BACKGROUND The respiratory mass spectrometer is the current gold-standard technique for performing multiple-breath inert gas washout (MBW), but is expensive and lacks portability. A number of alternative techniques have recently been described. OBJECTIVES We aimed to validate, using an in vitro lung model, an open-circuit MBW system that utilises a portable photoacoustic gas analyser, with su...

Introduction. Obesity is a condition that causes damage to the respiratory function. However, studies have demonstrated that weight loss due to bariatric surgery has resulted in a huge improvement on some lung volumes, but controversy still persists regarding the behavior of the respiratory muscle strength and IRV (inspiratory reserve volume). Objective. To evaluate the effect of weight loss, a...

OBJECTIVE To determine whether preoperative inspiratory muscle training is able to attenuate the impact of surgical trauma on the respiratory muscle strength, in the lung volumes, and diaphragmatic excursion in obese women undergoing open bariatric surgery. DESIGN Randomized controlled trial. SETTING Meridional Hospital, Cariacica/ES, Brazil. SUBJECTS Thirty-two obese women undergoing ele...

Traditional approaches to mechanical ventilation use tidal volumes of 10 to 15 ml per kilogram of body weight. These volumes are larger than those in normal subjects at rest (range, 7 to 8 ml per kilogram), but they are frequently necessary to achieve normal values for the partial pressure of arterial carbon dioxide and pH. Since atelectasis and edema reduce aerated lung volumes in patients wit...

We measured respiratory input impedance (1-25 Hz) in mice and obtained parameters for airway and tissue mechanics by model fitting. Lung volume was varied by inflating to airway opening pressure (Pao) between 0 and 20 cm H2O. The expected pattern of changes in respiratory mechanics with increasing lung volume was seen: a progressive fall in airway resistance and increases in the coefficients of...

We have examined the effect of the fractional concentration of nitrogen (FIN2) on the decrease in lung volumes which occurs during restricted breathing with oxygen-nitrogen mixtures. Conscious human subjects breathed one of five gas mixtures of oxygen and nitrogen for 15 min on each of five occasions. For the final 5 min of each 15-min period, functional residual capacity (FRC) was reduced by o...