Observational study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers - protocol study

Background: Obstructive sleep apnea (OSA) is a respiratory disease characterized by the collapse of the extrathoracic airway and has important social implications related to accidents and cardiovascular risk. The main objective of the present study was to investigate whether the drop in expiratory flow and the volume expired in 0.2 s during the application of negative expiratory pressure (NEP) are associated with the presence and severity of OSA in a population of professional interstate bus drivers who travel medium and long distances.Methods/Design: An observational, analytic study will be carried out involving adult male subjects of an interstate bus company. Those who agree to participate will undergo a detailed patient history, physical examination involving determination of blood pressure, anthropometric data, circumference measurements (hips, waist and neck), tonsils and Mallampati index. Moreover, specific questionnaires addressing sleep apnea and excessive daytime sleepiness will be administered. Data acquisition will be completely anonymous. Following the medical examination, the participants will perform a spirometry, NEP test and standard overnight polysomnography. The NEP test is performed through the administration of negative pressure at the mouth during expiration. This is a practical test performed while awake and requires little cooperation from the subject. In the absence of expiratory flow limitation, the increase in the pressure gradient between the alveoli and open upper airway caused by NEP results in an increase in expiratory flow.Discussion: Despite the abundance of scientific evidence, OSA is still underdiagnosed in the general population. In addition, diagnostic procedures are expensive, and predictive criteria are still unsatisfactory. Because increased upper airway collapsibility is one of the main determinants of OSA, the response to the application of NEP could be a predictor of this disorder. With the enrollment of this study protocol, the expectation is to encounter predictive NEP values for different degrees of OSA in order to contribute toward an early diagnosis of this condition and reduce its impact and complications among commercial interstate bus drivers.

Ambulatory blood pressure monitoring in children with obstructive sleep apnea and primary snoring

Objective: To evaluate the systemic blood pressure (BP) during daytime and nighttime in children with sleep breathing disorders (SBD) and compare parameters of BP in children with diagnosis of obstructive sleep apnea syndrome (OSA) to those one with primary snoring (PS).Methods: Children, both genders, aged from 8 to 12 years, with symptoms of SBD realized an overnight polysomnography followed by a 24 h recording of ambulatory BP.Results: All subjects presented with a history of snoring 7 nights per week. Children who have apnea/hipoapnea index >= four or a apnea index >= one presented a mean BP of 93 +/- 7 mmHg and 85 +/- 9 mmHg diurnal and nocturnal respectively whereas children who have a apnea/hipoapnea < four or a apnea index < one presented 90 +/- 7 mmHg and 77 +/- 2 mmHg. Eight children out of fourteen, from OSA group, lost the physiologic nocturnal dipping of the blood pressure. Among OSA children 57% were considered non-dippers. Two (16%) have presented absence of nocturnal dipping among children with primary snoring. The possibility of OSA children loosing physiologic blood pressure dipping was 6.66 higher than the possibilities of patients from PS group.Discussion: Our results indicate that children with sleep apnea syndrome exhibit a higher 24 h blood pressure when compared with those of primary snoring in form of decreased degree of nocturnal dipping and increased levels of diastolic and mean blood pressure, according to previous studies in literature. OSA in children seems to be associated to the development of hypertension or other cardiovascular disease. (C) 2012 Elsevier B.V. All rights reserved.

Microscopical Evaluation of Extracellular Matrix and Its Relation to the Palatopharyngeal Muscle in Obstructive Sleep Apnea

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Treatment of snoring and sleep apnea syndrome with a removable mandibular advancement device in patients without TMD

INTRODUCTION: Among the sleep disorders reported by the American Academy of Sleep, the most common is obstructive sleep apnea-hypopnea syndrome (OSAHS), which is caused by difficulties in air passage and complete interruption of air flow in the airway. This syndrome is associated with increased morbidity and mortality in apneic individuals. OBJECTIVE: It was the objective of this paper to evaluate a removable mandibular advancement device as it provides a noninvasive, straightforward treatment readily accepted by patients. METHODS: In this study, 15 patients without temporomandibular disorders (TMD) and with excessive daytime sleepiness or snoring were evaluated. Data were collected by means of: Polysomnography before and after placement of an intraoral appliance, analysis of TMD signs and symptoms using a patient history questionnaire, muscle and TMJ palpation. RESULTS: After treatment, the statistical analysis (t-test, and the before and after test) showed a mean reduction of 77.6% (p=0.001) in the apnea-hypopnea index, an increase in lowest oxyhemoglobin saturation (p=0.05), decrease in desaturation (p=0.05), decrease in micro-awakenings or EEG arousals (p=0.05) and highly significant improvement in daytime sleepiness (p=0.005), measured by the Epworth Sleepiness Scale. No TMD appeared during the monitoring period. CONCLUSION: The oral device developed in this study was considered effective for mild to moderate OSAHS.

Topography-specific spindle frequency changes in Obstructive Sleep Apnea

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of obstructive sleep apnea in obese patients scheduled for bariactric surgery

PURPOSE: To evaluate the frequency of obstructive sleep apnea (OSA) in obese patients scheduled for bariatric surgery and their identification for risk of OSA by Berlin Questionnaire (BQ) and excessive daytime sleepiness by Epworth Sleepiness Scale (ESS). METHODS: Fifty nine patients were evaluated by BQ and ESS. Out of these individuals, 35 performed a full-night sleep study using a type 3 portable monitoring (PM). The questionnaire results were compared for gender and BMI. The presence and severity of OSA was correlated with gender and both questionnaires. RESULTS: 94.75% of the respondents presented high risk for OSA by BQ and 59.65% presented positivity by ESS. Taking into account the AHI> 5 per hour for OSA diagnosis, all of them presented OSA, average AHI of 45.31±26.3 per hour and 68.6% have severe OSA (AHI>30). The male patients had a higher AHI (p<0.05). There was a positive correlation between the positivity in both questionnaires as well as the severity of OSA measured by AHI (p<0.05). CONCLUSION: The frequency and severe obstructive sleep apnea in the studied group is high. The Berlin Questionnaire and Epworth Sleepiness Scale had a positive correlation with the diagnosis of OSA in the group studied.

Loss of sleep spindle frequency deceleration in Obstructive Sleep Apnea

Objective: Sleep spindles have been suggested as surrogates of thalamo-cortical activity. Internal frequency modulation within a spindle's time frame has been demonstrated in healthy subjects, showing that spindles tend to decelerate their frequency before termination. We investigated internal frequency modulation of slow and fast spindles according to Obstructive Sleep Apnea (OSA) severity and brain topography. Methods: Seven non-OSA subjects and 21 patients with OSA contributed with 30 min of Non-REM sleep stage 2, subjected to a Matching pursuit procedure with Gabor chirplet functions for automatic detection of sleep spindles and quantification of sleep spindle internal frequency modulation (chirp rate). Results: Moderate OSA patients showed an inferior percentage of slow spindles with deceleration when compared to Mild and Non-OSA groups in frontal and parietal regions. In parietal regions, the percentage of slow spindles with deceleration was negatively correlated with global apnea-hypopnea index (r s = -0.519, p = 0.005). Discussion: Loss of physiological sleep spindle deceleration may either represent a disruption of thalamo-cortical loops generating spindle oscillations or some compensatory mechanism, an interesting venue for future research in the context of cognitive dysfunction in OSA. Significance: Quantification of internal frequency modulation (chirp rate) is proposed as a promising approach to advance description of sleep spindle dynamics in brain pathology. © 2013 International Federation of Clinical Neurophysiology.

Efficacy of an Oral Appliance for the Treatment of Obstructive Sleep Apnea

Purpose: The aim of this study was to validate the use of a mandibular repositioner appliance (MRA) to treat obstructive sleep apnea (OSA) and primary snoring, comparing polysomnographic and Epworth Sleepiness Scale (ESS) data obtained prior to and during MRA treatment. Materials and Methods: Sixty-three patients who presented with different degrees of OSA severity or primary snoring were fitted to a PM positioner between 2009 and 2011. The diagnosis was established by a polysomnogram (PSG) prior to treatment and after 6 months to verify the efficacy of MRA therapy. Subjective daytime sleepiness was evaluated by ESS questionnaire prior to treatment and at the follow-up. Results: Patients were divided into primary snoring and OSA groups. For the primary snoring group, PSG variables did not show significant results, except for a decrease in snoring. For the OSA group, the mean apnea-hypopnea index (AHI) was reduced from 23.0 +/- 11 to 5.3 +/- 4.0 and median ESS reduced significantly from 13.0 to 8.5. Complete response (AHI < 5) was found in 25 (40%) patients and partial response (AHI <= 10) in 27 (43%) patients. Conclusion: The findings validate the efficacy of the adjustable PM positioner for the safe treatment of OSA.

Correlation Between the Friedman Staging System and the Upper Airway Volume in Patients With Obstructive Sleep Apnea

Purpose: This study was designed to evaluate the correlation between computed tomography findings and data from the physical examination and the Friedman Staging System (FSS) in patients with obstructive sleep apnea (OSA). Patients and Methods: We performed a retrospective evaluation by reviewing the medical records of 33 patients (19 male and 14 female patients) with a mean body mass index of 30.38 kg/m 2 and mean age of 49.35 years. Among these patients, 14 presented with severe OSA, 7 had moderate OSA, 7 had mild OSA, and 5 were healthy. Results: The patients were divided into 2 groups according to the FSS: Group A comprised patients with FSS stage I or II, and group B comprised patients with FSS stage III. By use of the Fisher exact test, a positive relationship between the FSS stage and apnea-hypopnea index ( P = .011) and between the FSS stage and body mass index ( P = .012) was found. There was no correlation between age ( P = .55) and gender ( P = .53) with the FSS stage. The analysis of variance test comparing the upper airway volume between the 2 groups showed P =.018. Conclusions: In this sample the FSS and upper airway volume showed an inverse correlation and were useful in analyzing the mechanisms of airway collapse in patients with OSA.

Polysomnografic findings of obstrutive sleep apnea in children with adenotonsillar hypertrophy

Serous Background: There are few studies assessing the clinical manifestations of sleep breathing disorders and polysomnograms in several pediatric age ranges. This studied aimed to assess polysomnography results such as apnea-hypopnea index, mean oxygen saturation and sleep efficiency in children presenting with airway obstruction and adenotonsillar hypertrophy complaints, and to establish whether they are correlated to age and sex. Methods: A retrospective study with children of both sexes, aged between 2 and 12 years, with clinically suspected obstructive sleep apnea syndrome and adenotonsillar hypertrophy, who underwent polysomnography before surgery. The children were allocated to groups according to their age range (Group I: 2 to 4 years old; Group II: 5 to 8 years old; Group III: 9 to 12 years old). Apnea-hypopnea index, mean oxygen saturation and sleep efficiency data were compared between sexes and among the three groups (Student’s t test, p < 0.05). Results: Of 167 children studied by polysomnography, 76.6% were of school age and 67% were male. For all studied age ranges, there was no difference between sexes for the investigated parameters (body mass index, apnea-hypopnea index, mean oxygen saturation and sleep efficiency). As regards mean oxygen saturation, Group I showed the lowest value (89.9 ± 6.2). Apnea-hypopnea indexes were higher in male children aged between 2 and 4 years (9.9 ± 5.2). Group III had the lowest sleep efficiency (84.1 ± 9.2). Conclusion: There was a predilection of more severe cases of obstructive sleep apnea syndrome for children younger than four years, shown by higher apnea-hypopnea index per hour and lower mean oxygen saturation in this age range.

Cephalometric analysis for the diagnosis of sleep apnea: a comparative study between reference values and measurements obtained for Brazilian subjects

OBJECTIVE: To verify if the reference values of Sleep Apnea cephalometric analysis of North American individuals are similar to the ones of Brazilian individuals presenting no craniofacial anomalies. The study also aimed to identify craniofacial alterations in Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS) patients in relation to individuals without clinical characteristics of the disease through this cephalometric analysis. METHOD: It were used 55 lateral cephalograms consisting of 29 for the control group of adult individuals without clinical characteristics of OSAHS and 26 apneic adults. All radiographs were submitted to Sleep Apnea cephalometric analysis through Radiocef Studio 2.0. The standard values of this analysis were compared, by means of z test, to the ones obtained from the control group and these were compared to values from apneic group through Student's t test. RESULTS: There were no significant differences between values obtained from control group and standard values. On the group of OSAHS patients it was observed a decrease on the dimensions of upper airways and an increase on the soft palate length. CONCLUSIONS: The standard values of Sleep Apnea analysis can be used as reference in Brazilian individuals. Besides, through lateral cephalograms it was possible to identify craniofacial alterations in OSAHS patients.

Sleep apnea and automobile accidents: Review of regulation for drivers

Several studies show a crescent association between sleep-disordered breathing, excessive sleepiness and automobile accidents. Many countries already discussed about specific regulations for drivers with these conditions, including questionnaire and/or investigation by a qualified specialist. In Brazil, these discussions have barely begun. In view of that, we suggest some items to be included in our traffic law.

Estudo do comportamento da PIO de 24 horas e frequência de glaucoma em pacientes com síndrome da apnéia obstrutiva do sono

Purpose: To determine the frequency of glaucoma and evaluate the behavior of 24-hour intraocular pressure in patients with the obstructive sleep apnea syndrome (OSAS). Methods: Eleven consecutive patients with OSAS, diagnosed by polysonography, were avaliated in a cross-sectional study. Demographic data were analyzed: age, sex, race/color, weight, height and associated diseases. The patients were submitted to complete ophthalmologic examination, including the visual field, as well as to 24-hour intra-ocular pressure (IOP) evaluation by an applanation tonometer at 9h, 12h, 15h, 18h, 24h and 6h in the lying and sitting positions. The diagnostic criterion for glaucoma was alteration of the visual field (VF) compatible with glaucoma and one or more of the following alterations: cup-disc ratio >= 0.7, hemorrhage, wedge-shaped defect, bayonet-shaped vessels, Hoyt's sign, asymmetry > than 0.2 between cup/disc ratio of the eyes. The angle should be opened without alterations. Results: 9 (82%) of 11 patients showed glaucoma or were suspected to have glaucoma, 9% of which exhibited normal tension glaucoma and 73% were suspected to have glaucoma for presenting alterations in the optic nerve or ocular hypertension. The mean for the IOP values of the 11 patients was observed to be the highest at 6 o'clock, when they were lying down. Variations of IOP >= 5 mmHg occurred in 7 (64%) of the patients, and variations of up to 14 mmHg and IOP peaks of up to 32 mmHg were observed. Conclusion: OSAS may be an important risk factor for the development of glaucoma, particularly that of normal tension glaucoma. Patients with OSAS must be referred to an ophthalmologist and those professionals must be attentive to the association of sleep disorders in patients with open-angle glaucoma.

Avaliação dos níveis séricos de testosterona em pacientes com síndrome da apneia obstrutiva do sono

Homens com síndrome da apneia obstrutiva do sono (SAOS) podem apresentar diminuição dos níveis de testosterona devido à hipóxia. OBJETIVOS: Relacionar os níveis séricos da testosterona, em pacientes com SAOS, com parâmetros clínico-laboratoriais. MATERIAL E MÉTODOS: Foram revisados 103 prontuários de pacientes com SAOS, entre os anos de 2002 e 2009, e coletados os seguintes dados: idade à época da realização da polissonografia, valores do Hematócrito e Hemoglobina, nível sérico da testosterona total, IMC, índice de apneia/hipopneia(IAH) e SatO2. FORMA do ESTUDO: Estudo de casos retrospectivo em corte transversal. RESULTADOS: 79 pacientes (77%) não apresentaram alteração hormonal e 24 (23%) apresentaram níveis séricos inferiores. Dos pacientes com testosterona normal 70% estavam com sobrepeso, enquanto que 63% com testosterona alterada apresentaram obesidade grau I (p<0,05). Os pacientes com testosterona alterada apresentaram as dosagens médias do Ht e da Hb e dos níveis médios do andrógeno significantemente inferiores aos dos pacientes sem alteração androgênica. A média do IMC dos pacientes com alteração hormonal foi significativamente maior que a média daqueles sem alteração. CONCLUSÃO: A relação entre o perfil sérico da testosterona matinal e a obesidade e, em menor grau, a idade, o IAH e a hipóxia, podem ser responsáveis pela supressão central da testosterona nesses pacientes. A queda dos valores hematimétricos pode ser relacionada aos baixos níveis circulantes da testosterona.