RESUMO
PURPOSE: Negative expiratory pressure (NEP) is a simple technique for the evaluation of upper airway collapsibility in patients with obstructive sleep apnea (OSA). Most studies evaluated NEP using a mouthpiece that may exclude the cephalic portion of the upper airway. We hypothesize that NEP determination is influenced by interface and position. METHODS: We evaluated patients with suspected OSA using polysomnography, NEP (-5 cmH2O in sitting and supine position with mouthpiece and nasal mask). A subgroup also underwent computed tomography (CT) of the upper airway. RESULTS: We studied a total of 86 subjects (72 male, age 46 ± 12 yrs, body mass index 30.0 ± 4.4 kg/m2, neck circumference 40.0 ± 3.5 cm, AHI 32.9 ± 26.4, range 0.5 to 122.5 events/hour). NEP was influenced by interface and position (p = 0.007), and upper airway was more collapsible with mouthpiece than with nasal mask in sitting position (p = 0.001). Position influenced NEP and was worse in supine only when evaluated by nasal mask. Expiratory resistance (R 0.2) at 0.2 s during NEP was significantly higher and independent of position with mouthpiece than with nasal mask (20.7 versus 8.6 cmH2O/L s-1, respectively, p = 0.018). NEP evaluated with nasal mask in supine position and with mouthpiece in sitting position, but not when evaluated with mouthpiece in supine position, were correlated with upper airway anatomical measurements including tongue dimensions and pharyngeal length. CONCLUSIONS: Interface and position influence NEP. NEP evaluated with nasal mask in supine position may convey more relevant information for patients under investigation for OSA than when evaluated with mouthpiece.
Assuntos
Máscaras , Respiração com Pressão Positiva , Decúbito Ventral , Apneia Obstrutiva do Sono/terapia , Feminino , Humanos , Masculino , Nariz/fisiopatologia , Faringe/fisiopatologia , Polissonografia , Língua/fisiopatologiaRESUMO
OBJECTIVE:: To determine whether the use of a gel pillow with side cutouts designed to accommodate a continuous positive airway pressure (CPAP) mask and reduce head temperature improves the efficacy of and adherence to auto-CPAP therapy. METHODS:: Twenty-three consecutive CPAP-naïve patients with obstructive sleep apnea were enrolled in the study. Patients were given an auto-CPAP machine with an appropriate CPAP mask and were instructed to use CPAP for 15 nights. They were instructed to sleep with their own pillow (the control pillow) from nights 1 to 5 and with either a foam pillow or a gel pillow, both of which had side cutouts, for 5 consecutive nights each, in random order. After night 15, auto-CPAP machine data were downloaded and patients rated their satisfaction with each pillow on a visual analog scale. RESULTS:: Twenty-two patients completed the protocol. The pressures administered, residual apnea-hypopnea index, air leaks, and mean duration of CPAP use did not differ among the periods during which each pillow was used. Patients were significantly more satisfied with the gel pillow than with the control pillow and the foam pillow (p = 0.022 and p = 0.004, respectively), their level of satisfaction with the gel pillow correlating significantly with excessive daytime sleepiness (r2 = 0.19; p = 0.0443). CONCLUSIONS:: Among obstructive sleep apnea patients treated with nasal CPAP, the use of a gel pillow with side cutouts appears to have no impact on treatment effectiveness. Nevertheless, such patients seem to prefer a gel pillow over other types of pillows. OBJETIVO:: Determinar se o uso de um travesseiro de gel com recortes laterais para acomodar a máscara de continuous positive airway pressure (CPAP, pressão positiva contínua nas vias aéreas) e diminuir a temperatura em torno da cabeça melhora a eficácia do tratamento com auto-CPAP e a adesão dos pacientes ao tratamento. MÉTODOS:: Foram incluídos no estudo 23 pacientes consecutivos com apneia obstrutiva do sono que nunca haviam recebido tratamento com CPAP. Os pacientes receberam um aparelho de auto-CPAP com uma máscara apropriada e foram instruídos a usar CPAP durante 15 noites. Foram também instruídos a dormir com seu próprio travesseiro (o travesseiro controle) nas 5 primeiras noites e com um travesseiro de espuma ou um travesseiro de gel, ambos com recortes laterais, durante 5 noites consecutivas cada, em ordem aleatória. Depois da 15ª noite, os dados registrados nos aparelhos de auto-CPAP foram baixados e os pacientes determinaram seu grau de satisfação com cada travesseiro por meio de uma escala visual analógica. RESULTADOS:: Vinte e dois pacientes completaram o protocolo. Não houve diferenças entre os períodos durante os quais cada travesseiro foi usado quanto às pressões administradas, índice de apneia-hipopneia residual, vazamentos de ar e média de duração da CPAP. Os pacientes ficaram significativamente mais satisfeitos com o travesseiro de gel do que com o travesseiro controle e o travesseiro de espuma (p = 0,022 e p = 0,004, respectivamente), com correlação entre o grau de satisfação com o travesseiro de gel e a sonolência diurna excessiva (r2 = 0,19; p = 0,0443). CONCLUSÕES:: Em pacientes com apneia obstrutiva do sono tratados com CPAP nasal, o uso de um travesseiro de gel com recortes laterais aparentemente não tem nenhum impacto na eficácia do tratamento. No entanto, esses pacientes aparentemente preferem um travesseiro de gel a outros tipos de travesseiros.
Assuntos
Roupas de Cama, Mesa e Banho , Pressão Positiva Contínua nas Vias Aéreas/instrumentação , Desenho de Equipamento/instrumentação , Apneia Obstrutiva do Sono/terapia , Feminino , Géis , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente/estatística & dados numéricos , Apneia Obstrutiva do Sono/fisiopatologia , Resultado do TratamentoRESUMO
ABSTRACT Objective: To determine whether the use of a gel pillow with side cutouts designed to accommodate a continuous positive airway pressure (CPAP) mask and reduce head temperature improves the efficacy of and adherence to auto-CPAP therapy. Methods: Twenty-three consecutive CPAP-naïve patients with obstructive sleep apnea were enrolled in the study. Patients were given an auto-CPAP machine with an appropriate CPAP mask and were instructed to use CPAP for 15 nights. They were instructed to sleep with their own pillow (the control pillow) from nights 1 to 5 and with either a foam pillow or a gel pillow, both of which had side cutouts, for 5 consecutive nights each, in random order. After night 15, auto-CPAP machine data were downloaded and patients rated their satisfaction with each pillow on a visual analog scale. Results: Twenty-two patients completed the protocol. The pressures administered, residual apnea-hypopnea index, air leaks, and mean duration of CPAP use did not differ among the periods during which each pillow was used. Patients were significantly more satisfied with the gel pillow than with the control pillow and the foam pillow (p = 0.022 and p = 0.004, respectively), their level of satisfaction with the gel pillow correlating significantly with excessive daytime sleepiness (r2 = 0.19; p = 0.0443). Conclusions: Among obstructive sleep apnea patients treated with nasal CPAP, the use of a gel pillow with side cutouts appears to have no impact on treatment effectiveness. Nevertheless, such patients seem to prefer a gel pillow over other types of pillows.
RESUMO Objetivo: Determinar se o uso de um travesseiro de gel com recortes laterais para acomodar a máscara de continuous positive airway pressure (CPAP, pressão positiva contínua nas vias aéreas) e diminuir a temperatura em torno da cabeça melhora a eficácia do tratamento com auto-CPAP e a adesão dos pacientes ao tratamento. Métodos: Foram incluídos no estudo 23 pacientes consecutivos com apneia obstrutiva do sono que nunca haviam recebido tratamento com CPAP. Os pacientes receberam um aparelho de auto-CPAP com uma máscara apropriada e foram instruídos a usar CPAP durante 15 noites. Foram também instruídos a dormir com seu próprio travesseiro (o travesseiro controle) nas 5 primeiras noites e com um travesseiro de espuma ou um travesseiro de gel, ambos com recortes laterais, durante 5 noites consecutivas cada, em ordem aleatória. Depois da 15ª noite, os dados registrados nos aparelhos de auto-CPAP foram baixados e os pacientes determinaram seu grau de satisfação com cada travesseiro por meio de uma escala visual analógica. Resultados: Vinte e dois pacientes completaram o protocolo. Não houve diferenças entre os períodos durante os quais cada travesseiro foi usado quanto às pressões administradas, índice de apneia-hipopneia residual, vazamentos de ar e média de duração da CPAP. Os pacientes ficaram significativamente mais satisfeitos com o travesseiro de gel do que com o travesseiro controle e o travesseiro de espuma (p = 0,022 e p = 0,004, respectivamente), com correlação entre o grau de satisfação com o travesseiro de gel e a sonolência diurna excessiva (r2 = 0,19; p = 0,0443). Conclusões: Em pacientes com apneia obstrutiva do sono tratados com CPAP nasal, o uso de um travesseiro de gel com recortes laterais aparentemente não tem nenhum impacto na eficácia do tratamento. No entanto, esses pacientes aparentemente preferem um travesseiro de gel a outros tipos de travesseiros.
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Roupas de Cama, Mesa e Banho , Apneia Obstrutiva do Sono/terapia , Pressão Positiva Contínua nas Vias Aéreas/instrumentação , Desenho de Equipamento/instrumentação , Resultado do Tratamento , Satisfação do Paciente/estatística & dados numéricos , Apneia Obstrutiva do Sono/fisiopatologia , GéisRESUMO
STUDY OBJECTIVES: There is a growing interest to develop a simple method to characterize the mechanisms leading to upper airway collapse in order to guide treatment options in patients with obstructive sleep apnea (OSA). Critical closing pressure (Pcrit) during sleep is able to predict the anatomical component of OSA. However, Pcrit is a laborious method that is only used for research purposes. The application of negative expiratory pressure (NEP) is a simple method to assess upper airway collapsibility that can be easily performed during wakefulness. We hypothesized that NEP will be, similarly to Pcrit, associated with upper airway anatomy assessed by computed tomography (CT) scan. METHODS: Patients under investigation for OSA underwent polysomnography, CT of the upper airway, NEP while awake, and Pcrit during sleep. NEP was performed with -5 cm H2O in supine position using a nasal mask. Pcrit was measured during sleep induced by low doses of midazolam. RESULTS: Twenty-eight male subjects were studied (age 45 ± 13 y, body mass index 29.4 ± 4.9 kg/m2, apnea-hypopnea index (AHI) 30 ± 26, range 2 to 86 events/h). NEP and Pcrit were similarly associated with tongue area (r = 0.646 and r = 0.585), tongue volume (r = 0.565 and r = 0.613) and pharyngeal length (r = 0.580 and r = 0.611), respectively (p < 0.05 for all comparisons). NEP and Pcrit were also significantly correlated with AHI (r = 0.490 and r = 0.531). NEP and Pcrit were significantly higher in patients with severe OSA than the remaining population. CONCLUSIONS: NEP is a simple and promising method that is associated with the anatomical component of upper airway collapsibility. NEP may be valuable to select patients for noncontinuous positive airway pressure alternative therapies for OSA.
Assuntos
Obstrução das Vias Respiratórias/fisiopatologia , Expiração/fisiologia , Faringe/anatomia & histologia , Faringe/fisiopatologia , Apneia Obstrutiva do Sono/fisiopatologia , Vigília , Adolescente , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Faringe/diagnóstico por imagem , Polissonografia , Pressão , Apneia Obstrutiva do Sono/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
BACKGROUND: Chronic kidney disease (CKD) is one of the most serious public health problems. The increasing prevalence of CKD in developed and developing countries has led to a global epidemic. The hypothesis proposed is that patients undergoing dialysis would experience a marked negative influence on physiological variables of sleep and autonomic nervous system activity, compromising quality of life. METHODS/DESIGN: A prospective, consecutive, double blind, randomized controlled clinical trial is proposed to address the effect of dialysis on sleep, pulmonary function, respiratory mechanics, upper airway collapsibility, autonomic nervous activity, depression, anxiety, stress and quality of life in patients with CKD. The measurement protocol will include body weight (kg); height (cm); body mass index calculated as weight/height(2); circumferences (cm) of the neck, waist, and hip; heart and respiratory rates; blood pressures; Mallampati index; tonsil index; heart rate variability; maximum ventilatory pressures; negative expiratory pressure test, and polysomnography (sleep study), as well as the administration of specific questionnaires addressing sleep apnea, excessive daytime sleepiness, depression, anxiety, stress, and quality of life. DISCUSSION: CKD is a major public health problem worldwide, and its incidence has increased in part by the increased life expectancy and increasing number of cases of diabetes mellitus and hypertension. Sleep disorders are common in patients with renal insufficiency. Our hypothesis is that the weather weight gain due to volume overload observed during interdialytic period will influence the degree of collapsibility of the upper airway due to narrowing and predispose to upper airway occlusion during sleep, and to investigate the negative influences of haemodialysis in the physiological variables of sleep, and autonomic nervous system, and respiratory mechanics and thereby compromise the quality of life of patients. TRIAL REGISTRATION: The protocol for this study is registered with the Brazilian Registry of Clinical Trials (ReBEC RBR-7yhr4w and World Health Organization under Universal Trial Number UTN: U1111-1127-9390 [http://www.ensaiosclinicos.gov.br/rg/RBR-7yhr4w/]).
Assuntos
Doenças Cardiovasculares/mortalidade , Depressão/epidemiologia , Falência Renal Crônica/mortalidade , Falência Renal Crônica/reabilitação , Diálise Renal/psicologia , Apneia Obstrutiva do Sono/mortalidade , Estresse Psicológico/epidemiologia , Adolescente , Adulto , Ansiedade/epidemiologia , Ansiedade/mortalidade , Ansiedade/fisiopatologia , Sistema Nervoso Autônomo/fisiopatologia , Brasil/epidemiologia , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/fisiopatologia , Comorbidade , Depressão/fisiopatologia , Método Duplo-Cego , Feminino , Humanos , Falência Renal Crônica/diagnóstico , Masculino , Pessoa de Meia-Idade , Polissonografia/estatística & dados numéricos , Prevalência , Estudos Prospectivos , Qualidade de Vida , Testes de Função Respiratória/estatística & dados numéricos , Mecânica Respiratória , Fatores de Risco , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/fisiopatologia , Estresse Psicológico/fisiopatologia , Taxa de Sobrevida , Adulto JovemRESUMO
Workers in the transportation industry are at greater risk of an incorrect diet and sedentary behavior. The aim of our study was to characterize a population of professional bus drivers with regard to clinical and demographic variables, lipid profile, and the presence of cardiovascular risk factors. Data from 659 interstate bus drivers collected retrospectively, including anthropometric characteristics, systolic and diastolic blood pressure, lipid profile, fasting blood glucose, meatoscopy, and audiometry. All participants were male, with a mean age of 41.7 ± 6.9 years, weight of 81.4 ± 3.3 kg, and BMI 27.2 ± 3.3 Kg/m²; the mean abdominal and neck circumferences were 94.4 ± 8.6 cm and 38.9 ± 2.2 cm; 38.2% of the sample was considered hypertensive; mean HDL cholesterol was 47.9 ± 9.5 mg/dL, mean triglyceride level was 146.3 ± 87.9 mg/dL, and fasting glucose was above 100 mg/dL in 249 subjects (39.1%). Drivers exhibited reduced audiometric hearing at 4-8 kHz, being all sensorineural hearing loss. The clinical characterization of a young male population of interstate bus drivers revealed a high frequency of cardiovascular risk factors, as obesity, hypertension, hyperlipidemia, and hyperglycemia, as well as contributing functional characteristics, such as a low-intensity activity, sedentary behavior, long duration in a sitting position, and high-calorie diet, which lead to excessive weight gain and associated comorbidities.
Assuntos
Condução de Veículo/estatística & dados numéricos , Tamanho Corporal , Doenças Cardiovasculares/epidemiologia , Hiperlipidemias/epidemiologia , Hipertensão/epidemiologia , Veículos Automotores/estatística & dados numéricos , Obesidade/epidemiologia , Adulto , Distribuição por Idade , Brasil/epidemiologia , Comorbidade , Humanos , Masculino , Prevalência , Fatores de RiscoRESUMO
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. TRIAL REGISTRATION: Registro Brasileiro de Ensaios Clinicos (local acronym RBEC) [Internet]: Rio de Janeiro (RJ): Instituto de Informaçao Cientifica e Tecnologica em Saude (Brazil); 2010 - Identifier RBR-7dq5xx. Cross-sectional study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers; 2011 May 31 [7 pages]. Available from http://www.ensaiosclinicos.gov.br/rg/RBR-7dq5xx/.
Assuntos
Doenças Cardiovasculares/epidemiologia , Síndrome Metabólica/epidemiologia , Veículos Automotores , Apneia Obstrutiva do Sono/diagnóstico , Adulto , Estudos Transversais , Humanos , Masculino , Programas de Rastreamento , Observação , Polissonografia , Reprodutibilidade dos Testes , Projetos de Pesquisa , Apneia Obstrutiva do Sono/epidemiologia , Espirometria , Inquéritos e QuestionáriosRESUMO
The objective of this article was to describe a new method for assessing expiratory flow limitation during spontaneous breathing, using the negative expiratory pressure test to identify patients at risk for obstructive sleep apnea. Upper airway collapsibility is evaluated by measuring decreases in flow and in expired volume in the first 0.2 seconds after negative expiratory pressure application at 10 cmH2O. The negative expiratory pressure test is easily applied and could be adopted for the evaluation of expiratory flow limitation caused by upper airway obstruction in patients with obstructive sleep apnea.
Assuntos
Fluxo Expiratório Forçado/fisiologia , Testes de Função Respiratória/métodos , Apneia Obstrutiva do Sono/diagnóstico , HumanosRESUMO
OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea. METHODS: Flow limitation was evaluated in 155 subjects. All subjects underwent a diurnal negative expiratory pressure test and a nocturnal sleep study. The severity of sleep apnea was determined based on the apnea-hypopnea index. Flow limitation was assessed by computing the exhaled volume at 0.2, 0.5, and 1.0 s (V0.2, V0.5, and V1.0, respectively) during the application of a negative expiratory pressure and expressed as a percentage of the previous exhaled volume. Receiver-operating characteristic curves were constructed to identify the optimal threshold volume at 0.2, 0.5, and 1.0 s for obstructive sleep apnea detection. RESULTS: Mean expiratory volumes at 0.2 and 0.5 s were statistically higher (p <0.01) in healthy subjects than in all obstructive sleep apneic groups. Increasing disease severity was associated with lower expiratory volumes. The V0.2 (%) predictive parameters for the detection of sleep apnea were sensitivity (81.1%), specificity (93.1%), PPV (98.1%), and NPV (52.9%). Sensitivity and NPV were 96.9% and 93.2%, respectively, for moderate-to-severe obstructive sleep apnea, and both were 100% for severe obstructive sleep apnea. CONCLUSION: Flow limitation measurement by V 0.2 (%) during wakefulness may be a very reliable method to identify obstructive sleep apnea when the test is positive and could reliably exclude moderate and severe obstructive sleep apnea when the test is negative. The negative expiratory pressure test appears to be a useful screening test for suspected obstructive sleep apnea.
Assuntos
Polissonografia/efeitos adversos , Apneia Obstrutiva do Sono/diagnóstico , Vigília/fisiologia , Diagnóstico por Computador/métodos , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia/métodos , Ventilação Pulmonar/fisiologia , Fatores de Risco , Apneia Obstrutiva do Sono/etiologia , Volume de Ventilação Pulmonar/fisiologiaRESUMO
O objetivo deste artigo foi descrever um novo método para avaliar a limitação ao fluxo expiratório durante a respiração espontânea, possibilitando a identificação do risco para apneia obstrutiva do sono através do teste de pressão negativa expiratória. A colapsabilidade da via aérea superior é avaliada pela medida da queda de fluxo e de volume expirado a 0,2 segundos imediatamente após a aplicação de pressão negativa expiratória de 10 cmH2O. O teste de pressão negativa expiratória é de fácil aplicação e poderia ser utilizado na avaliação da limitação ao fluxo expiratório causada por obstrução da via aérea superior em sujeitos portadores de apneia obstrutiva do sono.
The objective of this article was to describe a new method for assessing expiratory flow limitation during spontaneous breathing, using the negative expiratory pressure test to identify patients at risk for obstructive sleep apnea. Upper airway collapsibility is evaluated by measuring decreases in flow and in expired volume in the first 0.2 seconds after negative expiratory pressure application at 10 cmH2O. The negative expiratory pressure test is easily applied and could be adopted for the evaluation of expiratory flow limitation caused by upper airway obstruction in patients with obstructive sleep apnea.
Assuntos
Humanos , Fluxo Expiratório Forçado/fisiologia , Testes de Função Respiratória/métodos , Apneia Obstrutiva do Sono/diagnósticoRESUMO
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 (ΔV) and expiratory volume were measured in the first 0.2 s (V(0.2)) of the negative expiratory pressure test. RESULTS: ΔV (%) and V(0.2) (%) 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% of the inspired volume compared to 34.2% for the normal subjects. Analysis of the receiver operating characteristics showed that V(0.2) (%) and ΔV (%) could accurately identify severe OSA in subjects with sensitivities of 95.8% and 91.7%, respectively, and specificities of 95.8% and 91.7%, respectively. CONCLUSIONS: V(0.2) (%) and ΔV (%) 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.
Assuntos
Obstrução das Vias Respiratórias/fisiopatologia , Testes de Função Respiratória/efeitos adversos , Apneia Obstrutiva do Sono/fisiopatologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Testes de Função Respiratória/métodos , Índice de Gravidade de Doença , Apneia Obstrutiva do Sono/patologiaRESUMO
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.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obstrução das Vias Respiratórias/fisiopatologia , Testes de Função Respiratória/efeitos adversos , Apneia Obstrutiva do Sono/fisiopatologia , Estudos de Casos e Controles , Valor Preditivo dos Testes , Testes de Função Respiratória/métodos , Índice de Gravidade de Doença , Apneia Obstrutiva do Sono/patologiaRESUMO
OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea. METHODS: Flow limitation was evaluated in 155 subjects. All subjects underwent a diurnal negative expiratory pressure test and a nocturnal sleep study. The severity of sleep apnea was determined based on the apneahypopnea index. Flow limitation was assessed by computing the exhaled volume at 0.2, 0.5, and 1.0 s (V0.2, V0.5, and V1.0, respectively) during the application of a negative expiratory pressure and expressed as a percentage of the previous exhaled volume. Receiver-operating characteristic curves were constructed to identify the optimal threshold volume at 0.2, 0.5, and 1.0 s for obstructive sleep apnea detection. RESULTS: Mean expiratory volumes at 0.2 and 0.5 s were statistically higher (p <0.01) in healthy subjects than in all obstructive sleep apneic groups. Increasing disease severity was associated with lower expiratory volumes. The V0.2 ( percent) predictive parameters for the detection of sleep apnea were sensitivity (81.1 percent), specificity (93.1 percent), PPV (98.1 percent), and NPV (52.9 percent). Sensitivity and NPV were 96.9 percent and 93.2 percent, respectively, for moderate-to-severe obstructive sleep apnea, and both were 100 percent for severe obstructive sleep apnea. CONCLUSION: Flow limitation measurement by V 0.2 ( percent) during wakefulness may be a very reliable method to identify obstructive sleep apnea when the test is positive and could reliably exclude moderate and severe obstructive sleep apnea when the test is negative. The negative expiratory pressure test appears to be a useful screening test for suspected obstructive sleep apnea.