BACKGROUND Lung-protective ventilation strategy suggests the use of low tidal volume, depending on ideal body weight, and adequate levels of PEEP. However, reducing tidal volume according to ideal body weight does not always prevent overstress and overstrain. On the contrary, titrating mechanical ventilation on airway driving pressure, computed as airway pressure changes from PEEP to end-inspir...

PURPOSE To evaluate the upper airway dimensions of obstructive sleep apnea (OSA) and control subjects using a cone-beam computed tomography (CBCT) unit commonly applied in clinical practice in order to assess airway dimensions in the same fashion as that routinely employed in a clinical setting. MATERIALS AND METHODS This was a retrospective analysis utilizing existing CBCT scans to evaluate ...

Introduction: Children with cleft lip and palate (CLP) are known to have airway problems. Introduction of ConeBeam CT (CBCT) and imaging software has facilitated generation of 3D images for assessing the volume of maxillary sinuses and pharyngeal airway. Consequently, the present study aimed at evaluating and comparing the maxillary sinus and pharyngeal airway volume of patients with cleft lip ...

The regional pattern and extent of airway closure measured by three-dimensional ventilation imaging may relate to airway hyperresponsiveness (AHR) and peripheral airways disease in asthmatic subjects. We hypothesized that asthmatic airways are predisposed to closure during bronchoconstriction in the presence of ventilation heterogeneity and AHR. Fourteen asthmatic subjects (6 women) underwent c...

OBJECTIVE Small upper airway measurements areas and high body mass index are recognized risk factors for obstructive sleep apnea syndrome (OSAS) in non-elderly populations; however, there is limited information regarding elderly patients. We evaluated whether upper airway volume is associated with OSAS and OSAS treated with continuous positive airway pressure (CPAP) treatment and whether BMI is...

We recently showed respiratory-related coactivation of both extrinsic and intrinsic tongue muscles in the rat. Here, we test the hypothesis that intrinsic tongue muscles contribute importantly to changes in velopharyngeal airway volume. Spontaneously breathing anesthetized rats were placed in a MRI scanner. A catheter was placed in the hypopharynx and connected to a pressure source. Axial and s...

Our hypothesis was that the simultaneous activation of tongue protrudor and retractor muscles (co-activation) would constrict and stiffen the pharyngeal airway more than the independent activation of tongue protrudor muscles. Upper airway stiffness was determined by injecting known volumes of air into the sealed pharyngeal airway of the anaesthetized rat while measuring nasal pressure under con...

Maximal expiratory flow in chronic obstructive pulmonary disease (COPD) could be reduced by three different mechanisms; loss of lung elastic recoil, decreased airway conductance upstream of flow-limiting segments; and increased collapsibility of airways. We hypothesized that decreased upstream conductance would be related to inflammation and thickening of the airway walls, increased collapsibil...

In an effort to determine which measure of airway dynamics was the most sensitive to airway obstruction, comparisons were made between a variety of tests. Twenty cigarette smokers were studied both before and immediately after smoking a cigarette. The maximum midexpiratory flow (FEV25-75) and the FEV1/FVC per cent were abnormal in the largest number of cases. Closing volume was abnormal in only...

OBJECTIVE To determine the extent to which thin-section and volumetric threedimensional CT can depict airway reactivity to bronchostimulator, and to assess the effect of different airway sizes on the degree of reactivity. MATERIALS AND METHODS In eight dogs, thin-section CT scans were obtained before and after the administration of methacholine and ventolin. Cross-sectional areas of bronchi a...