The effect of sleep position on sleep bruxism in adults with obstructive sleep apnea.

BACKGROUND: Most of the respiratory events in adults with obstructive sleep apnea (OSA) occurs in supine position. It has been reported that the contraction of masseter muscles is dependent on the occurrence of arousals rather than on the occurrence of respiratory events. OBJECTIVES: This study had two aims: (1) to compare the rhythmic masticatory muscle activity (RMMA) index in supine position (RMMA_sup) and in non-supine positions (RMMA_nsup) in adults with OSA; and (2) to determine the associations between RMMA index in both supine position and non-supine positions on the one hand, and several demographic and polysomnographic variables on the other hand. METHODS: One hundred OSA participants (36 females and 64 males; mean age = 50.3 years (SD = 10.5)) were selected randomly from among patients with a full-night polysomnographic recording. RMMA_sup index and RMMA_nsup index were compared using Mann-Whitney U-test. Multivariate linear regression analyses were used to predict RMMA index both in supine and non-supine positions based on several demographic and polysomnographic variables. RESULTS: In patients with OSA, the RMMA_sup index was significantly higher than the RMMA_nsup index (p < .001). RMMA_sup index was significantly associated with the arousal index (p = .002) and arousal index in supine position (p < .001). RMMA_nsup index was only significantly associated with the arousal index in non-supine positions (p = .004). CONCLUSION: Within the limitations of this study, RMMAs occur more frequently in supine position than in non-supine positions in patients with OSA. In both sleep positions, RMMAs are associated with arousals.

Temporal association between leg movements and respiratory events in patients with obstructive sleep apnea: description and differences between the AASM and WASM scoring criteria.

PURPOSE: To describe the temporal association between leg movements (LMs) and respiratory events in patients with obstructive sleep apnea (OSA), and to quantify the difference in scoring respiratory-related leg movement (RRLM) between the American Academy of Sleep Medicine (AASM) criterion and the criterion recommended by the World Association of Sleep Medicine (WASM). METHODS: Patients with OSA who presented with > 10 LMs of any type per hour of sleep were included in this study. For each participant, RRLMs were scored using both the AASM criterion and the recommended WASM criterion. The occurrence of LMs in relation to respiratory events and the difference in scoring RRLM between the AASM criterion and the criterion recommended by the WASM were quantified. RESULTS: In 32 patients enrolled, mean age was 48.1 ± 11.0 years and 78% were men. LMs were significantly more frequent after respiratory events, followed by before respiratory events, and were rare during respiratory events (P < 0.01). Compared with the AASM criterion, more LMs were classified as RRLMs based on the recommended WASM criterion (P = 0.01). CONCLUSION: LMs are more frequent after respiratory events than before and during respiratory events, and more LMs are scored as RRLMs based on the recommended WASM criterion than based on the AASM criterion.

Effects of continuous positive airway pressure and mandibular advancement appliance therapy on sleep bruxism in adults with obstructive sleep apnea: a pilot study.

STUDY OBJECTIVES: This study aimed to investigate the effects of continuous positive airway pressure (CPAP) and mandibular advancement appliance (MAA) therapy on rhythmic masticatory muscle activity (RMMA), a biomarker of sleep bruxism (SB), and to compare the effects of CPAP with MAA in adults with obstructive sleep apnea (OSA). METHODS: This cohort study included individuals with OSA who received treatment with CPAP or MAA. Polysomnographic recordings with and without therapy were performed in each individual. Statistical analyses were performed with repeated measures ANOVA. RESULTS: A total of 38 individuals with OSA were enrolled, 13 on CPAP and 25 with MAA, mean age 52.6 ± 10.6 years, 32 men, mean baseline apnea-hypopnea index (AHI) 26.5 ± 15.2 events/hour, mean RMMA index 3.5 ±events/hour. In the total group, the RMMA index decreased significantly with CPAP and MAA therapies (P < 0.05). The changes in the RMMA index with therapy did not differ significantly between CPAP and MAA (P > 0.05). The RMMA index decreased in 60% of the individuals with OSA, and the changes ranged widely, with a median of 52% and an interquartile range of 107%. CONCLUSIONS: Both CPAP and MAA therapies significantly reduce SB in individuals with OSA. However, the interindividual differences in the effects of these therapies on SB are large. CLINICAL TRIAL REGISTRATION: https://trialsearch.who.int (NL8516); April 08, 2020.

An interim oral appliance as a screening tool during drug-induced sleep endoscopy to predict treatment success with a mandibular advancement device for obstructive sleep apnea.

PURPOSE: Previous studies have shown a wide range of efficacy (29 to 71%) of a mandibular advancement device (MAD) in the treatment of obstructive sleep apnea (OSA). Currently, the ability to preselect suitable patients for MAD therapy based on individual characteristics related to upper airway collapsibility is limited. We investigated if the use of non-custom interim MAD during drug-induced sleep endoscopy (DISE) could be a valuable screening tool to predict MAD treatment outcome. METHODS: In a single-center prospective study including a consecutive series of patients with OSA, we compared DISE outcomes with a MAD in situ with polysomnography results after 3 months of using the same MAD that was used during DISE. RESULTS: Of 41 patients who completed the study, the median apnea-hypopnea index (AHI) was 16.0 events/h [IQR 7.4-23.4]. Respiratory outcomes on polysomnography, including apnea index (AI), total AHI, AHI in supine position, and oxygen desaturation index, all significantly improved after 3 months of MAD treatment. With complete improvement of the upper airway obstruction with the MAD in situ during DISE in supine position, patients were 6.3 times more likely to be a responder to MAD treatment compared to patients with a persisting complete obstruction, although not statistically significant (OR 6.3; 95%CI 0.9-42.7; p = 0.060). CONCLUSION: The potential predictive value with regard to MAD therapy outcomes of the use of an interim MAD during DISE would be an important finding, since the prediction of MAD therapy outcome is of great clinical and scientific interest. A study with a larger cohort should be performed to further investigate our findings.

Do dental parameters predict severity of obstructive sleep apnea and mandibular advancement device therapy outcomes? A pilot study.

BACKGROUND: Mandibular Advancement Devices (MAD's) are oral appliances commonly used in treatment of Obstructive Sleep Apnea (OSA). OSA severity and certain other factors, such as BMI and neck circumference, correlate with MAD therapy success. So far, the predictive value of dental parameters, such as dental profile, molar-classification, overjet, overbite, maximal retrusion, maximal protrusion and protrusive range, has not been fully investigated. OBJECTIVES: We aimed to investigate whether dental parameters influence OSA severity and MAD therapy outcome and could therefore be helpful in phenotyping OSA patients. Furthermore, we studied the predictive power of dental parameters for OSA severity and successful MAD therapy. We hypothesise that specific dental parameters correlate with more severe OSA and with more successful MAD treatment. METHODS: We performed a cohort study, including OSA patients diagnosed by polysomnography (PSG). Dental parameters were collected. Objective treatment outcome was collected by performing a PSG with MAD after three months of therapy. Differences between OSA severity groups and MAD treatment outcomes were analysed and dental parameters were correlated between groups. RESULTS: The relation between dental parameters and OSA severity was analysed in 143 patients, fifty patients had a PSG with MAD in situ after a 3-month therapy. The median baseline Apnea Hypopnea Index (AHI) significantly reduced from 17.6 (8.7-29.3) to 11.1 (5.5-17.5). Overbite and maximal retrusion differed significantly between mild, moderate and severe OSA. Other dental parameters did not differ significantly between the groups, nor correlated with OSA severity or MAD treatment outcome. CONCLUSION: In this study, no correlation between dental parameters and OSA severity or MAD treatment outcomes was found. Therefore, screening patients for OSA and MAD treatment outcome based on dental parameters is currently not possible.

Associations between snoring and dental sleep conditions: A systematic review.

BACKGROUND: It is important for dentists to know if the presence of snoring is associated with the presence of other dental sleep conditions (e.g. obstructive sleep apnea [OSA], sleep bruxism [SB], gastroesophageal reflux disease [GERD], xerostomia and oro-facial pain). If so, dentists could play a significant role in the early recognition and management of these conditions. OBJECTIVES: This systematic review aimed to: (i) investigate the associations between the presence of snoring and the presence of other dental sleep conditions; and (ii) determine if it is clinically relevant that dentists assess snoring in their population. METHODS: The literature search was performed in PubMed and Embase.com in collaboration with a medical librarian. Studies were eligible if they employed regression models to assess whether snoring was associated with other dental sleep conditions, and/or investigated the incidence of snoring in patients with other dental sleep conditions and vice versa. RESULTS: Of the 5299 retrieved references, 36 eligible studies were included. The available evidence indicates that the presence of snoring is associated with higher probabilities of OSA, GERD and headache. Due to limited evidence and conflicting findings, the currently available articles are not indicative of associations between the presence of snoring and the presence of SB and oral dryness. CONCLUSION: Within the limitations of this study, it can be concluded that the presence of snoring is associated with higher probabilities of OSA, GERD and headache. Therefore, it is clinically relevant that dentists assess snoring in their patient population.

Position-dependent obstructive sleep apnea and its influence on treatment success of mandibular advancement devices.

PURPOSE: Depending on the severity of pre-treatment obstructive sleep apnea (OSA) and the criteria used to define treatment success, the efficacy of mandibular advancement devices (MADs) ranges from 30 to 69%. Identifying suitable candidates is the key to increasing the efficacy of a MAD. Positive predictors include a low body mass index, a low apnea-hypopnea index (AHI), and low age. Another consideration is whether or not a patient's OSA is position dependent. To evaluate the effect of such dependency on MAD treatment success, we studied the following: treatment success across the patient's total AHI and in the supine and non-supine sleeping positions; the influence of pre-treatment position dependency on MAD treatment success; and the effect of MAD treatment on post-treatment shifts in position dependency. METHODS: This is a single-center retrospective study of patients with OSA. Patients were diagnosed through an overnight polysomnography and treated with a MAD between February 2015 and January 2018. They were defined as being positional if the AHI in supine sleeping position was at least twice as high as in the non-supine position. RESULTS: Complete treatment success was achieved in 32% of study population (n = 96) and partial success in 54%. Complete treatment success was significantly higher (p = 0.004) when a patient was sleeping in the non-supine position. Treatment success did not differ significantly between patients who were position dependent and those who were not. When treated with a MAD, patients did not spend significantly more time in supine position. Neither did we find any post-treatment shifts in position dependency. CONCLUSION: A MAD is an effective treatment modality that may significantly reduce the total AHI, supine, and non-supine AHI. Since position dependency has no impact on MAD treatment success, it does not determine whether or not a patient is a suitable candidate for MAD treatment.

Daytime polysomnography to perform titration for upper airway stimulation in patients with obstructive sleep apnea.

PURPOSE: Upper airway stimulation (UAS) is an innovative treatment for patients with obstructive sleep apnea (OSA). UAS titrations are performed 3 months after activation of the device to optimize its effectiveness. In general, these titrations are performed during an in-laboratory overnight polysomnography (PSG). However, overnight titrations are expensive and can be logistically challenging because they are labor-intensive which causes shortage of sleep technicians available for night shifts. In addition, recently, overnight PSGs were postponed and canceled due to the COVID-19 pandemic. We aimed to assess the feasibility of a daytime PSG to perform titration of UAS therapy as an alternative for a conventional overnight PSG. METHODS: We performed a prospective single-center observational cohort study. Patients were included when planned for UAS titration; this was approximately 6 months after UAS activation. Data on sleep architecture, patient experience, and respiratory outcomes were collected to evaluate the feasibility. An overnight follow-up PSG 12 months after implantation was used to compare sleep architecture and therapy response. RESULTS: Of 23 patients, four were excluded from analysis because of technical issues during PSG. Even though patients slept significantly shorter during the daytime PSG, this was enough time to complete the titration successfully with 30-min sleep in final therapeutic settings in 84% of the patients. Patients (94%) had a positive experience with the daytime titration. Respiratory outcomes were significantly reduced during titration and were maintained at the 12-month follow-up. CONCLUSION: Daytime titrations are a valuable alternative for conventional overnight titrations. Our findings suggest the implementation of daytime titrations as standard of care. This will contribute to easier logistics and better work circumstances for sleep technicians without jeopardizing titration quality.

Associated factors of primary snoring and obstructive sleep apnoea in patients with sleep bruxism: A questionnaire study.

BACKGROUND: By being aware of the associated factors of primary snoring (PS) and obstructive sleep apnoea (OSA) in sleep bruxism (SB) patients, dentists may contribute to the screening and early recognition of SB patients with PS or OSA. OBJECTIVE: To identify the associated factors of PS and OSA from questionnaire-based data in SB patients. METHODS: A total of 968 self-reported SB patients (31.6% men; median age 44.5 years) were retrospectively enrolled. Self-reported sleep-related breathing status (viz., no sleep-related breathing condition, PS and OSA) was the dependent variable. Independent variables were questionnaire-based data on demographics, lifestyle, psychological status, pain and sleep. RESULTS: For PS, no statistically significant associated factor was identified in analyses. For OSA, increased age (OR = 1.04 [1.03-1.06]), male gender (OR = 3.33 [2.17-5.00]), daily alcohol consumption (OR = 1.96 [1.18-3.33]), depression (OR = 1.10 [1.06-1.14]), daytime sleepiness (OR = 2.94 [1.85-4.76]) and high risk of gastroesophageal reflux disease (GERD; OR = 2.63 [1.52-4.76]) were found to be significant risk factors, while high risk of temporomandibular disorder (TMD) pain (OR = 0.51 [0.30-0.86]) and chronic pain (OR = 0.73 [0.59-0.90]) were significant protective factors. These results were confirmed in the subsequent network analysis. CONCLUSION: Within the limitations of this study, no associated factor is identified for PS. For OSA, dentists should keep in mind that increased age, male gender, daily alcohol consumption, depression, daytime sleepiness and high GERD risk are associated with increased OSA risk in SB patients, while high TMD-pain risk and chronic pain are associated with decreased OSA risk in this population.

The effect of postoperative CPAP use on anastomotic and staple line leakage after bariatric surgery.

PURPOSE: Almost two-thirds of the population undergoing bariatric surgery (BS) suffers from obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) is the standard treatment for moderate to severe OSA and is recommended in patients undergoing BS perioperatively. A severe and dreaded complication after BS is anastomotic leakage. There is theoretical concern that perioperative CPAP use may result in increased distension of the gastrointestinal tract and increase the risk of developing an anastomotic leakage. The aim of this study was to evaluate the effect of postoperative CPAP use on the risk of developing anastomotic leakages after BS. METHODS: Retrospectively, all patients from a single bariatric center who underwent BS from November 2007 to August 2019 were included. Presence and severity of OSA were determined using poly(somno)graphy. To evaluate the effect of postoperative CPAP use on anastomotic leakage, a multivariable logistic regression analysis was performed. RESULTS: A total of 4052 patients were included, with OSA being diagnosed in 62%. Overall, 970 patients (24%) used CPAP after BS. Anastomotic leakage occurred in 64 (1.6%) patients after BS. Leakage rate was 1.3% in non-CPAP group versus 2.5% in CPAP group (p = 0.01). CPAP use was associated with anastomotic leakage; however, after adjustment, CPAP use was not an independent predictor (OR = 1.40, 95% CI 0.60-3.28, p = 0.44). CONCLUSION: There is no independent relation between postoperative CPAP use and anastomotic leakage after BS. Only revision surgery was an independent predictor of anastomotic leakage.

Durability of treatment effects of the Sleep Position Trainer versus oral appliance therapy in positional OSA: 12-month follow-up of a randomized controlled trial.

PURPOSE: The Sleep Position Trainer (SPT) is a new option for treating patients with positional obstructive sleep apnea (POSA). This study investigated long-term efficacy, adherence, and quality of life during use of the SPT device compared with oral appliance therapy (OAT) in patients with POSA. METHODS: This prospective, multicenter trial randomized patients with mild to moderate POSA (apnea-hypopnea index [AHI] 5-30/h) to SPT or OAT. Polysomnography was performed at baseline and after 3 and 12 months' follow-up. The primary endpoint was OSA severity; adherence, quality of life, and adverse events were also assessed. RESULTS: Ninety-nine patients were randomized and 58 completed the study (29 in each group). Median AHI in the SPT group decreased from 13.2/h at baseline to 7.1/h after 12 months (P < 0.001); corresponding values in the OAT group were 13.4/h and 5.0/h (P < 0.001), with no significant between-group difference (P = 1.000). Improvements throughout the study were maintained at 12 months. Long-term median adherence was also similar in the two treatment groups; the proportion of patients who used their device for ≥ 4 h for 5 days in a week was 100% in the SPT group and 97.0% in the OAT group (P = 0.598). CONCLUSIONS: The efficacy of SPT therapy was maintained over 12 months and was comparable to that of OAT in patients with mild to moderate POSA. Adherence was relatively high, and similar in the two groups. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02045576).

Correction to: Durability of treatment effects of the sleep position trainer versus oral appliance therapy in positional OSA: 12-month follow-up of a randomized controlled trial.

The article "Durability of treatment effects of the Sleep Position Trainer versus oral appliance therapy in positional OSA: 12-month follow-up of a randomized controlled trial", by M. H. T. de Ruiter et al., was originally published online in SpringerLink on 15 September 2017 without open access.

European position paper on drug-induced sleep endoscopy: 2017 Update.

BACKGROUND: The first edition of the European position paper (EPP) on drug-induced sleep endoscopy (DISE) was published in 2014 with the aim to standardise the procedure, to provide an in-depth insight into the main aspects of this technique and to have a basis for future research. Since 2014, new studies have been published concerning new sedative agents or new insights into the pattern/levels of the obstruction depending on the depth of sedation. Therefore, an enlarged group of European experts in the field of sleep breathing disorders (SBD), including the most of the first DISE EPP main authors, has decided to publish an update of the European position paper on DISE, in order to include new evidence and to find a common language useful for reporting the findings of this endoscopic evaluation in adult population affected by SBD. METHODS: The authors have evaluated all the available evidence reported in the literature and have compared experience among various departments in leading European centres in order to provide an update regarding the standardisation of the DISE procedure and an in-depth insight into the main aspects of this technique. RESULTS: After the first European Position Consensus Meeting on DISE and its update, consensus was confirmed for indications, required preliminary examinations, where to perform DISE, technical equipment required, staffing, local anaesthesia, nasal decongestion, other medications, patient positioning, basics and special diagnostic manoeuvres, drugs and observation windows. So far, no consensus could be reached on a scoring and classification system. However, regarding this aim, the idea of an essential classification, such as VOTE with the possibility of its graded implementation of information and descriptions, seems to be the best way to reach a universal consensus on DISE classification at this stage. A common DISE language is mandatory, and attempts to come to a generally accepted system should be pursued.

Obstructive sleep apnea and bariatric surgical guidelines: summary and update.

PURPOSE OF REVIEW: Increasing numbers of bariatric surgical procedures and the high prevalence of obstructive sleep apnea (OSA) in this population have resulted in a growing interest in the perioperative management of OSA in bariatric surgery. This review provides a summary of the first consensus guideline on this topic as well as an update of the newest literature available. RECENT FINDINGS: All bariatric patients should be screened for OSA and obesity hypoventilation syndrome (OHS) to reduce the risk of perioperative complications. Intraoperative precautions are preoxygenation, induction and intubation in ramped position, continuous positive airway pressure (CPAP) and positive end-expiratory pressure during induction, maintenance of low tidal volumes during surgery, multimodal anesthesia and analgesia with avoidance of opioids and extubation when patients are free of neuromuscular blockage. CPAP therapy and continuous monitoring with a minimum of pulse oximetry is recommended in the early postoperative period. SUMMARY: Multiple precautions exist to minimize the risk of cardiopulmonary complications and to enhance recovery after surgery. A combination of these procedures seems to provide optimal perioperative care of OSA patients undergoing bariatric surgery. Nearly 75% of recommendations are based on low quality of evidence, indicating the high value of experts' opinion and potential for future research.

Upper-airway stimulation for obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea is associated with considerable health risks. Although continuous positive airway pressure (CPAP) can mitigate these risks, effectiveness can be reduced by inadequate adherence to treatment. We evaluated the clinical safety and effectiveness of upper-airway stimulation at 12 months for the treatment of moderate-to-severe obstructive sleep apnea. METHODS: Using a multicenter, prospective, single-group, cohort design, we surgically implanted an upper-airway stimulation device in patients with obstructive sleep apnea who had difficulty either accepting or adhering to CPAP therapy. The primary outcome measures were the apnea-hypopnea index (AHI; the number of apnea or hypopnea events per hour, with a score of ≥15 indicating moderate-to-severe apnea) and the oxygen desaturation index (ODI; the number of times per hour of sleep that the blood oxygen level drops by ≥4 percentage points from baseline). Secondary outcome measures were the Epworth Sleepiness Scale, the Functional Outcomes of Sleep Questionnaire (FOSQ), and the percentage of sleep time with the oxygen saturation less than 90%. Consecutive participants with a response were included in a randomized, controlled therapy-withdrawal trial. RESULTS: The study included 126 participants; 83% were men. The mean age was 54.5 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 28.4. The median AHI score at 12 months decreased 68%, from 29.3 events per hour to 9.0 events per hour (P<0.001); the ODI score decreased 70%, from 25.4 events per hour to 7.4 events per hour (P<0.001). Secondary outcome measures showed a reduction in the effects of sleep apnea and improved quality of life. In the randomized phase, the mean AHI score did not differ significantly from the 12-month score in the nonrandomized phase among the 23 participants in the therapy-maintenance group (8.9 and 7.2 events per hour, respectively); the AHI score was significantly higher (indicating more severe apnea) among the 23 participants in the therapy-withdrawal group (25.8 vs. 7.6 events per hour, P<0.001). The ODI results followed a similar pattern. The rate of procedure-related serious adverse events was less than 2%. CONCLUSIONS: In this uncontrolled cohort study, upper-airway stimulation led to significant improvements in objective and subjective measurements of the severity of obstructive sleep apnea. (Funded by Inspire Medical Systems; STAR ClinicalTrials.gov number, NCT01161420.).

Value of routine polysomnography in bariatric surgery.

BACKGROUND: Obstructive sleep apnea (OSA), present in 60-70 % of bariatric surgery patients, is a potentially life-threatening condition when not detected and managed appropriately. The best available method to identify the severity of OSA is polysomnography. However, routine polysomnography measurements have not been accepted as standard modality in bariatric surgery. We report our experience with routine polysomnography in a cohort of patients undergoing bariatric surgery to determine the true prevalence of OSA with respect to the different severity levels as determined by the apnea-hypopnea index (AHI). METHODS: AHI data were retrospectively collected from all patients who underwent bariatric surgery from 2012 onward, when the performance of preoperative polysomnography became mandatory. Mild, moderate and severe OSA were defined as an AHI ≥5, ≥15 and ≥30/h, respectively. Prevalence and number needed to screen (NNS) were calculated for all OSA severity levels. RESULTS: A total of 1358 patients were included. OSA was detected in 813 (59.9 %; NNS: 2) patients. Moreover, 405 (29.8 %; NNS: 4) patients were diagnosed with an AHI ≥15/h and 213 (15.7 %; NNS: 7) with severe OSA (AHI ≥30/h). Extreme AHI thresholds of ≥60 and ≥90/h were detected in 79 (5.8 %; NNS: 18) and 17 (1.3 %; NNS: 77) patients, respectively. CONCLUSION: One-third of the bariatric surgery patients have an AHI ≥15/h and would benefit from continuous positive airway pressure therapy. In order to increase perioperative safety and avoid the preventable risk of perioperative complications, we recommend mandatory P(S)G prior to bariatric surgery.

Positional obstructive sleep apnea in bariatric surgery patients: risk factor for postoperative cardiopulmonary complications?

BACKGROUND: Up to 80 % of the bariatric surgery (BS) patients suffer from obstructive sleep apnea (OSA). BS patients with moderate to severe OSA (apnea-hypopnea index (AHI) ≥15) are usually treated with continuous positive airway pressure (CPAP). This is not indicated in mild OSA patients (AHI <15). However, >50 % of patients with mild OSA have positional OSA (POSA); their AHI is at least twice as high in supine sleeping position than in other positions. Since many patients sleep in supine position for surgical safety reasons after BS, evaluating the AHI in this position might be more relevant in this group. The aim of this study is to evaluate the postoperative cardiopulmonary complication rate in mild OSA patients with and without POSA. Secondary aim is to evaluate predictive factors for POSA. METHODS: A single-institute retrospective analysis was achieved with all consecutive patients who underwent primary laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy between 2006 and 2014. All patients with an AHI between 5 and 15 were included. Postoperative complications were compared between POSA and non-POSA patients. Predictive factors were evaluated through univariate and multivariable logistic regression analysis. RESULTS: A total of 277 patients, 153 with and 124 without POSA, were included. After BS, three patients (1.1 %) experienced severe cardiopulmonary complications. No significant difference was found between POSA and non-POSA patients. In multivariate analysis, age and BMI were found to be negative predictors for POSA. CONCLUSION: In terms of 30-day postoperative cardiopulmonary outcome, CPAP therapy is not indicated in mild (P)OSA patients scheduled for BS.

Effect of upper-airway stimulation for obstructive sleep apnoea on airway dimensions.

Upper-airway stimulation (UAS) using a unilateral implantable neurostimulator for the hypoglossal nerve is an effective therapy for obstructive sleep apnoea patients with continuous positive airway pressure intolerance. This study evaluated stimulation effects on retropalatal and retrolingual dimensions during drug-induced sedation compared with wakefulness to assess mechanistic relationships in response to UAS. Patients with an implanted stimulator underwent nasal video endoscopy while awake and/or during drug-induced sedation in the supine position. The cross-sectional area, anterior-posterior and lateral dimensions of the retropalatal and retrolingual regions were measured during baseline and stimulation. 15 patients underwent endoscopy while awake and 12 underwent drug-induced sedation endoscopy. Increased levels of stimulation were associated with increased area of both the retropalatal and retrolingual regions. During wakefulness, a therapeutic level of stimulation increased the retropalatal area by 56.4% (p=0.002) and retrolingual area by 184.1% (p=0.006). During stimulation, the retropalatal area enlarged in the anterior-posterior dimension while retrolingual area enlarged in both anterior-posterior and lateral dimensions. During drug-induced sedation endoscopy, the same stimulation increased the retropalatal area by 180.0% (p=0.002) and retrolingual area by 130.1% (p=0.008). Therapy responders had larger retropalatal enlargement with stimulation than nonresponders. UAS increases both the retropalatal and retrolingual areas. This multilevel enlargement may explain reductions of the apnoea-hypopnoea index in selected patients receiving this therapy.

CPAP washout prior to reevaluation polysomnography: a sleep surgeon's perspective.

PURPOSE: Obstructive sleep apnea (OSA) is characterized by repetitive upper airway collapse during sleep, leading to decreased oxygen blood levels and arousal from sleep. The gold standard treatment option for moderate to severe OSA is considered continuous positive airway pressure (CPAP). In case primary treatment with CPAP fails, a reevaluation of disease severity [by means of the apnea/hypopnea-index (AHI)] can be required. A subset of patients that prefer a CPAP alternative is still using CPAP until the reevaluation polysomnography (PSG), and a so-called washout effect is not ruled out. The purpose of this study is to evaluate the evidence on the existence and duration of this washout effect and its clinical relevance for current practice. METHODS: To identify papers for this review, an extensive literature search was run electronically through MEDLINE and EMBASE databases. RESULTS: An overview of currently available literature on this washout effect and the findings of 13 studies on this topic are discussed. CONCLUSION: There is some evidence that CPAP washout exists in patients with a stable BMI throughout the follow-up period. However, the intensity and duration of this effect remains unclear. Within the limitations of the present study, it seems reasonable to maintain a washout period of 1 week, in case alternative treatments options are considered and especially when a baseline PSG (and subsequent repeat PSG after treatment) is needed in case of clinical trials.

A promising concept of combination therapy for positional obstructive sleep apnea.

PURPOSE: The objective of this randomized controlled trial was to assess the additional effect of a chest-worn sleep position trainer (SPT) in patients with residual supine-dependent obstructive sleep apnea (sdOSA) under mandibular advancement device (MAD) therapy. METHODS: Baseline and follow-up polysomnography with MAD were performed. Twenty patients with sdOSA under MAD therapy underwent two consecutive randomized polysomnographies: one with SPT and one with combination of SPT + MAD. Data are presented as median (quartile 1, quartile 3). RESULTS: The SPT reduced the time spent in supine sleeping position compared to baseline and MAD therapy. Both MAD and SPT were individually effective in reducing the overall apnea/hypopnea index (AHI) significantly when compared to baseline from 20.8 (15.1; 33.6)/h at baseline to 11.0 (6.7; 13.8)/h and to 11.1 (3.5; 17.7)/h with MAD or SPT, respectively. The combination of SPT + MAD further reduced the overall AHI to 5.7 (3.6; 7.4), which was significantly lower than with MAD alone (p < 0.001) and SPT alone (p < 0.008), respectively. CONCLUSIONS: The results of this study indicate that combination of SPT + MAD leads to a higher therapeutic efficacy in patients with sdOSA under MAD therapy when compared to one of the treatment modalities alone.