Health care-associated bacterial pneumonias due to multiple-drug resistant (MDR) pathogens are an important public health problem and are major causes of morbidity and mortality worldwide. In addition to antimicrobial resistance, these organisms have adapted to the milieu of the human airway and have acquired resistance to the innate immune clearance mechanisms that normally prevent pneumonia. ...

T he continuous cycle of respiratory infections and lung inflammation is a hallmark of cystic fibrosis (CF) lung disease and plays a central role in respiratory failure that develops in end-stage disease. Effective mucociliary clearance is an essential mechanism in host defence against infection and requires a functional ‘‘two-layer’’ mucus clearance system composed of a periciliary liquid laye...

Measuring the efficacy of one airway clearance technique over another is still challenging and sometimes frustrating in an evidence-based era. We want our patients clear and intuitively we assume that what they expectorate is what we have really cleared. As Sirens caught Ulysses along his journey, respiratory therapists and physiotherapists are often tempted to believe that sputum is the best a...

The role of the airway circulation in supporting mucociliary function has been essentially unstudied. We evaluated the airway clearance of inert, insoluble particles in anesthetized ventilated sheep (n = 8), in which bronchial perfusion was controlled, to determine whether airway mucosal blood flow is essential for maintaining surface transport of particles through airways. The bronchial branch...

Asthma is functionally characterized by increased airway sensitivity and reactivity. Multiple mechanisms are believed to underlie these functional disorders, including impairment of airway wall barrier function. One proposed mechanism of impaired barrier function is through the direct consequence of proteolytic properties of inhaled allergens, including house dust mite (HDM). Here, we have obse...

Previous investigations on tracheobronchial clearance in chronic bronchitis or chronic obstructive pulmonary disease (COPD) have usually referred to measurements during a short time-period, i.e. a few hours. The purpose of this study, therefore, was to study regional particle deposition and tracheobronchial clearance during 72 h. In 14 patients with chronic bronchitis clearance of 111In-labelle...

The effect of long acting beta(2)-adrenergic bronchodilators on impaired mucociliary clearance in chronic bronchitis is unknown. Using a radiolabeled aerosol (technetium-99m-labeled sulfur colloid) and gamma camera analysis, we measured the acute effect of salmeterol vs. placebo on mucociliary and cough clearance in mild-moderate chronic bronchitics (n = 14) over a 2h period. During the 1-1(1/2...

Cough is an important component of airway clearance, particularly in individuals with intrinsic pulmonary disease, weakness of respiratory muscles, or central nervous system disease that impairs breathing. The use of assisted cough to enhance airway clearance in individuals with neuromuscular disease is essential to produce and maintain peak cough flow above a minimum and thereby avoid retained...