth or reality?

Oropharyngeal surgery for Obstructive Sleep Apnea (OSA) has evolved from a radical excision of "redundant" soft tissue for the enlargment of the airway to a minimally invasive reconstruction to fulfill both preservation of pharyngeal function and improvement of sleep apnea. Recently, Alianza surgical technique has been successfully introduced as a new, non-resective procedure aimed to treat concentric pharyngeal collapse at the velum using Barbed Sutures. The aim of this study was to show the effectiveness and safety of Alianza technique as standalone surgical treatment in selected patients with moderate-severe OSA and concentric pharyngeal collapse that refused or did not tolerate Continuous Positive Airway Pressure therapy. Effectiveness of the surgical procedure was assessed by means of the Epworth Sleepiness Scale (ESS), Home Sleep Test, and a 0-10 snoring VAS. At the end of our selection process, 26 patients were enrolled, with a mean age of 52.7 ± 9.2years, that undergone Alianza tecnique. There was a statistically significant reduction in mean post-operative apnea-hypopnea indexes (34.1 ± 11.5-16.3 ± 10.3; p <0.01), mean oxygen desaturation index (29.0 ± 14.5-13.1 ± 9.2; p < 0.01), and mean ESS scores (12.1 ± 5.8 and 5.8 ± 4.4; p < 0.01).There was also a significant decrease in mean post-operative snoring VAS scores (7.85 ± 1.23 vs 3.2 ± 1.7, p < 0.01). There were no major complications. Our preliminary results suggest that Alianza technique is a safe and repeatable surgery. Further studies on a larger scale are needed to confirm these encouraging data supporting the role of Alianza alone or in OSA multilevel surgery in selected OSA patients.

Addressing rural health disparity with a novel hospital sleep apnea screening: Precision of a high-resolution pulse oximeter in screening for sleep-disordered breathing.

High-resolution pulse oximetry (HRPO) may offer a low-cost and simple screening option for sleep-disordered breathing (SDB) that could be vitally important in rural areas with limited healthcare resources and specialty care. Our team hypothesized that application of this technology to a broad cohort of rural dwelling hospitalized individuals would demonstrate congruence similar to previous urban studies comparing HRPO to portable sleep monitors. This retrospective study was conducted at West Virginia University Hospital and compared indices obtained from HRPO with those obtained from a type III portable sleep monitor (PM) on the same night. A total of 365 individuals underwent evaluation. The mean oxygen desaturation index (18.8 ± 19.3 events/h) from the HRPO was slightly higher than the mean respiratory event index (16.0 ± 18.1 events/h, p ≤ 0.001) from the PM. ROC curves were developed for thresholds of apnea severity predicted by the screening program. The AUC values for all three thresholds exceeded 0.92 and for a respiratory event index (REI) of ≥ 30 was 0.965. Indices from the PM and HRPO demonstrated agreement in those individuals with screening suggestive of moderatetosevere disease. This study demonstrates that use of HRPO in screening for SDB in hospitalized patients from rural communities is as accurate as PM and may serve as a simple cost-effective tool to address sleep health disparities in these regions with significant health inequity. Our data extend previous findings by applying HRPO to a larger hospitalized cohort with highly prevalent cardiopulmonary disease.

Sleep Study Measures on Postoperative Night 1 Following Implantation of the Hypoglossal Nerve Stimulator.

To examine the changes in measures of sleep apnea severity and hypoxemia on the first postoperative night following implantation of the hypoglossal nerve stimulator. This was a single-arm prospective cohort study. A single academic sleep surgical practice. Subjects with moderate to severe obstructive sleep apnea underwent implantation of the hypoglossal nerve stimulator (HGNS) and were discharged to home the same day as surgery. A single-night WatchPAT study was performed on the night immediately following surgery (PON 1) and was compared to baseline sleep testing. Twenty subjects who were an average of 58.6 ± 2.5 years old, were 25% female, and had a mean body mass index of 28.1 ± 0.9 kg/m2 completed the study. Mean O2 nadir at baseline was 79.6% ± 1.1% compared to 82.7% ± 0.9% (P = .013) on PON 1. One patient demonstrated a >10% worsening in O2 nadir. Only 2 additional patients demonstrated a worsening in O2 nadir on PON 1, each by only 1 percentage point. Neither mean time spent below SpO2 88% nor oxygen desaturation index (ODI) worsened postoperatively (mean time spent below oxygen saturation of 88%, 27.8 ± 7.85 vs 11.2 ± 5.2, P = .03; mean ODI, 29.6 ± 5.2/h vs 21.0 ± 5.4/h, P = .10). Mean obstructive apnea hypopnea index (AHI) was no worse (40.6 ± 4.7/h to 28.7 ± 4.2/h, P = .02), with only 2 patients experiencing an obstructive AHI >20% more severe than baseline. Only 1 patient demonstrated a clinically meaningful increase in central AHI on PON 1. Overall, AHI and measures of nocturnal hypoxemia are stable, if not improved, on PON 1 following HGNS implantation. These findings support the safety of same-day discharge following implantation of the hypoglossal nerve stimulator.

Period-to-Period Variability of Moderate/Severe Obstructive Sleep Apnoea.

IntroductionThe severity of obstructive sleep apnoea (OSA) is highly variable on a night-to-night basis. Patients are commonly categorised based on the severity of their OSA, and this is then used to influence management and reimbursement, including continuous positive airway pressure (CPAP). We aimed to establish to what extent the OSA severity category changes during two periods of OSA, based on mean and maximum oxygen desaturation index (ODI).MethodsPatients with a diagnosis of moderate to severe OSA who had been on CPAP for greater than 1 year were included in this study. Subjects underwent two periods of CPAP withdrawal for four nights each.ResultsTwenty-five patients completed the study. Based on the mean ODI of the four nights, 14 (56%) patients changed OSA severity categorisation, with three (12%) changing category to mild. Based on the maximum ODI of the four nights, nine (36%) patients changed OSA severity categorisation, with one (4%) changing category to mild. One third to a half of patients’ OSA severity category changed between the two periods of four night’s CPAP withdrawal.ConclusionsOSA is highly variable on a period-to-period basis as well as on a night-to-night basis. We believe the concept of patients having a definable and ‘real’ level of OSA severity is therefore flawed. OSA severity should be based mainly on symptoms, as these are the dominant reasons for treatment, and the sleep study should be used qualitatively to ascertain whether respiratory events are the likely cause of the symptoms.Trial RegistrationISRCTN17987510.

OBSTRUCTIVE SLEEP APNEA AS A RISK FACTOR OF INSULIN RESISTANCE IN NONDIABETIC PATIENTS

Objective: Obstructive sleep apnea (OSA) is a common sleep-breathing disorder characterised by collapsing of upper airway during sleep. The aim of this research was to assess relationship beetwen prevalence and severity of OSA and insulin resistance in nondiabetic individuals among patients with increased risk of OSA without diabetes mellitus. Design and method: Our study group estimated 102 individuals with suspected OSA, 71 men and 31 women, mean age 53.02 SD ± 12.37. We excluded individuals with diabetes mellitus and taking hypoglycemic drugs. All patients underwent standardized full night polysomnography in sleep laboratory to diagnose OSA. The Epworth Sleepiness Scale was used to assess daytime sleepiness. Serum insulin and glucose levels were analyzed by Laboratory. The HOMA index was calculated. Results: OSA was diagnosed in 85 patients. Mean AHI in whole study group was 25.78 ± 24.84, mean AHI in group with diagnosed OSA amount to 30.49 ± 24.64, mean AHI in nonapneic patients stands up to 2.23 ± 1.49. The difference was statistically significant p &lt; 0.001. The oxygen desaturation index (ODI) in our study sample estimated about 25 (24.99 ± 23.25), the difference between group with OSA (mean ODI 29.31 ± 23.14) and group without OSA (mean ODI 3.38 ± 2.42) was statistically relevant p &lt; 0.001. The statistically significant differences have occured between patients with (AHI = 15 or AHI &gt; 15) and AHI &lt; 15 taking into account level of insulin and the Homa index p &lt; 0.05, but no statistically significant difference was observed between patients with (ESS = 9 or ESS &gt; 9) and ESS &lt; 9. Conclusions: Individuals with moderate to severe obstructive sleep apnea without diabetes mellitus have higher insulin resistance estimated with HOMA- IR index. This study revealed that there is no evidence if the evaluation of daytime sleepiness using Epworth Sleepiness Scale is a predicting factor of developing IR. Higher AHI and ODI levels beyond individuals from our study sample are independent risk factors for higher fasting insulin levels and higher HOMA index. Increased duration of desaturation time below 90% is an independent risk factor for higher fasting glucose levels.

Study of Obstructive Sleep Apnea Parameters in Patients of Nasal Polyposis Using Peripheral Arterial Tonometry

Background: Obstructive sleep apnea (OSA) syndrome is characterized by partial or complete cessation of airflow and oxygen desaturation during sleep owing to upper airway collapse. This study assesses the OSA parameters in nasal polyposis patients before and after functional endoscopic sinus surgery (FESS) with the help of peripheral arterial tonometry (PAT) device. Methodology: This was a prospective study done in the months of April 2015 to June 2016. Patients with bilateral nasal polyps with Lund Mackay Scoring marking equal to and more than two of both sides. Thirty patients willing to undergo PAT sleep study before and after FESS were recruited. The sleep parameters thus obtained in the pre- and postoperative period were analyzed. Results: Out of 30 patients, 22 patients were male and eight patients were female. The mean age was 43.17 with standard deviation of 10.06 years. The mean body mass index was 29.12 with a standard deviation of 5.76. All patients underwent FESS. The PAT study was done before and after surgery. Snoring grading and Epworth Sleepiness Scale scoring improved in the majority of patients after surgery. The mean respiratory disturbance index (RDI) in the preoperative period was 32.7 which decreased to 11.34 in the postoperative period. The mean apnea hypopnea index (AHI) in the preoperative period was 22.85 which decreased to 6.34 in the postoperative period. The mean oxygen desaturation index (ODI) in the preoperative period was 16.8 which decreased to 4.4 after surgery. Significant correlation (P &lt; 0.001) was found between pre- and postoperative RDI, AHI, ODI, and oxygen desaturation events. Conclusion: The OSA parameters before and after endoscopic sinus surgery in nasal polyposis patients got improved. The PAT device, which is the newest novel plethysmograph, proved to be a reliable device for the assessment of sleep apnea parameters in nasal polyposis in the pre- or postoperative period.

Polysomnography findings and risk factors for sleep-disordered breathing in patients with systemic sclerosis.

Objectives This study aims to evaluate polysomnography findings and risk factors for sleep-disordered breathing in patients with systemic sclerosis (SSc).Patients and methods Thirty-nine patients (2 males, 37 females; mean age: 51.1±12.5 years; range, 21 to 76 years) who attended to the Rheumatology Clinic of Trakya University Medical Faculty between March 2014 and May 2014 were included in the study. Thoracic computed tomography, pulmonary function tests, carbon monoxide diffusion tests, echocardiography, and all-night polysomnography in a sleep laboratory were performed in all patients. Demographic and clinical characteristics of the patients were recorded. The Apnea-Hypopnea Index (AHI) scores were calculated. Disease activity was examined using the Medsger Disease Severity Scale (MDSS). Possible risk factors for sleep-disordered breathing were evaluated.Results Using the AHI of ≥5 for obstructive sleep apnea (OSA), 21 (53.8%) of the patients were classified as having OSA. There were no significant differences between the groups with and without OSA in terms of steroid use (p=0.4), CT involvement (p=0.3), and Warrick (p=0.6) and MDSS scores (p=0.5). Age, body mass index (BMI), and mean oxygen desaturation index were found to be significant in the univariate analysis (p<0.1); however, the multivariate analysis revealed only BMI as significant risk factor of OSA (p=0.028). In the multivariate analysis, the mean saturation was found to be significant risk factor for high pulmonary artery pressure (p<0.001).Conclusion Although OSA is common in SSc, only increased BMI is a significant risk factor of OSA, but not lung involvement, Warrick scores, or MDSS scores.

The Accuracy of Repeated Sleep Studies in OSA: A Longitudinal Observational Study With 14 Nights of Oxygen Saturation Monitoring

Strong evidence exists for clinically relevant night-to-night variability of respiratory events in patients with suspected OSA. How many sleep study nights are required to diagnose OSA accurately? Patients with suspected OSA underwent up to 14 nights of pulse oximetry (PO) at home and one night of in-hospital respiratory polygraphy (RP). The accuracy of each of the 13 sleep study nights was analyzed using the mean oxygen desaturation index 3%(ODI3%) of all 14 nights as a reference. Multiple regression analyses assessed possible predictors for night-to-night variability. One hundred three patients underwent in-hospital RP. Using only the results of the RP, 19.7%were misdiagnosed using an ODI3% cutoff of 15/h. One hundred eight patients underwent properly performed PO studies at home with a coefficient of variation (CV) of 31.5%(SD, 14.7%) across all nights. The first PO night demonstrated a sensitivity of 71.4%(95%CI, 55.4%-84.3%) and a specificity of 89.4%(95%CI, 79.4%-95.6%) to diagnose moderate OSA. Using only the first PO night, the negative predictive value was 83.1%. Adding a second recording night increased sensitivity up to 88.1%(95%CI, 74.4%-96.0%) with a slightly lower specificity of 85.9%(95%CI, 74.9%-93.4%). The ODI3% of the in-hospital RP showed an independent negative association to the log-transformed CV (exponentiated coefficient, 0.989; 95%CI, 0.984-0.995). One single night of in-hospital RP may miss relevant OSA. Multiple study nights, for example, using ambulatory oxygen saturation monitoring, increase accuracy for diagnosing moderate OSA. ClinicalTrials.gov; No.: NCT03819361; URL: www.clinicaltrials.gov.

Polysomnographic characteristics and sleep-disordered breathing in Schaaf-Yang syndrome.

Schaaf-Yang syndrome (SYS) is a genetic disorder caused by truncating variants in the MAGEL2 gene located in the maternally imprinted Prader-Willi syndrome (PWS) region at 15q11-13. The SYS phenotype shares features with PWS, a syndrome with known high incidence of sleep disorders. However, the spectrum of sleep-disorders in SYS has not been described. We performed a retrospective analysis of polysomnograms from 22 patients in an international SYS cohort. Sleep characteristics for individuals with the common c.1996dupC variant (n = 10) were compared to other truncating variants (n = 11). We collected 33 sleep study reports from 22 patients, ages 2 months - 18.5 years (mean 6.5 years). Mean sleep efficiency was 70.5% (range 45%-93%) with arousal index 14.1/h(1.2-45/h). The mean apnea-hypopnea index (AHI) was 19.1/h (0.9-49/h) with mean obstructive AHI (oAHI) of 16.3/h(0.6-49/h). Mean central apnea index was 2.8/h(0-14/h). Mean oxygen desaturation index was 20.8/h(range 0-85/hr). Obstructive sleep apnea (OSA) was diagnosed in 81%, and 62% had moderate or severe OSA. Elevated central apnea index occurred in 9.5%. Comparison by genotype groups and age did not reveal any difference in OSA findings. Periodic limb movement index (PLMI) was elevated in 4/15 (26%). OSA is frequently identified on polysomnography in patients with SYS. The mean PLMI is elevated compared to normative data. Patients with SYS should have routine polysomnography screening due to high risk of sleep disorders.