MELANIA DIRCE OLIVEIRA MARQUES
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina - Médico
3 resultados
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- Retropalatal and retroglossal airway compliance in patients with obstructive sleep apnea(2018) MARQUES, Melania; GENTA, Pedro R.; AZARBARZIN, Ali; SANDS, Scott A.; TARANTO-MONTEMURRO, Luigi; MESSINEO, Ludovico; WHITE, David P.; WELLMAN, AndrewObjectives: We hypothesized that preferential retropalatal as compared to retroglossal collapse in patients with obstructive sleep apnea was due to a narrower retropalatal area and a higher retropalatal compliance. Patients with a greater retropalatal compliance would exhibit a recognizable increase in negative effort dependence (NED). Methods: Fourteen patients underwent upper airway endoscopy with simultaneous recordings of airflow and pharyngeal pressure during natural sleep. Airway areas were obtained by manually outlining the lumen. Compliance was calculated by the change of airway area from end-expiration to a pressure swing of -5 cm H2O. NED was quantified for each breath as [peak inspiratory flow minus flow at -5 cm H2O]/[peak flow] x 100. Results: Compared to the retroglossal airway, the retropalatal airway was smaller at end-expiration (p < 0.001), and had greater absolute and relative compliances (p < 0.001). NED was positively associated with retropalatal relative area change (r = 0.47; p < 0.001). Conclusions: Retropalatal airway is narrower and more collapsible than retroglossal airway. Retropalatal compliance is reflected in the clinically-available NED value.
- Predicting epiglottic collapse in patients with obstructive sleep apnoea(2017) AZARBARZIN, Ali; MARQUES, Melania; SANDS, Scott A.; BEECK, Sara Op de; GENTA, Pedro R.; TARANTO-MONTEMURRO, Luigi; MELO, Camila M. de; MESSINEO, Ludovico; VANDERVEKEN, Olivier M.; WHITE, David P.; WELLMAN, AndrewObstructive sleep apnoea (OSA) is characterised by pharyngeal obstruction occurring at different sites. Endoscopic studies reveal that epiglottic collapse renders patients at higher risk of failed oral appliance therapy or accentuated collapse on continuous positive airway pressure. Diagnosing epiglottic collapse currently requires invasive studies (imaging and endoscopy). As an alternative, we propose that epiglottic collapse can be detected from the distinct airflow patterns it produces during sleep. 23 OSA patients underwent natural sleep endoscopy. 1232 breaths were scored as epiglottic/nonepiglottic collapse. Several flow characteristics were determined from the flow signal (recorded simultaneously with endoscopy) and used to build a predictive model to distinguish epiglottic from nonepiglottic collapse. Additionally, 10 OSA patients were studied to validate the pneumotachograph flow features using nasal pressure signals. Epiglottic collapse was characterised by a rapid fall(s) in the inspiratory flow, more variable inspiratory and expiratory flow and reduced tidal volume. The cross-validated accuracy was 84%. Predictive features obtained from pneumotachograph flow and nasal pressure were strongly correlated. This study demonstrates that epiglottic collapse can be identified from the airflow signal measured during a sleep study. This method may enable clinicians to use clinically collected data to characterise underlying physiology and improve treatment decisions.
- Palatal prolapse as a signature of expiratory flow limitation and inspiratory palatal collapse in patients with obstructive sleep apnoea(2018) AZARBARZIN, Ali; SANDS, Scott A.; MARQUES, Melania; GENTA, Pedro R.; TARANTO-MONTEMURRO, Luigi; MESSINEO, Ludovico; WHITE, David P.; WELLMAN, AndrewIn some individuals with obstructive sleep apnoea (OSA), the palate prolapses into the velopharynx during expiration, limiting airflow through the nose or shunting it out of the mouth. We hypothesised that this phenomenon causes expiratory flow limitation (EFL) and is associated with inspiratory '' isolated '' palatal collapse. We also wanted to provide a robust noninvasive means to identify this mechanism of obstruction. Using natural sleep endoscopy, 1211 breaths from 22 OSA patients were scored as having or not having palatal prolapse. The patient-level site of collapse (tongue-related, isolated palate, pharyngeal lateral walls and epiglottis) was also characterised. EFL was quantified using expiratory resistance at maximal epiglottic pressure. A noninvasive EFL index (EFLI) was developed to detect the presence of palatal prolapse and EFL using the flow signal alone. In addition, the validity of using nasal pressure was assessed. A cut-off value of EFLI >0.8 detected the presence of palatal prolapse and EFL with an accuracy of >95% and 82%, respectively. The proportion of breaths with palatal prolapse predicted isolated inspiratory palatal collapse with 90% accuracy. This study demonstrates that expiratory palatal prolapse can be quantified noninvasively, is associated with EFL and predicts the presence of inspiratory isolated palatal collapse.