Surgery for obstructive sleep apnoea

Development and application of a machine learning-based predictive model for obstructive sleep apnea screening

Objective

To develop a robust machine learning prediction model for the automatic screening and diagnosis of obstructive sleep apnea (OSA) using five advanced algorithms, namely Extreme Gradient Boosting (XGBoost), Logistic Regression (LR), Support Vector Machine (SVM), Light Gradient Boosting Machine (LightGBM), and Random Forest (RF) to provide substantial support for early clinical diagnosis and intervention.

Methods

We conducted a retrospective analysis of clinical data from 439 patients who underwent polysomnography at the Affiliated Hospital of Xuzhou Medical University between October 2019 and October 2022. Predictor variables such as demographic information [age, sex, height, weight, body mass index (BMI)], medical history, and Epworth Sleepiness Scale (ESS) were used. Univariate analysis was used to identify variables with significant differences, and the dataset was then divided into training and validation sets in a 4:1 ratio. The training set was established to predict OSA severity grading. The validation set was used to assess model performance using the area under the curve (AUC). Additionally, a separate analysis was conducted, categorizing the normal population as one group and patients with moderate-to-severe OSA as another. The same univariate analysis was applied, and the dataset was divided into training and validation sets in a 4:1 ratio. The training set was used to build a prediction model for screening moderate-to-severe OSA, while the validation set was used to verify the model's performance.

Results

Among the four groups, the LightGBM model outperformed others, with the top five feature importance rankings of ESS total score, BMI, sex, hypertension, and gastroesophageal reflux (GERD), where Age, ESS total score and BMI played the most significant roles. In the dichotomous model, RF is the best performer of the five models respectively. The top five ranked feature importance of the best-performing RF models were ESS total score, BMI, GERD, age and Dry mouth, with ESS total score and BMI being particularly pivotal.

Conclusion

Machine learning-based prediction models for OSA disease grading and screening prove instrumental in the early identification of patients with moderate-to-severe OSA, revealing pertinent risk factors and facilitating timely interventions to counter pathological changes induced by OSA. Notably, ESS total score and BMI emerge as the most critical features for predicting OSA, emphasizing their significance in clinical assessments. The dataset will be publicly available on my Github.

The effect of velar collapse patterns on unilateral upper airway stimulation therapy

PURPOSE

Hypoglossal nerve stimulation is a promising alternative therapy for patients with obstructive sleep apnea with continuous positive airway pressure intolerance or failure. Previous studies concluded that a velar complete concentric collapse might prohibit a good therapeutic outcome. However, certain patients have an upper velar anteroposterior collapse and a lower velar complete concentric collapse. The effect of this velar collapse pattern is unknown, preventing evidence-based decision-making for these patients. This study aimed to compare the results of upper airway stimulation therapy in these patients to patients with a pure anteroposterior velar collapse.

METHODS

A retrospective single-center cohort study was performed. Patients were included who were implanted with an upper airway stimulation device and had a 1-year follow-up.

RESULTS

Of 66 patients, 10 had an upper velar anteroposterior collapse and lower velar complete concentric collapse. Fifty-six patients had a complete or partial velar anteroposterior collapse. At follow-up, all respiratory outcomes were similarly changed between the two groups. The mean apnea and hypopnea index reduced equally (26.9 events/hour vs. 23.9 events/hour, 95% CI (-5.0, 11.0), p = 0.46). A similar decrease in the oxygen desaturation index of ≥ 4% was observed (12.0/hour versus 11.5/hour, 95% CI (-8.7, 9.7) p = 0.92) CONCLUSION: Patients with an upper velar anteroposterior collapse and a lower velar complete concentric collapse are suitable candidates for upper airway stimulation therapy. In these patients, the lower velum may represent a transition zone between the anteroposterior collapse of the upper velum and the lateral collapse of the oropharynx, instead of being a real concentric collapse.

An Overview of Systematic Reviews on the Surgical Management of Obstructive Sleep Apnoea

Background

Obstructive Sleep Apnoea (OSA) is a common sleep disorder marked by partial or total obstruction of the upper airway while a person is asleep leading to breathing difficulty, reduced oxygenation and frequent awakenings. This condition affects the general health significantly compromising quality of life. The objective of this overview  is to thoroughly assess the systematic reviews on current surgical therapies for the management of OSA in terms of patient outcomes.

Methods

A thorough literature search was performed from inception till 31st December 2022 using PubMed, and Cochrane databases. Studies evaluating the effectiveness and safety of different surgical techniques for the management of OSA were considered. The quality of articles was assessed using AMSTAR (A MeaSurement Tool to Assess systematic Reviews) and Glenny et al. checklist.

Results

Out of eighteen studies, only seven studies met the inclusion and exclusion criteria. Results showed that the majority of studies were in the pediatric age group except one systematic  review which assessed the adult age group.

Conclusion

None of the published articles had compared all surgical procedures based on the standard evaluating procedure nor followed all reporting guidelines in the primary studies. For better implementation, further multi center studies are warranted with unique reporting criteria and guidelines about pre- as well as post-operative phases. Future research should concentrate on contrasting strategies, combination therapies, and evaluating long-term effects.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12663-023-02051-x.

White matter microstructure and connectivity changes after surgery in male adults with obstructive sleep apnea: recovery or reorganization?

Study objectives

Obstructive sleep apnea (OSA) is a prevalent clinical problem significantly affecting cognitive functions. Surgical treatment is recommended for those unable to use continuous positive airway pressure. We aimed to investigate the therapeutic effect of upper airway surgery on the white matter (WM) microstructure and brain connectivity in patients with OSA.

Methods

Twenty-one male patients with moderate-to-severe OSA were recruited for multi-level upper airway surgery. Overnight polysomnography (PSG), neuropsychiatric tests, and brain MRI scans were acquired before and 6.1 ± 0.8 months after surgery. Nineteen male patients with untreated OSA were also included as a reference group. We calculated the longitudinal changes of diffusion tensor imaging (DTI) parameters, including fractional anisotropy (ΔFA) and mean/axial/radial diffusivity (ΔMD/AD/RD). We also assessed changes in network properties based on graph theory.

Results

Surgically treated patients showed improvement in PSG parameters and verbal memory after surgery. Globally, ΔFA was significantly higher and ΔRD was lower in the surgery group than in the untreated group. Especially ΔFA of the tracts involved in the limbic system was higher after surgery. In network analysis, higher Δbetweenness and lower Δclustering coefficients were observed in the surgical group than in the untreated group. Finally, the improvement of verbal memory after surgery positively correlated with ΔFA in superior thalamic radiation (p = 0.021), fronto aslant tracts (p = 0.027), and forceps minor tracts (p = 0.032).

Conclusion

Surgical treatment of OSA can alleviate alterations in WM integrity and disruptions in local networks, particularly for the tracts involved in the limbic system. These findings may further explain the cognitive improvement observed after the treatment of OSA.

Clinical study of transcranial sonography image characteristics in patients with obstructive sleep apnea

OBJECTIVE

This study aimed to explore the relationship between patients with obstructive sleep apnea (OSA) from subgroups of varying severity and substantia nigra (SN) hyperechogenicity as well as cerebral blood flow detected by transcranial sonography (TCS). The study also explored if there were differences in damage of the SN and in the cerebral blood flow between the bilateral sides.

METHODS

Right-handed men diagnosed with OSA by polysomnography were recruited from August 2018 to August 2020. The included patients were divided into 3 subgroups (mild, moderate, and severe OSA), and all patients underwent TCS.

RESULTS

Among the 157 study patients (30 with mild OSA, 25 moderate, and 102 severe), the overall prevalence of SN hyperechogenicity was 15% (23/157). The hyperechogenicity detection rates were 3% (4/157) in the right SN subgroup and 13% (20/157) in the left SN subgroup, which were significantly different. The left side always had reduced blood flow on TCS (P < 0.05). No correlation was observed between the severity of OSA and the detection rates of SN hyperechogenicity (P > 0.05).

CONCLUSION

Patients with OSA showed a higher detection rate of SN hyperechogenicity on the left compared with the right side. The left middle cerebral arteries had reduced blood flow, which was consistent with the more severe damage of the left SN. No relationship was observed between the severity of OSA and the detection rate of SN hyperechogenicity or hemodynamic parameters.

Pathophysiological mechanisms and therapeutic approaches in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a common breathing disorder in sleep in which the airways narrow or collapse during sleep, causing obstructive sleep apnea. The prevalence of OSAS continues to rise worldwide, particularly in middle-aged and elderly individuals. The mechanism of upper airway collapse is incompletely understood but is associated with several factors, including obesity, craniofacial changes, altered muscle function in the upper airway, pharyngeal neuropathy, and fluid shifts to the neck. The main characteristics of OSAS are recurrent pauses in respiration, which lead to intermittent hypoxia (IH) and hypercapnia, accompanied by blood oxygen desaturation and arousal during sleep, which sharply increases the risk of several diseases. This paper first briefly describes the epidemiology, incidence, and pathophysiological mechanisms of OSAS. Next, the alterations in relevant signaling pathways induced by IH are systematically reviewed and discussed. For example, IH can induce gut microbiota (GM) dysbiosis, impair the intestinal barrier, and alter intestinal metabolites. These mechanisms ultimately lead to secondary oxidative stress, systemic inflammation, and sympathetic activation. We then summarize the effects of IH on disease pathogenesis, including cardiocerebrovascular disorders, neurological disorders, metabolic diseases, cancer, reproductive disorders, and COVID-19. Finally, different therapeutic strategies for OSAS caused by different causes are proposed. Multidisciplinary approaches and shared decision-making are necessary for the successful treatment of OSAS in the future, but more randomized controlled trials are needed for further evaluation to define what treatments are best for specific OSAS patients.

Examining the impact of multilevel upper airway surgery on the obstructive sleep apnoea endotypes and their utility in predicting surgical outcomes

BACKGROUND AND OBJECTIVE

Upper airway surgery for obstructive sleep apnoea (OSA) is an alternative treatment for patients who are intolerant of continuous positive airway pressure (CPAP). However, upper airway surgery has variable treatment efficacy with no reliable predictors of response. While we now know that there are several endotypes contributing to OSA (i.e., upper airway collapsibility, airway muscle response/compensation, respiratory arousal threshold and loop gain), no study to date has examined: (i) how upper airway surgery affects all four OSA endotypes, (ii) whether knowledge of baseline OSA endotypes predicts response to surgery and (iii) whether there are any differences when OSA endotypes are measured using the CPAP dial-down or clinical polysomnographic (PSG) methods.

METHODS

We prospectively studied 23 OSA patients before and ≥3 months after multilevel upper airway surgery. Participants underwent clinical and research PSG to measure OSA severity (apnoea-hypopnoea index [AHI]) and endotypes (measured in supine non-rapid eye movement [NREM]). Values are presented as mean ± SD or median (interquartile range).

RESULTS

Surgery reduced the AHI_Total (38.7 [23.4 to 79.2] vs. 22.0 [13.3 to 53.5] events/h; p = 0.009). There were no significant changes in OSA endotypes, however, large but variable improvements in collapsibility were observed (CPAP dial-down method: ∆1.9 ± 4.9 L/min, p = 0.09, n = 21; PSG method: ∆3.4 [-2.8 to 49.0]%V_eupnoea , p = 0.06, n = 20). Improvement in collapsibility strongly correlated with improvement in AHI (%∆AHI_SupineNREM vs. ∆collapsibility: p < 0.005; R²  = 0.46-0.48). None of the baseline OSA endotypes predicted response to surgery.

CONCLUSION

Surgery unpredictably alters upper airway collapsibility but does not alter the non-anatomical endotypes. There are no baseline predictors of response to surgery.

Investigation of the Effectiveness of Traditional Breathing Therapy on Pulmonary Function in College Students with Obstructive Sleep Apnea

Background

Obstructive sleep apnea (OSA) is a problem that involves many body systems, but its impact on the respiratory system deserves special attention. While there are many studies investigating the use of continuous positive airway pressure (CPAP) to treat lung function in patients with sleep apnea, the lack of studies in the literature on the effects of traditional breathing therapy on lung function in patients with OSA prompted us to conduct such a study.

Objective

The present randomized trial aims to assess the effect of traditional breathing therapy on daytime sleepiness and pulmonary function in college students with OSA.

Methods

Forty college students (male) with OSA were randomly divided into two groups: the control group (CG) and the traditional breathing therapy group (TG). Daytime sleepiness symptoms in OSA are measured primarily by the Epworth Sleepiness Scale (ESS). Pulmonary function measurements included FVC, FEV1, PEE, and MEF50%. The changes in morning blood pressure (BP), including diastolic BP and systolic BP, were also recorded. Data were recorded before and after the experiment.

Results

A decrease in ESS at 12 weeks after intervention had statistical significance compared with values recorded before intervention (P < 0.05). A decrease in systolic and diastolic BP at 12 weeks after intervention had statistical significance compared with values recorded before intervention (P < 0.05). Comparisons made in terms of pulmonary functions demonstrated a statistically significant increase in 12-week postintervention values of FVC, FEV1, PEF, and MEF50% (P < 0.05).

Conclusion

Our study shows the positive effects of traditional breathing therapy on pulmonary function parameters. This suggests that traditional breathing therapy treatment in OSA patients is as effective as CPAP on pulmonary function, while there is an improvement in daytime sleepiness and a modest decline in the mean daytime systolic and diastolic BP.

The Use of Propofol versus Dexmedetomidine for Patients Receiving Drug-Induced Sleep Endoscopy: A Meta-Analysis of Randomized Controlled Trials

The sedation outcomes associated with dexmedetomidine compared with those of propofol during drug-induced sleep endoscopy (DISE) remains unclear. Electronic databases (i.e., the Cochrane controlled trials register, Embase, Medline, and Scopus) were searched from inception to 25 December 2020 for randomized controlled trials (RCTs) that evaluated the sedation outcomes with dexmedetomidine or propofol in adult patients diagnosed with obstructive sleep apnea (OSA) receiving DISE. The primary outcome was the difference in minimum oxygen saturation (mSaO2). Five RCTs (270 participants) published between 2015 and 2020 were included for analysis. Compared with dexmedetomidine, propofol was associated with lower levels of mSaO2 (mean difference (MD) = -7.24, 95% confidence interval (CI) -12.04 to -2.44; 230 participants) and satisfaction among endoscopic performers (standardized MD = -2.43, 95% CI -3.61 to -1.26; 128 participants) as well as a higher risk of hypoxemia (relative ratios = 1.82, 95% CI 1.2 to 2.76; 82 participants). However, propofol provided a shorter time to fall asleep and a lower risk of failed sedation compared with dexmedetomidine. No significant difference was found in other outcomes. Compared with propofol, dexmedetomidine exhibited fewer adverse effects on respiratory function and provided a higher level of satisfaction among endoscopic performers but was associated with an elevated risk of failed sedation.

Voice Assessment in Patients With Obstructive Sleep Apnea Syndrome After Transoral Robotic Surgery

Objectives: Removal of part of the tongue base, in combination with uvulopharyngopalatoplasty via transoral robotic surgery (TORS), for treating obstructive sleep apnea syndrome (OSAS) results in enlargement of the oropharynx and hypopharynx and change in the size of the resonance chamber. These procedures may also alter the laryngeal-hyoid bone complex, which is linked to vocal fold tension. Thus, there is the potential for change in phonation and pitch after surgery.

Study Design: Prospective, nonrandomized, institutional board-approved study.

Methods: From January to August 2018, 15 patients with OSAS receiving TORS underwent voice and pitch sampling. The multi-dimensional voice program (MDVP) was applied to the evaluation of preoperative sound parameters. Highest pitch and lowest pitch were obtained with real-time pitch software, with pitch synchronized to electronic organ or tuner. Subjects also completed the Voice Handicap Index-10 scale (VHI-10), to assess their subjective perception and to detect factors affecting the VHI-10 score. The relevant parameters were analyzed again 3 months after the operation.

Results: There was an increase in VHI-10 score 3 months after operation that did not reach statistical significance. There were also no significant differences in sound parameters. Increases in highest pitch (353.18 Hz shift to 387.99 Hz), highest semitone (F5# shift to F5#), lowest pitch (117.45 Hz shift to 131.42 Hz), and lowest semitone (C₃ shift to C₃) did not reach statistical significance. The increase in the lowest semitone was significantly related to change in VHI-10 score (r = −0.808, P = 0.028).

Conclusion: Patients with OSA undergoing TORS showed a negative correlation coefficient over 0.8 with change in VHI-10 score. That is, increase in the lowest semitone after operation correlated with increase in VHI-10 score which may cause perceive changes in subjective pronunciation.

Comparison of Findings between Clinical Examinations and Drug-Induced Sleep Endoscopy in Patients with Obstructive Sleep Apnea Syndrome

The Velum, Oropharynx, Tongue base and Epiglottis (VOTE) classification on drug-induced sleep endoscopy (DISE) is used widely for obstructive sleep apnea (OSA) syndrome, though research into comparative physical examinations with VOTE on DISE is still limited. The aim of this study was to evaluate the relationship between the findings of physical examinations and DISE in patients with OSA. Fifty-five patients with OSA were enrolled in this retrospective study. All of the patients received clinical explorations including a Brodsky classification, a modified Mallampati score (MMS), a modified Friedman’s staging system, and a Muller’s test. Drug-induced sleep endoscopy was further evaluated in the operating room. There were significant relationships between Brodsky classification, modified Friedman’s staging system, Muller’s test and oropharynx collapse during DISE (p < 0.05). Brodsky classification, MMS, modified Friedman’s staging system and retropalatal lateral-to-lateral (L–L) collapse of Muller’s test were significantly correlated with VOTE count (p < 0.05). The concordance between VOTE under DISE and Brodsky classification or modified Friedman’s staging system was moderate. In contrast, the concordance between VOTE under DISE and MMS or Muller’s test was slight. The study revealed that Brodsky classification and Friedman staging had a significant relationship with DISE on the velum and oropharynx, but the level of tongue base is uncertain between DISE and MMS. Correlation of awake evaluation of tongue base is still not correlated to the DISE findings. Pre-treatment evaluation of DISE is still warranted.

Comparison of upper airway obstruction during zolpidem-induced sleep and propofol-induced sleep in patients with obstructive sleep apnea: a pilot study

STUDY OBJECTIVES

Drug-induced sleep endoscopy (DISE) using propofol is commonly used to identify the pharyngeal structure involved in collapse among patients with obstructive sleep apnea. DISE has never been compared with zolpidem-induced sleep endoscopy. We hypothesized that propofol at recommended sedation levels does not influence upper airway collapsibility nor the frequency of multilevel pharyngeal collapse as compared with zolpidem-induced sleep.

METHODS

Twenty-one patients with obstructive sleep apnea underwent polysomnography and sleep endoscopy during zolpidem-induced sleep and during DISE with propofol. A propofol target-controlled infusion was titrated to achieve a bispectral index between 50 and 70. Airway collapsibility was estimated and compared in both conditions by peak inspiratory flow and the magnitude of negative effort dependence. Respiratory drive was estimated by the difference between end-expiratory and peak-negative inspiratory pharyngeal pressure (driving pressure). Site and configuration of pharyngeal collapse during zolpidem-induced sleep and DISE with propofol were compared.

RESULTS

The frequency of multilevel collapse during zolpidem-induced sleep was similar to that observed during DISE with propofol (72% vs 86%, respectively; difference: 14%; 95% confidence interval: -12% to 40%; P = .453). The endoscopic classification of pharyngeal collapse during both conditions were similar. Peak inspiratory flow, respiratory drive (effect size: 0.05 and 0.03, respectively), and negative effort dependence (difference: -6%; 95% confidence interval: -16% to 4%) were also similar in both procedures.

CONCLUSIONS

In this pilot study, recommended propofol doses did not significantly increase multilevel pharyngeal collapse or affect upper airway collapsibility and respiratory drive as compared with zolpidem-induced sleep.

CLINICAL TRIAL REGISTRATION

Registry: clinicaltrials.gov; Name: Natural and Drug Sleep Endoscopy; URL: https://clinicaltrials.gov/ct2/show/study/NCT03004014; Identifier: NCT03004014.

Endoscopia del sueño mediante sedación inducida por fármacos o somnoscopia

Introducción y objetivos: La somnoscopia es una herramienta diagnóstica para valorar las posibles obstrucciones de la vía aérea superior responsables del síndrome de apnea-hipopnea del sueño (SAHS). Nuestro objetivo de es mostrar nuestra experiencia con somnoscopia o DISE (endoscopia mediante sedación inducida por fármacos) en candidatos a cirugía por una patología obstructiva de vía aerodigestiva superior. Material y métodos Presentamos un estudio retrospectivo de 17 pacientes de los que se excluyen finalmente 2. La edad de los pacientes varió de 34 a 72 años. Se practica polisomnografía previa y el IAH medio fue 7,32±8,71. Discusión y conclusión: La DISE es una técnica segura, reproducible y aplicable en cualquier servicio de ORL. Así mismo, permite individualizar el tratamiento quirúrgico y probablemente evitar cirugías innecesarias.

Positional therapy for obstructive sleep apnoea

BACKGROUND

The modalities of therapy for obstructive sleep apnoea (OSA) include behavioural and lifestyle modifications, positional therapy, oral appliances, surgery and continuous positive airway pressure therapy (CPAP). Though CPAP has proven efficacy in treating OSA, adherence with CPAP therapy is suboptimal. Positional therapy (to keep people sleeping on their side) is less invasive and therefore expected to have better adherence. This review considered the efficacy of positional therapy compared to CPAP as well as positional therapy against no positional therapy. Devices designed for positional therapy include lumbar or abdominal binders, semi-rigid backpacks, full-length pillows, a tennis ball attached to the back of nightwear, and electrical sensors with alarms that indicate change in position.

OBJECTIVES

To compare the efficacy of positional therapy versus CPAP and positional therapy versus inactive control (sham intervention or no positional therapy intervention) in people with OSA.

SEARCH METHODS

We identified studies from the Cochrane Airways' Specialised Register (including CENTRAL, MEDLINE, Embase, CINAHL, AHMED and PsycINFO), ClinicalTrials.gov, and the World Health Organization trials portal (ICTRP). It also contains results derived from handsearching of respiratory journals and abstract books of major annual meetings. We searched all databases from their inception to September 2018, with no restrictions on language of publication or publication type.

SELECTION CRITERIA

We included randomised controlled trials comparing positional therapy with CPAP and positional therapy with inactive control.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted the data. We used a random-effects model in the meta-analysis to estimate mean differences and confidence intervals. We assessed certainty of evidence using the GRADE approach.

MAIN RESULTS

We included eight studies. The studies randomised 323 participants into two types of interventions. The comparison between positional therapy and CPAP included 72 participants, while the comparison between positional therapy and inactive control included 251 participants. Three studies used supine vibration alarm devices, while five studies used physical positioning like specially designed pillows or semirigid backpacks.Positional therapy versus CPAPThe three studies included for this comparison were randomised cross-over trials. Two studies found that there was no difference in Epworth Sleepiness Scale (ESS) scores between CPAP and positional therapy. Two studies showed that CPAP produced a greater reduction in Apnoea-Hypopnoea Index (AHI) with a mean difference (MD) of 6.4 events per hour (95% CI 3.00 to 9.79; low-certainty evidence) compared to positional therapy. Subjective adherence, evaluated in one study, was found to be significantly greater with positional therapy (MD 2.5 hours per night, 95% CI 1.41 to 3.59; moderate-certainty evidence).In terms of secondary outcomes, one study each reported quality-of-life indices and quality-of-sleep indices with no significant difference between the two groups. One study reported cognitive outcomes using multiple parameters and found no difference between the groups. There were insufficient data to comment on other secondary outcomes like respiratory disturbance index (RDI), and frequency and duration of nocturnal desaturation. None of the studies clearly reported adverse effects.Positional therapy versus inactive controlThree studies of positional therapy versus no intervention were randomised cross-over trials, while two studies were parallel-arm studies. Data from two studies showed that positional therapy significantly improved ESS scores (MD -1.58, 95% CI -2.89 to -0.29; moderate-certainty evidence). Positional therapy showed a reduction in AHI compared with control (MD -7.38 events per hour, 95% CI -10.06 to -4.7; low-certainty evidence). One study reported adherence. The number of participants who continued to use the device at two months was no different between the two groups (odds ratio (OR) 0.80, 95% CI 0.33 to 1.94; low-certainty evidence). The same study reported adverse effects, the most common being pain in the back and chest, and sleep disturbance but there was no significant difference between the two groups in terms of device discontinuation (OR 1.25, 95% CI 0.5 to 3.03; low-certainty evidence). One study each reported quality-of-life indices and quality-of-sleep indices, with no significant difference between the two groups. One study reported cognitive outcome, and found no difference between the groups. There was insufficient evidence to comment on other secondary outcomes (RDI, frequency and duration of nocturnal desaturation).

AUTHORS' CONCLUSIONS

The review found that CPAP has a greater effect on improving AHI compared with positional therapy in positional OSA, while positional therapy was better than inactive control for improving ESS and AHI. Positional therapy may have better adherence than CPAP. There were no significant differences for other clinically relevant outcomes such as quality of life or cognitive function. All the studies were of short duration. We are unable to comment on the long-term effects of the therapies. This is important, as most of the quality-of-life outcomes will be evident only when the therapies are given over a longer period of time. The certainty of evidence was low to moderate.

Achondroplasia: a comprehensive clinical review

Achondroplasia is the most common of the skeletal dysplasias that result in marked short stature (dwarfism). Although its clinical and radiologic phenotype has been described for more than 50 years, there is still a great deal to be learned about the medical issues that arise secondary to this diagnosis, the manner in which these are best diagnosed and addressed, and whether preventive strategies can ameliorate the problems that can compromise the health and well being of affected individuals. This review provides both an updated discussion of the care needs of those with achondroplasia and an exploration of the limits of evidence that is available regarding care recommendations, controversies that are currently present, and the many areas of ignorance that remain.

From CPAP to tailored therapy for obstructive sleep Apnoea

Obstructive Sleep Apnoea (OSA) is a common sleep disorder that is associated with daytime symptoms and a range of comorbidity and mortality. Continuous Positive Airway Pressure (CPAP) therapy is highly efficacious at preventing OSA when in use and has long been the standard treatment for newly diagnosed patients. However, CPAP therapy has well recognised limitations in real world effectiveness due to issues with patient acceptance and suboptimal usage. There is a clear need to enhance OSA treatment strategies and options. Although there are a range of alternative treatments (e.g. weight loss, oral appliances, positional devices, surgery, and emerging therapies such as sedatives and oxygen), generally there are individual differences in efficacy and often OSA will not be completely eliminated. There is increasing recognition that OSA is a heterogeneous disorder in terms of risk factors, clinical presentation, pathophysiology and comorbidity. Better characterisation of OSA heterogeneity will enable tailored approaches to therapy to ensure treatment effectiveness. Tools to elucidate individual anatomical and pathophysiological phenotypes in clinical practice are receiving attention. Additionally, recognising patient preferences, treatment enhancement strategies and broader assessment of treatment effectiveness are part of tailoring therapy at the individual level. This review provides a narrative of current treatment approaches and limitations and the future potential for individual tailoring to enhance treatment effectiveness.

Comorbidities as an Indication for Metabolic Surgery

Metabolic diseases, comprising type 2 diabetes mellitus (T2DM), dyslipidemia, and non-alcoholic steatohepatitis (NASH), are rapidly increasing worldwide. Conservative medical therapy, including the newly available drugs, has only limited effects and does neither influence survival or the development of micro- or macrovascular complications, nor the progression of NASH to liver cirrhosis, nor the development of hepatocellular carcinomas in the NASH liver. In contrast, metabolic surgery is very effective independent of the preoperative body mass index (BMI) in reducing overall and cardiovascular mortality in patients with T2DM. Furthermore, metabolic surgery significantly reduces the development of micro- and macrovascular complications while being the most effective therapy in order to achieve remission of T2DM and to reach the targeted glycemic control. Importantly, even existing diabetic complications such as nephropathy as well as the features of NASH can be reversed by metabolic surgery. Here, we propose indications for metabolic surgery due to T2DM and NASH based on a simple but objective, disease-specific staging system. We outline the use of the Edmonton Obesity Staging System (EOSS) as a clinical staging system independent of the BMI that will identify patients who will benefit the most from metabolic surgery.

The role of masseter muscle EMG during DISE to predict the effectiveness of MAD: preliminary results

The use of a mandibular advancement device (MAD) increases the activity of the temporo-mandibular (TM) complex and masseter (MM) muscles with the risk of reducing treatment compliance. Predictors of treatment outcome are of importance in selecting patients who might benefit from MAD without side effects. The role of mandibular advancement (MA) during drug-induced sleep endoscopy (DISE) is controversial. In three cases (BMI < 30) affected by non-severe OSAS (AHI < 30 e/h), we recorded the surface EMG signal of MM activity during DISE. At follow-up all cases improved the AHI, two cases that showed transient increase of MM activity did not suffer from changes of overjet and did not complain of discomfort with the use of MAD. The case that showed a continuing increase of MM activity reported TM discomfort without changes of dental occlusion. EMG of MM during DISE may contribute to ameliorate the selection of cases amenable to treatment with MAD.

A Comparison of Uvulopalatopharyngoplasty and Modified Radiofrequency Tissue Ablation in Mild to Moderate Obstructive Sleep Apnea: A Randomized Clinical Trial

STUDY OBJECTIVES

To compare the efficacy of modified radiofrequency tissue ablation (MRFTA) with uvulopalatopharyngoplasty (UPPP) based on both subjective and objective outcome measures in patients with mild to moderate obstructive sleep apnea (OSA).

METHODS

Forty patients with mild to moderate OSA were randomly divided into UPPP and MRFTA groups. Evaluation was made based on the apneahypopnea index (AHI), Sleep Apnea Quality of Life Index (SAQLI) and Epworth Sleepiness Scale (ESS), immediately before the surgery and 6 months postoperatively.

RESULTS

The postoperative AHI scores were improved significantly in both groups, although the postoperative AHI in the UPPP group was significantly lower than in the MRFTA group (P = .02). The difference between success rates for moderate OSA in UPPP and MRFTA was significant (77% versus 30%, P = .03) but there was no significant difference between success rates for mild OSA in UPPP and MRFTA groups (70% versus 50%, P = .36). Comparing postoperative ESS scores in the 2 groups showed no significant difference (P = .24). The postoperative scores in social interaction, treatment-related symptoms domain, and SAQLI total score were significantly higher in the MRFTA group.

CONCLUSIONS

MRFTA as well as UPPP can greatly improve daytime sleepiness and AHI, especially in patients with mild OSA. MRFTA proved to be more effective than UPPP to enhance quality of life of patients with OSA. Further studies with longer follow-up are required to evaluate long-term safety and efficacy of these procedures.

COMMENTARY

A commentary on this article appears in this issue on page 1023.

CLINICAL TRIAL REGISTRATION

Trial name: Comparison of RFTA (Radio-Frequency-Tissue-Ablation) and UPPP (Uvulopalatopharyngoplasty) in patients with mild to moderate obstructive sleep apnea. URL: http://en.search.irct.ir/view/18617. Registration number: IRCT2014060910160N3.

The role of physical exercise in obstructive sleep apnea

Obstructive sleep apnea (OSA) is a common clinical condition, with a variable and underestimated prevalence. OSA is the main condition associated with secondary systemic arterial hypertension, as well as with atrial fibrillation, stroke, and coronary artery disease, greatly increasing cardiovascular morbidity and mortality. Treatment with continuous positive airway pressure is not tolerated by all OSA patients and is often not suitable in cases of mild OSA. Hence, alternative methods to treat OSA and its cardiovascular consequences are needed. In OSA patients, regular physical exercise has beneficial effects other than weight loss, although the mechanisms of those effects remain unclear. In this population, physiological adaptations due to physical exercise include increases in upper airway dilator muscle tone and in slow-wave sleep time; and decreases in fluid accumulation in the neck, systemic inflammatory response, and body weight. The major benefits of exercise programs for OSA patients include reducing the severity of the condition and daytime sleepiness, as well as increasing sleep efficiency and maximum oxygen consumption. There are few studies that evaluated the role of physical exercise alone for OSA treatment, and their protocols are quite diverse. However, aerobic exercise, alone or combined with resistance training, is a common point among the studies. In this review, the major studies and mechanisms involved in OSA treatment by means of physical exercise are presented. In addition to systemic clinical benefits provided by physical exercise, OSA patients involved in a regular, predominantly aerobic, exercise program have shown a reduction in disease severity and in daytime sleepiness, as well as an increase in sleep efficiency and in peak oxygen consumption, regardless of weight loss.

Increased risk of Eustachian tube disorders in patients with sleep-disordered breathing

Sleep-disordered breathing (SDB) and Eustachian tube disorders (ETDs) share the same risk factors. The specific aim of this study was to determine the correlation between these 2 conditions and to determine whether treatments for SDB reduce the risk of ETD.This is a retrospective and large population-based cohort study. According to Taiwan's National Health Insurance Research Database, out of 1,000,000 insured patients, 24,251 patients were newly diagnosed with SDB from year 2000 through 2009. The control group for this study comprised 96,827 patients without SDB who were randomly selected from the same database at a ratio of 1:4, frequency matched for sex, age, and index year of SDB. The incidence of developing ETD was compared between these 2 groups; the main covariates were demographic data, interventions, and medical comorbidities.There was an increased risk of developing ETD among the SDB cohort compared with the control group (hazard ratio = 1.51, 95% confidence interval = 1.41-1.63). Compared with SDB patients who did not receive treatment, those who received the treatment, that is, pharyngeal or nasal surgery, CPAP, or multiple modalities (both surgery and CPAP), had a significantly reduced risk of developing ETD.This study showed that patients with SDB are at an increased risk of developing ETD and other comorbidities. The risk of developing ETD can be reduced by implementing prompt treatment for SDB. Multidisciplinary evaluation including ETD should be conducted in the management of patients presenting with SDB.

How does mandibular advancement with or without maxillary procedures affect pharyngeal airways? An overview of systematic reviews

BACKGROUND

Mandibular advancement surgery may positively affect pharyngeal airways and therefore potentially beneficial to obstructive sleep apnea (OSA).

OBJECTIVE

To collect evidence from published systematic reviews that have evaluated pharyngeal airway changes related to mandibular advancement with or without maxillary procedures.

METHODOLOGY

PubMed, EMBASE, Web of Science, and Cochrane Library were searched without limiting language or timeline. Eligible systematic reviews evaluating changes in pharyngeal airway dimensions and respiratory parameters after mandibular advancement with or without maxillary surgery were identified and included.

RESULTS

This overview has included eleven systematic reviews. Maxillomandibular advancement (MMA) increases linear, cross-sectional plane and volumetric measurements of pharyngeal airways significantly (p<0.0001), while reducing the apnea-hypopnea index (AHI) and the respiratory disturbance index (RDI) significantly (p<0.0001). Two systematic reviews included primary studies that have evaluated single-jaw mandibular advancement, but did not discuss their effect onto pharyngeal airways. Based on the included primary studies of those systematic reviews, single-jaw mandibular advancement was reported to significantly increase pharyngeal airway dimensions (p<0.05); however, conclusive long-term results were lacking.

CONCLUSION

MMA increases pharyngeal airway dimensions and is beneficial to patients suffering from OSA. However, more evidence is still needed to draw definite conclusion related to the effect of single-jaw mandibular advancement osteotomies on pharyngeal airways.

A novel implantable device for the treatment of obstructive sleep apnea: clinical safety and feasibility

OBJECTIVE

Many cases of obstructive sleep apnea (OSA) involve collapse of the tongue base and soft palate during sleep, causing occlusion of the upper airway and leading to oxygen desaturation. Existing therapies can be effective, but they are plagued by patient adherence issues and the invasiveness of surgical approaches. A new, minimally invasive implant for OSA has been developed, which is elastic and contracts a few weeks after deployment, stabilizing the surrounding soft tissue. The device has had good outcomes in preclinical testing; this report describes the preliminary feasibility and safety of its implementation in humans.

PATIENTS AND METHODS

A prospective, multicenter, single-arm feasibility study was conducted. Subjects were adults with moderate-to-severe OSA who had previously failed or refused conventional continuous positive airway pressure treatment. Intraoperative feasibility data, postoperative pain, and safety information were collected for a 30-day postoperative period.

RESULTS

Forty subjects participated (37 men, three women; average age of 46.1 years); each received two tongue-base implants and two soft-palate implants. Surgical procedure time averaged 43 minutes. Postsurgical pain resolved readily in most cases; at 30 days post implantation, <20% of subjects reported pain, which averaged less than two out of ten. Adverse events were generally the mild and expected sequelae of a surgical procedure with general anesthesia and intraoral manipulation. The device was well tolerated. Implant extrusions were reported with soft-palate implants (n=12), while tongue-base implants required few revisions (n=2). Quantitative and qualitative sleep effectiveness outcomes (including full-night polysomnographic and quality-of-life measures) will be presented in a subsequent report.

CONCLUSION

Implantation of the device was feasible. Although a relatively high rate of extrusions occurred in the now-discontinued palate implants, tongue-base implants were largely stable and well tolerated. The minimally invasive and maintenance-free implant may provide a new alternative to higher morbidity surgical procedures.

Effect of Laparoscopic Roux-en-Y Gastric Bypass Surgery on Obstructive Sleep Apnea in a Chinese Population with Obesity and T2DM

Background

Bariatric surgery has been reported to be an effective treatment for obstructive sleep apnea (OSA). However, this evidence was not enough for different populations. Thus, we conducted a follow-up study to evaluate the effect of bariatric surgery on OSA in a Chinese population with obesity and type 2 diabetes mellitus (T2DM).

Methods

From May 2011 to March 2014, 72 consecutive subjects with obesity and T2DM were recruited for this study. Before and at least 6 months after the laparoscopic Roux-en-Y gastric bypass (LYGB) surgery, all subjects were asked to undergo a polysomnography test. During the sleep center visit, anthropometric characteristic data, blood samples, and sleep questionnaires were collected.

Results

In total, 44 Chinese participants with OSA were included in the study. Compared with baseline data, the postoperative anthropometric characteristics, blood measurements, and sleep recording data, such as weight, apnea hypopnea index (AHI), and insulin resistance index, differed significantly (p < 0.001). The change in AHI was correlated significantly with preoperative weight (r = 0.298, p < 0.05), preoperative AHI (r = 0.729, p < 0.001), preoperative waist circumference (r = 0.307, p < 0.05), and preoperative insulin resistance (IR) index (r = −0.301, p < 0.05). Postoperative AHI was correlated significantly with age (r = 0.039, p = 0.039) and preoperative AHI (r = 0.445, p = 0.002), and the following prediction model was generated: log₁₀ (postoperative AHI) = 0.626 × log₁₀ (preoperative AHI) +0.010 × age −0.581.

Conclusions

Our findings indicate that LYGB could be an effective therapeutic intervention in the management of OSA for patients with both obesity and T2DM, and the preoperative AHI and age might be important factors that influence the effort of LYGB.

Electronic supplementary material

The online version of this article (doi:10.1007/s11695-014-1510-9) contains supplementary material, which is available to authorized users.

Otorhinolaryngological aspects of sleep-related breathing disorders

Snoring and obstructive sleep apnoea (OSA) are disorders within a wide spectrum of sleep-related breathing disorders (SRBD). Given the obesity epidemic, these conditions will become increasingly prevalent and continue to serve as a large economic burden. A thorough clinical evaluation and appropriate investigations will allow stratification of patients into appropriate treatment groups. A multidisciplinary team is required to manage these patients. Patient selection is critical in ensuring successful surgical and non-surgical outcomes. A wide range of options are available and further long term prospective studies, with standardised data capture and outcome goals, are required to evaluate the most appropriate techniques and long term success rates.

Relationship between Clinical and Polysomnography Measures Corrected for CPAP Use

OBJECTIVES

The changes in patient-reported measures of obstructive sleep apnea (OSA) burden are largely discordant with the change in apnea-hypopnea index (AHI) and other polysomnography measures before and after treatment. For patients treated with continuous positive airway pressure (CPAP), some investigators have theorized that this discordance is due in part to the variability in CPAP use. We aim to test the hypothesis that patient-reported outcomes of CPAP treatment have stronger correlations with AHI when it is corrected for mean nightly CPAP use.

METHODS

This was a cross-sectional study of 459 adults treated with CPAP for OSA. Five patient-reported measures of OSA burden were collected at baseline and after 6 months of CPAP therapy. The correlations between the change in each patient-reported measure and the change in AHI as well as mean nightly AHI (corrected for CPAP use with a weighted average formula) were measured after 6 months of treatment. The same analysis was repeated for 4 additional polysomnography measures, including apnea index, arousal index, lowest oxyhemoglobin saturation, and desaturation index.

RESULTS

The change in AHI was weakly but significantly correlated with change in 2 of the 5 clinical measures. The change in mean nightly AHI demonstrated statistically significant correlations with 4 out of 5 clinical measures, though each with coefficients less than 0.3. Similar results were seen for apnea index, arousal index, lowest oxyhemoglobin saturation, and desaturation index.

CONCLUSIONS

Correction for CPAP use yielded overall small but significant improvements in the correlations between patient-reported measures of sleep apnea burden and polysomnography measures after 6 months of treatment.

Diagnostic Accuracy of Obstructive Airway Adult Test for Diagnosis of Obstructive Sleep Apnea

Rationale. The gold standard for the diagnosis of Obstructive Sleep Apnea (OSA) is polysomnography, whose access is however reduced by costs and limited availability, so that additional diagnostic tests are needed. Objectives. To analyze the diagnostic accuracy of the Obstructive Airway Adult Test (OAAT) compared to polysomnography for the diagnosis of OSA in adult patients. Methods. Ninety patients affected by OSA verified with polysomnography (AHI ≥ 5) and ten healthy patients, randomly selected, were included and all were interviewed by one blind examiner with OAAT questions. Measurements and Main Results. The Spearman rho, evaluated to measure the correlation between OAAT and polysomnography, was 0.72 (p < 0.01). The area under the ROC curve (95% CI) was the parameter to evaluate the accuracy of the OAAT: it was 0.91 (0.81–1.00) for the diagnosis of OSA (AHI ≥ 5), 0.90 (0.82–0.98) for moderate OSA (AHI ≥ 15), and 0.84 (0.76–0.92) for severe OSA (AHI ≥ 30). Conclusions. The OAAT has shown a high correlation with polysomnography and also a high diagnostic accuracy for the diagnosis of OSA. It has also been shown to be able to discriminate among the different degrees of severity of OSA. Additional large studies aiming to validate this questionnaire as a screening or diagnostic test are needed.

Drug-induced sedation endoscopy versus clinical exploration for the diagnosis of severe upper airway obstruction in OSAHS patients

BACKGROUND

Identifying the sites of obstruction of the upper airway in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) is paramount for surgical planning. The aim of this study is to compare wake physical exam findings to the ones obtained during drug-induced sedation endoscopy (DISE) in the diagnosis of severe collapse of the upper airway in OSAHS patients.

METHODS

A retrospective chart review of OSAHS patients who underwent DISE at our institution during the 2006-2010 period was conducted. All the patients had previously undergone a physical examination that included modified Mallampati index (MMI), the Müller maneuver (MM), and the Friedman staging system. Level and severity of airway collapse were evaluated. A severe collapse was attributed to obstructions equal or greater than 75 % of the airway.

RESULTS

A total of 138 patients were included in the study. The incidence of severe airway collapse was compared between DISE and MM; at retropalatal level, no significant difference was found. At retrolingual level, 69 % of patients had severe collapse with DISE in comparison to a 28 % with the MM (p < 0.05). No relationship was found either with the MMI or with the Friedman staging system when compared to the incidence of severe retrolingual collapse diagnosed by DISE. Concordance was low between awake and DISE exploration in both retropalatal and retroglossal level.

CONCLUSION

The Müller maneuver underestimates tongue base severe obstruction diagnosis when compared to that obtained after DISE in OSAHS patients. The wake patient exploration does not accurately correlate to DISE exploration.

WITHDRAWN: Adenotonsillectomy for obstructive sleep apnoea in children

This review has been withdrawn because it has been split into the following reviews: '(Adeno)tonsillectomy versus non‐surgical management of obstructive sleep apnoea syndrome (OSAS) in children' (Schilder 2015) and 'Tonsillectomy versus tonsillotomy in children with sleep‐disordered breathing (including obstructive sleep apnoea)' (protocol) (Blackshaw 2014).

The editorial group responsible for this previously published document have withdrawn it from publication.

Pharmacodynamic Estimate of Propofol-Induced Sedation and Airway Obstruction Effects in Obstructive Sleep Apnea-Hypopnea Syndrome

PURPOSE

Sedatives must be carefully titrated for patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) as oversedation may lead to disastrous respiratory outcomes. This study aimed to investigate the relations between the effect-site concentration (Ce) of propofol and sedation and airway obstruction levels in patients with OSAHS.

MATERIALS AND METHODS

In 25 patients with OSAHS, sedation was induced by 2% propofol using target-controlled infusion. Sedation and airway obstruction levels were assessed using the Observer's Assessment of Alertness/Sedation Scale and a four-category scale, respectively. The relationships between propofol Ce and sedation and airway obstruction were evaluated using a sigmoid Emax model. Pharmacodynamic modeling incorporating covariates was performed using the Nonlinear Mixed Effects Modeling VII software.

RESULTS

Increased propofol Ce correlated with the depth of sedation and the severity of airway obstruction. Predicted Ce50(m) (Ce associated with 50% probability of an effect≥m) for sedation scores (m≥2, 3, 4, and 5) and airway-obstruction scores (m≥2, 3, and 4) were 1.61, 1.78, 1.91, and 2.17 μg/mL and 1.53, 1.64, and 2.09 μg/mL, respectively. Including the apnea-hypopnea index (AHI) as a covariate in the analysis of Ce50(4) for airway obstruction significantly improved the performance of the basic model (p<0.05).

CONCLUSION

The probability of each sedation and airway obstruction score was properly described using a sigmoid Emax model with a narrow therapeutic range of propofol Ce in OSAHS patients. Patients with high AHI values need close monitoring to ensure that airway patency is maintained during propofol sedation.

Obstructive sleep apnoea syndrome

Obstructive sleep apnoea syndrome (OSAS) is a common clinical condition in which the throat narrows or collapses repeatedly during sleep, causing obstructive sleep apnoea events. The syndrome is particularly prevalent in middle-aged and older adults. The mechanism by which the upper airway collapses is not fully understood but is multifactorial and includes obesity, craniofacial changes, alteration in upper airway muscle function, pharyngeal neuropathy and fluid shift towards the neck. The direct consequences of the collapse are intermittent hypoxia and hypercapnia, recurrent arousals and increase in respiratory efforts, leading to secondary sympathetic activation, oxidative stress and systemic inflammation. Excessive daytime sleepiness is a burden for the majority of patients. OSAS is also associated with cardiovascular co-morbidities, including hypertension, arrhythmias, stroke, coronary heart disease, atherosclerosis and overall increased cardiovascular mortality, as well as metabolic dysfunction. Whether treating sleep apnoea can fully reverse its chronic consequences remains to be established in adequately designed studies. Continuous positive airway pressure (CPAP) is the primary treatment modality in patients with severe OSAS, whereas oral appliances are also widely used in mild to moderate forms. Finally, combining different treatment modalities such as CPAP and weight control is beneficial, but need to be evaluated in randomized controlled trials. For an illustrated summary of this Primer, visit: http://go.nature.com/Lwc6te.

Surgical results of different palate techniques to treat oropharyngeal collapse

The aim of this study was to assess the surgical success rate of patients undergoing oropharyngeal surgery, selected through drug-induced sleep endoscopy. Secondly, to compare outcomes of the different oropharyngeal surgery techniques applied. The study design was retrospective case series of surgically treated patients from 2006 to 2013. All patients were diagnosed with either moderate or severe obstructive sleep apnea and did not tolerate conventional positive airway pressure. We performed five different surgical techniques to treat oropharyngeal collapse: partial palate resection, uvulopalatopharyngoplasty, Z-palatoplasty, lateral pharyngoplasty and expansion pharyngoplasty. Patients in whom multilevel surgery was performed were excluded. 53 patients were included in our study, 52.8 % were severe obstructive sleep apnea patients, mean age was 43.9 years, mean body mass index 27.5. The surgical success rate according to Sher's criteria was 71.7 %. 47.2 % had a postoperative apnea hypopnea index lower than 10. The highest success rate was measured in patients who underwent expansion pharyngoplasty (90 % according to Sher's criteria, 80 % with a postoperative apnea hypopnea index lower than 10) although it did not reach statistical significance. Our conclusion is that drug-induced sleep endoscopy is a good tool to select surgical candidates in patients with moderate-to-severe obstructive sleep apnea who are not compliant with the optimal therapy. Expansion pharyngoplasty was the surgical technique with the highest success rates.

Obstructive sleep apnea among hospitalized patients in Spain, analysis of hospital discharge data 2008-2012

BACKGROUND

The aim of this study is to describe clinical characteristics, diagnostic and therapeutic procedure (polysomnography and continuous positive airway pressure (CPAP)/bi-level positive airway pressure (BPAP)), comorbidity, length of hospital stay (LOHS), discharge destination, and in-hospital mortality (IHM) of patients hospitalized for obstructive sleep apnea (OSA) in Spain over a 5-year study period.

METHODS

We included all patients who were hospitalized for OSA (ICD9-CM code 327.23) as primary or secondary diagnosis between 2008 and 2012. Data were collected from the National Hospital Discharge Database, covering the entire Spanish population.

RESULTS

We identified 196,769 discharges of patients admitted for OSA. The number of patients with OSA as primary or secondary diagnosis increased from 2008 to 2012 from 5358 to 7992 and 14,916 to 51,135 respectively. The mean age was 50.7 ± 20.3 years in patients admitted for OSA as primary diagnosis (n = 32,010) and 63.7 ± 17.6 years in patients admitted for OSA as secondary diagnosis (n = 164,759). The most common secondary diagnoses for patients discharged with a primary diagnosis of OSA was arterial hypertension (19.0%), obesity (16.9%), disorders of lipid metabolism (8.01%) and diabetes mellitus (6.48%). The most common primary diagnoses for patients discharged with a secondary diagnosis of OSA were obesity (12.5%), heart failure (9.6%), and chronic bronchitis (4.5%). The percentage of patients that received continuous positive airway pressure (CPAP)/bi-level positive airway pressure (BPAP) therapy was 11.3%. Patients who received this therapy had a higher length of stay compared with those who did not (10.4 ± 14.1 versus 7.3 ± 9.5 days, respectively, p < 0.05) and were less likely to be discharged to home (87.2 versus 91.1%, p < 0.05). The mortality was higher in the first group of patients (9 versus 5.6%, p < 0.05). Multivariate analysis showed that each year from 2008 to 2012, the mean probability of having OSA as primary diagnosis increased an average of 8%, and 33% as secondary diagnosis, after adjusting for other variables.

CONCLUSIONS

The results of this study reveal a national perspective on the characteristics and management of OSA in hospitalized patients in Spain during the period of 2008-2012. The burden of the disease seems to be increasing in Spain. Clinical studies are needed to provide a better knowledge of OSA in this subgroup of patients.

Effects of exercise training on sleep apnea: a meta-analysis

BACKGROUND

Several studies have shown a favorable effect of supervised exercise training on obstructive sleep apnea (OSA). This meta-analysis was conducted to analyze the data from these studies on the severity of OSA (primary outcome) in adults. Secondary outcomes of interest included body mass index (BMI), sleep efficiency, daytime sleepiness and cardiorespiratory fitness.

METHODS

Two independent reviewers searched PubMed and Embase (from inception to March 6, 2013) to identify studies on the effects of supervised exercise training in adults with OSA. Pre- and postexercise training data on our primary and secondary outcomes were extracted.

RESULTS

A total of 5 studies with 6 cohorts that enrolled a total of 129 study participants met the inclusion criteria. The pooled estimate of mean pre- to postintervention (exercise) reduction in AHI was −6.27 events/h (95 % confidence interval [CI] -8.54 to -3.99; p < 0.001). The pooled estimates of mean changes in BMI, sleep efficiency, Epworth sleepiness scale and VO2 peak were -1.37 (95 % CI −2.81 to 0.07; p = 0.06), 5.75 % (95 % CI 2.47-9.03; p = 0.001), -3.3 (95 % CI -5.57 to -1.02; p = 0.004), and 3.93 mL/kg/min (95 % CI 2.44-5.42; p < 0.001), respectively.

CONCLUSIONS

This meta-analysis shows a statistically significant effect of exercise in reducing the severity of sleep apnea in patients with OSA with minimal changes in body weight. Additionally, the significant effects of exercise on cardiorespiratory fitness, daytime sleepiness, and sleep efficiency indicate the potential value of exercise in the management of OSA.

Pediatric obstructive sleep apnea

Obstructive sleep apnea syndrome (OSAS) is a disorder of airway obstruction with multisystem implications and associated complications. OSAS affects children from infancy to adulthood and is responsible for behavioral, cognitive, and growth impairment as well as cardiovascular and perioperative respiratory morbidity and mortality. OSAS is associated commonly with comorbid conditions, including obesity and asthma. Adenotonsillectomy is the most commonly used treatment option for OSAS in childhood, but efforts are underway to identify medical treatment options.

European position paper on drug-induced sedation endoscopy (DISE)

BACKGROUND

Although drug-induced sedation endoscopy (DISE) represents the most widespread diagnostic tool for upper airway endoscopic evaluation of snoring and obstructive sleep apnea hypopnea syndrome (OSAHS), many controversies exist about how to perform the sedation, the indications for DISE, and how to report DISE findings. The present position paper reports on a consensus as proposed by a group of European experts in the field of DISE after discussion during a recent dedicated meeting.

METHODS

The authors have evaluated all the available evidence reported in the literature and have compared experience among various departments in leading European centers in order to provide a standardization of the DISE procedure and an in-depth insight in the main aspects of this technique.

RESULTS

A proposal of the DISE procedure standardization has been achieved with a general agreement concerning the terminology, indications, contraindications, required preliminary examinations, setting, technical equipment required, staffing, local anesthesia and nasal decongestion, patient positioning, basis and special diagnostic maneuvers, and the applied sedation drugs and observation windows. Otherwise, no consensus has been reached on a scoring and classification system.

CONCLUSIONS

Although consensus has been reached on several aspects of the DISE procedure, some topics remain open to future research, such as a better analysis of the importance of positional aspects during DISE and a further comparison of the differences in degree, level and pattern of upper airway collapse observed during DISE versus during natural sleep and awake endoscopy. Finally, a universally accepted scoring and classification system is lacking.

Analysis of obstruction site in obstructive sleep apnea syndrome patients by drug induced sleep endoscopy

PURPOSE

We analyzed site, pattern and degree of obstruction in Korean male obstructive sleep apnea syndrome (OSAS) patients by drug-induced sleep endoscopy (DISE). We also investigated possible links between BMI, AHI and DISE findings.

MATERIALS AND METHODS

Sixty-nine male patients underwent DISE. DISE findings were reported using our classification system in which modified 'VOTE classification' - obstruction type, site of obstruction, degree of obstruction and anatomical site contributing obstruction - was reported. Associations were analyzed among the results of the polysomnography, patients' characteristics and DISE finding.

RESULTS

Multilevel airway obstruction was found in 84.06% of patients and 15.94% had a unilevel obstruction. Among those with unilevel obstruction, 90.90% had retropalatal level obstruction and 9.10% had retrolingual level obstruction. Palate with lateral pharyngeal wall obstruction (49.28%) is the most common obstruction type of the retropalatal level and tongue with lateral pharyngeal wall (37.68%) is the most common obstruction type of the retrolingual level. Examining the relation between obstruction site according to body mass index (BMI) and severity of OSAS (apnea hypopnea index, AHI), the lateral pharyngeal wall had an increasing tendency associated with higher BMI and higher AHI. But the lateral pharyngeal wall of both levels was statistically significant associated with higher AHI.

CONCLUSION

The majority of the Korean male OSAS patients have multilevel obstruction and according to BMI and AHI, the DISE findings indicate that the lateral pharyngeal wall is the most important anatomical site contributing to obstruction regardless of the level at which the obstruction lies.