INTRODUCTION Functional residual capacity (FRC) reference values are obtained from spontaneous breathing patients, and are measured in the sitting or standing position. During mechanical ventilation FRC is determined by the level of positive end-expiratory pressure (PEEP), and it is therefore better to speak of end-expiratory lung volume. Application of higher levels of PEEP leads to increased ...

The effects of atropine and glycopyrrolate on anatomical dead space, one and three second forced expiratory volume, maximal expiratory flow rate, and total forced expiratory volume were determined in ten healthy volunteers. Using Fowler's single breath nitrogen analyzing technique, atropine was found to increase dead space by 19.2 per cent at one hour, declining to 11.02 per cent at four hours....

BACKGROUND Severe obesity causes respiratory morbidity and mortality. The impact of obesity on the mechanics of breathing is not fully understood. PATIENTS AND METHODS We undertook a comprehensive observational study of lung volumes and elasticity in nine obese and nine normal weight subjects, seated and supine, during spontaneous breathing. Seated and supine total lung capacity (TLC) and sub...

Introduction: The forced expiratory flow at 25 and 75% of the pulmonary volume/forced vital capacity ratio (FEF25-75/FVC) as a spirometry parameter has been successful in the early diagnosis of chronic obstructive pulmonary disease (COPD) and the methacholine challenge test for assessing airway responsiveness.To determine the accuracy of FEF25-7...

We have measured lung mass and trachea dimensions in 46 giraffes of both genders ranging in body mass from 147 kg to 1441 kg, calculated static and dynamic lung volumes, and developed allometric equations that relate changes in them to growth. We found that relative lung mass is 0.6±0.2% of body mass which is significantly less than it is in other mammals (1.1±0.1%). Total lung volume is signif...

[Purpose] This study was designed to compare and clarify the relationship between expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation, with a focus on tidal volume. [Subjects and Methods] The subjects were 18 patients on prolonged mechanical ventilation, who had undergone tracheostomy. Each patient received expiratory rib cage com...

CONTEXT Osteopathic manipulative treatment (OMT) has long been advocated for patients with respiratory disorders, but little definitive evidence exists to support its use in this population. OBJECTIVE To investigate the immediate effect of OMT on pulmonary function parameters in elderly subjects with chronic obstructive pulmonary disease. METHODS Subjects aged 65 years or older with a force...

STUDY OBJECTIVES To clarify the pathophysiologic features of the relation between asthma and obesity, we measured the effects of weight reduction on peak expiratory flow (PEF) variability and airways obstruction, compared to simultaneous changes in lung volumes and ventilatory mechanics in obese patients with stable asthma. METHODS Fourteen obese asthma patients (11 women and 3 men; aged 25 t...

Thixotropy conditioning of inspiratory muscles consisting of maximal inspiratory effort performed at an inflated lung volume is followed by an increase in end-expiratory position of the rib cage in normal human subjects. When performed at a deflated lung volume, conditioning is followed by a reduction in end-expiratory position. The present study was performed to determine whether changes in en...

During forced vital capacity maneuvers in subjects with expiratory flow limitation, lung volume decreases during expiration both by air flowing out of the lung (i.e., exhaled volume) and by compression of gas within the thorax. As a result, a flow-volume loop generated by using exhaled volume is not representative of the actual flow-volume relationship. We present a novel method to take into ac...