The cervical sympathetic trunks innervate the carotid bodies, carotid baroreceptors, thyroid gland and the upper airway mucosa, structures which can influence breathing and upper airway resistance. However, their role in the control of ventilation and upper airway patency is poorly understood. A constant airflow was applied to the upper airway through a high-cervical tracheostomy in anaesthetiz...

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....

The density dependence of maximal expiratory flow is not an effective test of the site of airway narrowing in obstructive lung disease. We hypothesized that the density dependence of pulmonary resistance (DD,RL) would be more closely related to the degree of airway narrowing and peripheral airway pathology in smokers. We measured maximal expiratory flow at 50% vital capacity (V'max50) and lung ...

Unlike conventional methods, the interrupter method for measuring airway resistance is non-invasive and requires minimal patient co-operation. It can therefore be applied in critically ill patients, acute asthmatics, neonates, pre-school children, geriatric patients and unconscious patients. The method is based on transient interruption of airflow at the mouth for a brief period during which al...

This study showed that nasal allergy patients have increased nasal airway resistance and tissue kallikrein activity in nasal lavage in accordance with the severity of symptoms. Nasal airway resistance and tissue kallikrein activity were significantly increased in the nasal lavage collected 15 min after antigen challenge, placement of a disk containing house dust antigen. The free kinin level in...

To assess the effects of obesity on pulmonary function, 46 healthy subjects exhibiting various degrees of obesity underwent lung function tests. Subjects were divided into three groups according to body mass index (BMI): 13 had minimal obesity (BMI, 25 to 29 kg/m2, group 1); 24 had a BMI in the 30 to 40 range (group 2); and 9 displayed to morbid obesity (BMI > 40, group 3). Respiratory resistan...

The effect of bronchoconstriction on airway resistance is known to be spatially heterogeneous and dependent on tidal volume. We present a model of a single terminal airway that explains these features. The model describes a feedback between flow and airway resistance mediated by parenchymal interdependence and the mechanics of activated smooth muscle. The pressure-tidal volume relationship for ...

Abstract Purpose of Review The aim this analysis is to provide a synopsis the surgical methods utilized treat nasal valve collapse resulting in airway obstruction, and evaluate contrast lateral crural strut grafts (LCSG) tensioning (LCT). Recent Findings Lateral grafting major technique used external collapse. However, recent years, combined with articulated alar rim (AARG) has become popular. ...

The resistance of the airways to the airflow through them depends on the radius, length and number of the airways. It has long been apparent (1, 2) that the bronchi are distended as well as lengthened in the inspiratory position of the lung. These two changes in the dimensions of these airways would have opposite effects on their resistance to airflow, lengthening increasing resistance and wide...