Four patients with chronic airflow obstruction developed spontaneous sternal fractures. All had received repeated courses of high dose corticosteroids and three were receiving long term treatment with low dose corticosteroids. It is important to consider sternal fracture in the differential diagnosis when patients with chronic airflow obstruction present with chest pain.

Sweeping conclusions regarding the utility or nonutility of elevating expiratory pressure are not warranted. The effects of manipulating airway pressure in the setting of airflow obstruction depend heavily on the nature and severity of disease, as well as on the presence of airflow limitation during tidal breathing.

We report about a novel imaging technique for airflow analysis, particle image velocimetry (PIV), used in a moderate obstructive sleep apnea (OSA) patient. By measuring the airflow characteristics in the upper airway at different protrusion positions, the effect of mandibular advancement device (MAD) on OSA was further understood.

Obstructive lung diseases in the lower airways are a leading health concern worldwide. To improve our understanding of the pathophysiology of lower airways, we studied airflow characteristics in the lung between the 8th and the 14th generations using a three-dimensional computational fluid dynamics model, where we compared normal and obstructed airways for a range of breathing conditions. We em...

OBJECTIVE To investigate the aerodynamic consequences of conservative unilateral inferior turbinate reduction using computational fluid dynamics methods to accomplish detailed nasal airflow simulations. DESIGN A high-resolution, finite-element mesh of the nasal airway was constructed from magnetic resonance imaging data of a healthy man. Steady-state, inspiratory airflow simulations were cond...

BACKGROUND The airways of adult or elderly asthmatics are likely candidates for airway remodeling, resulting in persistent airflow obstruction. This population can provide a good model for cross-sectional evaluation of the effect of asthma duration on airflow. METHODS We evaluated postbronchodilator airflow and lung volumes at baseline and after a short course of oral prednisone in a group of...

Tracheostomy can influence the work of breathing by introducing additional resistance to airflow through the native airway. In a 1996 study, Hussey and Bishop determined that the presence of a deflated cuff in the airway significantly increased the work of breathing and theorized that a lower profile cuff would introduce less resistance to airflow. Hussey and Bishop also demonstrated that the p...

Clinical asthma is estimated to occur in 4 to 7 percent of the US population, but respiratory symptoms are much more common. The correlation between asthma, tests of bronchial hyperresponsiveness, and symptoms is imprecise and difficult to ascertain. The prevalence of exercise-induced airflow obstruction is not well known in healthy adults. We studied 100 consecutive US Air Force members to det...

THE effect of moisture content, fine material con­ centration and bulk density on the airflow resistance of long-grain rough rice was determined. Airflow resistance was measured at air velocities ranging from 0.013 to 0.387 mis, bulk densities from 480 to 604 kg/m3, fines concentrations from 0 to 30% and moisture contents from 12 to 24 %. Airflow resistance was accurately described by an empiri...