Polysomnography and sleep position, a Heisenberg phenomenon?: A large-scale series

Background The severity of position-dependent obstructive sleep apnea (POSA) depends on the nonsupine and supine apnea–hypopnea index (AHI) as well as the time spent in supine position. The latter in particular is susceptible to variation. Several small-scale studies suggest that wearing polysomnography (PSG) apparatus leads to an increase in supine sleeping position. Objectives The aim of this study was to evaluate the effect of wearing PSG apparatus on sleeping position and on OSA severity. Material and methods A large-scale, retrospective study was performed, including a consecutive series of POSA and non-apneic snoring patients who were prescribed positional therapy (Sleep Position Trainer [SPT]). The effect of wearing PSG apparatus on sleeping position was evaluated by comparing body position during the PSG night and inactive (diagnostic) phase of SPT. Results The mean percentage of total recording time (TRT) in supine position was 43.1% during the PSG night phase compared with 28.6% of TRT during the inactive (diagnostic) phase of SPT; i.e., a significant decrease of 33.6% (p < 0.001). When adjusting the AHI using TRT in different sleeping positions measured with the SPT, the median AHI decreased from 13.3/h (9.0–20.4) to 10.3/h (6.8–16.2); p < 0.001. When using the adjusted AHI, 33% (N = 66) of all patients had a change in OSA severity. Conclusions The results of this study indicate that wearing PSG apparatus leads to an increase in the percentage of supine sleeping position causing an overestimation of OSA severity, especially in patients with POSA. This can have significant impact on both clinical and scientific practice

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

© 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.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

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

© 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.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

Novel positional devices for the treatment of positional obstructive sleep apnea, and how this relates to sleep surgery

If untreated, obstructive sleep apnea (OSA) develops as a gradual progressive disease. In the early stage of the disease most patients with OSA are positional. The archetypical patient might progress from simple positional snoring via positional early-stage mild disease to less positional moderate and finally nonpositional severe OSA. At first, the apnea-hypopnea index (AHI) is high only in the supine position, and later is high in all sleeping positions. The phenomenon is reversible. After partial effective treatment, patients with severe OSA can reverse to less severe positional OSA or, in other words, the AHI drops more in the lateral position than in supine position. This has been shown for palatal surgery, multilevel surgery, bimaxillary osteotomies, and bariatric surgery. The absence or presence of positional dependency has a great influence on sleep surgery. First, the results of sleep surgery might be worse in positional patients. Second, the addition of positional therapy to sleep surgery might improve the overall outcome and, as such, enhance the indication of sleep surgery as an alternative to continuous positive airway pressure and mandibular advancement device treatment