PURPOSE To assess the efficacy of an adjustable inspiratory occlusion valve in experimental bronchopleural fistula during mechanical ventilation. METHODS We studied six mechanically ventilated pigs in a surgically created, reproducible model of bronchopleural fistula managed with mechanical ventilation and water-sealed thoracic drainage. An adjustable inspiratory occlusion valve was placed be...

INTRODUCTION The effect of expiratory endotracheal tube (ETT) resistance on dynamic lung inflation is unknown. We hypothesized that ETT resistance causes dynamic lung hyperinflation by impeding lung emptying. We further hypothesized that compensation for expiratory ETT resistance by automatic tube compensation (ATC) attenuates dynamic lung hyperinflation. METHODS A ventilator equipped with th...

Measurements of relaxed expiratory volume in one second (REV1.0) and forced inspiratory volume in one second (FIV1.0) were made on 50 subjects on two occasions to know the variability of these procedures in the individual subject. The mean coefficients of variation for REV1.0 and FIV1.0 were 6740' and 892%, respectively. The 95% confidence limit of difference between highest readings obtained o...

Volume (ml) This relationship between phrenic inhibition and lung volume may relate to the input-output characteristics of the inspiratory terminating mechanism, and the abrupt downstroke in the phrenic neurogram, commonly taken to signify the end of inspiration, may represent simply an extension of the alinear function. Also, because the vertical distances between iso-inhibition lines change l...

Nath, A. R. and Capel, L. H. (1974). Thorax, 29, 695-698. Inspiratory crackles and mechanical events of breathing. Forgacs (1967) has suggested that the timing of individual inspiratory crackles is determined by the elastic tension of the lung. This hypothesis was tested by recording the inspiratory crackles simultaneously with a recording of transpulmonary pressure, inspired volume, and inspir...

Background: Resistive Inspiratory Muscle Training (RIMT) is a well-known technique for rehabilitation of patients with Chronic Obstructive Pulmonary Disease (COPD). Incentive spirometry is another technique with potential viability for this application, but there is limited evidence in support of its efficacy in the rehabilitation of COPD patients. Aim: The objective of this study was to compar...

Upright immersion imposes a pressure imbalance across the thorax. This study examined the effects of air-delivery pressure on inspiratory muscle work during upright immersion. Eight subjects performed respiratory pressure-volume relaxation maneuvers while seated in air (control) and during immersion. Hydrostatic, respiratory elastic (lung and chest wall), and resultant static respiratory muscle...

INTRODUCTION The inspiratory flow pattern influences CO₂ elimination by affecting the time the tidal volume remains resident in alveoli. This time is expressed in terms of mean distribution time (MDT), which is the time available for distribution and diffusion of inspired tidal gas within resident alveolar gas. In healthy and sick pigs, abrupt cessation of inspiratory flow (that is, high end-in...

It is not completely described how aging affect ventilatory kinematics and what are the mechanisms adopted by the elderly population to overcome these structural modifications. Given this, the aim was to evaluate the acute effects of different inspiratory efforts on ventilatory pattern and chest wall compartmental distribution in elderly women. Variables assessed included: tidal volume (Vt), to...

APGAR: Activity Pulse Grimace Appearance Respiration; PImax: Maximal Inspiratory Pressure; PEmax: Maximal Expiratory Pressure; DLCO: Diffusion Capacity; β-HCG: Bbeta Human Chorionic Gonadotropin; BMI: Body Mass Index; FVC: Forced Vital Capacity; FEV1: Forced Expiratory Flow at One Second; FEF25-75: Forced Expiratory Flow 25-75; RV: Residual Volume; TLC: Total Lung Capacity; DLCO/VA: Diffusion C...