Obstructive Events Research Articles

Are there sex-related differences in therapeutic CPAP levels in adults undergoing in-laboratory titration?

The first-choice therapy for adults with moderate/severe obstructive sleep apnea is continuous positive airway pressure (CPAP). However, studies evaluating whether the therapeutic CPAP level obtained from a titration is affected by sex are surprisingly scarce. Our main objective was to verify if sex influenced the optimal CPAP measurement obtained during a titration. This cross-sectional study was conducted in adults diagnosed with moderate/severe obstructive sleep apnea [baseline apnea-hypopnea index (AHI) ≥ 15.0 events/h] who underwent auto-adjusting CPAP titration (S9 or S10 AutoSet ResMed) in a sleep laboratory setting. All participants used a nasal mask during the titration. The optimal pressure, leak, and residual AHI values were registered. Multiple linear regression was used to evaluate if clinical and polysomnographic data influenced the therapeutic CPAP level setting (95th percentile pressure). A total of 1,006 adults were enrolled: 354 women and 652 men. There were no statistically significant sex-related differences in the CPAP requirements and leak values delineated during the titration; all P-values > .005. However, the median residual AHI was significantly higher in males vs females: 2.7 events/h vs 2.2 events/h (P = .008). Body mass index (β: 0.292, P < .001), baseline AHI (β: 0.167, P < .001), and age (β: 0.065, P = .035) were independent predictors of the therapeutic CPAP level settings. Sex does not significantly influence the therapeutic CPAP settings. However, age, BMI, and baseline AHI emerge as independent predictors of the 95thpercentile CPAP requirement during an auto-adjusting CPAP titration. Duarte RLM, Magalhães-da-Silveira FJ, Gozal D. Are there sex-related differences in therapeutic CPAP levels in adults undergoing in-laboratory titration? JClin Sleep Med. 2021;17(9):1815-1820.

Pulse arrival time, a novel sleep cardiovascular marker: the multi-ethnic study of atherosclerosis

BackgroundPulse arrival time (PAT) is commonly used to estimate blood pressure response. We hypothesised that PAT response to obstructive respiratory events would be associated with increased cardiovascular risk in people...

Impact of Interface Type on Noninvasive Ventilation Efficacy in Patients With Neuromuscular Disease: A Randomized Cross-Over Trial

Background and objectiveAround 25% of patients with neuro-muscular diseases (NMD) are treated by home noninvasive ventilation (NIV) through an oronasal mask. However, there is growing evidence that nasal masks require lower NIV pressures and result in fewer residual obstructive events. We hypothesized that nasal masks would improve efficacy and reduce side effects compared to oronasal masks in this population. Methodsopen label, cross-over, randomized, study in 2 tertiary care hospitals. Patients with NMD treated by home NIV were randomized for one-week periods to nasal and oronasal interfaces respectively (cross-over). At the end of each period, nocturnal polygraphy (monitoring mouth opening) under NIV, synchronized with transcutaneous partial pressure in CO2 (tcCO2) was performed. Data were collected from the NIV built-in software and NIV side-effects were collected. Intention-to-treat and per protocol analyses were performed. The primary outcome was mean nocturnal SpO2. The secondary outcomes were: percentage of sleep with SpO2<90%, oxygen desaturation index (ODI), mean tcCO2, mean duration of mouth opening during sleep, level of non-intentional leaks and side-effects. ResultsThirty patients with NMD were included. There were no between-group differences for either the primary or secondary outcomes. Post hoc comparisons showed that changing between interfaces reduced NIV efficacy: mean nocturnal SpO2 (p=0.04), ODI (p=0.01), mean tcCO2 (p=0.048), side-effects (p=0.008). ConclusionNasal masks did not improve NIV efficacy or reduce side effects compared to oronasal masks in patients with NMD treated by home NIV. The efficacy of NIV is reduced during the transition to another interface, requiring close monitoring.Registration number: NCT03458507.

Prevalence and associations of co-morbid insomnia and sleep apnoea in an Australian population-based sample

IntroductionInsomnia and obstructive sleep apnoea (OSA) are the two most prevalent sleep disorders, and frequently co-occur (COMISA) in sleep clinic samples. However, few studies have investigated the prevalence or associations of COMISA in the general population. MethodsWe used population-based online survey data from 2044 Australian adults. The prevalence and associations of insomnia, OSA and COMISA were investigated according to symptom-level, and disorder-level definitions. Insomnia was defined according to chronic difficulties initiating and/or maintaining sleep (DIMS; symptom-level), and ICSD-3 chronic insomnia disorder (disorder-level). OSA was defined according to self-reported frequent obstructive events, snoring or doctor-diagnosed OSA (symptom-level), and doctor-diagnosed OSA (disorder-level). COMISA was defined if both conditions were met (for symptom-level, and disorder-level threshold). Associations with other conditions, and general health were investigated with Poisson regression analyses. ResultsChronic insomnia occurred more frequently among participants with doctor-diagnosed OSA (22.3%), compared to those without (14.3%, p = 0.010). Doctor-diagnosed OSA was more common among participants with chronic insomnia (10.2%) compared to those without (6.2%; p = 0.010). DIMS also occurred more frequently among participants with OSA symptoms (66.6%), compared to those without (47.2%; p < 0.001). Participants with symptom-level COMISA reported increased co-morbid conditions, and worse general health compared to participants with symptoms of insomnia-alone, OSA-alone, or neither insomnia/OSA. ConclusionsCOMISA at symptom and disorder level were common and associated with increased medical and psychiatric co-morbidity, as well as poor general health. More investigation is required to understand bi-directional associations underpinning the high co-morbidity, and improve diagnostic and treatment approaches for COMISA to reduce associated morbidity.

Potential impact of pediatric obstructive sleep apnea on mandibular cortical width dimensions.

To analyze differences in mandibular cortical width (MCW) among children diagnosed with obstructive sleep apnea (OSA) or at high- or low-risk for OSA. A total of 161 children were assessed: 60 children with polysomnographically diagnosed OSA, 56 children presenting symptoms suggestive of high-risk for OSA, and 45 children at low risk for OSA. Children at high- and low-risk for OSA were evaluated through the Pediatric Sleep Questionnaire. MCW was calculated using ImageJ software from panoramic radiograph images available from all participants. Differences between MCW measurements in the 3 groups were evaluated using analysis of covariance and Bonferroni post-hoc tests, with age as a covariate. The association between MCW and specific cephalometric variables was assessed through regression analysis. The participants' mean age was 9.6 ± 3.1 years (59% male and 41% female). The mean body mass index z-score was 0.62 ± 1.3. The polysomnographically diagnosed OSA group presented smaller MCW than the group at low-risk for OSA (mean difference = -0.385 mm, P = .001), but no difference with the group at high-risk for OSA (polysomnographically diagnosed OSA vs high-risk OSA: P = .085). In addition, the MCW in the group at high-risk for the OSA was significantly smaller than the group at low-risk for the OSA (mean difference = -0.301 mm, P = .014). The cephalometric variables (Sella-Nasion-A point angle (SNA) and Frankfort - Mandibular Plane angle (FMA)) explained only 8% of the variance in MCW. Reductions in MCW appear to be present among children with OSA or those at high-risk for OSA, suggesting potential interactions between mandibular bone development and/or homeostasis and pediatric OSA. Fernandes Fagundes NC, d'Apuzzo F, Perillo L, et al. Potential impact of pediatric obstructive sleep apnea on mandibular cortical width dimensions. J Clin Sleep Med. 2021;17(8):1627-1634.

Sleep-Disordered Breathing in Patients with Motor Neurone Disease: One Size Does Not Fit all

Introduction: Sleep-disordered breathing (SDB) in patients with motor neurone disease (MND) is normally attributed to hypoventilation due to muscle weakness. However, we have observed different patterns of SDB among MND patients referred for non-invasive ventilation, which do not appear to be explained by respiratory muscle weakness alone. Aim: The aim of this study was to examine the characteristics of SDB in MND. Methods: This is a retrospective analysis of sleep studies (using polysomnography [PSG]), pulmonary function tests, and arterial blood gases in MND patients referred to a tertiary sleep medicine service for clinical review. Sleep apnoeas were characterised as obstructive or central, and to further characterise the nature of SDB, hypopnoeas were classified as obstructive versus central. Results: Among 13 MND patients who had a diagnostic PSG, the mean ± SD age was 68.9 ± 9.8 years, BMI 23.0 ± 4.3 kg/m², forced vital capacity 55.7 ± 20.9% predicted, and partial pressure of CO₂ (arterial blood) 52.7 ± 12.1 mm Hg. A total of 38% of patients (5/13) showed evidence of sleep hypoventilation. The total apnoea/hypopnoea index (AHI) was (median [interquartile range]) 44.4(36.2–56.4)/h, with 92% (12/13) showing an AHI >10/h, predominantly due to obstructive events, although 8% (1/13) also showed frequent central apnoea/hypopnoeas. Conclusions: Patients with MND exhibit a wide variety of SDB. The prevalence of obstructive sleep apnoea (OSA) is surprising considering the normal BMI in most patients. A dystonic tongue and increased upper-airway collapsibility might predispose these patients to OSA. The wide variety of SDB demonstrated might have implications for ventilator settings and patients’ outcomes.

Arrhythmogenic mechanisms of acute obstructive respiratory events in a porcine model of drug-induced long QT

Obstructive sleep apnea is associated with increased risk of sudden cardiac death. The purpose of this study was to elucidate changes in ventricular repolarization and electromechanical interaction during obstructive respiratory events simulated by intermittent negative upper airway pressure (INAP) in pigs. We also investigated the effect of a reduced repolarization reserve in drug-induced long QT (LQT) following INAP-induced changes in ventricular repolarization. In sedated spontaneously breathing pigs, 75 seconds of INAP was applied by a negative pressure device connected to the endotracheal tube. Ventricular electromechanical coupling was determined by the electromechanical window (EMW) before (pre-INAP), during (INAP), and after INAP (post-INAP). Incidence rates of premature ventricular contractions (PVCs) were measured respectively. A drug-induced LQT was modeled by treating the pigs with the hERG1 blocker dofetilide (DOF). Whereas QT interval increased during and decreased after INAP (pre-INAP: 273 ± 5 ms; INAP 281 ± 6 ms; post-INAP 254 ± 9 ms), EMW shortened progressively throughout INAP and post-INAP periods (pre-INAP 81 ± 4 ms; post-INAP 44 ± 7 ms). DOF shortened EMW at baseline. Throughout INAP, EMW decreased in a comparable fashion as before DOF (pre-INAP/+DOF 61 ± 7 ms; post-INAP/+DOF 14 ± 9 ms) but resulted in shorter absolute EMW levels. Short EMW levels were associated with increased occurrence of PVCs (pre-INAP 7 ± 2 ms vs post-INAP 26 ± 6 ms; P = .02), which were potentiated in DOF pigs (pre-INAP/+DOF 5 ± 2 ms vs post-INAP/+DOF 40 ± 8 ms; P = .006). Administration of atenolol prevented post-INAP EMW shortening and decreased occurrence of PVCs. Transient dissociation of ventricular electromechanical coupling during simulated obstructive respiratory events creates a dynamic ventricular arrhythmogenic substrate, which is sympathetically mediated and aggravated by drug-induced LQT.

Normal values for respiratory sleep polygraphy in children aged 4 to 9 years at 2,560 m above sea level.

Obstructive sleep apnea syndrome affects 1%-4% of all children worldwide. Currently, diagnosis of obstructive sleep apnea is based on sea-level guidelines, without taking into account the altitude at which the populations live. It has been shown that at 3,200 m of altitude there is an increase in obstructive events in healthy children aged 7 to 16years; on the other hand, it is known that SpO2 dispersion between individuals becomes wider as altitude increases, a phenomenon that is more marked during sleep. About 17 million Colombians live in regions between 2,500m and 2,700m, as do significant populations in other Latin American countries. This research aimed to characterize respiratory polygraphy sleep parameters in healthy, non-snoring children aged 4-9years living at 2,560 m. We carried out home respiratory polygraphy in 32 children with a mean age of 6.2years (range 4-9 years). The average recorded sleep time was 7.8h, the median apnea-hypopnea index was 9.2/h, the obstructive apnea-hypopnea index had a median of 8.8/h (p5 4.2 to p95 17.9) and central apnea a median of 0.4/h. The median SpO2 was 93% (p5 90.5 to p95 94) and transcutaneous CO2 had a median of 39.4mmHg (p531.7 to p95 42.3). The median oxygen desaturation index≥3% was 11.2 and median oxygen desaturation index≥4% was 3.9. Normal measurements for respiratory polygraphy obtained at sea level do not apply to children at altitude. If such guidelines are used, obstructive sleep apnea will be over-diagnosed, resulting in unnecessary adenotonsillectomies, among other interventions.

Association Between Statin Use at the Time of Intra-abdominal Surgery and Postoperative Adhesion-Related Complications and Small-Bowel Obstruction

Adhesion-related complications (ARCs), including small-bowel obstruction, are common complications of intra-abdominal surgery. Statins, which have antifibrotic pleiotropic effects, inhibit adhesion formation in murine models but have not been assessed in humans. To assess whether statin use at the time of intra-abdominal surgery is associated with a reduction in ARCs. These 2 separate retrospective cohort studies (The Health Improvement Network [THIN] and Optum's Clinformatics Data Mart [Optum]) compared adults receiving statins with those not receiving statins at the time of intra-abdominal surgery. Individuals undergoing intra-abdominal surgery from January 1, 1996, to December 31, 2013, in the United Kingdom and from January 1, 2000, to December 31, 2016, in the US were included in the study. Those with obstructive events before surgery or a history of inflammatory bowel disease were excluded. Data analysis was performed from September 1, 2012, to November 24, 2020. The primary exposure was statin use at the time of surgery. The primary outcome was ARCs, defined as small-bowel obstruction or need for adhesiolysis, occurring after surgery. Sensitivity analyses included statin use preceding but not concurrent with surgery, fibrate use, and angiotensin-converting enzyme inhibitor use. All analyses were adjusted for age, sex, and conditions associated with microvascular disease, such as hypertension, hyperlipidemia, obesity, and tobacco use; surgical approach and site; and diagnosis of a malignant tumor. A total of 148 601 individuals met the inclusion criteria for THIN (mean [SD] age, 49.6 [17.7] years; 70.1% female) and 1 188 217 for Optum (mean [SD] age, 48.2 [16.4] years; 72.6% female). A total of 2060 participants (1.4%) experienced an ARC in THIN and 54 136 (4.6%) in Optum. Statin use at the time of surgery was associated with decreased risk of ARCs (THIN: adjusted hazard ratio [HR], 0.81; 95% CI, 0.71-0.92; Optum: adjusted HR, 0.92; 95% CI, 0.90-0.95). Similar associations were appreciated between statins and small-bowel obstruction (THIN: adjusted HR, 0.80; 95% CI, 0.70-0.92; Optum: adjusted HR, 0.88; 95% CI, 0.85-0.91). This study's findings suggest that, among individuals in 2 separate cohorts undergoing intra-abdominal surgery, statin use may be associated with a reduced risk of postoperative ARCs. Statins may represent an inexpensive, well-tolerated pharmacologic option for preventing ARCs.

Clinical features of sleep-disordered breathing in children with neuromuscular disease

OBJECTIVE To study the clinical features of sleep-disordered breathing (SDB) in children with neuromuscular disease (NMD). METHODS A retrospective analysis was performed on the medical data of 18 children who were diagnosed with NMD and underwent polysomnography (PSG) (NMD group). Eleven children without NMD who had abnormal sleeping habit and normal sleep structure on PSG were enrolled as the control group. The two groups were compared in terms of the daily and nocturnal symptoms of SDB, incidence rate of obstructive sleep apnea (OSA), pulmonary function, end-tidal partial pressure of carbon dioxide (PetCO2), features of sleep structure, and sleep respiratory events. RESULTS In the NMD group, 16 children (89%) had related daily and nocturnal symptoms of SDB, and the youngest age was 1 year at the onset of such symptoms. Compared with the control group, the NMD group had significant reductions in total sleep time and sleep efficiency (P < 0.05), a significant reduction in the proportion of rapid eye movement (REM) sleep (P < 0.05), significant increases in obstructive apnea and hypopnea events (P < 0.05) and oxygen reduction events during REM sleep (P < 0.05), and a significant reduction in blood oxygen saturation during REM sleep (P < 0.05). In the NMD group, 17 children (94%) were diagnosed with OSA, and all children had normal lung function and PetCO2. CONCLUSIONS There is a high proportion of children with SDB among the children with NMD, and SDB can be observed in the early stage of NMD, which results in the damage of sleep structure and the reduction in sleep efficiency. Respiratory events are mainly obstructive events, and oxygen reduction events are mainly observed during REM sleep.

Acute effects of noninvasive ventilation on sleep physiology in patients with moderate to severe stable chronic obstructive pulmonary disease: a pilot study

Objective/backgroundChanges in sleep architecture in patients with Chronic Obstructive Pulmonary Disease (COPD) can be explained by a combination of physiological changes in breathing during sleep, with impairment of respiratory mechanics and reduction of arterial oxygenation. This study aimed to evaluate the acute effects of noninvasive ventilation (NIV) – compared to spontaneous breathing – on sleep latency and stages, and on the occurrence of sleep-related respiratory events, nocturnal hypoxemia, and changes in heart rate (HR) in patients with moderate to severe stable COPD. Patients/methodsPatients completed two polysomnography (PSG) studies: one during spontaneous breathing and one while receiving NIV in bilevel mode and with backup respiratory rate (RR.) setting. Sleepware G3 software was used for the analysis of PSG and pressure, volume, and ventilator flow curves × time. ResultsParticipants were 10 female patients with a mean age of 68.1 ± 10.2 years. NIV during sleep decreased sleep onset latency (17 ± 18.8 min vs 46.8 ± 39.5 min; p = 0.02), increased REM sleep time (41.2 ± 24.7 min vs 19.7 ± 21.7 min; p = 0.03), and decreased the obstructive apnea index (OAI) (0 vs 8.7 ± 18.8; p = 0.01). Lower mean HR (66.6 ± 4.1 bpm vs 70.6 ± 5.9 bpm; p = 0.03) and lower maximum HR (84.1 ± 7.3 bpm vs 91.6 ± 7.8 bpm; p = 0.03) were observed in PSG with NIV. ConclusionsThe use of NIV in patients with moderate to severe stable COPD while they were sleeping increased REM sleep time and decreased sleep onset latency, the number of obstructive respiratory events, and the mean and maximum HR.

Correlation between short-time and whole-night obstruction level tests for patients with obstructive sleep apnea

Identification of obstructive level is crucial for successful surgical outcomes in patients with obstructive sleep apnea (OSA). Unfortunately, most of the dynamic airway evaluations are performed for a short duration under drug-induced sleep; therefore, it is uncertain whether they represent airway events that occur during a whole night of sleep. This study was aimed to evaluate the correlation between obstructive levels that were identified by a short-time and a whole-night test in patients with OSA. Total 101 patients with OSA underwent drug-induced sleep fluoroscopy (DISF) and pressure manometry (PM). For DISF, the obstructive pattern was classified into one of three groups: soft palate, tongue-based, and a combined obstruction. PM was used to measure the proportion of retroglossal events out of total whole-night obstructive events in each patient. The mean age of the patients was 43.8 years. The obstructive pattern was identified as soft palate in 56 patients, combined in 38 patients, and tongue-based in 7 patients following DISF. Results from PM showed that the mean percentage of retroglossal obstructive events was 31.2 ± 30.7%. The average proportion of retroglossal obstructive events that were identified by PM in patients with soft palate, combined, and tongue-based obstruction was 27.2%, 32.1%, and 59.0%, respectively (p = 0.033). There are limitations of evaluating obstructive events that occur during a whole night with short-time tests. Surgeons should be aware the possibility of disagreement in the obstructive level between short-time and whole-night tests.

Severe Obstructive Sleep Apnoea Leading to Raised Intracranial Pressure Hydrocephalus in a Patient with Aqueduct Stenosis.

Patients with severe obstructive sleep apnoea (OSA) and hypoventilation require AVAPS-AE ventilation to deal with obstructive and central events which may occur.Arterial blood gas analysis and MRI of the brain are indicated in the assessment of patients with severe OSA.Hydrocephalus may develop in patients with severe OSA if there is a structural brain abnormality but may resolve with OSA treatment.

Three-Stage Breathing Effort Quantification for Obstructive Sleep Apnea Detection Based on Thoracic and Abdominal Movement Signals

A level-IV home-based sleep apnea monitoring system that utilizes alternative sensors, such as dual respiratory inductance plethysmography (RIP) belts, is proposed to promote routine apnea monitoring. Notably, continued excursion may occur in RIP belt signals, owing to the imperfect relationship between thoracic and abdominal movements during obstructive events. Therefore, we propose a novel algorithm to detect obstructive apnea based on an obstructive reciprocal divergence (ORD) continued excursion model and to explore the possibility of a multistage breathing-effort evaluation model using only RIP signals. Using the developed approach, we detected obstructive sleep apnea with a high accuracy of 99.83 ± 0.71% and a slight reduction of 73.34 ± 28.35% in hypopnea performance with overall combined objective metrics of 89.38 ± 10.53%. We found that introducing many stages improves specificity (p $\text{R}^{2}=0.98$ ; p < 0.001). The proposed approach can assist sleep technologists in characterizing obstructive and nonobstructive apneic events. Moreover, ORD is competent for further quantitative and qualitative IFL analysis and will significantly benefit the automated IFL detection system studies.

Expiratory obstruction in patients with Duchenne muscular dystrophy under non-invasive ventilation: A step-by-step analysis of a new obstructive pattern.

Purpose: Non-invasive ventilation (NIV) is the reference standard for managing chronic hypoventilation in patients with Duchenne muscular dystrophy (DMD). In these patients, upper airway obstruction under NIV may compromise efficacy and adherence. We aim to describe a novel pattern of expiratory obstructive events occurring during nocturnal barometric NIV. Methods: We retrospectively included all patients with DMD who underwent full-night polygraphy during NIV as part of their usual follow-up between May 2018 and July 2019. Results: We provide a step-by-step description of this previously undescribed pattern of obstruction. Expiratory obstructions lead to end-inspiratory breath-holding and impossibility to take another inspiratory breath with a barometric mode until expiration occurs. These events were observed in 4 (36%) of 11 DMD patients under barometric NIV. Conclusion: Expiratory obstructions may be common in DMD patients receiving NIV and should be sought out routinely. This previously undescribed variant of obstructive event must be identified.

An Effective Method for Distinguishing Sleep Apnea and Hypopnea Based on ECG Signals

Good sleep quality is essential to our life and work. The two major challenges in evaluating sleep quality are the scoring of sleep stages and sleep apnea detection. In addition to sleep apnea, hypopnea is also a respiratory event that occurs at an equal or even higher frequency compared to that of apnea. However, the two phenomena are not only different in terms of physical manifestation, there are also significant differences in the methods and means of clinical treatment. Therefore, in this study we propose an effective algorithm to distinguish between hypopnea and apnea events. We consider two aspects of feature extraction. On the one hand, from the original time-domain waveform of electrocardiogram signals, we extract the time difference sequence between the appearance of the R-R wave in two adjacent QRS waves (RR intervals) and explore the way they change when apnea and hypopnea event occur. On the other hand, considering that the degree of sequence disorder caused by hypopnea and apnea events is different, multi-scale entropy and complexity are chosen as the features that describe this change. The results obtained using the proposed algorithm show that the classification between hypopnea events and any type of apnea events all reach an accuracy rate greater than 90%. For obstructive apnea events, which occur most frequently among the three different types of apneas, the classification accuracy, sensitivity, specificity and F1-score were 91.78%, 92.21%, 91.30%, 92.20%, respectively. The classification results between central apnea events and hypopnea events reached an accuracy of 93.18%, sensitivity of 95.00%, specificity of 91.67% and F1-score of 92.68%. At the same time, the algorithm achieved an accuracy of 92.59%, sensitivity of 90.38%, specificity of 94.64% and F1-score of 92.16% when classifying mixed apnea and hypopnea events. In the classification of normal breathing, hypopnea events and apnea events, the total accuracy rate achieved was 91.92%, with that for normal breathing reaching 93.62%, for hypopnea events reaching 90.39%, and 91.91% for apnea events, with a Kappa coefficient of 0.99. The algorithm proposed in this study constitutes an efficient and convenient approach for apnea and hypopnea event detection and classification.

Long-Term Adherence to Positive Airway Pressure Therapy in Saudi Ambulatory Patients with Obesity Hypoventilation Syndrome and Severe Obstructive Sleep Apnea: A One-Year Follow-Up Prospective Observational Study.

PurposeLong-term studies assessing positive airway pressure (PAP) therapy adherence in patients with obesity hypoventilation (OHS) are limited. The aim of this study was to assess PAP therapy adherence in Arab (Saudi) patients with OHS and an apnea-hypopnea index (AHI) >30/h.MethodsA prospective cohort study of consecutive adult patients diagnosed with OHS between March 2010 and September 2019 was conducted. During the therapeutic sleep study, all OHS patients were started on continuous PAP (CPAP). Patients who failed to maintain oxygen saturation ≥88% despite the elimination of obstructive respiratory events were shifted to bi-level PAP (BPAP). Objective assessment of adherence was performed at 1, 6, and 12 months after initiating PAP therapy. We adopted the American-Thoracic-Society criteria for PAP adherence.ResultsThe study included 101 patients (women = 65 patients) with OHS, an AHI ≥30/h, and a mean age of 54.9 ± 12.7 years. Successful titration on CPAP was achieved in 64.4% of the patients and BPAP was required for 35.6% of the patients who failed CPAP titration. At the end of the study, 43.6% of the patients used PAP therapy in an acceptable manner. Adherence after 1 and 6 months was the only independent predictors of adherence at 12 months.ConclusionPAP adherence among Saudi patients with OHS and severe obstructive sleep apnea was relatively low. Almost two-thirds of patients tolerated CPAP titration with the elimination of respiratory events and desaturation. Early adherence to PAP therapy was the only predictor of PAP therapy adherence at the end of the study.

Automatic Detection of Obstructive Sleep Apnea Events Using a Deep CNN-LSTM Model.

Obstructive sleep apnea (OSA) is a common sleep-related respiratory disorder. Around the world, more and more people are suffering from OSA. Because of the limitation of monitor equipment, many people with OSA remain undetected. Therefore, we propose a sleep-monitoring model based on single-channel electrocardiogram using a convolutional neural network (CNN), which can be used in portable OSA monitor devices. To learn different scale features, the first convolution layer comprises three types of filters. The long short-term memory (LSTM) is used to learn the long-term dependencies such as the OSA transition rules. The softmax function is connected to the final fully connected layer to obtain the final decision. To detect a complete OSA event, the raw ECG signals are segmented by a 10 s overlapping sliding window. The proposed model is trained with the segmented raw signals and is subsequently tested to evaluate its event detection performance. According to experiment analysis, the proposed model exhibits Cohen's kappa coefficient of 0.92, a sensitivity of 96.1%, a specificity of 96.2%, and an accuracy of 96.1% with respect to the Apnea-ECG dataset. The proposed model is significantly higher than the results from the baseline method. The results prove that our approach could be a useful tool for detecting OSA on the basis of a single-lead ECG.

Cardiac Complications in Patients with COVID-19: An Integrative Literature Review

Objective: To verify, based on the literature, what the main cardiac complications are in patients with COVID-19, during treatment in a hospital unit. Materials and methods: An integrative review, carried out by searching for studies in eight national and international databases. The final sample consisted of 16 studies published between January and May 2020, which were subjected to structural evaluation by the following instruments: Case Report Guidelines, for case reports; and Strengthening the Reporting of Observational Studies in Epidemiology, for observational studies. Results: The main cardiac complications were predominantly obstructive events, herein understood as acute myocardial infarction, followed by severe arrhythmic conditions and heart failure, all due to the hyperinflammation condition resulting from viral infection. Conclusions: The knowledge about cardiac complications during COVID-19 treatment has become important, since it can collaborate for the adoption of more effective treatment protocols and guide the assistance offered by health professionals, in order to identify such complications and intervene early.

Obstructive respiratory events transiently impair electromechanical coupling and increase premature ventricular contraction rate in a drug-induced Long-QT-2 pig model

Abstract Background Obstructive sleep apnea (OSA) is characterized by intermittent negative thoracic pressure fluctuations and intermittent hypoxemic events. Recent findings associate OSA with impaired ventricular repolarization during sleep and increased risk of sudden cardiac death, which may have special implications for Long-QT-2-syndrome patients. Therefore, we elucidated changes in ventricular repolarization and electromechanical coupling (electromechanical window; EMW) during either obstructive respiratory events simulated by intermittent negative upper airway pressure (INAP) or hypoxemic events simulated by intermittent hypoxia (IH) in vehicle (VEH) and dofetilide (DOF) treated pigs, as a simulation of drug induced Long-QT-2 syndrome. Methods In sedated spontaneously breathing pigs, either VEH or DOF (50 μg/kg) was perfused and INAP was applied by a negative pressure device connected to the intubation tube. For IH-application the device was connected and left turned off. INAP or IH was maintained for 75 seconds followed by a ten-minute resting period. In order to evaluate the electromechanical window, the time difference between electrical (QT-duration) and mechanical systole (Q-wave to the end of left ventricular pressure signal, QLVPend) was measured before (pre-INAP/-IH), during and 60 seconds after INAP/IH (post-INAP/-IH). Incidence rates of premature ventricular contractions (PVC) and ventricular tachycardia were compared pre- to post-INAP/-IH. Results In VEH-pigs, EMW shortened throughout INAP and post-INAP periods steadily (VEH: pre-INAP: 81.69±2.31ms; INAP: 55.65±6.13ms; post-INAP: 38±8.89ms. p=0.008). EMW shortening during post-INAP was associated with an increase in PVCs (VEH: pre-INAP 5.41±1.87 vs. post-INAP 26.5±8.15; p=0.04). In DOF-pigs, INAP-associated EMW-shortening was further potentiated (DOF: pre-INAP: 61.16±7.18ms; INAP: 38.09±9.84ms; post-INAP: 14.93±9.24ms. p=0.016), which was associated with an increase in PVCs (DOF: pre-INAP 4.75±2.36 vs. post-INAP 36.58±10.92; p=0.017). Administration of Atenolol could prevent post-INAP shortening of the EMW and decrease counts of premature ventricular contractions. While desaturations were comparable in INAP and IH, IH did not result in EMW-shortening or increased arrhythmia risk. Conclusion Transient dissociation of the ventricular electromechanical coupling during a simulated obstructive apnea, but not during IH, creates a dynamic and sympathetically driven arrhythmogenic substrate. Apnea associated ventricular electromechanical uncoupling was aggravated in a drug-induced Long-QT-2 simulation. Whether OSA represents a modifiable arrhythmogenic risk factor in Long-QT-2-patients warrants further studies. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Novo nordisk fonden