Breathing Disturbances Research Articles

Sleep Disturbances in Amyotrophic Lateral Sclerosis and Prognostic Impact—A Retrospective Study

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease associated with sleep disturbance, namely insomnia and sleep-disordered breathing. This study aims to evaluate the overall sleep characteristics of ALS patients, their association with lung function tests, and possible predictive survival factors. We conducted a retrospective observation study among ALS patients monitored during a pulmonology consultation. Type one polysomnography (PSG) and lung function tests were performed once the patients presented with sleep-related symptoms, and the relationship between their parameters was assessed, as well as a survival analysis. We included 35 patients, with an overall diminished sleep efficiency, a partially conserved forced vital capacity (FVC), and low maximal inspiratory pressure (MIP). A positive correlation between FVC and REM sleep percentage was observed. A survival analysis showed that a normal rapid eye movement (REM) sleep percentage and respiratory disturbance index (RDI) ≥ 15/h were independent predictors of survival. We observed a trend for higher sleep quality in patients with conserved lung function. A better sleep quality was associated with a higher survival. Obstructive events (reduced or absence of airflow associated with continued or increased inspiratory effort) did not seem to impact survival.

An Observational Study on the Treatment Outcomes of Adenotonsillar Hypertrophy in Children

Background: Adenotonsillar hypertrophy, marked by abnormal enlargement of the adenoids and tonsils, is common in children and can cause various health issues. For severe cases, surgical intervention, mainly adenotonsillectomy, is often recommended and has proven effective in improving airway obstruction, sleep quality, and overall health outcomes. This study aimed to assess the treatment Outcomes of adenotonsillar hypertrophy in children. Methods: This prospective observational study was conducted in the Department of Head & Neck Surgery (ENT), Dhaka National Medical Institute Hospital, Dhaka, Bangladesh from January 2023 to June 2023. A total of 57 children with primary symptoms of mouth breathing, snoring, and sleep disturbances were purposively enrolled as study subjects. For data analysis, MS Office tools were applied. Results: Most participants (61.4%) were aged 2-5 years and female (60%). All participants (100%) reported symptoms of nasal blockage, snoring, and mouth breathing. A majority (61.4%) had grade 2 tonsillar hypertrophy. After 3 months of medical treatment, 57.9% experienced complete relief of nasal symptoms, including sleep apnea, 24.6% showed moderate improvement, and 17.5% saw no improvement. Conclusion: Intranasal steroids, combined with oral amoxicillin e-clavulanic acid and montelukast, reduce adenotonsillar hypertrophy symptoms and lower surgical intervention rates. This approach targets inflammation and infection, potentially improving patients' quality of life. More studies are needed to establish guidelines and optimize treatment.

Reliable Contactless Monitoring of Heart Rate, Breathing Rate, and Breathing Disturbance During Sleep in Aging: Digital Health Technology Evaluation Study.

Longitudinal monitoring of vital signs provides a method for identifying changes to general health in an individual, particularly in older adults. The nocturnal sleep period provides a convenient opportunity to assess vital signs. Contactless technologies that can be embedded into the bedroom environment are unintrusive and burdenless and have the potential to enable seamless monitoring of vital signs. To realize this potential, these technologies need to be evaluated against gold standard measures and in relevant populations. We aimed to evaluate the accuracy of heart rate and breathing rate measurements of 3 contactless technologies (2 undermattress trackers, Withings Sleep Analyzer [WSA] and Emfit QS [Emfit]; and a bedside radar, Somnofy) in a sleep laboratory environment and assess their potential to capture vital signs in a real-world setting. Data were collected from 35 community-dwelling older adults aged between 65 and 83 (mean 70.8, SD 4.9) years (men: n=21, 60%) during a 1-night clinical polysomnography (PSG) test in a sleep laboratory, preceded by 7 to 14 days of data collection at home. Several of the participants (20/35, 57%) had health conditions, including type 2 diabetes, hypertension, obesity, and arthritis, and 49% (17) had moderate to severe sleep apnea, while 29% (n=10) had periodic leg movement disorder. The undermattress trackers provided estimates of both heart rate and breathing rate, while the bedside radar provided only the breathing rate. The accuracy of the heart rate and breathing rate estimated by the devices was compared with PSG electrocardiogram-derived heart rate (beats per minute) and respiratory inductance plethysmography thorax-derived breathing rate (cycles per minute), respectively. We also evaluated breathing disturbance indexes of snoring and the apnea-hypopnea index, available from the WSA. All 3 contactless technologies provided acceptable accuracy in estimating heart rate (mean absolute error <2.12 beats per minute and mean absolute percentage error <5%) and breathing rate (mean absolute error ≤1.6 cycles per minute and mean absolute percentage error <12%) at 1-minute resolution. All 3 contactless technologies were able to capture changes in heart rate and breathing rate across the sleep period. The WSA snoring and breathing disturbance estimates were also accurate compared with PSG estimates (WSA snore: r2=0.76; P<.001; WSA apnea-hypopnea index: r2=0.59; P<.001). Contactless technologies offer an unintrusive alternative to conventional wearable technologies for reliable monitoring of heart rate, breathing rate, and sleep apnea in community-dwelling older adults at scale. They enable the assessment of night-to-night variation in these vital signs, which may allow the identification of acute changes in health, and longitudinal monitoring, which may provide insight into health trajectories. RR2-10.3390/clockssleep6010010.

Effect of positive allosteric modulation and orthosteric agonism of dopamine D2-like receptors on respiration in mouse models of Rett syndrome

Rett syndrome (RTT) is an autism spectrum disorder caused by loss-of-function mutations in the methyl-CPG-binding protein 2 (Mecp2) gene. Frequent apneas and irregular breathing are prevalent in RTT, and also occur in rodent models of the disorder, including Mecp2Bird and Mecp2R168X mice. Sarizotan, a serotonin 5-HT1a and dopamine D2-like receptor agonist, reduces the incidence of apneas and irregular breathing in mouse models of RTT (Abdala et al., 2014). Targeting the 5HT1a receptor alone also improves respiration in RTT mice (Levitt et al., 2013). However, the contribution of D2-like receptors in correcting these respiratory disturbances remains untested. PAOPA, a dopamine D2-like receptor positive allosteric modulator, and quinpirole, a dopamine D2-like receptor orthosteric agonist, were used in conjunction with whole-body plethysmography to evaluate whether activation of D2-like receptors is sufficient to improve breathing disturbances in female heterozygous Mecp2Bird/+ and Mecp2R168X/+ mice. PAOPA did not significantly change apnea incidence or irregularity score in RTT mice. PAOPA also had no effect on the ventilatory response to hypercapnia (7 % CO2). In contrast, quinpirole reduced apnea incidence and irregularity scores and improved the hypercapnic ventilatory response in Mecp2R168X/+ and Mecp2Bird/+ mice, while also reducing respiratory rate. These results suggest that D2-like receptors could contribute to the positive effects of sarizotan in the correction of respiratory abnormalities in Rett syndrome. However, positive allosteric modulation of D2-like receptors alone was not sufficient to evoke these effects.

The effect of sulthiame on potential biomarkers in moderate to severe obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is a common disease with breathing disturbances during sleep. Sulthiame (STM), a carbonic anhydrase (CA) inhibitor, was recently shown to reduce OSA in a significant proportion of patients. CA activity and hypoxia-inducible factor (HIF)-1α are two potential biomarkers reported in severe OSA and hypoxia. Both have been considered to play roles in the development of OSA comorbidities. This study investigated the effects of STM on these biomarkers in OSA. This was an exploratory analysis of a randomised, double-blind, placebo-controlled trial of STM in OSA. Patients with moderate to severe OSA, body mass index 20-35 kg·m-2, aged 18-75 years and not accepting positive airway pressure treatment were randomised to 4 weeks with placebo, STM 200 mg or STM 400 mg. CA activity (n=43) and HIF-1α concentration (n=53) were determined at baseline, after 4 weeks of treatment and 2 weeks after treatment completion. In the 400 mg group, both CA activity and HIF-1α concentration were reduced (median difference -26% (95% CI -32- -12%) and -4% (95% CI -8- -2%); both p<0.05 versus placebo). The reductions were sustained 2 weeks after treatment completion. In the 200 mg group, both CA activity and HIF-1α were numerically reduced. The STM-induced reductions in CA activity and HIF-1α correlated significantly (r=0.443, p=0.023). STM treatment in OSA induced a reduction of both CA activity and HIF-1α concentration. The effects remained 2 weeks after treatment completion, suggesting prolonged effects of STM in OSA.

Improving breathing effort estimation in mechanical ventilation via optimal experiment design

Estimation of the breathing effort and relevant lung parameters of a ventilated patient is essential to keep track of a patient’s clinical condition. The aim of this paper is to increase estimation accuracy through experiment design. The main method is an experiment design approach across multiple breaths within a linear regression framework to accurately identify the patient’s condition. Identifiability and persistence of excitation are used to formulate an estimation problem with a unique solution. Furthermore, Fisher information is used for assessing the parameters sensitivity to slight changes of the ventilator settings to improve the variance of the estimation. The estimation method is applied to simulated patients who breathe regularly but also to patients who have variable breathing patterns. A virtual experiment is conducted for both situations to generate estimation results. The results are analyzed using mathematical tools and show that uniquely estimating the lung parameters and breathing effort over multiple breaths for both regularly and variably breathing patients is possible in the presented framework. The proposed estimation method obtains clinically relevant estimates for a large set of breathing disturbances from the simulation case-study.

Sleep Disturbance and Related Factors in the Patients with Relapsing-Remitting Multiple Sclerosis

Background. Sleep disturbances are commonly reported, although underestimated complaints from people with multiple sclerosis (MS). The aim of the study was to analyze the frequency and type of sleep disturbances in MS patients and to evaluate their relationships with demographics and clinical data. Methods. The study group consisted of 178 patients with relapsing-remitting MS: 130 females and 48 males. Clinical measures (disease duration, disability level in Expanded Disability Status Scale (EDSS), and treatment) were acquired from medical records. The questionnaire was applied, containing questions about sleep disturbances, somatic complaints, perception of fatigue, depression, anxiety, and problems at work and in social/family life. Athens Insomnia Scale (AIS) and Karolinska Sleepiness Scale (KSS) were performed to quantify sleep problems and Hamilton Depression Rating Scale (HDRS) and Addenbrooke’s Cognitive Examination (Mini-ACE) to assess level of depression and cognitive performance. Electroencephalography was recorded to identify electrophysiological indices of sleep. Results. 109 patients (61%) reported sleep disturbances, most frequently insomnia, snoring, and parasomnias. This subgroup had significantly higher scores in AIS (p&lt;0.0001) and KSS (p=0.010) and slightly higher EDSS score (p=0.048) and more often complained of fatigue (71% vs. 53%, p=0.0148), involuntary limb movement (42% vs. 25, p=0.0170), and breathing disturbances (10% vs. 0%). There was a significant correlation between the results of AIS and HDRS (Rs=0.715, p&lt;0.05). Conclusion. Sleep disturbances, predominantly insomnia, are reported by more than a half of the patients with relapsing-remitting MS. Significant associations were found between sleep problems and MS-related clinical symptoms and psychosocial issues.

Respiratory dysfunction in persistent somatic symptoms: A systematic review of observational studies

ObjectiveThis systematic review aims to analyze the existing literature investigating respiratory functioning in people with Persistent Somatic Symptoms (PSS) compared to healthy controls, to identify patterns of respiratory disturbances by symptom or syndrome, and describe any respiratory outcomes consistent across diagnoses. MethodsA systematic review following PRISMA guidelines was conducted. A comprehensive search was carried out across five databases (PubMed (NCBI), PsycArticles (Ovid), Web of Science (Core Collection), Embase, and Scopus) using two customised search strings for persistent somatic symptoms and objective respiratory parameters. Title/abstract screening and data extraction were carried out independently by two reviewers. The modified Newcastle-Ottawa Scale was used for quality assessment of the studies. Studies investigating baseline respiratory functioning in adult patients with PSS compared to healthy controls, using at least one objective respiratory were included. Results18 studies met the inclusion criteria for the review, with a pooled sample size of n = 3245. Chronic pain conditions were found to be the most prevalent subset of diagnoses of interest, comprising six of the studies. 10 studies included measures of lung capacity, flow and/or volume, nine studies reported measures of ventilation, and four studies investigated respiratory muscle functioning. 13 of the included studies reported significant differences in at least one objective respiratory measure between groups (at rest). Scores on self-reported measures of dysnpea and breathlessness were higher in patients compared to healthy controls, while objective respiratory outcomes were varied. ConclusionThe current systematic review is consistent with previous literature suggesting more pronounced experiences of breathlessness in patients with PSS, and significant disparities between reported dyspnea and objective respiratory outcomes. Research investigating the uncoupling between subjective and objective respiratory outcomes is needed to understand the mechanisms behind breathing disturbances in PSS.

Rett Syndrome and the Role of MECP2: Signaling to Clinical Trials.

Rett syndrome (RTT) is a neurological disorder that mostly affects females, with a frequency of 1 in 10,000 to 20,000 live birth cases. Symptoms include stereotyped hand movements; impaired learning, language, and communication skills; sudden loss of speech; reduced lifespan; retarded growth; disturbance of sleep and breathing; seizures; autism; and gait apraxia. Pneumonia is the most common cause of death for patients with Rett syndrome, with a survival rate of 77.8% at 25 years of age. Survival into the fifth decade is typical in Rett syndrome, and the leading cause of death is cardiorespiratory compromise. Rett syndrome progression has multiple stages; however, most phenotypes are associated with the nervous system and brain. In total, 95% of Rett syndrome cases are due to mutations in the MECP2 gene, an X-linked gene that encodes for the methyl CpG binding protein, a regulator of gene expression. In this review, we summarize the recent developments in the field of Rett syndrome and therapeutics targeting MECP2.

CLINICAL AND MORPHOLOGICAL CHARACTERISTICS AND EVALUATION OF TORUS TUBARIUS IN CHILDREN WITH PHARYNGEAL TONSIL HYPERTROPHY

Introduction: Among children with hypertrophy of pharyngeal tonsils undergoing adenoidectomy, 31.3% of cases show hypertrophy of the torus tubarius, even in the absence of middle ear pathology. However, the nature of the changes in this anatomical area in these children has not been described.&#x0D; The aim of the study: to investigate and evaluate morphological changes of pharyngeal tonsil and torus tubarius in children with hypertrophy of pharyngeal tonsil.&#x0D; Materials and methods: histological investigation and scanning electron microscopy were performed on fragments of pharyngeal tonsil and torus tubarius, obtained during adenoidectomy of 12 children with nasal breathing disturbances (Group 1) and 13 children with concomitant inflammatory diseases of the upper respiratory tract (Group 2).&#x0D; Results: In patients of Group 2, changes in the pharyngeal tonsil were more pronounced, showing inflammatory alterations such as infiltration by polymorphonuclear leukocytes in the covering epithelium and subepithelial layer, as well as lymphocytes in the covering epithelium, along with the presence of fibrosis compared to patients of Group 1. Additionally, samples covered by biofilms were significantly more frequently identified in Group 2 compared to Group 1 (53.8% vs. 16.6%, p&lt;0.05). The mucosal changes in the torus tubarius corresponded to the nature of the changes observed in the pharyngeal tonsil in the respective group. Biofilms in the torus tubarius samples were found in 38.5% of cases in Group 2 and 8.3% of cases in Group 1 (p&lt;0.05).&#x0D; Conclusions: 1. In children with hypertrophy of pharyngeal tonsil and torus tubarius, the morphological characteristics of the mucous membrane of torus tubarius are similar to those observed in the mucous membrane of pharyngeal tonsil of the respective group. 2. Biofilms were reliably more frequently identified on the surface of pharyngeal tonsil and torus tubarius in children with upper respiratory tract infections than in patients with nasal breathing disturbances. 3. The detected changes provide a basis for revising the therapeutic approach to hypertrophic torus tubarius in children with pharyngeal tonsil hypertrophy.

Adenoid Hypertrophy Managed With Artemisia Cina Dilution: A Study of Two Cases

Adenoid hypertrophy, is the enlargement of adenoid tissues in the nasopharynx, a common concern among children and often exhibits with nasal congestion, mouth breathing, snoring, and sleep disturbances. Spontaneous healing of enlarged adenoid is common in adolescents and adults, however, in this case study, we present two instances of pediatric patients who demonstrated adenoid-related health issues. After a thorough evaluation, and based on the principle of symptom similarity Artemisia cina was prescribed; this treatment continued for three consecutive weeks, and a follow-up lateral x-ray of nasopharynx was obtained one more week later. The use of homeopathic preparation of Artemisia cina appeared to ease their symptoms. This outcome suggests that Artemisia cina may hold promise as a homeopathic option for managing adenoid-related concerns in pediatric patients. However, we acknowledge that further research and a larger sample size are necessary to establish the usefulness of this approach. Bioresearch Commu. 10(1): 1449-1452, 2024 (January)

Diffuse idiopathic skeletal hyperostosis, beyond the musculoskeletal system

It has been suggested that diffuse idiopathic skeletal hyperostosis (DISH), a skeletal disease characterized by the ligamentous ossification of the anterolateral spine, is a radiological entity with no clinical implications; however, many patients suffer from chronic back pain, decreased spinal mobility, and postural abnormalities. Additionally, the pathological new bone formation at the cervical and thoracic levels may mainly produce dysphagia and breathing disturbances. Over the last 20 years, a close association between DISH, obesity, diabetes mellitus (DM), and metabolic syndrome (MS) has emerged. However, a causal relationship has not yet been established. It has been suggested that the longer life expectancy and the growing incidence of MS in Western populations, associated with the tendency of DISH to manifest in later life, may increase the DISH prevalence rates in the following decades. Future investigations should focus on the early DISH phase to clarify pathogenetic mechanisms and identify targeted therapies.

Autoantibodies in patients with post-COVID syndrome: a possible link with severity?

Coronavirus disease 2019 is an infectious disease associated with the respiratory system caused by the SARS-CoV-2 virus. Right now, an increasing number of patients with Post-COVID Syndrome show, without clear evidence of organ dysfunction, a plethora of severe symptoms, such as fatigue, pain, shortness of breath, cognitive impairment, and sleep disturbance. It has already been demonstrated that SARS-CoV-2 virus can disrupt the self-tolerance mechanism of the immune system, thus triggering autoimmune conditions. Several studies have recently documented the presence of autoantibodies in the sera of post-COVID patients, but until now, it is unclear whether the persistence of symptoms could be directly correlated with the presence of autoantibodies. In this study, serum autoantibodies (AAbs) levels against four G protein-coupled receptors in 78 patients with post-COVID syndrome have been analyzed. The AAbs investigated are clustered in two groups: adrenergic receptors (α1 and β2) and muscarinic acetylcholine receptors (M3 and M4). At least one or more AAbs were detected in 60.3% (47/78) of patients diagnosed with post-COVID syndrome, whereas 37.2% (29/78) of patients were positive for all receptors investigated. Interestingly, a strong correlation has been found between AAbs and pain intensity feeling by the patients measured by Visual Analogic Scale. A significant association was also obtained with insomnia and AABS-positive patients. The identification of AAbs and their correlation with pathological symptoms seriousness underly the possible role of AAbs as future therapeutic targets.

Measurement of Upper Airway Volume in Children with Craniofacial Abnormalities.

Previous literature has established a high prevalence of upper airway obstruction in children with craniofacial abnormalities. This study aims to perform quantitative airway volume measurements in patients with craniofacial abnormalities and compare them to age and sex-matched controls. We performed a retrospective review of the records of all children with craniofacial abnormalities who underwent head-and-neck computed tomography (CT) imaging at a single tertiary-care center between 1/1/13 and 12/31/20 using the ICD-10 codes Q75.1, Q75.4, and Q87.0. These patients were then matched by age and sex to patients with isolated craniosynostosis (Q75.0). CT scans were imported into Dolphin Imaging software, and airway volumes were measured for the nasal cavity, nasopharynx, oropharynx, and hypopharynx. The primary outcome was the total airway volume, defined as the sum of these measurements. Thirty subjects with craniofacial syndromes were matched to 30 patients with isolated craniosynostosis (controls). In both groups, 18 subjects (60%) were male (p = 0.99). The average ages for syndromic patients and controls were 12.1 and 12.9 months, respectively (p = 0.84). On average, the total airway volumes of syndromic patients were 25% lower than those of controls (p = 0.02). Syndromic patients had 39% smaller nasal cavity volumes (p < 0.001) and 32% smaller nasopharyngeal volumes (p < 0.01). Significant volume differences were not observed for the oropharynx or hypopharynx. We present a unique technique to measure airway volumes in patients with craniofacial abnormalities. These findings will help practitioners to further understand the anatomy and pathophysiology of disturbed breathing in children with craniofacial syndromes. III Laryngoscope, 134:2915-2921, 2024.

Prevalence and predictors of post-COVID-19 symptoms in general practice - a registry-based nationwide study

BackgroundWith Norwegian national registry data, we assessed the prevalence of post-COVID-19 symptoms at least 3 months after confirmed infection, and whether sociodemographic factors and pre-pandemic health problems were risk factors for these symptoms.MethodsAll persons with a positive SARS-CoV-2 PCR test from February 2020 to February 2021 (exposed) were compared to a group without a positive test (unexposed) matched on age, sex, and country of origin. We used Cox regression to estimate hazard ratios (HR) for 18 outcome symptoms commonly described as post-COVID-19 related, registered by GPs. We compared relative risks (RR) for fatigue, memory disturbance, or shortness of breath among exposed and unexposed using Poisson regression models, assessing sex, age, education, country of origin, and pre-pandemic presence of the same symptom and comorbidity as possible risk factors, with additional analyses to assess hospitalisation for COVID-19 as a risk factor among exposed.ResultsThe exposed group (N = 53 846) had a higher prevalence of most outcome symptoms compared to the unexposed (N = 485 757), with the highest risk for shortness of breath (HR 2.75; 95%CI 2.59–2.93), fatigue (2.08; 2.00-2.16) and memory disturbance (1.41;1.26–1.59). High HRs were also found for disturbance of smell/taste and hair loss, but frequencies were low. Concerning risk factors, sociodemographic factors were at large similarly associated with outcome symptoms in both groups. Registration of the outcome symptom before the pandemic increased the risk for fatigue, memory disturbance and shortness of breath after COVID-19, but these associations were weaker among exposed. Comorbidity was not associated with fatigue and shortness of breath in the COVID-19 group. For memory disturbance, the RR was slightly increased with the higher comorbidity score both among exposed and unexposed.ConclusionCOVID-19 was associated with a range of symptoms lasting more than three months after the infection.

Insights on mandibular jaw movements during polysomnography in obstructive sleep apnea.

Malhotra A, Martinot J-B, Pépin J-L. Insights on mandibular jaw movements during polysomnography in obstructive sleep apnea. J Clin Sleep Med. 2024;20(1):151-163.

Commonalities and differences in carotid body dysfunction in hypertension and heart failure.

Carotid body pathophysiology is associated with many cardiovascular-respiratory-metabolic diseases. This pathophysiology reflects both hyper-sensitivity and hyper-tonicity. From both animal models and human patients, evidence indicates that amelioration of this pathophysiological signalling improves disease states such as a lowering of blood pressure in hypertension, a reduction of breathing disturbances with improved cardiac function in heart failure (HF) and a re-balancing of autonomic activity with lowered sympathetic discharge. Given this, we have reviewed the mechanisms of carotid body hyper-sensitivity and hyper-tonicity across disease models asking whether there is uniqueness related to specific disease states. Our analysis indicates some commonalities and some potential differences, although not all mechanisms have been fully explored across all disease models. One potential commonality is that of hypoperfusion of the carotid body across hypertension and HF, where the excessive sympathetic drive may reduce blood flow in both models and, in addition, lowered cardiac output in HF may potentiate the hypoperfusion state of the carotid body. Other mechanisms are explored that focus on neurotransmitter and signalling pathways intrinsic to the carotid body (e.g. ATP, carbon monoxide) as well as extrinsic molecules carried in the blood (e.g. leptin); there are also transcription factors found in the carotid body endothelium that modulate its activity (Krüppel-like factor 2). The evidence to date fully supports that a better understanding of the mechanisms of carotid body pathophysiology is a fruitful strategy for informing potential new treatment strategies for many cardiovascular, respiratory and metabolic diseases, and this is highly relevant clinically.

Obstructive sleep apnea heterogeneity and autonomic function: a role for heart rate variability in therapy selection and efficacy monitoring.

Obstructive sleep apnea is a highly prevalent sleep-related breathing disorder, resulting in a disturbed breathing pattern, changes in blood gases, abnormal autonomic regulation, metabolic fluctuation, poor neurocognitive performance, and increased cardiovascular risk. With broad inter-individual differences recognised in risk factors, clinical symptoms, gene expression, physiological characteristics, and health outcomes, various obstructive sleep apnea subtypes have been identified. Therapeutic efficacy and its impact on outcomes, particularly for cardiovascular consequences, may also vary depending on these features in obstructive sleep apnea. A number of interventions such as positive airway pressure therapies, oral appliance, surgical treatment, and pharmaceutical options are available in clinical practice. Selecting an effective obstructive sleep apnea treatment and therapy is a challenging medical decision due to obstructive sleep apnea heterogeneity and numerous treatment modalities. Thus, an objective marker for clinical evaluation is warranted to estimate the treatment response in patients with obstructive sleep apnea. Currently, while the Apnea-Hypopnea Index is used for severity assessment of obstructive sleep apnea and still considered a major guide to diagnosis and managements of obstructive sleep apnea, the Apnea-Hypopnea Index is not a robust marker of symptoms, function, or outcome improvement. Abnormal cardiac autonomic modulation can provide additional insight to better understand obstructive sleep apnea phenotyping. Heart rate variability is a reliable neurocardiac tool to assess altered autonomic function and can also provide cardiovascular information in obstructive sleep apnea. Beyond the Apnea-Hypopnea Index, this review aims to discuss the role of heart rate variability as an indicator and predictor of therapeutic efficacy to different modalities in order to optimise tailored treatment for obstructive sleep apnea.

A Debate on Surgical and Nonsurgical Approaches for Obstructive Sleep Apnea: A Comprehensive Review.

Regular and unobstructed breathing during the night is the prerequisite for an undisturbed and restful sleep. The most prevalent nocturnal breathing disturbance with morbid consequences is obstructive sleep apnea syndrome. The prevalence of obstructive sleep apnea (OSA) is increasing, and a significant number of patients with OSA are undiagnosed. On the other hand, the "obesity epidemic" is a growing concern globally. A sleep test is required to diagnose sleep apnea and to individualize therapy. A multidisciplinary approach is the key to success. This narrative review presents a debate on whether surgery is a friend or a foe in the treatment of sleep apnea. Depending on the type and severity of the apnea, the causal factor, and the presence of obesity and hypercapnia as well as the associated pathologies, the optimal therapeutic method is determined for each individual case. The article concludes that each case is unique, and there is no ideal method. Positive pressure ventilation, although a therapeutic gold standard, has its disadvantages extensively discussed in this paper. Nevertheless, it is necessary prior to any surgical intervention, either for the curative treatment of the causal factor of apnea or for elective surgery for another condition. The anesthetic risks associated with the presence of apnea and obesity should not be neglected and should form the basis for decision making regarding surgical interventions for the treatment of sleep apnea.

Depicting and defining sleep disturbed breathing associated with vagal nerve stimulation

BackgroundVagal nerve stimulators (VNS), which have been approved for management of refractory epilepsy and depression, induce unique disturbances of breathing during sleep (SDBVNS) that are not captured well using standard criteria. The primary purpose of this retrospective study was to compare AASM definitions with alternative criteria to more accurately measure SDBVNS We also sought to assess outcome variables that may be clinically relevant and response to positive airway pressure therapy. MethodsWe analyzed the electronic medical records and comprehensive polysomnography results of all adult subjects with active VNS for epilepsy who were referred to the sleep center for suspected sleep apnea (2015–2020). We compared standard AASM criteria for defining apneas/hypopnea index (AHIAASM) with three novel scoring criteria for hypopnea according to degree of oxygen desaturation associated with VNS events: AHIVNS0 (none required); AHIVNS2 (2% required); and AHIVNS3 (3% required). ResultsTwenty-six subjects were included in the final analysis with 35 PSGs (14 females/12 males). The mean age was 33.6 years and mean body mass index (BMI) of 32.2 kg/m2. AHIAASM measured ≥ 15/hour in 7 (26.9%) subjects versus 21 (80.8%) by AHIVNS0; 15 (70.0%) by AHIVNS2; and 5 (19.2%) by AHIVNS3. Clinically significant hypoxemia was not present. The mean time SpO2<89% was 7 (20.8) minutes. Oximetry tracings often showed a desaturation pattern that resembled a sawfish rather than sawtooth. Arousals specifically linked to VNS activation were not elevated (2.9/hour). The baseline AHIVNS0 was 27.7/hour with a lowest AHIVNS0 on PAP of 27.9/hr. ConclusionsAASM scoring criteria significantly underestimated the degree of VNS induced respiratory disturbances. VNS events were not associated with increased arousals or significant hypoxemia. PAP therapy was an ineffective treatment in this population. This study adds to the increasing body of evidence of sleep disordered breathing related to VNS and questions the clinical significance of this finding.