Obstructive Sleep-related Breathing Disorders Research Articles

Obstructive sleep related breathing disorders and cardiometabolic risk factors – A Portuguese birth cohort

BackgroundPediatric obstructive sleep related breathing disorders (SRBD) are an important under-diagnosed health problem with associated cardiometabolic comorbidities, demonstrated with polysomnographic studies in selected samples. Our main goal was to assess the prevalence of SRBD in a population-based cohort and to analyze its association with cardiometabolic risk factors, in general and by sex. MethodsPediatric Sleep Questionnaire (PSQ) was applied to parents of 7-years-old children evaluated in the birth cohort, Generation XXI. Sex, anthropometrics, blood pressure (BP), lipid profile, glucose, insulin, HOMA-IR, and high-sensitivity C-reactive protein were compared among children with/without SRBD, using Chi-square, Mann-Whitney tests and logistic regression models. ResultsA total of 1931 children (51.2 % boys) were included; 17.5 % were overweight and 15.7 % obese. The prevalence of SRBD was 13.4 %, more frequent among boys (15.7 % vs.10.9 %, p = 0.002) and in overweight/obese children (22.0 % vs.13.6 % vs.11.3 % in obese, overweight and normal weight group, respectively, p < 0.001). Children with SRBD had higher systolic BP (107 ± 8 vs.105±9 mmHg; p = 0.001) and lower HDL-cholesterol levels (54 ± 11 vs.56 ± 11 mg/dL; p = 0.04) than children without SRBD. After adjustment for sex, age, birthweight-for-gestational age and maternal age, children with SRBD had higher BMI-z-score, systolic BP, insulin and HOMA-IR levels, and lower HDL-cholesterol, when compared to those without SRBD, but these associations were lost when adjusting to BMI z-score. Analyzing obese children with the same regression model, those with SRBD presented lower HDL-cholesterol than those without SRBD. ConclusionsOur results identified a male predominance of SRBD in pre-pubertal children and highlighted the potential contribution of SRBD to cardiovascular risk in obese children.

Implications of Obstructive Sleep-related Breathing Disorder in Dentistry: Focus on Snoring and Obstructive Sleep Apnea.

Obstructive sleep-related breathing disorder (SRBD) is an umbrella term that encompasses various types of upper airway dysfunctions during sleep characterized by increased respiratory effort secondary to snoring and/or increased upper airway resistance and pharyngeal collapse. Obstructive sleep apnea (OSA) is a representative SRBD that involves a significant decrease in or cessation of airflow despite the presence of respiratory effort. While snoring is considered a normal condition, it can cause serious noise disturbance to sleep partners and is considered a predictor of OSA. Snoring and OSA are highly correlated with obesity. SRBDs can lead to cardiovascular disease, hypertension, decreased quality of life, decreased work efficiency, daytime sleepiness, decreased neurocognitive activity, and psychological impairments. In dentistry, research on sleep problems has focused on temporomandibular disorder (TMD)/orofacial pain. The relationship between OSA and TMD/orofacial pain has been reported, but it is not clear whether it is a simple correlation or a causal relationship. Therefore, we aimed to review the causes of SRBDs including snoring and OSA and to review and infer the relationship between these SRBDs and TMD/orofacial pain. The effects of snoring and OSA extend beyond sleep disturbances and are worthy of future research, especially with regard to TMD.

Evaluation of a nasopharyngeal stent in patients with obstructive sleep-related breathing disorders

ObjectiveThis study was performed to evaluate the therapeutic effect and diagnostic value of a novel nasopharyngeal stent (Naśtent; Corinium Medical Equipment Ltd., Cirencester, UK). The Naśtent is designed to stent palatal collapse in patients with sleep-related breathing disorders.MethodsThe study was conducted from 2018 to 2019. Patients who did not qualify for continuous positive airway pressure therapy underwent split-night examination with an inserted Naśtent for the first half of the night. The next morning, drug-induced sleep endoscopy (DISE) was performed.ResultsOf the 122 enrolled patients, 21 were excluded because of Naśtent intolerance (n = 14) or technically invalid examinations (n = 7). Among the remaining 101 patients, in correlation with DISE, the apnea–hypopnea index was significantly reduced in patients with palatal obstructions, mainly in those with anteroposterior collapse patterns. The Naśtent did not influence retrolingual or multilevel obstructions. Using a 40% reduction of the apnea–hypopnea index by the Naśtent as a cut-off value, 85.7% of soft palate obstructions were detected compared with DISE.ConclusionsThe Naśtent is a viable tool to reduce palatal obstructions, although it is not readily tolerated. It may also be helpful for diagnosis of sleep-related breathing disorders when DISE is unavailable.

Subjective sleep-related breathing disorders and executive function in children with intermittent or mild persistent asthma.

The impact on executive function performance of sleep-related disorders in asthmatic children has been scarcely studied in community settings. The aims of the present study were to assess the prevalence of sleep-related breathing disorders (SRBD) in children with intermittent or mild persistent asthma in primary care settings, and to examine the possible correlations with measures of executive function. We performed a case-control study including 76 children with asthma (intermittent or mild persistent) and 85 healthy controls. The parents of both patients and controls completed the Paediatric Seep Questionnaire (PSQ) and the Behaviour Rating Inventory of Executive Function (BRIEF) questionnaire. We did not find any statistically significant differences regarding the scales of PSQ. Additionally, there were no statistical differences between asthmatic children and controls regarding the scales of the BRIEF questionnaire. In both asthmatic children and controls the score of the scale of obstructive sleep-related breathing disorder was significantly correlated with the T scores of the two composite scales (BRI and MI) and the Global Executive Composite. In children with intermittent or mild persistent asthma under the care of private general paediatricians there were no statistically significant differences regarding subjective SBD compared to the healthy controls. Also there were no statistical differences between asthmatic children and controls regarding behavioural correlates of executive function during everyday life.

Measurement and State-Dependent Modulation of Hypoglossal Motor Excitability and Responsivity In-Vivo

Motoneurons are the final output pathway for the brain’s influence on behavior. Here we identify properties of hypoglossal motor output to the tongue musculature. Tongue motor control is critical to the pathogenesis of obstructive sleep apnea, a common and serious sleep-related breathing disorder. Studies were performed on mice expressing a light sensitive cation channel exclusively on cholinergic neurons (ChAT-ChR2(H134R)-EYFP). Discrete photostimulations under isoflurane-induced anesthesia from an optical probe positioned above the medullary surface and hypoglossal motor nucleus elicited discrete increases in tongue motor output, with the magnitude of responses dependent on stimulation power (P < 0.001, n = 7) and frequency (P = 0.002, n = 8, with responses to 10 Hz stimulation greater than for 15–25 Hz, P < 0.022). Stimulations during REM sleep elicited significantly reduced responses at powers 3–20 mW compared to non-rapid eye movement (non-REM) sleep and wakefulness (each P < 0.05, n = 7). Response thresholds were also greater in REM sleep (10 mW) compared to non-REM and waking (3 to 5 mW, P < 0.05), and the slopes of the regressions between input photostimulation powers and output motor responses were specifically reduced in REM sleep (P < 0.001). This study identifies that variations in photostimulation input produce tunable changes in hypoglossal motor output in-vivo and identifies REM sleep specific suppression of net motor excitability and responsivity.

0936 Sleep Disturbances in Wolfram Syndrome

Abstract Introduction Wolfram syndrome is a rare disorder associated with diabetes mellitus, diabetes insipidus, optic nerve atrophy, hearing and vision loss, and neurodegeneration. Sleep complaints are common but have not been studied with objective measures. Our goal was to assess rates of sleep apnea and objective and self-reported measures of sleep quality, and to determine the relationship of sleep pathology to other clinical variables in Wolfram syndrome patients. Methods Genetically confirmed Wolfram syndrome patients were evaluated at the 2015 and 2016 Washington University Wolfram Syndrome Research Clinics. Patients wore an actigraphy device and a type III ambulatory sleep study device and completed the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index (PSQI) and/or the Pediatric Sleep Questionnaire (PSQ). PSQI and PSQ questionnaire data were compared to a previously collected group of controls. Patients were characterized clinically with the Wolfram Unified Rating Scale (WURS) and a subset underwent magnetic resonance imaging (MRI) for brain volume measurements. Results Twenty-one patients were evaluated ranging from age 8.9 - 29.7 years. Five of 17 (29%) adult patients fit the criteria for obstructive sleep apnea (OSA; apnea-hypopnea index [AHI] ≥ 5) and all 4 of 4 (100%) children aged 12 years or younger fit the criteria for obstructive sleep apnea (AHI’s ≥1). Higher AHI was related to greater disease severity (higher WURS Physical scores). Higher mixed apnea scores were related to lower brainstem and cerebellar volumes. Patients’ scores on the PSQ were higher than those of controls, indicating greater severity of childhood obstructive sleep-related breathing disorders. Conclusion Wolfram syndrome patients had a high rate of OSA. Further study would be needed to assess how these symptoms change over time. Addressing sleep disorders in Wolfram syndrome patients would likely improve their overall health and quality of life. Support (If Any) This work was supported by the NICHD (HD070855; Hershey, PI) and supported by CTSA (UL1 RR024992) and Diabetes Research Center (DK 020579).

Cardiovascular effects of oral appliances in obstructive sleep apnea

Oral appliances (ОА) are one of the leading methods of effective treatment of sleep-related breathing disorders. Obstructive sleep apnea (OSA) is a widespread disturbance in the general population. It is closely associated with many cardiovascular diseases (hypertension, cardiac arrhythmias, chronic heart failure, ischemic heart disease). Timely detection and treatment of OSA is an important task in the process of reducing the number of cardiac complications. Modern devices for the treatment of OSA are custom-made devices which allow to change the position of the mandible and its extension providing personalized treatment of snoring and sleep apnea. Changing the degree of the mandible extension, the ОА retains the upper respiratory tract in open position and indirectly stimulates the muscles, determining their tone. The effectiveness of the ОА is evaluated by the complete elimination of all respiratory events (snoring, upper airway resistance syndrome, OSA and hypopnea), as well as the influence on the sleep structure and the wakefulness functioning (excessive daytime sleepiness). The effects of ОА on cardiovascular diseases are of great importance, as they showed a decrease in both systolic and diastolic blood pressure, as well as a positive effect on the impaired endothelial function. Among all the treatment options, ОА take the leading positions, only slightly inferior in effectiveness to noninvasive ventilation, so called CPAP therapy. Regarding the long-term adherence to therapy (which is especially important in the cardiovascular prevention) оral appliances exceed CPAP therapy. Thus, the OA therapy is one of the leading therapeutic directions in modern sleep medicine for obstructive sleep-related breathing disorders.

Indications of Pediatric Tonsillectomy

Possible indications for tonsillectomy include sleep apnea and other obstructive sleep-related breathing disorders, recurrent tonsillitis, peritonsillar abscess, periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA), and other miscellaneous rare conditions. Over the last century indications have changed, with a decrease in infectious causes and an increase in sleep apnea disorders. Sleep apnea in children is difficult to diagnose short of polysomnography (PSG) which is expensive and disturbing, especially in young children. In sleep apnea confirmed by PSG, tonsillectomy relieves the trouble in close to 80% of patients. What remains unclear is how to diagnose sleep-related breathing disorders without PSG and the efficacy of tonsillectomy in this population. Recurrent tonsillitis is generally poorly documented and randomized studies assessing the efficacy of tonsillectomy are sparse. When frequent infections are present for several years (>7 episodes/1 year, >5/2, >3/3) some benefit from tonsillectomy could be found. If fewer infectious episodes are present, the benefit of tonsillectomy is low. Peritonsillar abscess tends to be treated with quinsy tonsillectomy. Some PFAPA and psoriasis children might benefit from tonsillectomy. Tonsillectomy for other conditions is not warranted.

Cardiac Resynchronization Therapy and Obstructive Sleep‐Related Breathing Disorder in Patients with Congestive Heart Failure

To assess the impact of cardiac resynchronization therapy (CRT) with or without atrial overdrive pacing, on sleep-related breathing disorder (SRBD). CRT may have a positive influence on SRBD in patients who qualify for the therapy. Data are inconclusive in patients with obstructive SRBD. Consenting patients eligible for CRT underwent a baseline polysomnography (PSG) 2 weeks after implantation during which pacing was withheld. Patients with an apnea hypopnea index (AHI) ≥15 but <50 were enrolled and randomized to atrial overdrive pacing (DDD) versus atrial synchronous pacing (VDD) with biventricular pacing in both arms. Patients underwent two further PSGs 12 weeks apart. Nineteen men with New York Heart Association class III congestive heart failure participated in the study (age 67.2 ± 7.5, Caucasian 78.9%, ischemic 73.7%). The score on Epworth Sleepiness Score was 7.3 ± 4.0, Pittsburgh Sleep Quality Index 7.4 ± 3.1, and Minnesota Living with Heart Failure Questionnaire 36.9 ± 21.9. There were no differences between the groups. At baseline, patients exhibited poor sleep efficiency (65.3 ± 16.6%) with nadir oxygen saturation of 83.5 ± 5.3% and moderate to severe SRBD (AHI 21.5 ± 15.3) that was mainly obstructive (central apnea index 3.3 ± 6.7/hour). On both follow-up assessments, there was no improvement in indices of SRBD (sleep efficiency [68.3 ± 17.9%], nadir oxygen saturation of 82.8 ± 4.6%, and AHI 24.9 ± 21.9). In a cohort of elderly male CHF patients receiving CRT, CRT had no impact on obstructive SRBD burden with or without atrial overdrive pacing.

Why do palatine tonsils grow back after partial tonsillectomy in children?

Within the last decade, adenoidectomy with partial tonsillectomy has been revived in children with obstructive sleep-disordered breathing caused by adenotonsillar hyperplasia, generating debate about remaining tonsillar tissue regrowth. The study examined potential risk factors of the regrowth. Prospective, nonrandomised, case series feasibility study of children meeting the criteria for palatine tonsils regrowth after partial tonsillectomy performed in patients with obstructive sleep-related breathing disorder was carried out. Out of 793 operated children, 294 after adenoidectomy and 373 after adenotonsillotomy were followed up for 4 years in 12-month intervals. In 27 children after adenotonsillotomy, regrowth of tonsillar tissue was observed. In 22 individuals after adenoidectomy alone, hyperplasia of palatine tonsils was noted. The children had bacterial cultures of pharyngeal smears and blood samples tested for anti-streptolysin O, C-reactive protein and total IgE. Caregivers completed a questionnaire reporting on: their child's breathing after surgery; frequency, severity and treatment of upper respiratory tract infections; diet; family history of adenoidal and/or tonsillar hyperplasia; and history of allergy. As controls, 272 participants after adenoidectomy alone and 346 after adenotonsillotomy were examined. The amount of sugar in the diet and the incidence of upper respiratory tract infections after surgery differed between the groups of patients and controls. Other differences were insignificant. The tonsillar tissue remaining after partial tonsillectomy in children has a remarkable tendency to grow back, related to a diet abundant in sugar and numerous upper respiratory tract infections. Tonsillar regrowth was age related and occurred most frequently in individuals older than 7 years.

Von der Mandelkappung über die Tonsillektomie zur Tonsillotomie

Medicine has been dealing with palatine tonsil disorders since its beginnings. With the initial aim of eliminating chronic centres of inflammation, over time manifold surgical processes to extract tonsils were developed and tested. Very early on it already became clear that the complete extraction of the tonsil along its connective tissue capsule can lead to serious complications: the risk of bleeding after a tonsillectomy is well-known to currently practising surgeons. In order to reduce this risk and due to not yet existing safe anaesthesia, various techniques were developed aimed at merely reducing the size of the tonsils that is partially removing them within their capsules. Since only smaller intratonsillar blood vessels were affected in this process and bigger peritonsillar feeding arteries and veins remained unharmed, the risk of secondary haemorrhage was reduced considerably. The subtlest instruments for this process were created primarily during the 19 th century. This intracapsular, partial tonsillectomy, also referred to as tonsillotomy or " tonsil capping ", became widespread during that time. Due to its fast and easy application, as well as the low complication rates, it was used especially for children. However, the development of safer anaesthetic techniques at the beginning of the 20 th century meant that the extraction of the entire tonsil, tonsillectomy in toto, eventually became more feasible even in children. Against this background as well as a result of intense discussions on possible secondary scarring of the remaining tonsil tissue accompanied by inflammatory after-eff ects, the technique of tonsillotomy, the partial extraction of the tonsils, was gradually abandoned in favour of that of tonsillectomy and eventually almost completely forgotten during the latter half of the 20 th century. The advances in sleep research and the discovery of general developmental physiological impairment arising from disrupted sleep patterns during infancy led to a rebirth of this surgical application. Tonsillotomy is currently widely accepted as a safe and effective method of treatment for obstructive sleep-related breathing disorders in children. However, due to the history of this procedure, the problem of possible long-term inflammatory complications remains. In the following chapters, fi rst, an abstract of the history of the tonsillotomy is presented. Several historic papers on inflammatory secondary disorders in large patient collectives will be introduced based on a search of the existing literature. Despite the correct diagnostic evaluation as well as the limitation to children unfavourable clinical experiences following a tonsillotomy could not be confirmed even then. The development of tonsillotomy to full tonsillectomy procedures in the 20 th century will be illustrated by means of these historic sources.

Conservative Treatment Effectiveness in Obstructive Sleep-Related Breathing Disorders and Upper Airway Pressure Analysis

We evaluated upper airway patency in conservative treatment of sleep-related obstructive breathing disorders. Subjects numbered 51−44 men and 7 women with a mean age of 55.3±10.2 years, a mean body mass index (BMI) of 26.9±3.2 kg/m2—with obstructive sleep apnea or snoring. All underwent daytime polysomnography with simultaneous upper airway and intraesophageal pressure monitoring. Nine lost weight, going from a baseline BMI of 30.1±2.9 kg/m2 to 26.8±3.4 kg/m2 after one year. Weight loss significantly reduced the apnea+hypopnea index from 80.7±30.3/h to 43.9±35.9/h and improved mesopharyngeal and intraesophageal pressure. Good response—defined as at least 50% reduction in the initial apnea+hypopnea index—was 50% (4/8) in patients using TheraSnore, and 58.8% (10/17) in patients using custom-made prosthetic mandibular advancement. Good responders were 40% (6/15) in patients with SNOR-X, and 57.1% (4/7) in patients with a custom-made tongue-retention device. Mesopharyngeal, hypopharyngeal, and intraesophageal pressure significantly improved with oral appliances. Pressure differences between the epipharynx and mesopharynx and between the mesopharynx and hypoparynx also significantly improved with oral appliances. We concluded that upper airway patency after conservative treatment is confirmed by simultaneous upper airway and intraesophageal pressure monitoring during polysomonography.

Effectiveness of surgical treatments for obstructive sleep-related breathing disorders: Upper airway pressure analysis

In this retorospective study, the upper airway and intraesophageal pressure was evaluated after surgical treatments for obstructive sleep-related breathing disorders. Seventy-two patients (63 men and 9 women; mean age 45.2 years) with obstructive sleep apnea or snoring underwent daytime polysomnography and simultaneous upper airway and intraesophageal pressure monitoring with a multisensor pressure catheter. An improvement of 50% or greater in the apnea plus hypopnea index was defined as a good response. The ratios of good responders were 16.7% (2/12), 28.6% (2/7), 88.9% (8/9), and 56.8% (25/44) after nasal surgery, uvulectomy, tonsillectomy, and uvulopalatopharyngoplasty, respectively. The pressure difference between the mesopharynx and the hypopharynx indicated a significant improvement after tonsillectomy. The pressure differences between the epipharynx and mesopharynx, and between the mesopharynx and hypopharynx also indicated significant improvement after uvulopalatopharyngoplasty. These results suggest that the effectiveness of a surgical treatment may be confirmed by the simultaneous monitoring of upper airway and intraesophageal pressure in polysomnography.

Changes in Pharyngeal Airway Space and Hyoid Bone Positions After Body Ostectomies and Sagittal Split Ramus Osteotomies

Although mandibular setback might lead to possible pharyngeal narrowing, the development of obstructive sleep-related breathing disorders may occur because of multiple factors. In this study, the changes in the pharyngeal airway space (PAS) and the hyoid bone position have been evaluated before and after surgery in patients who underwent body ostectomy (BO) and sagittal split ramus osteotomy (SSRO). In addition, the effects of the BO on PAS and on hyoid bone position have been compared with the effects of the SSRO. Thirty patients with mandibular prognathism underwent mandibular setback osteotomy. The patients were divided into two groups: BO group, 15 patients (5 men, 10 women) who underwent BO; and SSRO group, 15 patients (11 men, 4 women) who underwent SSRO. Changes in PAS and hyoid bone position were analyzed throughout the preoperative and early and long-term postoperative periods via lateral cephalometric radiographs. A decrease has been observed in the PAS area and the anteroposterior dimension of the PAS detected in all patients in the long-term period. Hyoid bone revealed backward and downward movement during the early postoperative period; however, it showed a tendency to return to its original anatomic position during the long-term postoperative period. None of the patients had disturbances in respiration. After BO and SSRO, a decrease in PAS area was observed, and this decrease also continued in the long-term period. Our results revealed a decrease in PAS area after BO, but the decrease was less than that in cases having SSRO.

Obstructive sleep-related breathing disorders in patients evaluated for bariatric surgery.

Obesity is a well known risk factor for obstructive sleep apnea (OSA). Medical therapy is not effective for morbid obesity. Bariatric surgery is therefore a reasonable option for weight reduction for patients with clinically severe obesity. Unrecognized OSA, especially in those patients receiving abdominal surgery, has influenced perioperative morbidity and morality. The incidence of OSA for patients being evaluated for bariatric surgery has not been previously defined. 40 consecutive patients being evaluated for bariatric surgery were examined with a history, physical examination and laboratory data. Polysomnography (PSG) was conducted in all patients regardless of symptoms. An obstructive sleep-related breathing disorder (OSRBD) was present in 88% of the patients. OSA was present in 29 of 41 (71%) and upper airway resistance syndrome (UARS) in 7 of 41 (17%). The mean low oxygen desaturation was 84% and continuous positive airway pressure (CPAP) was 10 cm H2O pressure. The majority of the patients were women and mean BMI was 47 kg/m2. Patient characteristics failed to predict the severity of OSRBD. This population of clinically severe obese patients being evaluated for bariatric surgery had an 88% incidence of an OSRBD, 71% with OSA. Appropriate therapy with CPAP perioperatively would theoretically prevent hypoxic complications associated with OSRBD. Providers should have a low threshold for ordering a PSG as part of the preoperative evaluation for bariatric surgery. Empiric CPAP at 10 cm H2O should be considered for those patients who cannot complete a PSG before surgery.

Temperature-controlled radiofrequency tonsil reduction in children.

To evaluate the safety and efficacy of temperature-controlled radiofrequency tonsil reduction in the treatment of children with a sleep-related breathing disorder associated with tonsillar obstructive hypertrophy. Prospective, nonrandomized, case series feasibility study of children meeting the criteria for tonsillectomy or adenotonsillectomy for the treatment of an obstructive sleep-related breathing disorder. Community-based hospital. Patients Ten children, aged 4 to 13 years, presenting consecutively to a community-based otolaryngology practice with tonsillar or adenotonsillar obstructive hypertrophy implicated clinically in causing a sleep-related breathing disorder; their parents consenting to temperature-controlled radiofrequency tonsil reduction instead of surgical tonsillectomy. Intervention Temperature-controlled radiofrequency tonsil reduction, along with surgical adenoidectomy, if adenoids were present, under general anesthesia. Tonsil size reduction, treatment morbidity, and symptom improvement with follow-up to 1 year. Baseline and 3-month posttreatment polysomnographic data were used. There was a reduction in tonsil size at 1 year of 75.0% on average, without evidence of regrowth during the 1-year follow-up. All children were drinking liquids in the recovery room, and most were eating soft diets within 6 hours; 8 of the 10 children were eating a normal diet by day 5. On average, the return to normal activity was 3.9 days, with 2.9 days of parental loss of work time. Quality-of-life variables all improved. Snore indexes decreased by 88.6%. Polysomnography at 3 months revealed an 84.2% reduction in the apnea index and a 52.3% reduction in the apnea/hypopnea index. There were no complications. Temperature-controlled radiofrequency tonsil reduction seems to be a safe, effective, and minimally morbid treatment for tonsil hypertrophy in children with obstructive sleep-related breathing disorders.

Uvulopalatopharyngoplasty for obstructive sleep-related breathing disorders: one-year follow up.

The effectiveness of uvulopalatopharyngoplasty was evaluated in 28 patients (25 men and three women; mean age 47.6 years) with obstructive sleep apnea by comparing preoperative daytime polysomnography with those carried out 6 months and 1 year postoperatively. The mean apnea plus hypopnea index (AHI) in the supine position decreased from 51.0/h to 23.0/h 6 months postoperatively and 57.1% of patients showed a 50% or more reduction of AHI. By changing the sleep position from supine to lateral, 71.4% of the 28 patients indicated a 50% or more reduction in AHI before surgery, which increased to 92.3% of 26 patients 6 months postoperatively. The positive results of uvulopalatopharyngoplasty were maintained at least until 1 year after surgery.

Assessment of upper airway dynamics in awake patients with sleep apnea using phrenic nerve stimulation.

Phrenic nerve stimulation can reproduce during wakefulness the dissociation between upper airway and inspiratory muscles that is associated with obstructive sleep-related breathing disorders. This could provide a useful management tool in the study of passive upper airway (UA) dynamics during wakefulness in patients with the obstructive sleep apnea-hypopnea syndrome (OSAHS). To assess the feasibility of the technique in this setting, we studied the dynamics of diaphragm twitch-associated inspiratory flow in eight patients with OSAHS. Cervical magnetic stimulation (CMS) and bilateral anterior magnetic phrenic stimulation (BAMPS) were applied at end-expiration during exclusive nasal breathing. Electrical phrenic nerve stimulation (ES) proved not feasible. The driving pressure and the respiratory resistance at peak twitch esophageal pressure obtained at maximal stimulation intensity were significantly higher with BAMPS than with CMS. A twitch-flow limitation pattern was observed in seven of eight subjects; VI(max) values of flow-limited twitches obtained at 100% stimulation intensity was 0.81 +/- 0.5 L/s with BAMPS and 0.87 +/- 0.5 L/s with CMS (p = 0.4). The number of flow-limited BAMPS twitches dropped from an average 77.5% to 18.4% with nasal continuous positive airway pressure (CPAP) levels corresponding to the patient's home treatment. We conclude that (1) BAMPS is potentially a useful tool to evaluate the dynamics of flow through the passive UA in awake OSAHS patients, (2) BAMPS may be superior to CMS in evaluating UA properties in OSAHS.

Validation of the POLY-MESAM Seven-Channel Ambulatory Recording Unit

To determine the recording capabilities of the POLY-MESAM (PM) unit (MAP; Martinsried, Germany), an American Sleep Disorders Association level III system, and to compare it with simultaneous 12-channel polysomnography in the sleep laboratory. Fifty-three patients (49 men and 4 women) with obstructive sleep-related breathing disorders of varying severity were included. The apnea-hypopnea indexes (AHIs) obtained using the two methods differed significantly from each other, although the correlation was close. The PM unit produced false-negative results in patients with mild to moderate obstructive sleep apnea (OSA). The sensitivity of the PM unit in detecting patients with an AHI > 10 was 92%, while the specificity was 96.3%. The correlation of AHIs obtained with polysomnography and with the PM unit is close. However, in some cases, the PM may underestimate OSA parameters. The PM unit produces false-negative results in patients with mild to moderate OSA. While inpatient polysomnography remains the "gold standard," the PM unit may provide an inexpensive alternative in some special cases.

Pediatric sleep questionnaire (PSQ): validity and reliability of scales for sleep-disordered breathing, snoring, sleepiness, and behavioral problems

Objective: To develop and validate questionnaire scales that can be used in research to investigate the presence of childhood SRBDs and prominent symptom complexes, including snoring, daytime sleepiness, and related behavioral disturbances. Background: Obstructive sleep-related breathing disorders (SRBDs) are common but usually undiagnosed among children. Methods to help identify SRBDs without the expense of polysomnography could greatly facilitate clinical and epidemiological research. Methods: Subjects were children aged 2–18 years who had polysomnographically-confirmed SRBDs ( n=54) or appointments at either of two general pediatrics clinics ( n=108). Parents completed a Pediatric Sleep Questionnaire which contained items under consideration for inclusion in desired scales. Results: Item reduction, based on data from a randomly selected 50% of the subjects (group A), produced a 22-item SRBD score that was strongly associated with diagnosis of an SRBD ( P<0.0001) in a logistic regression model that accounted for age and gender. Diagnosis was also strongly associated with subscores for snoring (four items, P<0.0001), sleepiness (four items, P=0.0003), and behavior (six items, P<0.0001) among group A subjects. The scales performed similarly well among group B subjects, and among subjects of different ages and gender. In group A and B subjects, respectively, a selected criterion SRBD score produced a sensitivity of 0.85 and 0.81; a specificity of 0.87 and 0.87; and a correct classification for 86 and 85% of subjects. The scales showed good internal consistency and, in a separate sample ( n=21), good test-retest stability. Conclusions: These scales for childhood SRBDs, snoring, sleepiness, and behavior are valid and reliable instruments that can be used to identify SRBDs or associated symptom-constructs in clinical research when polysomnography is not feasible.