Biomedical subjects

M Y Rouleau

Publications and source records attributed to M Y Rouleau.

3 recordsLinked to original sources

PubMed1998

Randomised controlled trial of inhaled corticosteroids in patients with chronic obstructive pulmonary disease.

BACKGROUND: Inhaled corticosteroids are known to be beneficial for patients with asthma, but their role in treating patients with stable chronic obstructive pulmonary disease (COPD) remains controversial. A study was undertaken to determine whether inhaled corticosteroids are of functional benefit in patients who did not show improvement with a trial of oral corticosteroids. METHODS: In phase I patients with stable COPD were given a two week course of oral placebo followed by two weeks of prednisone 40 mg per day in a single blind manner to distinguish between responders and non-responders to oral corticosteroids. In phase II a double blind, randomised, parallel group trial of inhaled budesonide 1600 micrograms per day versus placebo was carried out in 79 nonresponders to oral corticosteroids. The primary outcome measure was forced expiratory volume in one second (FEV1), and secondary outcome measures were exercise capacity, dyspnoea with exertion, quality of life, peak expiration flow rate, and respiratory symptoms. RESULTS: Randomisation allocated 39 subjects to inhaled corticosteroids and 40 to placebo. There was no difference in the change in FEV1 from baseline between the treatment and placebo groups; mean difference -12 ml (95% CI -88 to 63) at three months and -4 ml (95% CI -95 to 87) at six months. The proportion of patients with a 15% or greater improvement was no higher among those receiving inhaled corticosteroids than in the placebo group at any of the follow up visits. Changes in secondary outcomes were also no different. CONCLUSIONS: Inhaled corticosteroids, even at high doses, were of no physiological or functional benefit in these patients with advanced COPD.

Administration, Inhalation↗

PubMed1996

Combined smoke inhalation and body surface burns injury does not necessarily imply long-term respiratory health consequences.

This study was undertaken to assess the long-term respiratory health consequences of smoke inhalation in patients who are burns survivors. Patients with smoke inhalation resulting from domestic flame or fire were studied. Medical records were the primary source for the selection of the patients. Smoke inhalation was diagnosed on the basis of the visual appearance of the airways on the reported bronchoscopy. Patients who participated in the study were compared on important characteristics with those who did not participate. The participants were then assessed by questionnaire, physical examination, chest radiograph and pulmonary function tests. Twenty three out of 45 patients who had survived smoke inhalation participated in the study. Participants and nonparticipants were comparable with respect to gender, age, time since injury, aetiology of injury, and total body surface burned. Participants had more facial burns, more severe bronchoscopic findings of smoke inhalation and required intubation more frequently. Respiratory symptom assessment and pulmonary function tests were performed 45 +/- 23 months after smoke inhalation. Four patients reported an increase in dyspnoea, one an increase in cough and one an increase in phlegm. All the patients had pulmonary function tests and bronchial responsiveness (provocative concentration of histamine resulting in a 20% fall in forced expiratory volume in one second (PC20) > 16 mg.mL-1) within normal limits. The four patients complaining of increased dyspnoea had results within normal limits for cardiac and respiratory variables on maximal exertion. The present study indicates that, in burn patients, smoke inhalation resulting from a single domestic fire does not necessarily imply long-term respiratory health consequences.

Adult↗

PubMed1981

Ventilation in exercise studied with circulatory occlusion.

Five male subjects exercised on a cycle ergometer (100 W) for 8 min; circulation to the legs was occluded by cuffs during the first 2 and last 2 min. Ventilation (VE), oxygen intake (VO2), and carbon dioxide output (VCO2) were measured breath by breath. Repeat studies were used to follow arterial PCO2 (PaCO2) and rebreathing mixed venous PCO2 (PVCO2). The results were compared to studies without cuffing, but which were otherwise identical. The initial period of cuffing was associated with marked hyperpnea, high VE/VCO2 ratio, and low PaCO2 and PVCO2. Following release of occlusion at the end of the first 2 min, there was an immediate fall in VE, followed by an increase after an average of 12 s. VE/VCO2 fell and end-tidal PCO2 rose after 4-5 s and reached control values after 12 s. Studies during rebreathing established that CO2 reached the lungs from the legs 4-5 s after release of occlusion, and control PVCO2 was reached after 12 s. Repeated occlusion for the final 2 min of exercise was associated with hyperpnea of similar degree to the initial occlusion. An identical study performed in a patient with absent ventilatory response to CO2 and reduced ventilatory response to exercise showed normal hyperventilatory response to cuffing but did not show an increase in ventilation associated with the arrival of CO2 in the lungs, following release of occlusion. The studies confirmed the importance of CO2 in mediating rapid changes in ventilation during exercise.

Carbon Dioxide↗