MELANIA DIRCE OLIVEIRA MARQUES
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina - Médico
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Predicting sleep apnea responses to oral appliance therapy using polysomnographic airflow(2020) VENA, Daniel; AZARBARZIN, Ali; MARQUES, Melania; BEECK, Sara Op de; VANDERVEKEN, Olivier M.; EDWARDS, Bradley A.; CALIANESE, Nicole; HESS, Lauren B.; RADMAND, Reza; HAMILTON, Garun S.; JOOSTEN, Simon A.; TARANTO-MONTEMURRO, Luigi; KIM, Sang-Wook; VERBRAECKEN, Johan; BRAEM, Marc; WHITE, David P.; SANDS, Scott A.; WELLMAN, AndrewStudy Objectives: Oral appliance therapy is an increasingly common option for treating obstructive sleep apnea (OSA) in patients who are intolerant to continuous positive airway pressure (CPAP). Clinically applicable tools to identify patients who could respond to oral appliance therapy are limited. Methods: Data from three studies (N = 81) were compiled, which included two sleep study nights, on and off oral appliance treatment. Along with clinical variables, airflow features were computed that included the average drop in airflow during respiratory events (event depth) and flow shape features, which, from previous work, indicates the mechanism of pharyngeal collapse. A model was developed to predict oral appliance treatment response (>50% reduction in apnea-hypopnea index [AHI] from baseline plus a treatment AHI <10 events/h). Model performance was quantified using (1) accuracy and (2) the difference in oral appliance treatment efficacy (percent reduction in AHI) and treatment AHI between predicted responders and nonresponders. Results: In addition to age and body mass index (BMI), event depth and expiratory ""pinching"" (validated to reflect palatal prolapse) were the airflow features selected by the model. Nonresponders had deeper events, ""pinched"" expiratory flow shape (i.e. associated with palatal collapse), were older, and had a higher BMI. Prediction accuracy was 74% and treatment AHI was lower in predicted responders compared to nonresponders by a clinically meaningful margin (8.0 [5.1 to 11.6] vs. 20.0 [12.2 to 29.5] events/h, p < 0.001). Conclusions: A model developed with airflow features calculated from routine polysomnography, combined with age and BMI, identified oral appliance treatment responders from nonresponders. This research represents an important application of phenotyping to identify alternative treatments for personalized OSA management. Statement of Significance Treatment response to oral appliance in patients with obstructive sleep apnea can be predicted at baseline from metrics derived from routine polysomnography.
- Quantifying the Arousal Threshold Using Polysomnography in Obstructive Sleep Apnea(2018) SANDS, Scott A.; TERRILL, Philip I.; EDWARDS, Bradley A.; MONTEMURRO, Luigi Taranto; AZARBARZIN, Ali; MARQUES, Melania; MELO, Camila M. de; LORING, Stephen H.; BUTLER, James P.; WHITE, David P.; WELLMAN, AndrewStudy Objectives: Precision medicine for obstructive sleep apnea (OSA) requires noninvasive estimates of each patient's pathophysiological ""traits."" Here, we provide the first automated technique to quantify the respiratory arousal threshold-defined as the level of ventilatory drive triggering arousal from sleep-using diagnostic polysomnographic signals in patients with OSA. Methods: Ventilatory drive preceding clinically scored arousals was estimated from polysomnographic studies by fitting a respiratory control model (Terrill et al.) to the pattern of ventilation during spontaneous respiratory events. Conceptually, the magnitude of the airflow signal immediately after arousal onset reveals information on the underlying ventilatory drive that triggered the arousal. Polysomnographic arousal threshold measures were compared with gold standard values taken from esophageal pressure and intraoesophageal diaphragm electromyography recorded simultaneously (N = 29). Comparisons were also made to arousal threshold measures using continuous positive airway pressure (CPAP) dial-downs (N = 28). The validity of using (linearized) nasal pressure rather than pneumotachograph ventilation was also assessed (N = 11). Results: Polysomnographic arousal threshold values were correlated with those measured using esophageal pressure and diaphragm EMG (R = 0.79, p < .0001; R = 0.73, p = .0001), as well as CPAP manipulation (R = 0.73, p < .0001). Arousal threshold estimates were similar using nasal pressure and pneumotachograph ventilation (R = 0.96, p < .0001). Conclusions: The arousal threshold in patients with OSA can be estimated using polysomnographic signals and may enable more personalized therapeutic interventions for patients with a low arousal threshold.
- Stable Breathing in Patients With Obstructive Sleep Apnea Is Associated With Increased Effort but Not Lowered Metabolic Rate(2017) MELO, Camila M. de; TARANTO-MONTEMURRO, Luigi; BUTLER, James P.; WHITE, David P.; LORING, Stephen H.; AZARBARZIN, Ali; MARQUES, Melania; BERGER, Philip J.; WELLMAN, Andrew; SANDS, Scott A.Study objectives: In principle, if metabolic rate were to fall during sleep in a patient with obstructive sleep apnea (OSA), ventilatory requirements could be met without increased respiratory effort thereby favoring stable breathing. Indeed, most patients achieve periods of stable flow-limited breathing without respiratory events for periods during the night for reasons that are unclear. Thus, we tested the hypothesis that in patients with OSA, periods of stable breathing occur when metabolic rate (VO2) declines. Methods: Twelve OSA patients (apnea-hypopnea index > 15 events/h) completed overnight polysomnography including measurements of VO2 (using ventilation and intranasal PO2) and respiratory effort (esophageal pressure). Results: Contrary to our hypothesis, VO2 did not differ between stable and unstable breathing periods in non-REM stage 2 (208 +/- 20 vs. 213 +/- 18 mL/min), despite elevated respiratory effort during stable breathing (26 +/- 2 versus 23 +/- 2 cmH(2)O, p =.03). However, VO2 was lowered during deeper sleep (244 to 179 mL/min from non-REM stages 1 to 3, p =.04) in conjunction with more stable breathing. Further analysis revealed that airflow obstruction curtailed metabolism in both stable and unstable periods, since CPAP increased VO 2 by 14% in both cases (p =.02,.03, respectively). Patients whose VO2 fell most during sleep avoided an increase in PCO2 and respiratory effort. Conclusions: OSA patients typically convert from unstable to stable breathing without lowering metabolic rate. During sleep, OSA patients labor with increased respiratory effort but fail to satisfy metabolic demand even in the absence of overt respiratory events.