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Biomedical subjects

R Lecours

Publications and source records attributed to R Lecours.

7 recordsLinked to original sources
PubMed2005

Randomised trial of ambulatory oxygen in oxygen-dependent COPD.

Long-term oxygen therapy may limit a patient's ability to remain active and may be detrimental to the rehabilitation process. This study aimed to determine the effect of ambulatory oxygen on quality of life and exercise capacity in patients with chronic obstructive pulmonary disease fulfilling the usual criteria of long-term oxygen therapy. In a 1-yr, randomised, three-period, crossover trial, 24 patients (mean age 68 yrs; mean arterial partial pressure of oxygen at rest 7.1 kPa (53 mmHg)) were allocated to one of the six possible sequences generated by three interventions: 1) standard therapy (home oxygen therapy with an oxygen concentrator only); 2) standard therapy plus as-needed ambulatory oxygen; and 3) standard therapy plus ambulatory compressed air. The comparison of ambulatory oxygen versus ambulatory compressed air was double blind. The main outcomes were quality of life (Chronic Respiratory Questionnaire), exercise tolerance (6-min walk test) and daily duration of exposure to oxygen therapy. The trial was stopped prematurely after an interim analysis. On average, the patients used few ambulatory cylinders (7.5 oxygen cylinders versus 7.4 compressed air cylinders over a 3-month study period). Ambulatory oxygen had no effect on any of the outcomes. In conclusion, the current results do not support the widespread provision of ambulatory oxygen to patients with oxygen-dependent chronic obstructive pulmonary disease.

Aged↗
PubMed1990

Mechanisms of hyperinflation in asthma.

We studied 11 mild asthmatics to verify whether the mechanisms of hyperinflation in asthma could be inhibited or overcome by passively changing lung volumes. On day 1, we induced a fall in forced expiratory volume in one second (FEV1) of 30-60% by methacholine inhalation and measured the resulting increase in FRC (delta FRC). The delta FRC was 729 +/- 378 ml (mean +/- SD). On day 2, with the subject supine in an iron lung, we measured oesophageal (Poes), gastric (Pgas) and transdiaphragmatic (Pdi) pressures, and changes in functional residual capacity (FRC) (delta V) induced by extrathoracic pressures from -20 to +20 cmH2O before and after bronchoprovocation. With positive pressures, the FRC decreased and reached a plateau at 10 cmH2O pressure or higher. This plateau was at a mean FRC of 839 ml higher after the bronchoprovocation than before. Pdi at FRC varied in the same direction as the extrathoracic pressure and was not modified by the bronchospasm. Peak inspiratory Pdi, without pressure applied in the iron lung, increased from 13.6 +/- 5.4 to 28.1 +/- 13.5 cmH2O after methacholine; extrathoracic pressure of -20 cmH2O decreased this latter value to 15.4 +/- 7.3 cmH2O (p less than 0.01). The increased lung volume and the displaced chest wall recoil curve after provocation were not inhibited by positive or negative extrathoracic pressures. Our data show that the mechanisms of hyperinflation are not eliminated or overcome by passively changing lung volumes and support the hypothesis that persisting activity of inspiratory muscles other than the diaphragm during expiration and perhaps a prolonged expiratory time constant are responsible for hyperinflation in asthma.

Asthma↗
PubMed1986

Bronchoalveolar lavage in pulmonary mycotoxicosis (organic dust toxic syndrome).

Two cases of pulmonary mycotoxicosis (organic dust toxic syndrome) are described in which bronchoalveolar lavage was undertaken during the acute phase and after recovery. Both cases occurred after exposure to mould dust in a silo in the course of removing the top mouldy layer of silage or oats at the start of unloading. The workers suffered an acute febrile illness accompanied by cough and dyspnoea. One patient had impaired ventilatory function and both had arterial desaturation in the acute phase. There was mild impairment of diffusing capacity (transfer factor). Bronchoscopy showed inflammation of the bronchial mucosa in one patient. Fungal spores were cultured from the lavage fluid in both patients. In both patients there was an increase in the percentage of neutrophils in the lavage fluid without increase in lymphocytes. The immunoglobulin concentration in the lavage fluid was normal. At the follow up lavage the neutrophils had returned to normal while a mild lymphocytosis of the lavage fluid was seen in both patients.

Acute Disease↗
PubMed1982

Celiac compression syndrome.

The authors present their experience at the Hôpital St-Luc in Montreal with seven patients who had celiac compression syndrome. All underwent section of the median arcuate ligament to free the celiac axis and resection of the connecting nerve fibers of the solar plexus (periarterial neurectomy). At a mean follow-up of 36 months all patients were asymptomatic. In some cases, extrinsic compression of the celiac axis by the arcuate ligament can explain upper abdominal plain. An epigastric bruit in the presence of a normal digestive tract is an indication for lateral aortography to detect extrinsic compression. The pain in this syndrome cannot be explained solely on hemodynamic grounds; surgical treatment should include release of the celiac axis and complete periarterial neurectomy.

Abdomen↗