Obstructive sleep apnea: current perspectives

Effect of minimally invasive surgery on the sleep quality and work ability of patients with obstructive sleep apnea-hypopnea syndrome

OBJECTIVE

To explore the effect of minimally invasive surgical treatment on the sleep quality and work ability of patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

Fifty-one patients who underwent minimally invasive surgery in the Sleep Respiratory Disease Diagnostic and Treatment Center of the West China Fourth Hospital of Sichuan University from January 2017 to January 2019 were selected as study subjects. All subjects completed polysomnography monitoring (PSG), an Epworth sleepiness scale (ESS), and a work ability index (WAI) before and 1 year after the minimally invasive surgery so that the changes could be compared.

RESULTS

(1) The apnea-hypopnea index (AHI), microarousal index (MAI), ESS, longest duration of apnea, and longest duration of hypoventilation in OSAHS patients decreased, while the lowest blood oxygen saturation (LsaO₂) increased after minimally invasive surgery. The differences were statistically significant (p < 0.05). (2) The WAI questionnaire score increased from (37.76 ± 4.46) to (40.00 ± 4.53) after minimally invasive surgery (P < 0.05). (3) The change in the WAI questionnaire score after minimally invasive surgery was influenced by the occupational category and the change in ESS.

CONCLUSION

Minimally invasive surgical treatment shows significant benefit in improving the sleep quality and working ability of patients with OSAHS.

Dimethyl Fumarate and Its Esters: A Drug with Broad Clinical Utility?

Fumaric acid esters (FAEs) are small molecules with anti-oxidative, anti-inflammatory and immune-modulating effects. Dimethyl fumarate (DMF) is the best characterised FAE and is approved and registered for the treatment of psoriasis and Relapsing-Remitting Multiple Sclerosis (RRMS). Psoriasis and RRMS share an immune-mediated aetiology, driven by severe inflammation and oxidative stress. DMF, as well as monomethyl fumarate and diroximel fumarate, are commonly prescribed first-line agents with favourable safety and efficacy profiles. The potential benefits of FAEs against other diseases that appear pathogenically different but share the pathologies of oxidative stress and inflammation are currently investigated.

Prevalence of Sleep-Disordered Breathing in a Cohort of Adult Fontan Patients

Sleep-disordered breathing (SDB) is described in patients with acquired heart failure but its prevalence in adults with congenital heart disease is not well documented. It is likely that single-ventricle patients who have undergone Fontan palliation poorly tolerate the additional stress of SDB on their fragile cardiac physiology. This study sought to determine the prevalence of SDB in a population of adult Fontan patients. We performed a retrospective chart review of adult Fontan patients followed in our program (n = 55). All charts were evaluated for documentation of polysomnography (PSG). SDB was characterized as nocturnal hypoxemia without apnea or obstructive sleep apnea (OSA). Baseline demographics and clinical characteristics were documented, as were PSG findings including Apnea Hypopnea Index (AHI, events/hour) and desaturation events of > 5% from baseline saturation. Twenty-two of our 55 patients (40%) had undergone PSG (45% male, mean age 29 years). Of these patients, 17 had a PSG positive for SDB (77%). Nine patients (41%) had nocturnal hypoxemia without apnea, while 8 patients (36%) had a PSG positive for OSA. Lower baseline oxygen saturations, but not BMI or age, were statistically significantly correlated with higher AHI. SDB was present in the majority of our Fontan cohort who had undergone PSG, occurring at a higher prevalence than what is described in the general population, suggesting that screening should be considered for all Fontan patients. However, further study is needed to confirm this prevalence in a larger population, and if therapy has an impact on clinical outcomes.

Sudden death in individuals with obstructive sleep apnoea: protocol for a systematic review and meta-analysis

INTRODUCTION

Obstructive sleep apnoea (OSA) is a form of sleep-disordered breathing, characterised by blockage of the airway, snoring, gasping for air during sleep, daytime sleepiness and fatigue. OSA is associated with increased risk of cardiovascular and cerebrovascular morbidity and mortality, and sudden cardiac death (SCD). The magnitude of this risk varies in the literature and therefore we aim to systematically assess this risk. This study protocol proposes a meta-analysis and systematic review aimed to estimate the magnitude of the association between OSA, 'sudden death' and cardiovascular death.

METHODS

We will conduct a systematic review and meta-analysis of studies published from the inception of each database, which report the risk of 'sudden death' or cardiovascular death (including SCD) in individuals diagnosed with OSA versus persons without OSA. The primary outcome of interest in this study will be the relative risk of 'sudden death' in patients diagnosed with OSA in comparison to those without an OSA diagnosis. We will search the following electronic research databases: PubMed (MEDLINE), Cochrane, OVID (Healthstar), OVID (Medline), Scopus and Joana Briggs Institute EBP Database. This protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines. The checklist for this document is included in the supplemental material. Two reviewers will screen articles for inclusion criteria, extracting appropriate data and evaluating the quality of the included studies. The methodological quality of studies will be appraised using an appropriate tool. Funnel plots and the Egger's test will be employed to evaluate potential publication bias. We will fit random-effects model with inverse-variance methods for the pooling effect estimates. We will conduct a meta-regression analysis, using numerous variables of interest including age, gender, race, body mass index, hypertension and diabetes, to explore sources of study heterogeneity.

PROSPERO REGISTRATION NUMBER

CRD42020164941.

ETHICS AND DISSEMINATION

No ethics clearance was required for this protocol, for no primary data are being collected on research subjects. Only secondary analysis of pre-existing data in scientific databases will be evaluated. The findings of this meta-analysis will be published in a peer-reviewed journal and presented at scientific conferences. These results may assist professionals in the prevention and management of OSA and SCD.

Variations in loop gain and arousal threshold during NREM sleep are affected by time of day over a 24-hour period in participants with obstructive sleep apnea

We investigated whether time of day affects loop gain (LG) and the arousal threshold (AT) during non-rapid eye movement (NREM) sleep. Eleven men with obstructive sleep apnea (apnea-hypopnea index > 5 events/h) completed a constant-routine protocol that comprised 3-h sleep sessions in the evening [10 PM (1) to 1 AM], morning (6 AM to 9 AM), afternoon (2 PM to 5 PM), and subsequent evening [10 PM (2) to 1 AM]. During each sleep session LG and the AT were measured during NREM sleep with a model-based approach. Our results showed the presence of a rhythmicity in both LG (P < 0.0001) and the AT (P < 0.001) over a 24-h period. In addition, LG and the AT were greater in the morning compared with both evening sessions [6 AM vs. 10 PM (1) vs. 10 PM (2): LG (1 cycle/min): 0.71 ± 0.23 vs. 0.60 ± 0.22 (P = 0.01) vs. 0.56 ± 0.10 (P < 0.001), AT (fraction of eupneic breathing): 1.45 ± 0.47 vs. 1.28 ± 0.36 (P = 0.02) vs. 1.20 ± 0.18 (P = 0.001)]. No difference in LG and the AT existed between the evening sessions (LG: P = 0.27; AT: P = 0.24). LG was correlated to measures of the hypocapnic ventilatory response (i.e., a measure of chemoreflex sensitivity) (r = 0.72 and P = 0.045) and the critical closing pressure (i.e., a measure of airway collapsibility) (r = 0.77 and P = 0.02) that we previously published. We conclude that time of day, independent of hallmarks of sleep apnea, affects LG and the AT during NREM sleep. These modifications may contribute to increases in breathing instability in the morning compared with other periods throughout the day/night cycle in individuals with obstructive sleep apnea. In addition, efficaciousness of treatments for obstructive sleep apnea that target LG and the AT may be modified by a rhythmicity in these variables.NEW & NOTEWORTHY Loop gain and the arousal threshold during non-rapid eye movement (NREM) sleep are greater in the morning compared with the afternoon and evening. Loop gain measures are correlated to chemoreflex sensitivity and the critical closing pressure measured during NREM sleep in the evening, morning, and afternoon. Breathing (in)stability and efficaciousness of treatments for obstructive sleep apnea may be modulated by a circadian rhythmicity in loop gain and the arousal threshold.

Screening for obstructive sleep apnea with novel hybrid acoustic smartphone app technology

Background

Obstructive sleep apnea (OSA) has a high prevalence, with an estimated 425 million adults with apnea hypopnea index (AHI) of ≥15 events/hour, and is significantly underdiagnosed. This presents a significant pain point for both the sufferers, and for healthcare systems, particularly in a post COVID-19 pandemic world. As such, it presents an opportunity for new technologies that can enable screening in both developing and developed countries. In this work, the performance of a non-contact OSA screener App that can run on both Apple and Android smartphones is presented.

Methods

The subtle breathing patterns of a person in bed can be measured via a smartphone using the "Firefly" app technology platform [and underpinning software development kit (SDK)], which utilizes advanced digital signal processing (DSP) technology and artificial intelligence (AI) algorithms to identify detailed sleep stages, respiration rate, snoring, and OSA patterns. The smartphone is simply placed adjacent to the subject, such as on a bedside table, night stand or shelf, during the sleep session. The system was trained on a set of 128 overnights recorded at a sleep laboratory, where volunteers underwent simultaneous full polysomnography (PSG), and "Firefly" smartphone app analysis. A separate independent test set of 120 recordings was collected across a range of Apple iOS and Android smartphones, and withheld for performance evaluation by a different team. An operating point tuned for mid-sensitivity (i.e., balancing sensitivity and specificity) was chosen for the screener.

Results

The performance on the test set is comparable to ambulatory OSA screeners, and other smartphone screening apps, with a sensitivity of 88.3% and specificity of 80.0% [with receiver operating characteristic (ROC) area under the curve (AUC) of 0.92], for a clinical threshold for the AHI of ≥15 events/hour of detected sleep time.

Conclusions

The "Firefly" app based sensing technology offers the potential to significantly lower the barrier of entry to OSA screening, as no hardware (other than the user's personal smartphone) is required. Additionally, multi-night analysis is possible in the home environment, without requiring the wearing of a portable PSG or other home sleep test (HST).

Cardiovascular Outcomes Post Percutaneous Coronary Intervention in Patients with Obstructive Sleep Apnea and Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is a major risk factor for the occurrence of cardiovascular diseases. Similar to T2DM, obstructive sleep apnea (OSA) is also known to be a risk factor for cardiovascular diseases. In this analysis, we aimed to systematically compare the post-interventional cardiovascular outcomes observed in patients with T2DM with versus without OSA.

METHODS

Electronic databases were searched for relevant publications comparing the cardiovascular outcomes following percutaneous coronary intervention (PCI) in patients with T2DM with OSA. Cardiovascular outcomes were considered as the relevant endpoints. The RevMan software 5.3 was used to carry out the statistical analysis. Odds ratios (OR) with 95% confidence intervals (CI) were used to represent the results following data assessment.

RESULTS

A total of 1168 participants with T2DM were included in this analysis, of whom 614 had co-existing OSA. The time period of patients' enrollment varied from year 2002 to 2017. Our current analysis showed that major adverse cardiac events (MACEs) (OR 2.28, 95% CI 1.24-4.18; P = 0.008) and all-cause mortality (OR 1.95, 95% CI 1.08-3.54; P = 0.03) were significantly higher in the OSA subgroup. However, major adverse cerebrovascular and cardiovascular (MACCEs) (OR 1.38, 95% CI 0.97-1.98; P = 0.07) and cardiac death (OR 1.79, 95% CI 0.77-4.16; P = 0.18) were not significantly different post PCI. In addition, hospitalization for heart failure (OR 1.99, 95% CI 0.43-9.25; P = 0.38), re-infarction (OR 1.52, 95% CI 0.85-2.70; P = 0.16), stroke (OR 1.81, 95% CI 0.81-4.08; P = 0.15), target vessel revascularization (TVR) (OR 1.54, 95% CI 0.98-2.42; P = 0.06), and target lesion revascularization (TLR) (OR 1.32, 95% CI 0.80-2.18; P = 0.28) were also not significantly different post PCI in the patients with T2DM with versus without OSA.

CONCLUSION

OSA was associated with a significant increase in all-cause mortality and MACEs post PCI in these patients with T2DM. Therefore, special care and continuous follow-up might be required for patients with T2DM with associated OSA after PCI. However, as a result of the limited number of participants, further larger studies would be required to confirm these hypotheses.

Phenotype of ventilatory control in children with moderate to severe persistent asthma and obstructive sleep apnea

STUDY OBJECTIVES

To examine the role of ventilatory control in asthmatic children with obstructive sleep apnea (OSA) and the relationships between measures of ventilatory control, OSA severity, and pulmonary function.

METHODS

Five- to 18-year-old children with persistent asthma and nightly snoring were enrolled in the study. Children had physical examination, pulmonary function test, and polysomnography. Loop and controller gains were derived from 5 min segments which included a sigh during nonrapid eye movement sleep by applying a mathematical model that quantifies ventilatory control from the ensuing responses to the sighs. Plant gain was derived from 5 min segments of spontaneous breathing (i.e. without sighs). Nonparametric statistical tests were used for group comparisons. Cluster analysis was performed using Bayesian profile regression.

RESULTS

One hundred thirty-four children were included in the study, 77 with and 57 without OSA. Plant gain was higher in children with OSA than in those without OSA (p = 0.002). A negative correlation was observed between plant gain and forced expiratory volume in 1 second (p = 0.048) and the ratio of f forced expiratory volume to forced vital capacity (p = 0.02). Plant gain correlated positively with severity of OSA. Cluster analysis demonstrated that children with more severe OSA and abnormal lung function had higher plant gain and a lower controller gain compared with the rest of the population.

CONCLUSIONS

Children with OSA and persistent asthma with abnormal lung function have phenotypic characteristics which consist of diminished capacity of the lungs to maintain blood gas homeostasis reflected by an increase in plant gain and decreased chemoreceptor sensitivity.

Imaging of sleep-disordered breathing in adults

Sleep-disordered breathing (SDB) is a term that includes several chronic conditions in which partial or complete cessation of breathing occurs multiple times throughout the night. Central sleep apnoea (CSA) is uncommon and defined by the episodic cessation of airflow without respiratory effort. Lesions involving the respiratory centre in the brainstem or the origin of the phrenic nerve from the mid-cervical cord are the commonest structural causes of CSA; magnetic resonance imaging (MRI) will demonstrate the lesion and frequently suggest the likely aetiology. In contrast, obstructive sleep apnoea (OSA) is defined as upper airway obstruction despite ongoing respiratory effort. Repetitive episodes of narrowing or closure of the upper airway are the predominant cause leading to snoring and OSA, respectively. OSA affects 33-40% of the adult population and is associated with multiple adverse health consequences, including a significantly increased risk of serious morbidity and mortality. The incidence is increasing proportionally to the worldwide rise in obesity. Imaging, performed primarily without the involvement of radiologists, has been integral to understanding the anatomical basis of SDB and especially OSA. This article will review the pathophysiology, imaging findings, and sequelae of these common conditions. The role of imaging both in suggesting the incidental diagnoses of SDB and in the investigation of these conditions when the diagnosis is suspected or has been established are also discussed.

Alzheimer's Disease in Patients with Obstructive Sleep Apnea Syndrome

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is a disorder with high prevalence among adults and is an independent risk factor for various diseases, especially those affecting the central nervous system (CNS). Continuous positive airway pressure (CPAP) is usually the optimal choice of treatment for OSAS. Alzheimer's disease (AD) is a neurodegenerative disease affecting a large proportion of the elderly population. The purpose of this study was to collect information concerning the two pathological entities and investigate the effectiveness of CPAP in the treatment of AD.

MATERIALS AND METHODS

In this review, Twenty articles were found concerning OSAS and AD, of which one article was about treatment with donepezil and seven articles considered treatment with CPAP.

RESULTS

Serious OSAS and short sleep duration are associated with a high risk of developing dementia. Respiratory distress during sleep is associated with developing mild cognitive impairment at younger ages. The cerebrovascular damage of AD patients is correlated with the severity of OSAS. Lower cerebrospinal fluid levels are associated with memory disturbances and oxygen saturation parameters in patients with OSAS-AD. Continuous use of CPAP is related to the delayed onset of cognitive impairment and is suggested as an effective method of protecting cognitive function, depression, sleep quality and architecture, and daytime sleepiness in AD patients with good compliance. Treatment of CPAP patients with OSAS-AD is suggested as an effective method of protecting cognitive function.

CONCLUSION

Clinicians dealing with AD patients should consider CPAP treatment when OSAS coexists.

Prevalence and patterns of tongue deformation in obstructive sleep apnea: A whole-night simultaneous ultrasonographic and polysomnographic study

Tongue deformation during whole-night natural sleep in adult patients with obstructive sleep apnea has not been well evaluated. Through simultaneous ultrasonography and polysomnography during whole-night sleep, we examined the prevalence and patterns of tongue depth changes and their relationship with the severity of obstructive sleep apnea. Sixty consecutive eligible adults presenting with symptoms suggesting obstructive sleep apnea were enrolled. We observed that 88.4% (38/43) of patients with obstructive sleep apnea exhibited a significant increase in the maximum ultrasonographic tongue depth when hypopnea or apnea occurred during sleep. A mixed-model analysis of variance demonstrated that compared with patients with primary snoring or mild obstructive sleep apnea, those with moderate to severe obstructive sleep apnea have significantly greater maximum ultrasonographic tongue depth during respiratory events (p = .0047). We identified three different ultrasonographic patterns of tongue deformation, namely en bloc, tongue body and tongue base. Approximately 82% (27/33) of patients with moderate to severe obstructive sleep apnea demonstrated an en bloc tongue deformation. By contrast, 70% (19/27) of primary snorers or patients with mild obstructive sleep apnea showed a tongue body obstruction. Recognizing the prevalence and patterns of tongue deformation during sleep may provide insights into pathogenesis and treatment decisions in patients with obstructive sleep apnea. Future studies are warranted to verify the treatment results of various tongue procedures by using this approach.

Performance of brief ICF-sleep disorders and obesity core set in obstructive sleep apnea patients

BACKGROUND

Clinical questionnaires are mainly applied as screening tools for identification of the Obstructive sleep apnea (OSA) patients. Little attention has been paid to assess the body functions and health status of the patients. International Classification of Functioning, Disability and Health (ICF) was designed for better understanding and describing functioning and disability of patients. This study adopted the Brief ICF-Sleep Disorders and Obesity Core Set to evaluate the impairment of functioning and health status of OSA patients.

METHODS

Five hundred ninety-two participants were enrolled in this cross-sectional study. Data were collected using Brief ICF-Sleep Disorders and Obesity Core Set Polysomnography was performed and basic characteristics of the patients were recorded.

RESULTS

The scores for the component Body Functions and Code b130, b134, b140, b440, b530, s330, d160, d240, d450 of the two core sets were significantly different among the patients divided by apnea-hypopnea index (AHI) or oxygen saturation (SaO2) nadir, but the frequency of code s330, d160, d240, d450 was low. The Body Functions component of the both sets were closely related to neck circumference (NC), body mass index (BMI), apnea-hypopnea index (AHI) of the OSA patients. Body Functions of the Brief ICF-Sleep Disorders performed better with a threshold of 4 with sensitivity, specificity and area under the receiver operating characteristic curve (AUC) as 0.62, 0.74, 0.68(AHI ≥ 5), 0.69, 0.63, 0.66 (AHI ≥ 15), 0.75, 0.56, 0.66 (AHI ≥ 30), 0.56, 0.70, 0.63 (SaO2 nadir≤90%), 0.67, 0.66, 0.66 (SaO2 nadir<85%), 0.71, 0.59, 0.65 (SaO2 nadir<80%), separately.

CONCLUSION

The Body Functions component of both two sets could be an evaluation tool of impairment of body functions for OSA patients. The Brief ICF-Sleep Disorders Body Functions component performed better with a threshold of 4 and might provide a new insight for physicians to assess OSA patients.

Dynamics of ACTH and Cortisol Secretion and Implications for Disease

The past decade has seen several critical advances in our understanding of hypothalamic-pituitary-adrenal (HPA) axis regulation. Homeostatic physiological circuits need to integrate multiple internal and external stimuli and provide a dynamic output appropriate for the response parameters of their target tissues. The HPA axis is an example of such a homeostatic system. Recent studies have shown that circadian rhythmicity of the major output of this system-the adrenal glucocorticoid hormones corticosterone in rodent and predominately cortisol in man-comprises varying amplitude pulses that exist due to a subhypothalamic pulse generator. Oscillating endogenous glucocorticoid signals interact with regulatory systems within individual parts of the axis including the adrenal gland itself, where a regulatory network can further modify the pulsatile release of hormone. The HPA axis output is in the form of a dynamic oscillating glucocorticoid signal that needs to be decoded at the cellular level. If the pulsatile signal is abolished by the administration of a long-acting synthetic glucocorticoid, the resulting disruption in physiological regulation has the potential to negatively impact many glucocorticoid-dependent bodily systems. Even subtle alterations to the dynamics of the system, during chronic stress or certain disease states, can potentially result in changes in functional output of multiple cells and tissues throughout the body, altering metabolic processes, behavior, affective state, and cognitive function in susceptible individuals. The recent development of a novel chronotherapy, which can deliver both circadian and ultradian patterns, provides great promise for patients on glucocorticoid treatment.

Screening for obstructive sleep apnea amongst patients with retinal vein occlusion

OBJECTIVE

To evaluate the prevalence and varying severity of obstructive sleep apnea (OSA) amongst those newly diagnosed with retinal vein occlusion (RVO), and screen patients with the use of 2 in-office-administered questionnaires validated against polysomnography.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS

Consecutive adult patients (≥18 years of age) with a new diagnosis of RVO confirmed with intravenous fluorescein angiography were enrolled.

METHODS

The study was conducted at a tertiary academic centre between March 22, 2017, and April 7, 2018. Patients completed the Berlin and STOP-BANG questionnaires screening for OSA at presentation. Diagnostic test properties of the 2 questionnaires compared with polysomnography at a certified sleep laboratory centre as the gold standard for detection of OSA were calculated.

RESULTS

A total of 27 patients (37% females) with a mean (standard deviation) age of 69.6 (11.5) years completed the study. The diagnosis of OSA based on polysomnography was made in 96% (41% severe OSA) of patients with RVO. The Berlin questionnaire had a sensitivity of 43% (confidence interval [CI]: 22%-66%) and specificity of 67% (CI: 22%-96%). The STOP-BANG questionnaire had a sensitivity of 86% (CI: 64%-97%) and specificity of 50% (CI: 12%-88%).

CONCLUSIONS

Given the high prevalence of severe OSA amongst those with a new diagnosis of RVO, all patients should be strongly considered for polysomnography. The use of in-office questionnaires may aid in triaging urgency of referrals.

An assessment of a simple clinical technique to estimate pharyngeal collapsibility in people with obstructive sleep apnea

Study Objectives

Quantification of upper airway collapsibility in obstructive sleep apnea (OSA) could help inform targeted therapy decisions. However, current techniques are clinically impractical. The primary aim of this study was to assess if a simple, novel technique could be implemented as part of a continuous positive airway pressure (CPAP) titration study to assess pharyngeal collapsibility.

Methods

A total of 35 participants (15 female) with OSA (mean ± SD apnea–hypopnea index = 35 ± 19 events/h) were studied. Participants first completed a simple clinical intervention during a routine CPAP titration, where CPAP was transiently turned off from the therapeutic pressure for ≤5 breaths/efforts on ≥5 occasions during stable non-rapid eye movement (non-REM) sleep for quantitative assessment of airflow responses (%peak inspiratory flow [PIF] from preceding 5 breaths). Participants then underwent an overnight physiology study to determine the pharyngeal critical closing pressure (Pcrit) and repeat transient drops to zero CPAP to assess airflow response reproducibility.

Results

Mean PIF of breaths 3–5 during zero CPAP on the simple clinical intervention versus the physiology night were similar (34 ± 29% vs. 28 ± 30% on therapeutic CPAP, p = 0.2; range 0%–90% vs. 0%–95%). Pcrit was −1.0 ± 2.5 cmH2O (range −6 to 5 cmH2O). Mean PIF during zero CPAP on the simple clinical intervention and the physiology night correlated with Pcrit (r = −0.7 and −0.9, respectively, p &lt; 0.0001). Receiver operating characteristic curve analysis indicated significant diagnostic utility for the simple intervention to predict Pcrit &lt; −2 and &lt; 0 cmH2O (AUC = 0.81 and 0.92), respectively.

Conclusions

A simple CPAP intervention can successfully discriminate between patients with and without mild to moderately collapsible pharyngeal airways. This scalable approach may help select individuals most likely to respond to non-CPAP therapies.

Upper airway collapsibility measured using a simple wakefulness test closely relates to the pharyngeal critical closing pressure during sleep in obstructive sleep apnea

STUDY OBJECTIVES

A collapsible or crowded pharyngeal airway is the main cause of obstructive sleep apnea (OSA). However, quantification of airway collapsibility during sleep (Pcrit) is not clinically feasible. The primary aim of this study was to compare upper airway collapsibility using a simple wakefulness test with Pcrit during sleep.

METHODS

Participants with OSA were instrumented with a nasal mask, pneumotachograph and two pressure sensors, one at the choanae (PCHO), the other just above the epiglottis (PEPI). Approximately 60 brief (250 ms) pulses of negative airway pressure (~ -12 cmH2O at the mask) were delivered in early inspiration during wakefulness to measure the upper airway collapsibility index (UACI). Transient reductions in the continuous positive airway pressure (CPAP) holding pressure were then performed during sleep to determine Pcrit. In a subset of participants, the optimal number of replicate trials required to calculate the UACI was assessed.

RESULTS

The UACI (39 ± 24 mean ± SD; range = 0%-87%) and Pcrit (-0.11 ± 2.5; range: -4 to +5 cmH2O) were quantified in 34 middle-aged people (9 female) with varying OSA severity (apnea-hypopnea index range = 5-92 events/h). The UACI at a mask pressure of approximately -12 cmH2O positively correlated with Pcrit (r = 0.8; p < 0.001) and could be quantified reliably with as few as 10 replicate trials. The UACI performed well at discriminating individuals with subatmospheric Pcrit values [receiver operating characteristic curve analysis area under the curve = 0.9 (0.8-1), p < 0.001].

CONCLUSIONS

These findings indicate that a simple wakefulness test may be useful to estimate the extent of upper airway anatomical impairment during sleep in people with OSA to direct targeted non-CPAP therapies for OSA.

Qualitative Phenotyping of Obstructive Sleep Apnea and Its Clinical Usefulness for the Sleep Specialist

INTRODUCTION

The anatomical collapsibility of the upper airway, neuromuscular tone and function, sleep-wake and ventilatory control instability, and the arousal threshold all interact and contribute to certain pathophysiologic features that characterize different types of obstructive sleep apnea (OSA). A model of qualitative phenotypizationallowsus to characterize the different pathophysiological traits in OSA patients.

METHODS

A narrative review was performed, to analyze the available literature evidence, with the purpose of generating a model of qualitative phenotypization to characterize pathophysiological traits in patients with OSA.

RESULTS

96 out of 3829 abstracts were selected for full-text review. Qualitative phenotyping model of OSA:Data concerning the OSA qualitative pathophysiological traits' measurement can be deducted by means of clinical PSG, grade of OSA severity, and therapeutic level of Continuous Positive Airway Pressure (CPAP) and are reported in the text. This approach would allow qualitative phenotyping with widely accessible methodology in a routine clinical scenario and is of particular interest for the sleep specialist, surgical treatment decision-making, and customized OSA multimodality treatment.

Mobile health application to support CPAP therapy in obstructive sleep apnoea: design, feasibility and perspectives

Background

Current continuous positive airway pressure (CPAP) devices can be monitored remotely; however, in-person visits are kept for clinical follow-up in order to promote CPAP use and resolve potential side-effects. Mobile health is a promising way to provide remote and easy clinical control for CPAP follow-up and support. We aimed to evaluate the feasibility and acceptance by obstructive sleep apnoea (OSA) patients and healthcare professionals of a newly designed mobile app (Appnea-Q) to promote clinical control through a self-monitoring tool for patients with CPAP supervised by sleep professionals.

Methods

Appnea-Q incorporates a simple follow-up questionnaire with automated responses, together with frequent problems and lifestyle recommendations sections. Feasibility, acceptance and usefulness were assessed. First, an internal validation was performed during outpatient CPAP follow-up visits with sleep professionals from various sleep units. Second, an external validation was performed in a subgroup of 15 patients at home.

Results

Most patients (n=75) considered the app useful and were willing to use it and recommend it (72-88%). Up to 64.87% agreed on its capacity to reduce hospital visits. Appnea-Q was rated as acceptable (79.37±19.29) by the system usability score. Sleep professionals (n=30) concurred on its usefulness for OSA patient follow-up, particularly during the first month of CPAP therapy. The external validation showed its feasibility among 11 out of 15 patients and their data were received accordingly on the professionals' web platform.

Conclusions

According to our validation process, and the viewpoints of the patients and professionals, our new mobile app is a feasible and well-received tool for personal OSA management. Future clinical trials should substantiate its performance and cost-effectiveness in the clinical arena.

Effects of a comprehensive physical therapy on moderate and severe obstructive sleep apnea- a preliminary randomized controlled trial

BACKGROUND

Critically compromised by upper airway anatomical impaired properties, obstructive sleep apnea (OSA) can be categorized into different phenotypic traits, mainly including oropharyngeal muscle dysfunction. The upper airway muscle strength training was targeted on oropharyngeal muscle dysfunction by re-educating the oropharyngeal muscles to maintain the upper airway patency. OSA was characterized with multilevel collapsibility of the upper airway; however, the programs are still inconsistent and the effects are unknown. Therefore, the purpose of this study was to investigate the effects of a comprehensive physical therapy on OSA.

METHODS

Fifteen subjects with newly diagnosed moderate or severe OSA (AHI ≥ 15) were randomized into intervention and control groups. The intervention group underwent a 12-week-intervention of hospital based physical therapy, while the control group was kept on waiting for 12 weeks. Polysomnography (PSG) data, oropharyngeal and respiratory muscle performance were measured before and after intervention.

RESULTS

In intervention group (n = 8), AHI was significantly improved (from 46.96 ± 19.45 to 32.78 ± 10.78 events/h, p = 0.017); in control group (n = 7), AHI was significantly increased (from 35.77 ± 17.49 to 42.96 ± 17.32 events/h, p = 0.043). While the control group remained no change between pre- and post- intervention, the intervention group demonstrated that other PSG outcomes significantly improved, including arousal index (46.04 ± 18.9 versus 32.98 ± 8.35/h), mean SpO₂ (92.88 ± 2.1 versus 94.13 ± 1.46%), and oxygen desaturation index (ODI) (31.13 ± 19.48 versus 20.57 ± 7.83/h).

CONCLUSION

This comprehensive physical therapy can be prescribed for the significant clinical improvement on sleep apnea for the patients with moderate and severe OSA.

A Review of Current Tools Used for Evaluating the Severity of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common and heterogeneous disease characterized by episodic collapse within the upper airways, which leads to reduced ventilation and adverse consequences, including hypoxia, hypercapnia, sleep fragmentation, and long-term effects such as cardiovascular comorbidities. The clinical diagnosis of OSA and its severity classification are often determined based on the apnea-hypopnea index (AHI), defining the number of apneic and hypopnea events per hour of sleep. However, the limitations of the AHI to assess disease severity have necessitated the exploration of other metrics for additional information to reflect the complexity of OSA. Novel parameters such as the hypoxic burden have the potential to better capture the main features of OSA by maximizing the information available from the polysomnogram. These emerging measures have described multidimensional qualities of sleep-disordered breathing events and breathing irregularity and will ultimately result in better management of OSA.

[Effectiveness of spirolactone on the treatment of laryngeal edema and complications after H-uvulopalatopharyngoplasty for patients with obstructive sleep apnea]

Objective:To determine whether taking spirolactone orally after H-UPPP may relieve laryngeal edema and complications for patients with obstructive sleep apnea（OSA）. Method:Fifty patients with OSA to undergo H-UPPP operation were randomly divided equally to the intervention group（taking spirolactone 20 mg orally twice a day for 7 days after H-UPPP） or the control group, all patients received conventional therapy after H-UPPP including anti-infection, hemostatic treatment, fluid replacement and expectorant by fogged absorption. The pharyngeal wound, diet, sleep and speaking pronunciation of all patients in each group were evaluated every other day in 7 days postoperation. The minimum oxygen saturation of blood（SaO2） during sleep at night each day and the period needed for staphyledema resolution of all patients were recorded and compared between each group. Result:Postoperatively, the intervention group had significantly slighter bleeding at wound site, better sleep and more legible speaking pronunciation than the control group after 3 days to 5 days（P<0.05）. The wound dehiscence of the intervention group was significantly slighter than the control group within 7 days after operation（P<0.05）. During 3 days to 7days after operation, the intervention group had a significantly better diet than the control group（P<0.05）. The average minimum SaO2during sleep at night in the intervention group was significantly higher than that in the control group from 3 days to 5 days post operation（P<0.05）. Period needed for staphyledema resolution in the intervention group（4.1±1.5） days was significantly shorter than that in the control group（5.9±1.8） days （P<0.05）. Conclusion:Taking spirolactone orally after H-UPPP may relieve laryngeal edema and complications for OSA patients, and it will also shorten the period needed for staphyledema resolution.

Gender Differences in the Clinical and Polysomnographic Characteristics Among Australian Aboriginal Patients with Obstructive Sleep Apnea

BACKGROUND

In this study, we assessed the clinical and polysomnographic (PSG) characteristics according to gender among Australian Aboriginal men and woman diagnosed to have obstructive sleep apnea (OSA).

METHODS

In this retrospective study, all adult Aboriginal patients over 18 years of age diagnosed to have OSA with an apnea hypopnea index (AHI) > 5/hour over a 5 year period were included.

RESULTS

Of the 337 patients (168 females and 169 males), who underwent a diagnostic PSG, 297 (88%) were diagnosed to have OSA (AHI) >5/hour), 154/297 males (52%) and 143/297 females (48%). Amongst male and female patients with OSA, 63% and 37% were in the severe spectrum (AHI>30/hour). The male cohort had higher stage N1 NREM sleep (P<0.001), reduced N3 NREM sleep (P<0.001), higher AHI severity (P<0.001), higher NREM AHI (P<0.001), and high arousal index (P<0.005). REM sleep-related AHI was higher among female patients with all severity of OSA, along with severe oxygen desaturation during REM sleep. Among patients with severe OSA, the female cohort were younger (age 46 years vs 49 years, P=0.030) and had higher BMI with all severity of OSA, while males had larger neck circumference compared to females. Hypertension increased the odds of severe OSA versus the combined odds of mild and moderate OSA for both genders.

CONCLUSION

This study highlights some important differences in the way sleep apnea manifests in Australian Aboriginal males and females and further studies are warranted to explore avenues to look for a physiological basis for these observations and targeted interventions.

Relationship between the activity of the genioglossus, other peri-pharyngeal muscles and flow mechanics during wakefulness and sleep in patients with OSA and healthy subjects

INTRODUCTION

In patients with OSA, substantial increases in genioglossus (GG) activity during hypopneas/apneas usually fail to restore normal airflow. The present study was undertaken to evaluate if this phenomenon can be explained by reduced activation of other peri-pharyngeal muscles.

METHODS

We recorded EMGs of the GG and four other peri-pharyngeal muscles (accessory dilators, AD), in 8 patients with OSA and 12 healthy subjects, during wakefulness and sleep. Repetitive events of flow limitation were induced during sleep. The events with the highest increases in AD activity were evaluated, to assess if combined activation of both the GG and AD to levels higher than while awake ameliorate airflow reduction during sleep.

RESULTS

Flow limitation triggered large increases in GG-EMG, but only modest augmentation in AD activity. Nevertheless, phasic EMG activity was present in 40 % of the ADs during sleep. In multiple events, increases of both GG and AD activity to levels substantially higher than while awake were not associated with improvement in airflow.

CONCLUSIONS

We conclude that sleep-induced reduction in AD response to airway obstruction cannot completely explain the failure of upper airway dilators to maintain pharyngeal patency. We speculate that reduction in dilator muscle efficacy may be due to the alterations in motor units recruitment patterns during sleep.

Co-Morbid Insomnia and Sleep Apnea (COMISA): Prevalence, Consequences, Methodological Considerations, and Recent Randomized Controlled Trials

Co-morbid insomnia and sleep apnea (COMISA) is a highly prevalent and debilitating disorder, which results in additive impairments to patients' sleep, daytime functioning, and quality of life, and complex diagnostic and treatment decisions for clinicians. Although the presence of COMISA was first recognized by Christian Guilleminault and colleagues in 1973, it received very little research attention for almost three decades, until the publication of two articles in 1999 and 2001 which collectively reported a 30%-50% co-morbid prevalence rate, and re-ignited research interest in the field. Since 1999, there has been an exponential increase in research documenting the high prevalence, common characteristics, treatment complexities, and bi-directional relationships of COMISA. Recent trials indicate that co-morbid insomnia symptoms may be treated with cognitive and behavioral therapy for insomnia, to increase acceptance and use of continuous positive airway pressure therapy. Hence, the treatment of COMISA appears to require nuanced diagnostic considerations, and multi-faceted treatment approaches provided by multi-disciplinary teams of psychologists and physicians. In this narrative review, we present a brief overview of the history of COMISA research, describe the importance of measuring and managing insomnia symptoms in the presence of sleep apnea, discuss important methodological and diagnostic considerations for COMISA, and review several recent randomized controlled trials investigating the combination of CBTi and CPAP therapy. We aim to provide clinicians with pragmatic suggestions and tools to identify, and manage this prevalent COMISA disorder in clinical settings, and discuss future avenues of research to progress the field.

GCH1 (rs841) polymorphism in the nitric oxide-forming pathway has protective effects on obstructive sleep apnea

Several studies have recently investigated the contribution of genetic factors in obstructive sleep apnea (OSA). Patients with OSA suffer from a reduction in nitric oxide (NO) serum level. This study investigated rs841, A930G p22phox, and rs1799983 polymorphisms in three critical genes involved in NO formation. A total of 94 patients with OSA and 100 healthy controls were enrolled into the study. Results showed there was no association between rs841, A930G p22phox and rs1799983 polymorphism and the risk of OSA (P = 0.51, P = 0.4 and P = 0.33, respectively). Moreover, rs841 GA genotype had a reverse relationship with the severity of OSA (P = 0.005). On the other hand, rs841 GA and A930G p22phox AA genotypes had a protective effect on daytime sleepiness in OSA patients (P = 0.01and P = 0.02, respectively). Additionally, the combination of rs841 and A930G p22phox (AG/AG and AG/AA) genotypes was significantly associated with a reduction in daytime sleepiness in OSA patients (P = 0.03 and P = 0.03, respectively). According to the results of our study, GA genotype of rs841 and GA/AA genotypes of A930G p22phox polymorphisms significantly reduced the severity of the problem and daytime sleepiness in OSA patients.

Adult obstructive sleep apnoea: Pathogenesis, importance, diagnosis and imaging

Obstructive sleep apnoea (OSA) is a serious worldwide health problem. Moderate-to-severe OSA has been found in up to 50% of men and 25% of women in the middle-aged population. It results in a fourfold increase in all causes of mortality. The prevalence of OSA is underestimated, partly due to absence of symptoms but also lack of knowledge amongst the population at large as well as sectors of the medical profession. Imaging, performed predominantly by clinicians and research scientists, has been integral to evaluating the anatomical basis of OSA. Increased nasal resistance and a narrowed and elongated oropharynx lead to increased collapsibility of the upper airway, predisposing to airway collapse and apnoea during sleep when there is reduction in tone of the pharyngeal dilator muscles. Unfortunately, a significantly narrowed upper airway is usually ignored by radiologists: it is not part of their reporting 'check-list'. The imaging findings in the upper airway that are strongly associated with OSA and its sequelae in various organ systems are discussed. Imaging can strongly suggest OSA; the diagnosis requires a polysomnogram for confirmation. Treatment of moderate-to-severe disease is primarily with positive airway pressure applied by a nasal or oral mask which splints the upper airway. Although highly effective, compliance is limited and other treatment modalities are increasingly being utilized.

[The contribution of orofacial myofunctional reeducation to the treatment of obstructive sleep apnoea syndrome (OSA): a systematic review of the literature]

Obstructive sleep apnoea syndrome (OSA) is a widespread and under-diagnosed condition, making it a major public health and safety problem. Orofacial myofunctional reeducation (OMR) has been shown to be effective in the multidisciplinary treatment of OSA in children, adolescents and adults and is prescribed at several stages of OSA management. The main objective of this systematic literature review was to evaluate the effectiveness of active or passive orofacial myofunctional reeducation (OMR) in the treatment of obstructive sleep apnoea syndrome in children, adolescents and adults. The systematic literature review was undertaken from the three electronic databases: Medline (via PubMed), Cochrane Library, Web of Science Core Collection, and supplemented by a limited grey literature search (Google Scholar) in order to identify the studies evaluating the effectiveness of the OMR on OSA. The primary outcome of interest was a decrease in the Apnea-Hypopnea Index (AHI) of at least five episodes per hour compared to the baseline state. Secondary outcomes were an improvement in subjective sleep quality, sleep quality measured by night polysomnography and subjectively measured quality of life. Only ten studies met all the inclusion criteria. Eight were randomized controlled clinical trials, one was a prospective cohort study and another was a retrospective cohort study. Six studies were devoted to adult OSA and four to pediatric OSA. All included studies were assessed as "low risk of bias" based on the 12 bias risk criteria of the Cochrane Back Review Group. Based on the available evidence, RMO allows a significant reduction in AHI, up to 90.6% in children and up to 92.06% in adults. It significantly reduces the intensity and frequency of snoring, helps reduce daytime sleepiness, limits the recurrence of OSA symptoms after adenoamygdalectomy in children and improves adherence to PPC therapy. Passive RMO, with the assistance provided to the patient by wearing a custom orthosis, increases adherence to reeducation, significantly improves snoring intensity, AHI and significantly increases the upper airway. Published data show that orofacial myofunctional rééducation is effective in the multidisciplinary treatment of OSA in children, adolescents and adults and should be widely prescribed at several stages of OSA management. Passive RMO, with the pearl mandibular advancement orthosis designed by Michèle Hervy-Auboiron, helps to compensate for the frequent non-compliance observed during active RMO treatments.

Obese Tracheostomy: A Challenging Path From Surgery to Decannulation

PURPOSE

Well-defined or standardized tracheostomy decannulation guidelines are not available, and the long-term data on the outcomes in the obese are limited. The purpose of the present study was to determine the outcomes associated with tracheostomy for obese patients from surgery to decannulation. The specific aims were to measure 1) the rate of successful tracheostomy downsize; 2) the rate of successful tracheostomy decannulation; and 3) the associated pre-, intra-, and postoperative subject variables with tracheostomy downsizing and decannulation success.

PATIENTS AND METHODS

A retrospective cohort study was implemented to determine the outcomes associated with downsizing and decannulation after obese tracheostomy. The predictive value of the independent variables from the subjects' pre-, intra-, and postoperative periods were evaluated as they related to successful downsizing and decannulation. The included subjects had undergone tracheostomy from April 2016 to December 2018. The primary outcomes were successful downsizing and successful decannulation. A downsize checklist was created with the following yes/no criteria that should reasonably be met before downsizing a tracheostomy in an obese subject. The secondary analysis was the association between the checklist criteria and successful downsize and decannulation. The data were analyzed using the χ² test, analysis of variance, t test, likelihood ratio, Kaplan-Meier analysis with Cox regression, and logistic binary regression, with statistical significance set at P < .05.

RESULTS

The study sample included 82 obese subjects (body mass index [BMI] >30 kg/m²), with a mean age of 55.7 ± 15.0 years; 56% were men. Only 62 of the subjects could be downsized (75.6%) and 39 (47.6%) could be decannulated. The general trend showed that an increased BMI resulted in an increased time to decannulation, long-term tracheostomy dependence, and less successful downsize and decannulation. For patients with a BMI of 30 kg/m² or more, the downsize success rate was 93.5% and the decannulation success rate was 89.7%.

CONCLUSIONS

Obese patients have a greater likelihood of complications and an increased risk of remaining tracheostomy dependent. Consideration of the patient's BMI is crucial when initiating the decannulation progression.

Utility of acoustic pharyngometry for screening of obstructive sleep apnea

OBJECTIVE

To determine whether combining acoustic pharyngometric parameters with cephalometric and clinical parameters could improve the predictive power for significant obstructive sleep apnea (OSA) in a Korean population.

METHODS

A total of 229 consecutive adult patients with suspected OSA were enrolled. The predictability for significant OSA using acoustic pharyngometric or cephalometric parameters or combining these parameters and clinical factors was calculated and compared using multivariate logistic regression and receiver operating characteristic (ROC) curves.

RESULTS

In multivariate logistic regression, age, sex, minimum upper airway cross-sectional area (UA-CSA), and mandibular plane to hyoid distance (MPH) were all significant independent predictors of significant OSA. The minimum UA-CSA of 0.85 cm² provided fair discrimination for OSA [area under the curve (AUC): 0.60, 95% confidence interval (CI): 0.52-0.67]. The MPH of 18.75 mm provided fair discrimination for OSA (AUC; 0.65, 95% CI: 0.58-0.72). The discriminative ability of the final model of multivariate ROC curve analyses that included the minimum UA-CSA, age, sex, body mass index (BMI), and MPH was better than the minimum UA-CSA alone (AUCs: 0.77 vs. 0.60). Optimal cut-off values of predictors for discriminating significant OSA were as follows: male for sex, 40 years for age, 25.5 kg/m² for BMI, 1.06 cm² for minimum UA-CSA, and 18 mm for MPH.

CONCLUSION

Minimum UA-CSA measured using acoustic pharyngometry while sitting might be a useful method to predict OSA. Combining minimum UA-CSA with age, sex, BMI and MPH improved the predictive value for significant OSA.

Coordinated program between primary care and sleep unit for the management of obstructive sleep apnea

The purpose of this study is to develop and validate a work model in the primary health-care setting for identifying patients with obstructive sleep apnea–hypopnea syndrome (OSAHS) based on clinical variables and an ambulatory sleep monitoring study. After screening, patients with mild–moderate OSAHS could be managed by primary care physicians, whereas those identified with severe OSAHS would be referred to specialists from sleep units for starting specific treatment. The proposed model does not move the entire health-care process to a generally overburdened primary care level and favors the coordinated work and the necessary flexibility to adapt the model to challenges and perspectives of OSAHS.

[Pathophysiology of obstructive sleep apnea]

The prevalence of obstructive sleep apnea (OSA) is considered to be very high in western industrialized countries. There are conservative and surgical forms of treatment for OSA; however, the pathophysiology is largely unexplained and cannot be explained by anatomical abnormalities alone. In recent years, a number of non-anatomical factors have been found that favor the development of OSA. These include the respiratory excitation threshold (arousals), the respiratory drive (loop gain), as well as the control and function of the muscular upper airway dilators. The understanding of the individual pathophysiological processes may be helpful in the future to develop individual treatment approaches for patients.

SENP1-mediated NEMO de-SUMOylation inhibits intermittent hypoxia induced inflammatory response of microglia in vitro

Among the seven small ubiquitin-like modifier (SUMO)-specific proteases (SENPs), our previous work showed that SENP1 suppressed nuclear factor kappa B (NF-κB) activation and alleviates the inflammatory response in microglia. However, the mechanism is still largely unknown. In this study, western blot analysis and enzyme-linked immunosorbent assay were utilized for evaluating the extent of NF-κB activation and expression of proinflammatory cytokines. qPCR and western blot analysis were performed to detect SENP1 expression. Coimmunoprecipitation followed by western blot analysis was applied to measure the changes in SUMOylation of NF-κB essential modulator (NEMO) and P65 in microglia with or without overexpression of SENP1. As the results, we found that intermittent hypoxia (IH) triggered the activation of NF-κB and upregulated the expression levels of tumor necrosis factor-α and interleukin-6. Interestingly, our data indicated that the SUMOylation of NEMO was enhanced by IH while SUMOylation of P65 was not affected. Further, our data showed that overexpression of SENP1 could decrease the extent of NF-κB activation and inhibit the inflammatory response of microglia through regulating the SUMOylation of NEMO. Collectively, this study presents the first report of the SENP1-controlled de-SUMOylation process of NEMO and its critical role in regulating NF-κB activation and proinflammatory cytokines secretion in microglia cells. This study would benefit for clarifying the role of SENP1 in IH-induced activation of microglia, thus providing potential therapeutic targets for obstructive sleep apnea treatment.

Association between the ADAMTS proteinases and obstructive sleep apnea

BACKGROUND

A disintegrin and metalloproteinase with thrombospondin type-1 motifs (ADAMTS) proteinases have important roles in degradation/repairing of extracellular matrix (ECM). They are thought to play a key role in pathogenesis of many diseases. We aimed to investigate the association between ADAMTS 2, 3, and 14 (procollagen) and obstructive sleep apnea (OSA).

METHODS

Eighty-six individuals who were suspected of OSA were included. All cases underwent polysomnography. Participants were divided into 3 groups according to apnea-hypopnea index (AHI): control (n = 22), mild-to-moderate OSA (n = 36), and severe OSA (n = 28). ADAMTS proteinases 2, 3, and 14 were analyzed in serum samples.

RESULTS

When compared with other groups, patients with severe OSA showed significantly higher body mass index (BMI) (p = 0.001), whereas they showed significantly lower ADAMTS 3 levels (p = 0.016). No difference was found between groups with respect to the levels ADAMTS 2 and 14. There was a negative relation between the levels of ADAMTS 3 and the severity of OSA (Kendall's tau = - 0.19, p = 0.021). The levels of ADAMTS 3 were also found to be positively correlated with minimum SpO₂ (r = 0.31, p = 0.004) and negatively correlated with BMI, AHI, oxygen desaturation index (ODI), time duration with oxygen saturation < 90% (T90), and CRP (r = - 0.31 to - 0.49, p < 0.05). Multivariable regression analysis revealed that BMI (p = 0.013) and CRP levels (p = 0.005) were significantly associated with the levels of ADAMTS 3.

CONCLUSIONS

ADAMTS 3, one of the procollagen proteinases, was decreased in severe OSA. Lack of ADAMTS 3 proteinase may contribute to process of sleep apnea due to insufficient collagen syntheses.

Obstructive sleep apnoea and its knowledge and attitude among Indian anaesthesiolgists - A survey study

BACKGROUND AND AIMS

Obstructive sleep apnoea (OSA) has an estimated prevalence of 2%-4% in adult population and is increasing. Most of these are detected late which is the cause for higher perioperative morbidity. This survey was aimed to seek the level of knowledge and attitude of Indian anaesthesiologists towards OSA.

METHODS

The OSA Knowledge and Attitude (OSAKA) questionnaire (23-statements) was distributed to the anaesthesiologists attending the difficult airway conference in December 2017. The first section has 18 statements pertaining to OSA knowledge. The second section consists of five statements to evaluate self-confidence in the management of OSA. Age, gender, professional title, type of hospital, years of experience, and bariatric experience were analysed.

RESULTS

205 out of 350 participants responded. In all, 201 (57.4%) fully completed responses were analysed. The mean ± standard deviation knowledge and attitude scores were 12.01 ± 2.88 (66.72% ± 16%) and 18.16 ± 3.75 (72.64% ± 15%) respectively. On exclusion of junior residents (n = 56), knowledge and attitude scores of qualified anaesthesiologists were 12.7 ± 2.55 (70.55% ± 14.16%) and 18.78 ± 3.91 (75.12% ± 15.64%), respectively. Anaesthesiologists with bariatric experience had a significantly higher attitude score when compared with those who do not practice bariatric surgeries (P < 0.01). There is weak but significant, positive linear correlation between knowledge and attitude score (r_s= 0.370, P < 0.01).

CONCLUSION

Deficit of adequate knowledge about OSA exists among Indian anaesthesiologists. Experience of managing cases with OSA seems to improve knowledge and attitude towards OSA.

Idiopathic Edema: A Case Report

Edema occurs when excess fluid is retained by interstitial tissue and is associated with several systemic conditions. The diagnosis of edema is generally made by physical and clinical assessment, and diuretics are the common treatment. Idiopathic edema predominantly affects women and occurs in patients who do not have any other pre-existing systemic problems. The etiology behind idiopathic edema has yet to be determined. We present a case of a 46-year-old woman diagnosed with idiopathic edema.