Ioannis Koutsourelakis

Surgery for obstructive sleep apnea: Sleep endoscopy determinants of outcome

Although drug‐induced sleep endoscopy is often employed to determine the site of obstruction in patients with obstructive sleep apnea (OSA) who will undergo upper airway surgery, it remains unknown whether its findings are associated with surgical outcome. This study tested the hypothesis that drug‐induced sleep endoscopy variables can predict the outcome of upper airway surgery in OSA patients.

Analysis of the influence of head rotation during drug-induced sleep endoscopy in obstructive sleep apnea

Currently, drug‐induced sleep endoscopy (DISE) in obstructive sleep apnea (OSA) is predominantly performed in supine position. When positional therapy (avoidance of supine sleeping position in positional OSA (POSA) is implemented as (part of the) treatment, one should assess levels of obstruction in the other sleeping positions. Therefore, the current study examined the influence of difference head positions during DISE in patients with OSA and POSA.

Determinants of subjective sleepiness in suspected obstructive sleep apnoea

Although daytime sleepiness is commonly associated with obstructive sleep apnoea (OSA), the relationship between OSA severity and subjective sleepiness has been documented elusive. This study aimed to identify clinical and polysomnographic determinants of subjective sleepiness among patients suspected of having OSA. A sleep clinic‐based sample of 915 patients was interviewed with a structured questionnaire and underwent diagnostic overnight polysomnography. Subjective sleepiness was quantified by Epworth Sleepiness Scale (ESS). Excessive daytime sleepiness (defined as ESS score > 10) was present in 38.8% of patients. In multiple linear regression analysis, respiratory disturbance index [RDI; used to define (whenever RDI was >5) and quantify OSA], depression and diabetes were the most important determinants of ESS score accounting for 17%, 11% and 6% of its variability respectively. Chronic obstructive pulmonary disease (COPD), stroke, heart disease, alcohol use and body mass index were less important determinants of ESS score explaining 1–3% of its variability. In conclusion, OSA should not be considered the sole potential cause of increased subjective sleepiness in patients suspected of having OSA. Primarily depression and diabetes, but also COPD, stroke, heart disease, alcohol use and increased body mass index may contribute to increased subjective sleepiness.

The effect of nasal tramazoline with dexamethasone in obstructive sleep apnoea patients

Although there is a strong correlation between oral/oro-nasal breathing and apnoea/hypopnoea index in patients with obstructive sleep apnoea and normal nasal resistance at wakefulness, it remains unknown whether the pharmacological prevention of potential nasal obstruction during sleep could decrease oral/oro-nasal breathing and increase nasal breathing and subsequently decrease the apnoea/hypopnoea index. This study evaluated the effect of a combination of a nasal decongestant with corticosteroid on breathing route pattern and apnoea/hypopnoea index. 21 patients with obstructive sleep apnoea (mean apnoea/hypopnoea index 31.1 events per hour) and normal nasal resistance at wakefulness were enrolled in a randomised crossover trial of 1 weeks’ treatment with nasal tramazoline and dexamethasone compared with 1 weeks’ treatment with nasal placebo. At the start and end of each treatment period, patients underwent nasal resistance measurement and overnight polysomnography with attendant measurement of breathing route pattern. Nasal tramazoline with dexamethasone was associated with decrease in oral/oro-nasal breathing epochs and concomitant increase in nasal breathing epochs, and mean decrease of apnoea/hypopnoea index by 21%. The change in nasal breathing epochs was inversely related to the change in apnoea/hypopnoea index (Rs=0.78; p<0.001). In conclusion, nasal tramazoline with dexamethasone in OSA patients with normal nasal resistance at wakefulness can restore the preponderance of nasal breathing epochs and modestly improve apnoea/hypopnoea index. Nasal tramazoline with dexamethasone in OSA patients can restore nasal breathing epochs and improve AHI modestly http://ow.ly/mxu4T

Nasal steroids in snorers can decrease snoring frequency: a randomized placebo-controlled crossover trial

Although it is anecdotally known that nasal obstruction is associated with snoring, it remains unknown whether the application of nasal steroids could decrease oral/oro‐nasal breathing and increase nasal breathing, and subsequently decrease snoring indices. This study evaluated the effect of nasal budesonide on breathing route pattern and snoring. Twenty‐four snorers were enrolled in a randomized, double‐blind, crossover trial of 1‐week treatment with nasal budesonide compared with 1‐week intervention with nasal placebo. At the start and end of each treatment period, patients underwent nasal resistance measurement and overnight polysomnography with concomitant measurement of breathing route pattern and snoring. Twelve patients were randomly assigned to a 1‐week treatment with nasal budesonide, followed by 2‐week washout period and a 1‐week intervention with the nasal placebo; and 12 patients were randomly assigned to a 1‐week intervention with nasal placebo, followed by 2‐week washout period and a 1‐week treatment with nasal budesonide. Nasal budesonide was associated with a decrease in oral/oro‐nasal breathing epochs and concomitant increase in nasal breathing epochs, decrease of snoring frequency by [median (interquartile range)] 15.8% (11.2–18.8%), and an increase of rapid eye movement sleep; snoring intensity decreased only in patients with increased baseline nasal resistance by 10.6% (6.8–14.3%). The change in nasal breathing epochs was inversely related to the change in snoring frequency (Rs = 0.503; P < 0.001). Nasal budesonide in snorers can increase nasal breathing epochs, modestly decrease snoring frequency and increase rapid eye movement sleep.

Resolution of apnoeas in slow wave sleep

Dear Editor: Obstructive sleep apnoea (OSA) is a prevalent disorder, which is associated with excessive daytime sleepiness, and with an increased risk for hypertension, cardiovascular, and cerebrovascular incidents, and type II diabetes. The gold standard for the evaluation of OSA is the polysomnography and the resulting apnoea-hypopnoea index (AHI), which corresponds to the total number of complete or partial upper airway obstructive events lasting 10 s or more, divided by total sleep time. AHI is known to be strongly influenced by factors such as sleep posture, head position, and sleep stage. Indeed, it has been reported that OSA worsens during rapid eye movement (REM) sleep and improves during slow wave sleep [1]. However, the studies which have examined the effect of slow wave sleep on the number of apnoeas included relatively small number of rather selected patients [1–3] and demonstrated considerably variable results ranging from complete resolution in some patients to a modest decrease in some others. Thus, it is plausible to suggest that the importance of this effect has been poorly assessed [3]. Understanding the extent of slow wave sleep-mediated improvements in OSA could ultimately lead to new therapeutic approaches for this disorder. Therefore, the purpose of this study was to investigate the effect of slow wave sleep on the frequency of respiratory events in a large cohort of consecutive patients referred for the investigation of possible OSA. Patients screened for the current prospective cohort study were all consecutive subjects who referred to the Center of Sleep Disorders of “Evangelismos” General Hospital of Athens for sleep-disordered breathing between January 2012 and February 2013. Inclusion criteria were an AHI >5 events·h and central apnoeas ≤5 % of total apnoeas at baseline diagnostic full-night polysomnography (EMBLA S7000, Medcare Flaga, Iceland). Exclusion criterion was <15 consecutive minutes of sleep stages N2, N3, and REM in supine or lateral sleep position. In order to investigate the effect of body position, sleep stage, and their interaction on AHI, we performed repeated-measures two-way analysis of variance followed by the Scheffé test for post hoc analyses. The level of significance was set at p<0.05. Among 652 patients screened, 223 did not meet the inclusion criteria (211 had AHI ≤5 events·h and 12 had central apnoeas >5 % of total apnoeas). Of 429 eligible patients, 195 were excluded from analysis because they had <15 consecutive minutes of sleep stages N2, N3, or REM in supine or lateral sleep position. The resulting cohort was composed of 234 patients (152 men) aged (mean±SD) 52.0±11.5 years, with body mass index 31.0±5.9 kg·m. At the full-night polysomnography, their total sleep time (TST) was 309± 90 min, sleep efficiency was 87.6±12.9 %, and AHI was 22.6±19.5 events·h (AHI in supine and lateral positions was 34.1±27.2 and 12.6±18.0 events·h, respectively). Time spent in N1 was 24.5±12.5 (8.0±4.3 % of TST), time spent in N2 was 172.1±58.8 min (57.1±14.3 % of TST), time spent in N3was 61.1±40.0 min (19.3±10.2% of TST), and time spent in REM sleep was 51.3±34.8 min (15.6±8.9 % of TST). AHI in supine position was 36.5±29.1, 0.3±0.9, and 35.1 ±31.2 events·h in N2, N3, and REM sleep, respectively. AHI in lateral position was 12.1±19.8, 0.4±1.7, and 13.5± 20.1 events·h in N2, N3, and REM sleep, respectively. Thus, AHI was lower in lateral versus supine position in N2 and * Ioannis Koutsourelakis ikoutsourelakis@gmail.com

Drug-Induced Sleep Endoscopy and Sleep Position

Drug-induced sleep endoscopy (DISE) has been used in the last two decades in order to determine under fiberoptic visualization the exact site of upper airway collapse in obstructive sleep apnea patients. By directing surgical procedures towards obstruction-specific structures, surgical outcomes improve. Additionally, with the help of passive maneuvers, the potential efficacy of mandibular repositioning devices can be estimated. The shared use of the VOTE classification for the assessment of DISE can facilitate its scientific evaluation in individual centers and also the collection of data across multiple centers. Head rotation during DISE improves upper airway collapse. This improvement is predominantly seen in positional obstructive sleep apnea patients. In addition, there is no difference in upper airway collapse between right and left head rotation and also no difference between rotation of the head and lateral positions. We recommend that in positional patients, DISE should be performed in supine and lateral positions.

Short-Term (4 Weeks) Results of the Sleep Position Trainer for Positional Therapy

A limited number of studies focus on decreasing the severity of obstructive sleep apnoea by influencing sleep position. In these studies an object was strapped to the back (tennis balls, special vests) preventing patients from sleeping in supine position. Frequently, this was not successful due to arousals whilst turning from one position to the other, thereby disturbing sleep architecture and sleep quality. In this chapter we present a novel device for treating POSA patients. Patients older than 18 years with mild to moderate POSA slept with the sleep position trainer (SPT), strapped to the chest, for a month. SPT measures the body position and vibrates when the patient lies in supine position. Thirty-one patients (mean age 48.1 ± 11.0 years; mean body mass index 27.0 ± 3.7 kg m−2) completed the study protocol. The median percentage of supine sleeping time decreased from 49.9 to 0.0 % (p < 0.001). The median AHI decreased from 16.4 to 5.2 (p < 0.001). Fifteen patients developed an overall AHI below five. Epworth Sleepiness Scale decreased significantly. Functional Outcomes of Sleep Questionnaire increased significantly. Compliance was found to be 100 %.