Demonstration of small apical pneumothoraces is supposed to be facilitated by expiratory chest radiographs. This study aimed to analyse the assumed enhancement of visual contrast on expiratory chest radiographs in patients with small apical pneumothoraces. Optical densities (OD) were obtained with a densitometer (X-rite 3001) on 54 paired inspiratory and expiratory chest radiographs of 22 conse...

OBJECTIVE To study the expiratory muscle force and the ability to cough estimated by the peak expiratory flow and peak cough flow in patients with Duchenne muscular dystrophy and amyotrophic lateral sclerosis. DESIGN A total of 27 patients with amyotrophic lateral sclerosis and 52 patients with Duchenne muscular dystrophy were studied. From the group of 144 normal subjects of this laboratory,...

Cystic fibrosis (CF) eventually leads to hyperinflation linked to tidal expiratory flow limitation (FL) and ventilatory failure. Presence of FL was assessed at rest in 22 seated children and adults with CF (forced expiratory volume in one second (FEV1) range: 16-92% predicted), using both the negative expiratory pressure (NEP) technique and the "conventional" method based on comparison of tidal...

We determined the effects of augmented expiratory intrathoracic pressure (P(ITP)) production on cardiac output (Q(TOT)) and blood flow distribution in healthy dogs and dogs with chronic heart failure (CHF). From a control expiratory P(ITP) excursion of 7 +/- 2 cmH2O, the application of 5, 10, or 15 cmH2O expiratory threshold loads increased the expiratory P(ITP) excursion by 47 +/- 23, 67 +/- 3...

Synaptic connections between medullary expiratory neurons and phrenic motoneurons were studied in anesthetized cats using spike-triggered averaging of synaptic noise in phrenic motoneurons. Monosynaptic inhibition of phrenic motoneurons originating from the rostral medullary expiratory neurons of the Bötzinger complex was revealed. Neither mono- nor disynaptic inhibition from expiratory neurons...

We hypothesized that contractions of the expiratory muscles carried out to the point of task failure would cause an increase in muscle sympathetic nerve activity (MSNA). We measured MSNA directly in six healthy men during resisted expiration (60% maximal expiratory pressure) leading to task failure with long [breathing frequency (f(b)) = 15 breaths/min; expiratory time (TE)/total respiratory cy...