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...

BACKGROUND Breathing pattern description and chest wall kinematics during phonation have not been studied in male and female patients with chronic obstructive pulmonary disease. OBJECTIVES We used optoelectronic plethysmography to provide a quantitative description of breathing pattern and chest wall kinematics. METHODS Volumes of chest wall compartments (rib cage and abdomen) were assessed...

INTRODUCTION Thixotropy is a passive property of the skeletal muscle that depends on the muscle's immediate history of contraction and length change. Inspiratory-muscle thixotropy affects the end-expiratory position of the rib cage in normal subjects. OBJECTIVE To determine whether a reduction in end-expiratory chest-wall volume occurs after thixotropy conditioning of inspiratory muscles in p...

Expiratory muscle activity has been studied in the external oblique muscle during anaesthesia with spontaneous breathing in twenty-two patients. Expiratory muscle activity was absent in all subjects before induction but developed within 29 minutes of induction in twenty patients, remaining absent in the other two. Deepening the level of halothane anaesthesia reduced, but in only one case abolis...

Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory ratio in the first second (FEV1% VC), forced expiratory flow between 200 and 1200 ml (FEF200-1200), and forced mid expiratory flow between 25% and 75% of FVC (FMF) were measured in 275 Libyan men ranging from 20 to 60 years. All values were lower with increasing age and, apart from FEV1% VC, were posit...

OBJECTIVES To evaluate pulmonary function in the first and third trimesters of pregnancy and analyze the influence of parity and smoking on spirometry parameters. METHODS This longitudinal prospective study included a cohort of 120 pregnant women. The inclusion criteria were as follows: singleton pregnancy, gestational age less than 13.86 weeks, and no preexisting maternal diseases. The exclu...

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...

It had been hypothesized that the regions of prefrontal cortex which are involved in respiratory control can modulate Hering-Breuer reflexes evoked by vagal input from pulmonary stretch receptors. In the present study, experiments were performed on urethane anesthetized spontaneously breathing Wistar rats. The expiratory-promoting reflex was evaluated from changes in expiratory time immediately...

BACKGROUND Orthopnea is a common feature in COPD patients, although its nature is poorly understood. OBJECTIVE To study the role of tidal expiratory flow limitation (FL) in the genesis of orthopnea in patients with stable COPD. MEASUREMENTS Tidal FL was assessed in 117 ambulatory COPD patients in sitting and supine positions using the negative expiratory pressure method. The presence or abs...

[Purpose] The purpose of this study was to investigate the correlation between respiratory muscle strength and cough capacity in stroke patients. [Subjects and Methods] Forty-two stroke patients were assigned to 2 different groups (intervention group=21, control group=21). Both groups participated in a conventional stroke rehabilitation program, with the intervention group also receiving respir...