State-dependent changes in the upper airway assessed by multidetector CT in healthy individuals and during obstructive events in patients with sleep apnea / Alterações nas vias aéreas superiores avaliadas por TC multidetectores durante a vigília e o sono em indivíduos saudáveis e em pacientes com apneia do sono durante eventos obstrutivos

ABSTRACT Objective: To determine whether airway narrowing during obstructive events occurs predominantly at the retropalatal level and results from dynamic changes in the lateral pharyngeal walls and in tongue position. Methods: We evaluated 11 patients with severe obstructive sleep apnea (OSA) and 7 healthy controls without OSA during wakefulness and during natural sleep (documented by full polysomnography). Using fast multidetector CT, we obtained images of the upper airway in the waking and sleep states. Results: Upper airway narrowing during sleep was significantly greater at the retropalatal level than at the retroglossal level in the OSA group (p < 0.001) and in the control group (p < 0.05). The retropalatal airway volume was smaller in the OSA group than in the control group during wakefulness (p < 0.05) and decreased significantly from wakefulness to sleep only among the OSA group subjects. Retropalatal pharyngeal narrowing was attributed to reductions in the anteroposterior diameter (p = 0.001) and lateral diameter (p = 0.006), which correlated with an increase in lateral pharyngeal wall volume (p = 0.001) and posterior displacement of the tongue (p = 0.001), respectively. Retroglossal pharyngeal narrowing during sleep did not occur in the OSA group subjects. Conclusions: In patients with OSA, upper airway narrowing during sleep occurs predominantly at the retropalatal level, affecting the anteroposterior and lateral dimensions, being associated with lateral pharyngeal wall enlargement and posterior tongue displacement.

Resumo Objetivo: Determinar se o estreitamento das vias aéreas durante eventos obstrutivos ocorre predominantemente na região retropalatal e resulta de alterações dinâmicas nas paredes laterais da faringe e na posição da língua. Métodos: Avaliamos 11 pacientes com apneia obstrutiva do sono (AOS) grave (grupo AOS) e 7 indivíduos saudáveis sem AOS (grupo controle) durante a vigília e o sono natural (documentado por meio de polissonografia completa). Por meio de TC multidetectores rápida, obtivemos imagens das vias aéreas superiores no estado de vigília e de sono. Resultados: O estreitamento das vias aéreas superiores durante o sono foi significativamente maior na região retropalatal do que na região retrolingual no grupo AOS (p < 0,001) e no grupo controle (p < 0,05). O volume da via aérea retropalatal foi menor no grupo AOS do que no grupo controle durante a vigília (p < 0,05) e diminuiu significativamente da vigília ao sono apenas no grupo AOS. O estreitamento retropalatal da faringe foi atribuído à redução do diâmetro anteroposterior (p = 0,001) e lateral (p = 0,006), que se correlacionou com o aumento do volume das paredes laterais da faringe (p = 0,001) e o deslocamento posterior da língua (p = 0,001). Não ocorreu estreitamento retrolingual da faringe durante o sono no grupo AOS. Conclusões: Em pacientes com AOS, o estreitamento das vias aéreas superiores durante o sono ocorre predominantemente na região retropalatal e afeta as dimensões anteroposterior e lateral, além de estar relacionado com aumento das paredes laterais da faringe e deslocamento posterior da língua.

Obstructive Sleep Apnea is Common and Associated with Heart Remodeling in Patients with Chagas Disease / Apneia Obstrutiva do Sono é Comum e está Associada à Remodelação Cardíaca em Pacientes com Doença de Chagas

Abstract Background: Chagas Disease (CD) is an important cause of morbimortality due to heart failure and malignant arrhythmias worldwide, especially in Latin America. Objective: To investigate the association of obstructive sleep apnea (OSA) with heart remodeling and cardiac arrhythmias in patients CD. Methods: Consecutive patients with CD, aged between 30 to 65 years old were enrolled. Participants underwent clinical evaluation, sleep study, 24-hour Holter monitoring, echocardiogram and ambulatory blood pressure monitoring. Results: We evaluated 135 patients [age: 56 (45-62) years; 30% men; BMI: 26 ± 4 kg/m2, Chagas cardiomyopathy: 70%]. Moderate to severe OSA (apnea-hypopnea index, AHI, ≥ 15 events/h) was present in 21% of the patients. OSA was not associated with arrhythmias in this population. As compared to patients with mild or no OSA, patients with moderate to severe OSA had higher frequency of hypertension (79% vs. 72% vs. 44%, p < 0.01) higher nocturnal systolic blood pressure: 119 ± 17 vs. 113 ± 13 vs. 110 ± 11 mmHg, p = 0.01; larger left atrial diameter [37 (33-42) vs. 35 (33-39) vs. 33 (30-36) mm, p < 0.01]; and a greater proportion of left ventricular dysfunction [LVEF < 50% (39% vs. 28% vs. 11%), p < 0.01], respectively. Predictor of left atrial dimension was Log10 (AHI) (b = 3.86, 95% CI: 1.91 to 5.81; p < 0.01). Predictors of ventricular dysfunction were AHI > 15 events/h (OR = 3.61, 95% CI: 1.31 - 9.98; p = 0.01), systolic blood pressure (OR = 1.06, 95% CI: 1.02 - 1.10; p < 0.01) and male gender (OR = 3.24, 95% CI: 1.31 - 8.01; p = 0.01). Conclusions: OSA is independently associated with atrial and ventricular remodeling in patients with CD.

Resumo Fundamento: A doença de Chagas (DC) é uma causa importante de morbimortalidade por insuficiência cardíaca e arritmias malignas em todo o mundo, especialmente na América Latina. Objetivo: Investigar a associação entre apneia obstrutiva do sono (AOS) com remodelação cardíaca e arritmias cardíacas em pacientes com DC. Métodos: Foram incluídos pacientes consecutivos com DC, com idade entre 30 e 65 anos. Os participantes foram submetidos à avaliação clínica, estudo do sono, Holter de 24 horas, ecocardiograma e monitorização ambulatorial da pressão arterial. Resultados: Foram avaliados 135 pacientes [idade: 56 (45-62) anos; 30% homens; IMC: 26 ± 4 kg/m2, cardiomiopatia chagásica: 70%]. AOS moderada a grave (índice de apneia-hipopneia, IAH, ≥ 15 eventos/h) estava presente em 21% dos pacientes. AOS não estava associada a arritmias nessa população. Em comparação com pacientes com AOS leve ou ausente, pacientes com AOS moderada a grave apresentaram maior frequência de hipertensão (79% vs. 72% vs. 44%, p < 0,01) e pressão arterial sistólica noturna mais alta: 119 ± 17 vs. 113 ± 13 vs. 110 ± 11 mmHg, p = 0,01; diâmetro do átrio esquerdo maior [37 (33‑42) vs. 35 (33-39) vs. 33 (30-36) mm, p < 0,01]; e maior proporção de disfunção ventricular esquerda [FEVE < 50% (39% vs. 28% vs. 11%), p < 0,01], respectivamente. O preditor de dimensão do átrio esquerdo foi Log10 (IAH) (β = 3,86, IC 95%: 1,91 a 5,81; p < 0,01). Os preditores de disfunção ventricular foram IAH >15 eventos/h (OR = 3,61, IC 95%: 1,31 - 9,98; p = 0,01), pressão arterial sistólica (OR = 1,06, IC95%: 1,02 - 1,10; p < 0,01) e sexo masculino (OR = 3,24, IC 95%: 1,31 - 8,01; p = 0,01). Conclusões: A AOS está independentemente associada à remodelação atrial e ventricular em pacientes com DC.

Evaluation of tongue/mandible volume ratio in children with obstructive sleep apnea

ABSTRACT Objective: The present study was an attempt to investigate tongue/mandible volume ratio in children, using volumetric magnetic resonance imaging (MRI) for early screening and to aid in treatment planning. Methods: Volumetric evaluation of tongue volume/mandible volume ratio (TV/MV ratio) in children with obstructive sleep apnea (OSA) using MRI was carried out retrospectively on available DICOM MR images of children in the age group of 10-14 years. MRI image records of patients diagnosed with OSA were obtained from interventional radiology department records, at Sharad Pawar Dental College and Hospital (Datta Meghe Institute of Medical Sciences, Nagpur/India). The age, gender, height and weight of the subjects were retrieved from patient database and registered. For the control group, available MRI images of healthy subjects without OSA were retrieved. Body mass index (BMI) was also calculated using the height and the weight present in the records. Measurements from MR images were made using DICOM image processing software. Soft tissue and bony structure segmentation was performed by manual tracing. The tongue volume and mandible volume were directly computed using the software. The tongue volume/mandible volume ratio (TV/MV) was generated using the above values and expressed as a percentage for both groups. Results: The difference between OSA group and control group with respect to TV/MV ratio was found to be highly significant at 0.05 level of significance. There was no significant correlation between BMI and TV/MV ratio in OSA group (p= 0.451) as well as in control group (p= 0.094). Conclusion: TV/MV ratio may be an appropriate variable to evaluate the risk of OSA, representing the balance between skeletal morphology and soft tissue morphology in craniofacial complex.

Resumo Objetivo: o presente estudo foi uma tentativa de investigar a relação volumétrica língua/mandíbula em crianças, usando imagens de ressonância magnética (IRM), para triagem inicial e como meio auxiliar no plano de tratamento. Métodos: a avaliação da relação volume da língua/volume da mandíbula (relação VL/VM) em crianças com apneia obstrutiva do sono (AOS) utilizando IRM foi realizada retrospectivamente em imagens de RM em formato DICOM disponíveis de crianças na faixa etária de 10 a 14 anos. As documentações com IRM de pacientes com diagnóstico de AOS foram obtidas nos arquivos do departamento de radiologia da Sharad Pawar Dental College and Hospital (Datta Meghe Institute of Medical Sciences, Nagpur/Índia). A idade, o sexo, altura e peso dos indivíduos foram obtidos a partir dos registros dos pacientes. Para o grupo controle, foram selecionadas imagens de RM disponíveis de indivíduos saudáveis sem AOS. O índice de massa corporal (IMC) também foi calculado a partir da altura e do peso constantes nos registros. As medições nas imagens de RM foram feitas usando um software de processamento de imagens DICOM. A segmentação entre tecidos moles e estrutura óssea foi realizada por delineamento manual. O volume da língua e o volume da mandíbula foram calculados diretamente com o software. A relação volume da língua/volume da mandíbula (VL/VM) foi calculada usando os valores acima e expressa em porcentagens, para ambos os grupos. Resultados: a diferença entre o grupo com AOS e o grupo controle, quanto à relação VL/VM, foi altamente significativa ao nível de significância de 0,05. Não houve, porém, correlação significativa entre o IMC e a relação VL/VM, nem no grupo AOS (p= 0,451), nem no grupo controle (p= 0,094). Conclusão: a relação VL/VM pode ser uma variável apropriada para se avaliar o risco de AOS, representando o equilíbrio entre a morfologia esquelética e a morfologia dos tecidos moles no complexo craniofacial.

Abordaje diagnóstico de la hipertensión arterial secundaria / Diagnostic Approach Of Secondary Hypertension

Introducción: La hipertensión arterial es una de las enfermedades más prevalentes en atención primaria y el principal factor de riesgo para enfermedad cardivoascular. La hipertensión arterial secundaria es frecuente entre los pacientes con diagnóstico de hipertensión arterial, con una prevalencia del 10 % que puede incrementar hasta 20 % o 40 % en pacientes con hipertensión refractaria al tratamiento. Su identificación temprana se asocia con mejores desenlaces. Objetivo: Evaluar en la literatura las principales causas de hipertensión arterial secundaria e identificar el abordaje diagnóstico inicial de las patologías asociadas. Métodos: Selección y lectura de artículos de bases de datos Pubmed y Google Scholar y de revisiones de UpToDate que trataran el tema de hipertensión arterial secundaria. Conclusiones: Es importante reconocer aquellos pacientes que puedan estar cursando con hipertensión arterial de causa secundaria, ya que esto modifica el enfoque terapéutico, facilita el tratamiento y mejora los desenlaces; incluso puede llegar a la cura y resolución.

Hypertension is one of the most common diseases encountered in primary care settings and a major risk. factor for cardiovascular disease. Secondary hypertension is common in patients with hypertension diagnosis; its prevalence is about 10% and can be as high as 40% in patients whom are resistant to treatment. Its early recognition and treatment allows for better outcomes. Objective: To evalúate and identify the main causes for secondary' hypertension and to identify the diagnosis and evaluation of related conditions. Nfethods: Selection and review of articles from Pubmed and Google scholar and Iiterature reviews from Uptodate. Conclusions: It is important to identify secondary hypertension since this will modify treatment, outcomes and in some scenarios might be curable.

Research Progress of the Relationship between SUNDS and OSAHS / 法医学杂志

Sudden unexplained nocturnal death syndrome （SUNDS） is always a difficulty in forensic medicine researches. Although the development of molecular genetics promotes the etiologic study of SUNDS, the pathogenesis of most such cases is still unclear. Sleep apnea syndrome （SAS） is one of the common forms of sleep disorders, and obstructive sleep apnea hypopnea syndrome （OSAHS） is the most common. In recent years, some domestic and international researches show that OSAHS is related to the development of cardiovascular disease, which may cause cardiac arrhythmia, even sudden death. This article reviews the relationship between SUNDS and OSAHS and aims to provide new ideas for the pathogenesis of SUNDS.

Evaluation of posterior ocular changes using enhanced depth imaging-optical coherence tomography in patients with obstructive sleep apnea syndrome / Avaliação das alterações oculares posteriores utilizando tomografia de coerência óptica de profundidade aprimorada em pacientes com síndrome de apneia obstrutiva do sono

ABSTRACT Purpose: Evaluation of the nerve fiber thicknesses of the macula, choroid, and retina using the apnea-hypopnea index in individuals with obstructive sleep apnea syndrome (OSAS) without systemic components. Methods: Prospective, controlled study. The central macular, choroidal, and retinal nerve fiber layer (RNFL) thicknesses were evaluated using enhanced depth imaging-spectral domain optical coherence tomography in individuals with OSAS. In people with severe OSAS who had received treatment, posterior ocular structures were examined over 3 months (4th and 12th weeks), and changes were evaluated. Only the right eyes of the participants were evaluated in the study. Results: A total of 72 people were involved in the study, with 18 in the control group and 19 with mild, 16 with moderate, and 19 with severe OSAS. No significant difference was found among the groups in terms of demographic measures. No significant differences were found among the groups in terms of the measures of central macular, central subfoveal choroidal (CSCT), temporal choroidal, nasal choroidal, and RNFL thicknesses. In severe OSAS cases in which treatment was administered, although subjective clinical recovery was observed, statistically significant thinning was detected during the 3-month follow-up period in the CSCT, general RNFL, as well as in the inferior and superior nasal quadrants, and temporal superior quadrant (p=0.005, p=0.009, p=0.039, p=0.003, and p=0.02, respectively). Conclusion: In the group with severe OSAS, thinning in some posterior ocular tissues was observed. Although patients with severe OSAS may experience clinical recovery, we recommend that they would be followed up in terms of ocular ischemic injury.

RESUMO Objetivo: Avaliação de espessuras das fibras nervosas da mácula, coroide e da retina de acordo com os índices de apnéia e hipopnéia (AHI) em indivíduos com síndrome da apneia obstrutiva do sono (OSAS), sem componentes sistêmicos. Métodos: Estudo prospectivo, controlado. As espessuras centrais maculares, da coroide e da camada de fibras nervosas da retina foram avaliadas tomografia de coerência óptica de domínio espectral de profundidade aprimorada em indivíduos com síndrome da apneia obstrutiva do sono. Em pessoas com OSAS grave a quem foi aplicado o tratamento, estruturas oculares posteriores foram examinados por três meses (4ª e 12ª semanas) e as alterações foram avaliadas. Apenas os olhos direitos dos participantes foram envolvidos no estudo. Resultados: 72 pessoas foram envolvidas no estudo, 18 no grupo controle e, 19 com OSAS leve, 16 com OSAS moderada e 19 com OSAS grave. Não houve diferença significativa entre os grupos em relação às medidas demográficas. Não houve diferenças significativas estavam presentes entre os grupos em termos de medidas de espessura macular central (CMT), espessura subfoveal central da coroide (CSCT), espessura da coroide temporal (TCT), espessura da coroide nasal (NCT) e, a camada de fibras nervosas da retina (RNFL). Em casos de OSAS graves onde o tratamento foi aplicado, apesar de ter sido observada recuperação clínica subjetiva, detectou-se afinamento estatisticamente significativo durante os três meses de acompanhamento, em CSCT, RNFL geral, quadrantes nasais inferior e superior, e quadrante temporal superior (p=0,005, p=0,009, p=0,039, p=0,003, p=0,02). Conclusão: No grupo com OSAS grave, foi observado afinamento em algumas áreas posteriores dos tecidos oculares. Embora os pacientes com OSAS grave possam apresentar recuperação clínica, recomendamos que eles sejam seguidos em termos de lesão isquêmica ocular.

Síndrome de apnea obstructiva del sueño en niños (SAOS) / Obstructive sleep apnea syndrome in children (OSAS)

El síndrome de la apnea obstructiva del sueño (SAOS) es ocasionado por una obstrucción de las vías aéreas superiores, resultado de un desequilibrio entre la fuerza de succión respiratoria y la compensación de los músculos dilatadores faríngeos. El diagnóstico positivo es establecido por el registro polisomnográfico nocturno durante el sueño que define las características y la severidad de esta enfermedad. El objetivo del siguiente artículo es difundir los diversos aspectos clínicos y diagnósticos de una enfermedad recientemente descripta de alta prevalencia y que cruza las fronteras de múltiples especialistas (pediatras, neurólogos, neumólogos, otorrinolaringólogos, psiquiatras, psicólogos, odontoestomatólogos, ortodoncistas), así contribuiremos a su diagnóstico precoz a partir de los niños que roncan, evitando las importantes secuelas del SAOS infantil...

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.

OBJETIVO: verificar se os valores de referência da análise cefalométrica para apneia do sono, referentes a indivíduos norte-americanos, são semelhantes aos de indivíduos brasileiros não portadores de anomalias craniofaciais. Identificar, também por meio dessa análise cefalométrica, alterações craniofaciais em indivíduos portadores de síndrome da apneia obstrutiva do sono (SAOS) em relação a indivíduos sem características clínicas da doença. MÉTODOS: foram utilizadas 55 radiografias cefalométricas laterais advindas de arquivos, sendo 29 radiografias para o grupo controle, sendo composto de indivíduos adultos sem características clínicas de SAOS, e 26 de indivíduos adultos apneicos. Todas as radiografias foram submetidas à análise cefalométrica para apneia do sono por meio do software Radiocef Studio 2.0. Por meio do teste z, valores-padrão dessa análise foram comparados aos valores obtidos do grupo controle, e esses, por sua vez, foram comparados aos valores do grupo de apneicos por meio do teste t de Student. RESULTADOS: não houve diferenças significativas entre os valores obtidos do grupo controle e os valores-padrão. No grupo de indivíduos portadores de SAOS, observou-se diminuição nas dimensões das vias aéreas superiores e aumento do comprimento do palato mole. CONCLUSÕES: os valores-padrão da análise de apneia do sono podem ser utilizados como referência em indivíduos brasileiros. Além disso, por meio da radiografia cefalométrica lateral foi possível identificar alterações craniofaciais em indivíduos portadores de SAOS.

Comparação da área da faringe na vigília e durante o sono induzido em pacientes com Síndrome da Apneia Obstrutiva do Sono (SAOS) / Comparison of the area of the pharynx during wakefulness and induced sleep in patients with Obstructive Sleep Apnea (OSA)

O estudo da Síndrome da Apneia Obstrutiva do Sono (SAOS) tem merecido atenção crescente nos últimos anos, uma vez que vários aspectos não foram ainda suficientemente esclarecidos. OBJETIVO: Avaliar, com o uso da Ressonância Magnética (RM), as modificações da área da faringe durante vigília e sono induzido em pacientes portadores de SAOS. MATERIAL E MÉTODOS: Estudo prospectivo de 32 pacientes com diagnóstico polissonográfico de SAOS. Todos foram submetidos à aquisição das Imagens por RM, com sequências sagitais de alta definição anatômica, realizadas inicialmente com o paciente em vigília e durante o sono induzido por Propofol. Uma área foi definida no plano sagital na linha média da faringe. Essa região passou a ser denominada como área do plano mediano da faringe (PMF). RESULTADOS: As medidas (mm²) da área do PMF de cada paciente, na vigília e durante o sono induzido, apresentaram diferença estatisticamente significante p< 0,000001. CONCLUSÕES: Os pacientes portadores de SAOS sofrem uma significativa redução de 75,5 por cento da área da faringe durante o sono induzido quando comparado à vigília.

The study of obstructive sleep apnea (OSA) has received growing attention over the past years since various aspects have not been sufficiently established. AIM: To evaluate, with the use of magnetic resonance imaging (MRI), changes in the area of the pharynx during wakefulness and induced sleep in patients with OSA. MATERIALS AND METHODS: A prospective study of thirty-two patients with a polysomnographic diagnosis of OSA. All patients were submitted to MR imaging in order to obtain high-definition anatomical sagittal sequences during wakefulness and during sleep induced with Propofol. An area was defined on the sagittal plane in the midline of the pharynx. This region was called pharyngeal midplane (PMP) area. RESULTS: A significant difference in PMP area (mm²) was observed between wakefulness and induced sleep in each patient (p < 0.000001). CONCLUSION: The patients with OSA suffer a significant reduction of 75,5 percent in the area of the pharynx during induced sleep compared to wakefulness.

Evaluation of craniofacial morphology in patients with obstructive sleep apnea using lateral cephalometry and dynamic MRI.

Context: Obstructive sleep apnea (OSA) is a potentially life-threatening disorder, characterized by repeated collapse of the upper airway during sleep with cessation of breathing. The altered mouth breathing produces morphological changes in craniofacial region. Aim: This study was designed to compare and validate the craniofacial morphological characteristics in patients with OSA using lateral cephalometry and to investigate the dentofacial characteristics of patients with OSA with respect to the obstructive sites determined by dynamic magnetic resonance imaging (MRI) to more accurately clarify the pathophysiological features. Materials and Methods: 10 patients with OSA were divided into two groups of five each according to their obstructive site determined by dynamic MRI. (1) Obstruction at the retropalatal and retroglossal region (Rp + Rg group) and (2) obstruction at the retropalatal region (Rp group). Lateral cephalogram both in upright and supine position was taken for all the subjects. In addition, dynamic MRI was performed to identify the sites of obstruction of the upper airway. Statistical analysis used: Independent t-test was performed to evaluate the significant difference in the upright cephalometric variables between the study and control group and between the two groups. The changes in skeletal and soft tissue parameters with change in posture was assessed within the study and control group by paired t test. P value of ≤0.05 was considered as statistically significant. Results: The study indicated that the first group of patients with both retropalatal and retroglossal obstruction showed signs of skeletal discrepancy that predisposed to obstruction at the retroglossal level and the soft tissue components like the soft palate and tongue that contributed to retropalatal obstruction. However, the second group of patients with only retropalatal obstruction had primarily soft tissue components associated with increased BMI that contributed to retropalatal obstruction. Conclusion: Evaluation of craniofacial morphology in OSA patients is bound to help the concerned specialist in recognizing the morphological changes induced by altered sleep pattern so as to provide the appropriate treatment.

Upper airway collapsibility evaluated by a negative expiratory pressure test in severe obstructive sleep apnea

OBJECTIVES: To investigate the usefulness of measuring upper airway collapsibility with a negative expiratory pressure application as a screening test for severe obstructive sleep apnea (OSA). INTRODUCTION: OSA is a risk factor for cardiovascular disease, and it may have serious consequences. Its recognition may have important implications during the perioperative period. Increased upper airway collapsibility is one of the main determinants of OSA, and its evaluation could be useful for identifying this condition. METHODS: Severe OSA and normal subjects (24 in each group) were matched by body mass index and referred to our sleep laboratory. The subjects were enrolled in an overnight sleep study, and a diurnal negative expiratory pressure test was performed. Flow drop (DV) and expiratory volume were measured in the first 0.2 s (V02) of the negative expiratory pressure test. RESULTS: DV ( percent) and V02 ( percent) values were statistically different between normal and OSA subjects. OSA patients showed a greater decrease in flow than normal subjects. In addition, severely OSA patients exhaled during the first 0.2 s of the negative expiratory pressure application was an average of only 11.2 percent of the inspired volume compared to 34.2 percent for the normal subjects. Analysis of the receiver operating characteristics showed that V02 ( percent) and DV ( percent) could accurately identify severe OSA in subjects with sensitivities of 95.8 percent and 91.7 percent, respectively, and specificities of 95.8 percent and 91.7 percent, respectively. CONCLUSIONS: V02 ( percent) and DV ( percent) are highly accurate parameters for detecting severe OSA. The pharyngeal collapsibility measurement, which uses negative expiratory pressure during wakefulness, is predictive of collapsibility during sleep.

Tonsil volume, tonsil grade and obstructive sleep apnea: is there any meaningful correlation?

OBJECTIVES: The aims of this study were to evaluate the correlation between oropharyngeal examination and objective palatine tonsil volume in snoring adults and verify the influence of the oropharyngeal anatomy, body mass index, age, and severity of obstructive sleep apnea on actual tonsil volume. In addition, we aimed to assess the influence of tonsil size on obstructive sleep apnea in adults. INTRODUCTION: Pharyngeal wall geometry is often altered in adults who have obstructive sleep apnea, and this might influence the findings of the oropharyngeal examination that, in turn, are the key factors when considering surgical management for this condition. Furthermore, the correlation between the actual tonsil volume and the severity of obstructive sleep apnea in adults is currently unknown. METHODS: We prospectively studied 130 patients with obstructive sleep apnea or primary snoring who underwent pharyngeal surgery with intraoperative measurement of tonsil volume. We compared tonsil volume with preoperative polysomnography, oropharyngeal examination, and anthropometric data. RESULTS: We found a significant correlation between actual tonsil volume and subjective tonsil grade. We also found a significant correlation between tonsil volume and the apnea-hypopnea index. Using a multivariate linear regression model, tonsil volume was found to be significantly correlated with age, body mass index, and oropharyngeal examination, but not with polysomnography. Clinically, only the rare tonsil grade IV was indicative of more severe obstructive sleep apnea. CONCLUSIONS: There is a strong correlation between clinical tonsil grade and objective tonsil volume in snoring adults, and this correlation exists regardless of the presence or severity of obstructive sleep apnea. Pharyngeal tissue volume likely reflects the body mass index rather than obstructive sleep apnea severity.

Aplicación de distracción osteogénica mandibular en niños con el síndrome de apnea obstructiva del sueño / Application of a mandibular osteogenic distraction in children with sleep obstructive apnea

Objetivos: mostrar los resultados de los primeros pacientes con síndrome de apnea obstructiva del sueño (SAOS) de tipo periférico esqueletal tratados en nuestro país con osteogénesis por distracción mandibular. Métodos: se trataron 9 pacientes con distracción osteogénica mandibular bilateral, con distractores marca Leibinger y Synthes. El periodo de latencia fue de 72 horas. La tasa de distracción mandibular, a razón de 1,0 mm cada 12 horas y la contención fue de 8 semanas. Luego se inició el tratamiento ortodóncico posquirúrgico. Se evaluaron los resultados a través de polisomnografía y estudios cefalométricos antes de la intervención, luego y al año del tratamiento. Resultados: el 89 por ciento de los casos fueron curados, el 11 por ciento tuvo mejoría. Dentro de las complicaciones encontradas, el 55 por ciento de los pacientes presentaron limitación temporal de la apertura bucal, que remitió con fisioterapia, y dos pacientes necesitaron traqueostomía con fines anestésicos. Conclusiones: la osteogénesis por distracción mandibular resultó ser un método terapéutico eficaz para el tratamiento del SAOS de tipo periférico, esqueletal(AU)

Objectives: to show the results from the first patients presenting with sleep obstructive apnea syndrome (SOAS) of skeletal peripheral type treated in our country with osteogenesis by mandibular distraction. Methods: Nine patients were treated with bilateral mandibular osteogenic distraction using Leibinger and Synthes distraction devices. Latency period was of 72 hours. Mandibular distraction rate at 1,0 mm each 12 hours and restraint was of 8 weeks. Then, postsurgical orthodontics treatment was started. Results were assessed by polysomnography and cephalometry studies before intervention, after it and at a year of treatment. Results: The 89 percent of cases had a good recovery, the 11 percent showed an improvement. Complications included: a temporary limitation of mouth opening in 55 percent disappearing with physiotherapy and two patients needed tracheostomy for anesthetic purposes. Conclusions: Osteogenesis by mandibular distraction was an effective therapeutical method for treatment of peripheral skeletal SOAS(AU)

Continuous positive airway pressure therapy: New generations.

Continuous positive airway pressure (CPAP) is the treatment of choice for obstructive sleep apnoea syndrome (OSAS). However, CPAP is not tolerated by all patients with OSAS and alternative modes of pressure delivery have been developed to overcome pressure intolerance, thereby improving patient comfort and adherence. Auto-adjustable positive airway pressure (APAP) devices may be utilised for the long-term management of OSAS and may also assist in the initial diagnosis of OSAS and titration of conventional CPAP therapy. Newer modalities such as C-Flex and A-Flex also show promise as treatment options in the future. However, the evidence supporting the use of these alternative modalities remains scant, in particular with regard to long-term cardiovascular outcomes. In addition, not all APAP devices use the same technological algorithms and data supporting individual APAP devices cannot be extrapolated to support all. Further studies are required to validate the roles of APAP, C-Flex and AFlex. In the interim, standard CPAP therapy should continue as the mainstay of OSAS management.

CPAP no tratamento da apneia obstrutiva do sono: indicações e implicações / CPAP in the treatment of obstructive sleep apnea: indications and implications

A apneia obstrutiva do sono (AOS) é altamente prevalente, porém de fácil diagnóstico e tratamento. Indivíduos com esta condição possuem características como ronco, pausas respiratórias presenciadas e sono excessivo. Sinais físicos, como obesidade, pescoço alargado, mandíbula e maxila pequena ou retrognata e uma via aérea estreitada, sugerem o diagnóstico da AOS. O médico especialista em sono confirma o diagnóstico de AOS por polissonografia (PSG). Após o diagnóstico, o paciente possui várias opções de tratamento, incluindo perda de peso e outras mudanças comportamentais, assim como CPAP (continuous positive airway pressure), cirurgias das vias aéreas e aparelhos intraorais. O paciente com AOS deve ser monitorado de perto durante o período de tratamento, pois a aderência ao regime de tratamento pode ser difícil e resultar em sonolência diurna residual.

Obstructive sleep apnoea/hypopnoea syndrome and hypertension

The obstructive sleep apnoea/hypopnoea syndrome [OSAHS] is a common disorder, affecting around 2-4% of the middle-aged population. There is a strong association between OSAHS and hypertension, based on animal, large epidemiological and interventional studies. The epidemiological studies have shown a dose-response relationship between apnoea/hypopnoea index [AHI] and the risk of developing hypertension. Different mechanisms may have a role in the process of elevated blood pressure in OSAHS. Sympathetic activity is increased in OSAHS patients during sleep and wakefulness. This increase in sympathetic activity is probably due to activation of baroreflexes and chemoreflexes by frequent arousals and hypoxaemia a result of apnoea or hypopnoea events. Continuous positive airway pressure [CPAP] has been shown to reduce sympathetic stimulation and blood pressure in OSAHS patients. Altered endothelial function may also have a role in the pathogenesis of hypertension in OSAHS subjects. Reduction of nitric oxide [NO] production and increase in the formation of free radicals may be responsible for the impairment of the vasodilatation of micro-vasculature in these subjects as a result of hypoxaemia. It has been shown that effective CPAP therapy has a reversible effect on endothelial dysfunction

Avaliação da obstrução da via aérea superior através da videonasofaringoscopia: comparação da manobra de Müller com o sono induzido / Evaluation of airway obstruction by nasopharyngoscopy: comparison of the Müller maneuver versus induced sleep

A nasofaringoscopia com realização de Manobra de Müller é freqüentemente utilizada para determinar o local da obstrução na via aérea superior. No entanto, sua utilidade é controversa, uma vez que é realizada com o paciente acordado e pode não reproduzir os fenômenos obstrutivos que ocorrem durante o sono. OBJETIVOS: Comparar o grau de obstrução faríngea nas regiões retropalatal e retrolingual que ocorrem durante a manobra de Müller com aquelas que ocorrem durante o sono induzido. MATERIAL E MÉTODOS: Estudo prospectivo de 8 pacientes (3 homens e 5 mulheres) com idade (média ±desvio padrão) de 48,6 ± 9,2 anos de idade através de videonasofaringoscopia durante a manobra de Müller e durante o sono induzido por midazolam endovenoso. RESULTADOS: Observamos obstrução retropalatal similar durante a manobra de Müller e sono induzido (média + desvio padrão 3,13 + 0,99 e 2,75 + 0,46, respectivamente, p= 0,234). Em contraste, a obstrução retrolingual foi significantemente menor durante a manobra de Müller (média + desvio padrão 0,63 + 1,06 e 2,63 + 1,30, respectivamente, p= 0,005). CONCLUSÃO: O método do sono induzido foi seguro sob as condições de monitorização adotadas, tendo detectado maior ocorrência de colapso retrolingual do que a manobra de Müller.

The use of nasopharyngoscopy during the application of intrathoracic pressure (Müller maneuver) is frequently employed to establish the site of upper airway obstruction. The Müller maneuver, however, is used when the patient is awake and therefore may not correlate with obstruction occurring during sleep. AIM: to compare the degree of pharyngeal obstruction in the retropalatal and retroglossal regions during the Müller maneuver versus induced sleep using nasopharyngoscopy. STUDY DESIGN: A prospective, case series study. MATERIAL AND METHODS: Eight patients (three males, five females), with a mean age of 48.6 +/- 9,2 year, underwent nasopharyngoscopy to assess airway anatomy and funciton during the Müller maneuver while awake and during sleep induced by drip infusion of Midazolam. RESULTS: Retropalatal obstruction was similar during the Müller maneuver and sleep (mean + standard deviation = 3.13 +/- 0.99 and 2.75 +/- 0.46, p= 0.234). Retroglossal obstruction was significantly lower during Müller maneuver compared to sleep (mean + standard deviation 0.63 +/- 1.06 and 2.63 +/- 1.30, respectively, p= 0.005). CONCLUSIONS: The sleep inducing method was safe under the monitored conditions of this study, and detected more retroglossal obstruction than the Müller maneuver.

Uso de CPAP nasal en el largo plazo en síndrome de apnea-hipopnea del sueño / Long-term continuous positive airway pressure (CPAP) use in obstructive sleep apnea

Background: The use of CPAP is the conventional therapy for the Obstructive Sleep Apnea Syndrome (OSAS). Aim To establish the proportion of OSAS patients with CPAP indication who use it in the long-term and to determine predictive factors of adherence. Patients and Methods: Structured survey through personal interview or phone call, applied to all patients who had polisomnographically documented OSAS and CPAP titration at the Pontificia Universidad Católica de Chile Sleep Disorders Center between January 1998 and November 2001. Patients were divided in "Permanent Users" (Group I) and "Non Users" (Group II). Results: Of 440 patients that fulfilled inclusion criteria, 162 (32.8 percent) answered the survey. Seventy percent (114/162) of these patients had used CPAP and 86 percent (98/114) continued to use it at the time of the interview, with a mean follow-up of 12.3 months (Group I 60.5 percent of the interviewed population). Group II included 64 patients (39.5 percent of the interviewed patients). Among the latter, 25 percent (16/64) stopped using CPAP due to intolerance, 25 percent (16/64) could not use it because of economical restrictions, 20.5 percent (13/64) preferred other therapies and 29.5 percent (15/64) merely refused treatment. Predictors of long-term use of CPAP were number of respiratory events (p <0.01), hypersomnolence (p <0.01) and age (p =0.03). Conclusions: Approximately two thirds of patients with OSAS, with an indication for CPAP, continue to use this therapy in the long term in a Chilean population. This figure is similar to other reports from abroad. It is also possible to identify predictive factors for CPAP discontinuation in this population.

Síndrome da apnéia e da hipopnéia obstrutiva do sono em crianças / Obstructive sleep apnea syndrome in children

Os autores fazem uma revisão bibliográfica atualizada sobre a Síndrome de Apnéia e Hipopnéia Obstrutivas do Sono (SAHOS) em crianças. Sua incidência, etiopatogenia, diagnóstico, conseqüências relacionadas à doença, manejo e prognóstico são abordados

Cardiovascular and ventilatory acclimatization induced by chronic intermittent hypoxia: A role for the carotid body in the pathophysiology of sleep apnea

Patients with obstructive sleep apnea (OSA) show augmented ventilatory, sympathetic and cardiovascular responses to hypoxia. The facilitatory effect of chronic intermittent hypoxia (CIH) on the hypoxic ventilatory response has been attributed to a potentiation of the carotid body (CB) chemosensory response to hypoxia. However, it is a matter of debate whether the effects induced by CIH on ventilatory responses to hypoxia are due to an enhanced CB activity. Recently, we studied the effects of short cyclic hypoxic episodes on cat cardiorespiratory reflexes, heart rate variability, and CB chemosensory activity. Cats were exposed to cyclic hypoxic episodes repeated during 8 hours for 4 days. Our results showed that CIH selectively enhanced ventilatory and carotid chemosensory responses to acute hypoxia. Exposure to CIH did not increase basal arterial pressure, heart rate, or their changes induced by acute hypoxia. However, the spectral analysis of heart rate variability of CIH cats showed a marked increase of the low/high frequency ratio and an increased variability in the low frequency band of heart rate variability, similar to what is observed in OSA patients. Thus, it is likely that the enhanced CB reactivity to hypoxia may contribute to the augmented ventilatory response to hypoxia.