TO THE EDITOR: In view of the Viewpoint by Solbert Permutt (3) in this issue of the Journal of Applied Physiology, it is becoming clear that the extent of decline in pulmonary function in asthmatics is not a simple function of the degree of smooth muscle shortening, but is the manifestation of complicated relationships among baseline airway structure, the degree of airway smooth muscle shorteni...

Interaction between airway edema and lung inflation on responsiveness of individual airways in vivo. J. Appl. Physiol. 83(2): 366-370, 1997.-Inflammatory changes and airway wall thickening are suggested to cause increased airway responsiveness in patients with asthma. In five sheep, the dose-response relationships of individual airways were measured at different lung volumes to methacholine (MC...

Background: Sleep disordered breathing, specifically obstructive sleep apnea (OSA) is due to constriction of the oropharyngeal airway during sleep and has major public health implications. By conservative estimates, 3% of the adult population are suffering from OSA characterized by sleep deprivation, fatigue during the day and somnolence. The most common treatment for sleep apnea is continuous ...

Increased wheeze and asthma diagnosis in obesity may be due to reduced lung volume with subsequent airway narrowing. Asthma (wheeze and airway hyperresponsiveness), functional residual capacity (FRC) and airway conductance (Gaw) were measured in 276 randomly selected subjects aged 28-30 yrs. Data were initially adjusted for smoking and asthma before examining relationships between weight and FR...

An index of airway caliber can be tracked in near-real time by measuring airway resistance (Raw) as indicated by lung resistance at 8 Hz. These measurements require the placing of an esophageal balloon. The objective of this study was to establish whether total respiratory system resistance (Rrs) could be used rather than Raw to track airway caliber, thereby not requiring an esophageal balloon....

BACKGROUND Increasing intra-abdominal volume (IAV) can lead to intra-abdominal hypertension (IAH) or abdominal compartment syndrome. Both are associated with raised morbidity and mortality. IAH can increase airway pressures and impair ventilation. The relationship between increasing IAV and airway pressures is not known. We therefore assessed the effect of increasing IAV on airway and intra-abd...

Recent reports have suggested that flow volume curve abnormalities may be of interest in the diagnosis of obstructive sleep apnea syndromes by showing either extrathoracic airway obstruction (ratio of expiratory flow to inspiratory flow at 50 percent of forced vital capacity [FEF50/FIF50] exceeding 1) or upper airway fluttering (indicated by a sawtooth aspect on the mid-half of the inspiratory ...

We describe a patient at 20-22 weeks gestation, with a known difficult airway, who underwent eight sessions of electroconvulsive therapy using the ProSeal laryngeal mask airway and controlled ventilation. The airway management options for brief periods of general anaesthesia in patients with increased gastric volume are discussed.

We investigated the effects of isoproterenol on the pulmonary mechanics of eight healthy male subjects. We measured the flow-volume, pressure-volume, resistance-volume, and pressure-flow relationships of the lungs of our subjects in addition to the forced expiratory volume (FEV(1)). The results of this study confirm earlier observations that isoproterenol produces a considerable decrease in air...

results sixty patients were involved in this study. in asv mode, values including peak airway pressure (p-peak), end-tidal carbon dioxide (etco2), tidal volume and respiratory dead space were significantly lower than simv mode. although the mean value for dynamic compliance had no significant difference in the two types of ventilation, it was better in asv mode. methods in a crossover study, pa...