Navegando por Palavras-chave "Hypoxemia"

Agora exibindo 1 - 2 de 2
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    The effect of sildenafil on sleep respiratory parameters and heart rate variability in obstructive sleep apnea
    (Elsevier B.V., 2010-06-01) Neves, Christiane [UNIFESP]; Tufik, Sergio [UNIFESP]; Monteiro, Marina Ariza [UNIFESP]; Chediek, Felipe [UNIFESP]; Jose, Fabio Freire [UNIFESP]; Roizenblatt, Suely [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Objective: To evaluate the magnitude of effects of sildenafil on respiratory parameters and heart rate variability (HRV) in slow wave sleep (SWS) and REM sleep of patients with severe obstructive sleep apnea (OSA).Methods: Thirteen male patients with untreated severe OSA (aged 43 +/- 10 years, body mass index of 26.7 +/- 1.9 kg/m(2)) were studied on two nights, one with sildenafil 50 mg and one with a placebo, in a double-blind, randomized fashion. All-night polysomnography and HRV were simultaneously recorded. Short-term HRV measures were performed in apnea-free intervals. Respiratory parameters were separately assessed in non-REM and REM sleep and compared to total sleep time (TST). Short-term HRV analysis was conducted in samples with regular respiration obtained in SWS and REM sleep.Results: Comparing to placebo, during sildenafil night there was an increase in apnea-hypopnea index (AHI) in TST and also in non-REM and REM sleep. Increase in central AHI occurred in non-REM sleep; increase in obstructive AHI and decrease in oxyhemoglobin saturation occurred in both non-REM and REM sleep. Additionally, an increase in arousal index and in low/high frequency component of HRV ratio (LF/HF) was significant only in REM sleep. Correlation between sleep architecture and respiratory parameters were more frequent in non-REM sleep for placebo and in REM sleep for sildenafil.Conclusion: in severe OSA, the use of sildenafil 50 mg at bedtime plays a detrimental role on respiratory parameters in both non-REM and REM sleep, fragmentation in REM sleep, and a prolonged increase in LH/HF component of HRV after resumption of ventilation. (C) 2010 Elsevier B.V. All rights reserved.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Evaluation of 6-minute walk test (6MWT) in adults with sickle cell disease in São Paulo/SP
    (Universidade Federal de São Paulo (UNIFESP), 2017-03-01) Norvil, Wesny [UNIFESP]; Figueiredo, Maria Stella [UNIFESP]; http://lattes.cnpq.br/0736747630522639; http://lattes.cnpq.br/6652873085167567; Universidade Federal de São Paulo (UNIFESP)
    Introduction: Sickle-cell Disease (SCD) is the hematological disease, with the most hereditary, monogenic and autosomal features in the world. Its pathophysiology involves hemolysis and vaso-occlusion, which can affect several organs, including the lung. It is observed that hypoxemia in the steady state is a common manifestation in SCD and it has been proven an association with the level of anemia and the degree of hemolysis in previous studies. The 6-minutes-walking test (6MWT) is a simple functional capacity test that evaluates the exercise tolerance according to the distance covered in 6 minutes and with monitoring of the behavior of oxygen saturation and blood pressure. It has been gaining importance in sickle cell disease, since lots of results were found showing the impact of baseline oxygen(O2) desaturation in the 6MWT performance in children with sickle cell disease whereas just a few have been found in adults. Objective: In this current study we aimed at evaluating hypoxemia in sickle-cell adults though the 6MWT and its relation with the clinical-laboratory parameters. Methods: A cross-sectional, analytical and descriptive study was performed in 44 patients with SCD and 19 healthy controls based on the 6MWT and clinical-laboratory data. Results: The group of patients covered a shorter distance [median (interquartile): 416.9m (406.6-444.8)] than controls [652.5m (634.4-665.0); p<0001]. No individual in the control group had baseline or post-test desaturation. Moderate O2 desaturation at rest (defined as SpO2<95%) was observed in 25.0% (n=11) of the patients. The distance walked by the patients showed a positive correlation with hemoglobin (r=0.461, 95% CI: 0.170- 0.678, p=0.002) and negative with reticulocytes count (r=-0.352, 95% CI:-0.601- - 0.041; p=0.023). Patients with moderate desaturation at rest had odds of increase 6.5-fold of post-test desaturation development (OR: 6.5; 95% CI: 1.47-28.71; p=0.021). When evaluating the patients in relation to the absence (G1) or presence (G2) of post-test desaturation (defined as decline O2≥3% from baseline), 14 (31.8%) of the individuals belonging to G2 were observed. Regarding the hemolytic biomarkers, G2 presented a lower HbF level (p=0.041), lower BMI (p=0.007), higher reticulocytes count (p=0.007) and DHL (p=0.002) compared with G1. Conclusion: It was detected a high prevalence of moderate desaturation at steady state as well as post 6MWT in adults with SCD. Desaturation was associated with elevation of hemolysis biomarkers, suggesting being associated with the greater severity of the disease. The detection of these abnormalities in the 6MWT underscores the importance of considering this non-invasive test as a means of monitoring patients with FD, although additional studies are needed to elucidate the role of 6MWT in adults with SCD.