A noninvasive electromyographic study on threshold and intensity of cough in humans.

The assessment of cough threshold and intensity is important in respiratory medicine. We have developed a method for objectively and noninvasively assessing cough threshold and intensity of expiratory muscle efforts in response to inhalation of ultrasonically nebulized distilled water (UNDW). Thirty (83%) out of 36 volunteers studied coughed in response to UNDW inhalation.

[Physical exercise in the thromboembolism of the pulmonary artery].

In order to evaluate post-embolic pulmonary gas exchange responses to exercise, we studied 7 patients who had previously suffered from an acute pulmonary embolism but were presently free from clinical and functional signs of cardiorespiratory diseases. Patients came to the laboratory on two occasions, 30 and 120 days following the episode of acute embolism, respectively, and performed an incremental ramp exercise test up to the maximum attainable workload. On both occasions, the dead volume/tidal volume (VD/VT) ratio at rest increased.

[Medico-legal aspects of chronic respiratory insufficiency under long-term oxygen inhalation therapy].

Ninety-one subjects affected by severe pulmonary insufficiency necessitating continuous treatment with oxygen were studied. The social and professional realities and their status within the national health service were determined. The results of the research, obtained through the use of the questionnaires, showed that the lives of these subjects are very much influenced by their pathology.

Prostaglandin synthesis blockade by ketoprofen attenuates respiratory and cardiovascular responses to static handgrip.

We investigated the effects of prostaglandin synthesis blockade on the changes in breathing pattern, mean blood pressure (MBP), and heart rate (HR) elicited by 3 min of static handgrip at 30% of the maximum voluntary contraction in 12 healthy volunteers. Before each handgrip trial, subjects were treated with intravenous administration of either saline placebo (control) or 1 mg/kg of ketoprofen. Muscle tension and integrated electromyographic activity of exercising muscles remained fairly constant during each trial.

Comparison of dose-response slopes obtained by simultaneous assessment of changes in FEV1 and transcutaneous oxygen partial pressure during methacholine challenges in asthmatic patients.

We aimed to ascertain whether monitoring changes in transcutaneous (tc) oxygen partial pressure (PO2) may be used to determine the slope of the dose-response curves to inhaled methacholine. In 10 adult asthmatic patients, FEV1 and tcPO2 were simultaneously measured during inhalation of doubling methacholine concentrations. In each patient, the slopes of the methacholine dose-response curves for FEV1 and tcPO2 were similar and strongly correlated (r = 0.

Respiratory and cardiovascular responses to static handgrip exercise in humans.

We studied the time course of respiratory and cardiovascular responses by evaluating changes in the breathing pattern, mean blood pressure (MBP), and heart rate elicited by 3 min of static handgrip at 15, 25, and 30% of the maximum voluntary contraction (MVC) in 15 healthy volunteers. Muscle tension and integrated electromyographic activity remained fairly constant during each trial. During 15% MVC bouts, initially only mean inspiratory flow increased; then, tidal volume and minute ventilation (VI) also rose progressively.

Changes in transcutaneous oxygen partial pressure as an index of response to inhaled methacholine in asthmatic patients.

Bronchoconstriction and hypoxemia have been reported to occur during airway challenges, but the correlation between changes in forced expiratory volume in 1 s (FEV1) and transcutaneous oxygen partial pressure (tcPO2) during methacholine provocation tests has not yet been established (to our knowledge). In 15 symptom-free atopic asthmatic patients and 5 normal subjects, variations in tcPO2 and FEV1 were simultaneously measured during inhalation of doubling methacholine concentrations; the drug concentrations causing a 20 percent decrease in control FEV1 and tcPO2 (PC20FEV1 and PC20tcPO2, respectively) were subsequently calculated. In patients, geometric mean PC20FEV1 and PC20TcPO2 were 1.

Anaerobic threshold: reproducibility out from ventilatory parameter estimation.

Anaerobic threshold (AT) during exercise is usually noninvasively determined by assuming a two-segment mathematical relationship between two ventilatory parameters. In the literature, all the possible pairs of segments are first considered, and the most appropriate pair is then selected according to at least-squares method. In such a model, the AT is considered to be related to the joining point of the two segments.

Effect of aminophylline aerosol on the bronchial response to ultrasonic mist of distilled water in asthmatic patients.

To ascertain whether inhaled aminophylline was effective in preventing the bronchial response induced by inhalating of an ultrasonic mist of distilled water (UMDW), we examined 8 asthmatic patients who had previously been shown to be reactive to this agent. Patients were given either 30 mg aminophylline or saline placebo aerosols followed by inhalation of 60 liters of UMDW; measurements of specific airway conductance (sGaw) were made before and after aminophylline or saline administration and after UMDW challenge. UMDW consistently induced a significant decrease in sGaw in all patients; however, in our subjects as a group, the degree of UMDW-induced bronchoconstriction was significantly less after premedication with aminophylline aerosol than after saline (p less than 0.

Serum theophylline concentrations and pulmonary function tests after administration of two sustained-release formulations containing theophylline in patients affected by chronic obstructive lung disease.

We compared serum theophylline concentrations in patients treated with one of two commercially available theophylline preparations: a sustained-release aminophylline and a sustained-release theophylline. Two comparable groups of 15 out-patients with stable, chronic obstructive lung diseases were studied: one group was given sustained-release aminophylline while the other took sustained-release theophylline. Both drugs were administered orally for 7 days at a daily dose, equivalent to 12 mg/kg in terms of anhydrous theophylline.

Bronchoprovocation tests in bronchial asthma and other respiratory disorders: a short review and some personal contributions.

The purpose of this paper, after a brief review of the main features of bronchoprovocation challenges, was to determine whether the administration of an ultrasonic mist of distilled water can influence the bronchial tone of normal subjects and patients affected by various respiratory disorders, in order to assess the effectiveness of this bronchoprovocation test in discriminating between patients. Of the 129 subjects tested 13 were classified as normal, 60 as extrinsic asthmatics, 21 as intrinsic asthmatics, 25 as allergic rhinitics and 37 as chronic bronchitics. Ultrasonic mist, was administered for 5 min and the bronchial response was evaluated in terms of difference between that after the mist minus baseline values of specific airways conductance.

Comments on subacute and long-term studies.

Long-term therapy with Duovent was always superior in comparison to the other drugs. An immediate efficacy with increasing levels until the 90th day was always obtained. There were no signs of tachyphylaxis and side effects were insignificant.

Histamine-induced bronchial response after administration of placebo, salbutamol and a combination of a beta-2-adrenergic drug (fenoterol) with an anticholinergic agent (ipratropium bromide) in asymptomatic asthma patients.

We examined 12 non-smoking patients affected by extrinsic bronchial asthma in steady state. Histamine PD20 FEV1 was assessed 4 h after the administration of salbutamol 200 micrograms, a combination of fenoterol 200 micrograms and ipratropium bromide 80 micrograms, and placebo. Despite the absence of any relevant bronchodilator effect, both salbutamol and the combination fenoterol + ipratropium bromide showed a strong protective effect against the bronchial response to histamine compared to placebo, the combination being more effective than salbutamol (p less than 0.

Effects of theophylline-ethylendiamine on chronic pulmonary arterial hypertension secondary to chronic obstructive pulmonary disease.

The use of theophylline in the treatment of chronic lung disease is wide spread thanks to the positive effects on the bronchial tree, on ventilation and on diaphragmatic contractile activity, which are well documented. On the other hand, the cardiovascular effects of this drug have not been studied much, particularly the effects on the hemodynamics of the pulmonary circulation. The latest studies were carried out by Parker (1966 and 1967) and by Jezek (1970) with heart catheterization and by Matthay (1978) with isotopic angiocardiography, but the problem has not been fully explored from the standpoint of pulmonary arterial hypertension.

Classification of respiratory functional impairment in chronic obstructive pulmonary disease.

Starting from a paper published in 1964 by Wilson et al., we explored the possibility of classifying the clinical and functional deficit of patients with chronic obstructive lung disease into six classes, class 0 representing normality and class 5 greatest severity. Each symptom or sign was classified into six degrees of increasing severity.

[The ventilation-perfusion ratio, with special reference to muscular exercise].

The values of VA/Q obtained at rest in 12 normal subjects undergoing cardiac catheterization in a supine position were between 0.63 and 1.695, with a mean of 1.