Objetivos: Determinar o tempo de espera para o diagnóstico e início do tratamento da síndrome da apneia obstrutiva do sono (SAOS) em hospital público brasileiro. Desenho do estudo: Estudo transversal. Métodos: Foi avaliada, com um questionário específico, uma amostra de conveniência composta por 68 pacientes com síndrome da apneia obstrutiva do sono (SAOS), com indicação de tratamento com pressão positiva em vias aéreas (PAP) e que utilizaram o aparelho durante acompanhamento ambulatorial, no período de janeiro de 2005 a dezembro de 2009. Foram excluídos os pacientes menores de 18 anos, incapazes de responder ao questionário ou que se negaram a participar. Resultados: Dos pacientes avaliados, a maioria era de homens (62%), com média de idade de 54,4 (+ 10,7) anos e obesos (IMC médio 33,7 + 7,1 Kg/m2); 76% eram hipertensos, 22% portadores de diabete melito e igual número de doença arterial coronariana; 10% destes apresentavam hipoventilação associada. A mediana do tempo entre a primeira consulta médica e a realização da PSG diagnóstica foi de 8,3 (intervalos interquartis [IQ] 3,3-14,3) meses e a mediana do tempo da indicação da PAP até a aquisição do aparelho foi de 10,5 (IQ 3,1-16,7) meses. Sessenta e quatro pacientes (94%) eram usuários de CPAP e 4 usuários de bilevel (6%). A maioria dos aparelhos (57%) foi obtida de forma gratuita por meio da rede pública de saúde. Conclusão: O presente estudo evidenciou a demora excessiva para diagnóstico e tratamento dos pacientes portadores de SAOS em atendimento em um hospital público de referência no Brasil. / Objectives: To determine the waiting time for the diagnosis and beginning of treatment of syndrome of obstructive sleep apnea (OSA) in Brazilian public hospital. Study design: cross-sectional study Methods: A convenience sample composed of 68 patients with syndrome of obstructive sleep apnea (OSA) was assessed through a specific questionnaire. All patients were indicated a treatment with positive airway pressure (PAP) and that used the unit during de period between January 2005 and December 2009. Patients who were under 18 years old, who were uncapable of answering the questionnaire or who refused to answer were excluded. Results: Among the patients, the majority were men (62%), with an average age of 54.4 (+10.7) years and obese (mean BMI 33.7 + 7.1 kg/m2); 76% were hypertensive, 22% diabetes mellitus patients and an equal number with coronary artery disease, 10% of them had associated hypoventilation. The average time between the first medical consultation and the implementation of diagnostic PSG was 8.3 (interquartile range [IQ] 3.3 to 14.3) months and the average time indication of the PAP until the purchase of the equipment was 10,5 (CI 3.1 to 16.7) months. Sixty-four patients (94%) were users of CPAP and 4 were users of bilevel (6%). Most appliances (57%) were obtained free of charge through the public health system. Conclusion: The present study demonstrated the excessive delay to diagnosis and treatment of patients with OSAS in attendance at a public hospital of reference in Brazil.

Background: Positive expiratory pressure (PEP) and continuous positive airway pressure (CPAP) are two forms of resistance breathing used in spontaneously breathing patients. With a threshold resistor or a flow resistor, both PEP and CPAP provide a positive (elevated) pressure level during the expiratory phase. With PEP, inspiratory pressure is negative, i.e. lower than ambient air pressure, as during a normal inspiration, but with CPAP, the inspiratory pressure is positive, i.e. higher than ambient air pressure. Methods: This thesis is based on four separate studies in which four different breathing devices, a PEP-bottle (threshold resistor device), a PEP-mask (flow resistor device), a threshold resistor CPAP and a flow resistor device were investigated. Paper I, II and III are based on studies in healthy volunteers. Paper IV is a bench study performed in a hypobaric chamber. Paper I examined differences between two PEP devices, the PEP-bottle and the PEP-mask. Paper II evaluated the performance of a flow resistor CPAP device, (Boussignac CPAP). Paper III investigated the effect of two PEP-devices, a PEP-bottle and a PEP-mask and two CPAP devices, a threshold resistor CPAP and a flow resistor CPAP, on inspiratory capacity (IC). In paper IV, the effect of changes in ambient pressure on preset CPAP levels in two different CPAP devices was compared. Results: With the PEP bottle, both expiration and inspiration began with a zero-flow period during which airway pressure changed rapidly. With the PEP-mask, the zero-flow period was very short and the change in airway pressure almost non-existent (paper I). During normal breathing with the Boussignac CPAP, changes in airway pressure were never large enough to reduce airway pressure below zero. During forced breathing, as airflow increased, both the drop in inspiratory airway pressure and the increase in expiratory airway pressure were potentiated (paper II). IC decreased significantly with three of the breathing devices, the PEP-mask and the two CPAP devices (paper III). With the threshold resistor CPAP, measured pressure levels were close to the preset CPAP level. With the flow resistor CPAP, as the altitude increased CPAP produced pressure levels increased (paper IV). Conclusion: The effect on airway pressure, airflow, IC and the effect of changes in ambient air pressure differ between different kinds of resistance breathing devices. These differences in device performance should be taken into consideration when choosing the optimal resistance breathing device for each patient.

Objetivos: Determinar o tempo de espera para o diagnóstico e início do tratamento da síndrome da apneia obstrutiva do sono (SAOS) em hospital público brasileiro. Desenho do estudo: Estudo transversal. Métodos: Foi avaliada, com um questionário específico, uma amostra de conveniência composta por 68 pacientes com síndrome da apneia obstrutiva do sono (SAOS), com indicação de tratamento com pressão positiva em vias aéreas (PAP) e que utilizaram o aparelho durante acompanhamento ambulatorial, no período de janeiro de 2005 a dezembro de 2009. Foram excluídos os pacientes menores de 18 anos, incapazes de responder ao questionário ou que se negaram a participar. Resultados: Dos pacientes avaliados, a maioria era de homens (62%), com média de idade de 54,4 (+ 10,7) anos e obesos (IMC médio 33,7 + 7,1 Kg/m2); 76% eram hipertensos, 22% portadores de diabete melito e igual número de doença arterial coronariana; 10% destes apresentavam hipoventilação associada. A mediana do tempo entre a primeira consulta médica e a realização da PSG diagnóstica foi de 8,3 (intervalos interquartis [IQ] 3,3-14,3) meses e a mediana do tempo da indicação da PAP até a aquisição do aparelho foi de 10,5 (IQ 3,1-16,7) meses. Sessenta e quatro pacientes (94%) eram usuários de CPAP e 4 usuários de bilevel (6%). A maioria dos aparelhos (57%) foi obtida de forma gratuita por meio da rede pública de saúde. Conclusão: O presente estudo evidenciou a demora excessiva para diagnóstico e tratamento dos pacientes portadores de SAOS em atendimento em um hospital público de referência no Brasil. / Objectives: To determine the waiting time for the diagnosis and beginning of treatment of syndrome of obstructive sleep apnea (OSA) in Brazilian public hospital. Study design: cross-sectional study Methods: A convenience sample composed of 68 patients with syndrome of obstructive sleep apnea (OSA) was assessed through a specific questionnaire. All patients were indicated a treatment with positive airway pressure (PAP) and that used the unit during de period between January 2005 and December 2009. Patients who were under 18 years old, who were uncapable of answering the questionnaire or who refused to answer were excluded. Results: Among the patients, the majority were men (62%), with an average age of 54.4 (+10.7) years and obese (mean BMI 33.7 + 7.1 kg/m2); 76% were hypertensive, 22% diabetes mellitus patients and an equal number with coronary artery disease, 10% of them had associated hypoventilation. The average time between the first medical consultation and the implementation of diagnostic PSG was 8.3 (interquartile range [IQ] 3.3 to 14.3) months and the average time indication of the PAP until the purchase of the equipment was 10,5 (CI 3.1 to 16.7) months. Sixty-four patients (94%) were users of CPAP and 4 were users of bilevel (6%). Most appliances (57%) were obtained free of charge through the public health system. Conclusion: The present study demonstrated the excessive delay to diagnosis and treatment of patients with OSAS in attendance at a public hospital of reference in Brazil.

Objetivos: Determinar o tempo de espera para o diagnóstico e início do tratamento da síndrome da apneia obstrutiva do sono (SAOS) em hospital público brasileiro. Desenho do estudo: Estudo transversal. Métodos: Foi avaliada, com um questionário específico, uma amostra de conveniência composta por 68 pacientes com síndrome da apneia obstrutiva do sono (SAOS), com indicação de tratamento com pressão positiva em vias aéreas (PAP) e que utilizaram o aparelho durante acompanhamento ambulatorial, no período de janeiro de 2005 a dezembro de 2009. Foram excluídos os pacientes menores de 18 anos, incapazes de responder ao questionário ou que se negaram a participar. Resultados: Dos pacientes avaliados, a maioria era de homens (62%), com média de idade de 54,4 (+ 10,7) anos e obesos (IMC médio 33,7 + 7,1 Kg/m2); 76% eram hipertensos, 22% portadores de diabete melito e igual número de doença arterial coronariana; 10% destes apresentavam hipoventilação associada. A mediana do tempo entre a primeira consulta médica e a realização da PSG diagnóstica foi de 8,3 (intervalos interquartis [IQ] 3,3-14,3) meses e a mediana do tempo da indicação da PAP até a aquisição do aparelho foi de 10,5 (IQ 3,1-16,7) meses. Sessenta e quatro pacientes (94%) eram usuários de CPAP e 4 usuários de bilevel (6%). A maioria dos aparelhos (57%) foi obtida de forma gratuita por meio da rede pública de saúde. Conclusão: O presente estudo evidenciou a demora excessiva para diagnóstico e tratamento dos pacientes portadores de SAOS em atendimento em um hospital público de referência no Brasil. / Objectives: To determine the waiting time for the diagnosis and beginning of treatment of syndrome of obstructive sleep apnea (OSA) in Brazilian public hospital. Study design: cross-sectional study Methods: A convenience sample composed of 68 patients with syndrome of obstructive sleep apnea (OSA) was assessed through a specific questionnaire. All patients were indicated a treatment with positive airway pressure (PAP) and that used the unit during de period between January 2005 and December 2009. Patients who were under 18 years old, who were uncapable of answering the questionnaire or who refused to answer were excluded. Results: Among the patients, the majority were men (62%), with an average age of 54.4 (+10.7) years and obese (mean BMI 33.7 + 7.1 kg/m2); 76% were hypertensive, 22% diabetes mellitus patients and an equal number with coronary artery disease, 10% of them had associated hypoventilation. The average time between the first medical consultation and the implementation of diagnostic PSG was 8.3 (interquartile range [IQ] 3.3 to 14.3) months and the average time indication of the PAP until the purchase of the equipment was 10,5 (CI 3.1 to 16.7) months. Sixty-four patients (94%) were users of CPAP and 4 were users of bilevel (6%). Most appliances (57%) were obtained free of charge through the public health system. Conclusion: The present study demonstrated the excessive delay to diagnosis and treatment of patients with OSAS in attendance at a public hospital of reference in Brazil.

A pressão positiva contínua nas vias aéreas(CPAP) é a forma mais simples de ventilação não invasiva. O objetivo deste estudo é comparar o desempenho de dois modelos de gerador de fluxo com um ventilador projetado especificamente para ventilação não invasiva no modo CPAP, através de um modelo mecânico de pulmão e em voluntários sadios, em três diferentes alimentações de pressão e em CPAP de 5, 10 e 15 cm H2O. Conclui-se que os geradores de fluxo têm capacidade similar ao ventilador específico para manter o nível de CPAP, se ajustados para sua melhor pressão de alimentação, que foi ao redor de 100 L/min / Continuous positive airway pressure (CPAP) is the simplest form of noninvasive ventilation. Mechanical ventilators designed to invasive ventilation, ventilators specifically designed to noninvasive ventilation (NIV-Ventilator) and continuous flow generators can provide CPAP. The objectives of this study is compare the performance of two continuous flow generators with a ventilator designed to NIV to deliver continuous positive airway pressure (CPAP) and compare flow generators using different oxygen pressure supplies in lung model and healthy subjects, in CPAP of 5, 10 and 15 cm H2O. It was observed that flow generators had similar performance to noninvasive ventilator if they were adjust in their best output flow, that was around 100 L/min

Orientadores: Ivete Alonso Bredda Saad, Lair Zambon / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T00:25:19Z (GMT). No. of bitstreams: 1 Passarini_JulianaNalindeSouza_M.pdf: 2072157 bytes, checksum: 3d2a54d3e91c2db910e546c24bcdb356 (MD5) Previous issue date: 2012 / Resumo: O objetivo deste estudo foi analisar os casos de insuficiência respiratória aguda (IRpA) decorrente do Edema Agudo de Pulmão (EAP) e agudização da Doença Pulmonar Obstrutiva Crônica (DPOC) submetidos a ventilação mecânica não invasiva (VNI) a fim de identificar fatores associados ao sucesso ou insucesso do método em um serviço de urgência e emergência. Trata-se de um estudo descritivo e analítico prospectivo. Estabeleceu-se uma pressão expiratória entre 5 e 8 cmH2O, e pressão inspiratória entre 10 e 12 cmH2O, com suplementação de oxigênio para manter a saturação periférica de oxigênio (SpO2) superior a 90%. A variável desfecho considerada foi a intubação endotraqueal (IE). Foram incluídos 152 pacientes, o tempo de VNI foi de 10 horas para os pacientes com DPOC (n=60) e de 7,5 para os pacientes com EAP (n=92). Foi observada diferença estatisticamente significante nos pacientes que evoluíram para IE quanto menor SpO2 e pior escore de APACHE II (p<0,001). O uso de BiPAP mostrou 2,3 vezes mais chance de ocorrência de IE em comparação com os pacientes que usaram CPAP (p=0,032). Entre os pacientes com diagnóstico de EAP a chance de evolução para IE foi 63% menor. Dos 152 casos, 75,7% evoluíram com sucesso. As variáveis associadas a IE foram taquipneia, SpO2 abaixo de 80%, pacientes que receberam BiPAP, com maior valor de APACHE II, menor valor de escala de coma de Glasgow (ECG) e aqueles com diagnóstico de DPOC / Abstract: The objective of this study was to analyze the cases of acute respiratory failure (ARF) due to acute pulmonary edema and acute exacerbation of Chronic Obstructive Pulmonary Disease (COPD) undergoing noninvasive ventilation (NIV) to identify factors associated with success or failure of the method in an emergency department. This is a prospective descriptive and analytical study. It was established an expiratory pressure of 5 to 8 cmH2O, inspiratory pressure of 10 to 12 cmH2O and supplemental oxygen to maintain oxygen saturation (SpO2) above 90%. The outcome variable was considered endotracheal intubation (EI). The study included 152 patients NIV time was 10 hours for COPD patients (n = 60) and 7.5 hours to APE patients (n = 92). Statistically significant difference was observed in patients who developed EI for the lower SpO2 and worse APACHE II score (p <0.001). The use of BiPAP showed 2.3 times greater chance of occurrence of IE compared with patients who used CPAP (p = 0.032). Among patients diagnosed with EAP the chance of developing into IE was 63% lower. Of the 152 cases, 75.7% progressed successfully. Variables associated with IE were tachypnea, SpO2 below 80%, patients who received BiPAP, with the highest APACHE II, lower value of Glasgow coma scale (GCS) and those diagnosed with COPD / Mestrado / Fisiopatologia Cirúrgica / Mestre em Ciências

Introduction: During cardiac surgery several factors contribute to the development of pulmonary complications and the installation of postoperative comorbidities. Non-invasive Ventilation (NIV) is being used as promising therapeutic instrument to improve the functionality in this cases. Objective: To evaluate the functional capacity of patients in the postoperative period of myocardial revascularization and heart valve replacement submitted to non-invasive prophylactic ventilation. Method: Randomized controlled clinical trial developed in four groups of patients submitted to two cardiac surgeries: Revascularization and Valve Replacement. It was enrolled patients of both genders, aged 20 to 70 years. In the revascularized group, the sample consisted of 40 patients, assigned to the Experimental Group (GE) with 21 patients and Control Group (CG) with 19 patients. The group undergoing valve replacement was composed of 50 patients, 25 in the GE and 25 in the CG. At the time of hospital admission, the patient underwent a preoperative evaluation, which included patient identification, vital signs, clinical diagnosis, type of surgery, personal history, medication and ejection fraction and Functional Independence Measure (MIF). After the surgical procedure, the patients were referred to the Intensive Care Unit (ICU) and submitted to the standard physiotherapeutic treatment. Patients enrolled in experimental groups, also used NIV in the CPAP mode, 3 times within the first 26 hours after extubation, with positive pressure of 10 cmH2O and treatment duration of 1h each application. A functional reevaluation was made on the 3rd and 5th postoperative day (POD) and in the 7th POD/ discharge hospital day, besides the functional evaluation, the 6-minute walk test (6MWT) and gait velocity test (T10) was performed. It was also monitored the length of surgery, extracorporeal circulation, ICU and hospital stay, in addition to the postoperative ejection fraction of both groups. Results: In the group of revascularized patients, the TC6 analysis presented a difference between groups, where the GC 207.05 ± 68.8 meters and the GE 284.73 ± 94.8 meters (p = 0.006). The variable T10 also presented difference, where the GC 0.68 ± 0.22 m / s and the GE 1.08 ± 0.39 m / s (p <0.0001). The total MIF at hospital discharge was 117.19 ± 11.04 and the GC was 82.52 ± 13.26 (p = 0.01). There was no difference in ICU and hospital admission times between groups. The heart valve replacement patients groups, the 6MWT analysis also showed a significance diference between groups, the GC 264.34 ± 76 meters and the GE 334.07 ± 71 meters (p = 0.002). On the other hand, the analysis of T10, MIF and ICU and hospital admission times did not present differences between the groups. Conclusion: NIV as a therapeutic resource proved to be effective, suggesting an improvement in the functionality of the patients studied in the postoperative period of cardiac surgery, however, it did not influence the length of ICU stay or the general time of hospitalization of the patients with cardiopathy. Brazilian Registry of Clinical Trials RBR - 8bxdd3. / Introdução: A cirurgia cardíaca está atrelada a alguns fatores que contribuem para o desenvolvimento de complicações pulmonares e instalação de comorbidades pós-operatórias. A Ventilação Não Invasiva (VNI) é um recurso terapêutico utilizado na melhora da funcionalidade deste tipo de paciente. Objetivo: Avaliar a capacidade funcional de pacientes no pós-operatório de revascularização do miocárdio e de troca valvar cardíaca submetidos à ventilação não invasiva profilática. Método: Ensaio clínico controlado, randomizado, desenvolvido em dois grupos de cirurgias cardíacas: Revascularização (RM) e Troca Valvar (TV), em indivíduos de ambos os sexos, com idade de 20 a 70 anos. No grupo dos revascularizados, a amostra foi composta por 40 pacientes, alocados em Grupo Experimental (GE) com 21 pacientes e Grupo Controle (GC) com 19 pacientes. Já o grupo submetido à troca valvar foi composto por 50 pacientes, sendo 25 no GE e 25 no GC. No momento da internação hospitalar o paciente foi submetido a uma avaliação pré-operatória, que constava da sua identificação, sinais vitais, diagnóstico clínico, tipo de cirurgia, antecedentes pessoais, medicamentos e fração de ejeção e Medida de Independência Funcional (MIF). Após procedimento cirúrgico, os pacientes foram encaminhados à Unidade de Terapia Intensiva (UTI) e submetidos ao tratamento fisioterapêutico padrão, sendo acrescido ao GE o uso da VNI, no modo CPAP, por 3 aplicações dentro das primeiras 26h pós extubação, com pressão positiva de 10 cmH2O, duração de tratamento de 1h cada aplicação. Foi realizada reavaliação no 3º e 5ºDPO através da MIF e no 7ºDPO/Alta além da MIF, foram aplicados o teste de caminhada de 6 minutos (TC6) e o teste de velocidade de marcha (T10), realizado o monitoramento dos tempos de cirurgia, de circulação extra-corpórea, de UTI e de internação hospitalar, além da fração de ejeção pós-operatória de ambos os grupos. Resultados: Avaliando os pacientes revascularizados, a variável TC6 apresentou diferença entre os grupos, o GC = 207,05 ± 68,8 metros e o GE = 284,73 ± 94,8 metros (p= 0,006). A variável T10 também apresentou diferença, o GC = 0,68 ± 0,22 m/s e o GE = 1,08 ± 0,39 m/s (p<0,0001). A MIF total na alta hospitalar GE 117,19 ± 11,04 e do GC 82,52 ± 13,26 (p=0,01). Não houve diferença estatística nos tempos de UTI e de internamento hospitalar entre os grupos. Os pacientes de troca valvar, na análise do TC6, o GC = 264,34 ± 76 metros e o GE = 334,07 ± 71 metros (p=0,002). Já a análise do T10, MIF e dos tempos de UTI e de internamento hospitalar, não apresentaram diferenças estatísticas entre os grupos. Conclusão: A VNI como recurso terapêutico se mostrou eficaz, sugerindo melhora da funcionalidade dos pacientes no pós-operatório de RM e TV, porém não influenciou no tempo de internação na UTI, nem no tempo geral de hospitalização dos pacientes cardiopatas estudados. Registro Brasileiro de Ensaios Clínicos RBR – 8bxdd3. / Aracaju, SE

No description available.

Obstructive sleep apnea (OSA) and asthma are potentially linked at several levels. The pathophysiology of these two conditions seems to overlap significantly, as airway obstruction, inflammation, obesity, and several other factors are implicated in the development of both diseases. Gastroesophageal reflux disease (GERD), cardiovascular complications, obesity itself, and the underlying inflammatory processes are all complex contributory factors that provide hypothetical links. Furthermore, a collateral rise in prevalence of both OSA and asthma has been noticed during the past few years, occurring in association with the emerging epidemic of obesity, a common risk factor for both conditions. OSA and asthma share many other risk factors as well. We propose a hypothetical OSA-asthma relationship that has implications on the diagnosis and management of patients presenting with either condition singly. Clinicians should be aware that OSA might complicate asthma management. Based on this hypothesis, we suggest that the treatment of the individual patient who experiences both asthma and OSA needs to be multidisciplinary and comprehensive. This hypothetical association of asthma and OSA, though described anecdotally, has not been systematically studied. In particular, the influence of continuous positive airway pressure therapy (for sleep apnea) on asthma outcomes (such as quality of life, steroid utilization, emergency room visits) and fatality needs to be studied further.

Obstructive sleep apnea (OSA) is a disorder that affects a significant portion of middle-aged adult population. Patients exhibit recurring episodes of upper airway obstruction during sleep that decrease blood oxygen concentration (hypoxia) and are terminated by brief arousals. Epidemiologically, OSA has been extensively linked to cardiovascular dysfunction and is an independent risk factor for the development of hypertension. The proposed mechanism of cardiovascular dysfunction in patients is chronic sympathoexcitation and altered vascular tone, with a predominance of the vasoconstrictor endothelin-1 (ET-1) and removal of the vasodilator nitric oxide (NO). Means to reduce the effects of ET-1 and increase synthesis of NO may have beneficial effects on the cardiovascular co-morbidity commonly associated with OSA. OBJECTIVES: The major aim of this study was to assess the relative importance of circulating biomarkers of ET-1 and NO in hemodynamic function in OSA patients. Potential production of ET-1 by circulating mononuclear cells was also measured to assess their contribution to plasma ET-1 levels. Biomarker levels before and after 12 wk of continuous partial airway pressure (CPAP) therapy were used to assess standard treatment. Mild/moderate exercise training was initiated with CPAP therapy in a subgroup of OSA patients to evaluate the potential benefits of physical activity on hemodynamic function and NO and ET-1 levels. METHODS: Overall, 16 newly diagnosed OSA patients (5 female, 11 male; age 45.4 ± 2.7 yr; RDI 24.6 ± 4.0 events/hr) were selected for study. Seven apparently healthy control volunteers (5 female, 2 male; age 39.43 ± 2.6 yr) screened for OSA served as control subjects. Blood pressure was recorded over one complete day and prior to, during, and following maximal exercise testing on a cycle ergometer. Blood samples were taken prior to exercise testing and assessed for nitrate and nitrite by HPLC and for big endothelin-1 and ET-1 by ELISA. Relative gene expression of preproendothelin-1 was measured by real-time RT-PCR. Following initial testing, patients were stratified into either a standard therapy group (nCPAP) or a standard therapy group with a mild/moderate intensity aerobic training regimen (nCPAP+Ex). Baseline testing was repeated following 12 wk of treatment. Statistical significance was set at p < 0.05 a priori. RESULTS: 24 hr ambulatory systolic and diastolic blood pressure were elevated in OSA patients vs. control subjects (systolic: 128.9 ± 3.8 mmHg vs. 108.8 ± 1.3 mmHg, respectively; diastolic: 97.5 ± 2.0 mmHg vs. 82.1 ± 1.9 mmHg, respectively). OSA patients experienced significant elevations in systolic (OSA 209.7 ± 5.7 mmHg; Control 174.5 ± 6.2 mmHg) and mean arterial pressures (OSA 125.8 ± 3.2 mmHg; Control 109.05 ± 4.5 mmHg) at peak exercise. No differences in nitrate, nitrite, or big endothelin-1 were noted. Plasma endothelin-1 concentrations were below assay detection limit. Big endothelin-1 levels were significantly correlated with BMI in both OSA patients (r=0.955; p=0.001) and control subjects (r=0.799; p=0.045). Relative gene expression of preproendothelin-1 was not elevated in OSA patients (0.40 ± 0.20 fold increase over control subjects). Group nCPAP usage was above minimum therapeutic threshold, but was non-uniform in both groups, with an overall range of 182 to 495 min mean usage per night. A mild/moderate exercise training program failed to elicit a training response through standard hemodynamic or cardiopulmonary indices. Plasma nitrite levels rose from 55.3 ± 4.7 μg/ml to 71.0 ± 7.6 μg/ml in the nCPAP group. CONCLUSIONS: Moderate OSA is associated with elevated blood pressure at rest and during exercise stress that bears no relationship to circulating biomarkers of NO and ET-1 or immune preproendothelin production in patients without diagnosed hypertension. nCPAP therapy failed to elicit significant improvements in hemodynamic function, with or without moderate exercise. Plasma nitrite levels rose following nCPAP therapy, indicating a possible increase in basal nitric oxide formation. Higher intensity exercise regimens may be needed to elicit the positive benefits of exercise training in OSA patients without significant cardiovascular dysfunction. / Ph. D.