European reference equations for CO and NO lung transfer.

The aim of the present study was to calculate reference equations for carbon monoxide and nitric oxide transfer, measured in two distinct populations. The transfer factor of the lung for nitric oxide (T(L,NO)) and carbon monoxide (T(L,CO)) were measured in 303 people aged 18-94 yrs. Measurements were similarly made in two distant cities, using the single-breath technique. Capillary lung volume (V(c)) and membrane conductance, the diffusing capacity of the membrane (D(m)), for carbon monoxide (D(m,CO)) were derived. The transfer of both gases appeared to depend upon age, height, sex and localisation. The rate of decrease in both transfers increased after the age of 59 yrs. T(L,NO)/alveolar volume (V(A)) and T(L,CO)/V(A) were only age-dependent. The mean T(L,NO)/T(L,CO) was 4.75 and the mean D(m)/V(c) was 6.17 min(-1) x kPa(-1); these parameters were independent of any covariate. V(c) and D(m,CO) calculations depend upon the choice of coefficients included in the Roughton-Forster equation. Values of 1.97 for D(m,NO)/D(m,CO) ratio and 12.86 min x kPa(-1) for 1/red cell CO conductance are recommended. The scatter of transfer reference values in the literature, including the current study, is wide. The present results suggest that differences might be due to the populations themselves and not the methods alone.

[COLIBRI: Improving clinical practice and producing relevant scientific data]. / COLIBRI : optimiser la pratique clinique et produire des données scientifiques pertinentes.

COLIBRI-COPD is a francophone consultation web portal accessible to pulmonologists in the hospital and in the community. We present this observation which describes the phenotype of COPD patients entered (anthropometry, exposures, addictions, functional impairments, questionnaires: MRC, DIRECT, CAT, HAD, Epworth, co-morbidities, incidence of exacerbations, drug treatment or other treatments). The results of the first 1079 patients show a high level of completeness for the main data items. A comparison of patients seen in outpatient consultations shows significant variability between patients with the same GOLD stage, regarding the incidence of exacerbations, signs of anxiety-depression, of diabetes mellitus, or the prescriptions of anticholinergics and inhaled corticosteroids. These initial results suggest that data collection in real life gives a reliable database to obtain longitudinal data on various aspects of COPD. The data quality (completeness, reliability) is partly related to the usability of the web tool and to the possibility of doing self-assessment of practitioners' own recorded data.

Cardiac output response to dynamic exercise after atrial switch repair for transposition of the great arteries.

Results from this study showed that patients who underwent successful operation for transposition of the great arteries had no appropriate increase in stroke volume in response to exercise of a nature similar to common recreational activities. The impairment, most likely due to disturbances in both venous return and ventricular systolic function, is compensated for by an increase in peripheral oxygen extraction; however, this increase may not be adequate with maturation or during prolonged exercise when cardiovascular constraints are more important.

Early onset of pulmonary gas exchange disturbance during progressive exercise in healthy active men.

Some recent studies of competitive athletes have shown exercise-induced hypoxemia to begin in submaximal exercise. We examined the role of ventilatory factors in the submaximal exercise gas exchange disturbance (GED) of healthy men involved in regular work-related exercise but not in competitive activities. From the 38 national mountain rescue workers evaluated (36 +/- 1 yr), 14 were classified as GED and were compared with 14 subjects matched for age, height, weight, and maximal oxygen uptake (VO2 max; 3.61 +/- 0.12 l/min) and showing a normal response (N). Mean arterial PO2 was already lower than N (P = 0.05) at 40% VO2 max and continued to fall until VO2 max (GED: 80.2 +/- 1.6 vs. N: 91.7 +/- 1.3 Torr). A parallel upward shift in the alveolar-arterial oxygen difference vs. %VO2 max relationship was observed in GED compared with N from the onset throughout the incremental protocol. At submaximal intensities, ideal alveolar PO2, tidal volume, respiratory frequency, and dead space-to-tidal volume ratio were identical between groups. As per the higher arterial PCO2 of GED at VO2 max, subjects with an exaggerated submaximal alveolar-arterial oxygen difference also showed a relative maximal hypoventilation. Results thus suggest the existence of a common denominator that contributes to the GED of submaximal exercise and affects the maximal ventilatory response.

Muscle protein degradation in severely malnourished patients with chronic obstructive pulmonary disease subject to short-term total parenteral nutrition.

Patients with chronic obstructive pulmonary disease (COPD) often lose weight and muscle mass with progression of the disease. Muscle protein degradation in patients with COPD has never been examined before and during hypercaloric feeding. Eight severely malnourished patients with COPD were examined at home consuming their usual intake, in the hospital after 3 days of a meat-free regular oral diet (period B), and during a hypercaloric (55 kcal/kg) high-lipid (55%) parenteral formula (total parenteral nutrition [TPN]). During period B, 8 well-nourished patients and 10 malnourished cancer patients were used as control groups. Measurements included plasma assays, leg blood flow, leg exchange (of 3-methylhistidine [3MeH], glucose, lactate, and oxygen) and urinary measures of 3MeH, creatinine, and nitrogen. During period B, net release of 3MeH across the leg in patients with COPD was similar to that in well-nourished control subjects and cachectic cancer patients. In COPD patients, there was only a transient decrease in leg exchange values of 3MeH with administration of TPN. COPD patients demonstrated a reduction (p less than .01) in urinary 3MeH excretion and an increase in nitrogen balance (p less than .01) with TPN compared with period B. The decrease in muscle protein degradation with administration of TPN accounts for about 50% of the increase in nitrogen retention in patients with COPD. These data suggest that in severely malnourished patients with COPD the weight loss is not dependent on increased rates of skeletal muscle protein degradation; nevertheless, degradation rates attenuate with a positive nitrogen balance during nutrition repletion.

[Cardiac metastasis from a Merkel cell skin carcinoma. A case report]. / Métastase cardiaque d'un carcinome cutané à cellules de Merkel. A propos d'un cas.

The authors report the case of a cardiac metastasis of a Market cell skin tumour in a 72 year old woman, presenting with chest pain and infero-lateral myocardial ischaemia simulating an acute coronary syndrome. The diagnosis, suspected on echocardiography, was confirmed by thoracic CT scan. Markel cell carcinoma is a rare skin tumour classified among the malignant neuroendocrine tumours. It has a high metastatic potential, especially to the gastrointestinal tract and the lung. On the other hand, cardiac metastases are quite exceptionally rare.

[Cardiorespiratory and metabolic changes during prolonged exercise at 50% of the maximal load. Application to rehabilitation of severe cardiac insufficiencies]. / Modifications cardiorespiratoires et métaboliques au cours d'un effort prolongé à 50% de la charge maximale. Application à la rééducation des insuffisants cardiaques sévères.

The object of physical training in patients with chronic cardiac failure and severe left ventricular dysfunction is to improve skeletal muscle adaptation without impairing myocardial function. It is acknowledged that aerobic exercise limits increased ventricular strain. Therefore, the authors decided to determine whether exercise at 50% maximal power load constituted aerobic training. Eight patients with chronic cardiac failure (age 57 +/- 10 years; resting radionuclide ejection fraction: 25 +/- 5%) performed a rectangular submaximal exercise for 20 minutes at 50% of maximal aerobic load (MAL) as determined by a prior triangular exercise test at 10 W/mn (MAL = 92 +/- 26 Watts-Peak VO2 = 14.8 +/- 2.4 ml/Kg/mn). Gaseous exchanges (VO2, VCO2) minute volume (MV) and serum lactates were measured at rest and every 5 minutes during exercise. MV, VO2 and VCO2 increased significantly (p < 0.005) with a change of less than 5% between the 20th and 10th minute. Respiratory quotient was unchanged until the end of exercise and serum lactate levels stabilised between the 10th (3.4 +/- 0.66 mmol/l) and the 20th minute of exercise (3.5 +/- 0.47 mmol/l). No significant relationship was observed between ventilation and serum lactate or between respiratory quotient and serum lactate. These results confirm that exercise at 50% of maximal load is aerobic training even in patients with severe left ventricular dysfunction. This parameter would appear to be more useful than using the heart rate which is often abnormal in chronic cardiac failure (abnormal chronotropic response, atrial or ventricular arrhythmias).

[Cardiac output evaluation during exercise in children treated with atrial surgery for transposition of great vessels]. / Evaluation du débit cardiaque à l'exercice chez des enfants traités par chirurgie atriale d'une transposition des gros vaisseaux.

The long-term physiopathological consequences of atrial surgery (Senning or Mustard procedures) for transposition of the great vessels with respect to exercise capacity are not well known. We measured the cardiac index by the technique of CO2 rebreathing at two submaximal levels of exercise corresponding to a stable oxygen consumption of 20 (E20) and 30 (E30) ml/min/kg in 7 patients successfully operated for transposition of the great vessels and in 7 control children paired for age, gender and body surface area. Despite an identical chronotropic response to exercise in the two groups, the increase in cardiac index was not as great in the children operated for transposition (from 6.86 +/- 0.51 to 7.71 +/- 0.78 l/min/m2) as in the control population (from 7.71 +/- 0.78 to 10.2 +/- 0.51 l/min/m2; p < 0.02). The stroke volume index was therefore significantly lower in the transposition group at both levels of exercise (52 +/- 3.2 vs 63 +/- 4.1 ml/m2; p < 0.04 at E20; and 46.4 +/- 4.3 vs 66 +/- 5.1 ml/m2 at E30). The main cause of this reduction of the stroke volume index is probably a lack of adaptation of right ventricular systolic function on exercise but it is not possible to exclude diastolic dysfunction due to reduce compliance secondary to the intraatrial patch. The conditions of preload are in fact instrumental in increasing stroke volume index at submaximal exercise levels.

[Malnutrition and chronic obstructive bronchopathies]. / Malnutrition et bronchopathies chroniques obstructives.

A knowledge of the relationship between nutrition and the respiratory system applied in chronic airflow obstruction (BCO) enables a better understanding of the increased frequency (30 to 50%) of protein-energy malnutrition (MEP) in this population. The physiology of the wasting in chronic airflow obstruction seems to relate to hypermetabolism (HMB) which is not compensated by an increased alimentary intake. The HMB is linked to a rise in the work of the respiratory muscles whose efficiency is altered by intrathoracic hyperinfiltration and also the consequences of MEP on the mass and function of the respiratory muscles. In the animal MEP induced by alimentary restrictions leads to a model of pulmonary emphysema and to the diminution of the synthesis of surfactant. This emphysema seems to be principally due to an alteration of the process of protein synthesis and to a diminution of lysyl-oxydase activity. The nutrients (utilised notably by the venous route) have their own pharmacological role, and in addition they have an effect on the natural equilibrium of the energy and nitrogen balance. Lipids (rich in polyunsaturated fatty acids) intervene in the synthesis of prostaglandins, and exercise some effects on the inflammatory process and the activity in the bronchial and vascular smooth muscles. Based on this fact they have been used for their anti-inflammatory role at the pulmonary level in the treatment of mucoviscidosis. The administration of amino acids changes ventilation by acting on the central neuro-muscular command mechanism (VT/TI). The perfusion of amino acids enables a restoration of the chemo-sensitivity to oxygen and to CO2 abolished by the prolonged restricted diet. Finally the partial pressure of oxygen ought to be interpreted with respect to meal times because an oral dose of glucose can provoke an increase in the PaO2 of around 10 mmHg for healthy subjects and those with BCO. A preventive and therapeutic attitude vis a vis BCO should take account of the relationship between nutrition and the respiratory system in parallel with a correction of hypoxaemia in order to avoid the development of wasting.

[Late diagnosis of mucoviscidosis based on the association of bronchiectasis and sterility]. / Mucoviscidose diagnostiquée tardivement devant l'association bronchectasies-stérilité.

We report a case of a man aged 36, in whom a diagnosis of mucoviscidosis was diagnosed based on the association of diffuse bronchiectasis and obstructive azoospermia. We discussed some clinical and biological aspects leading to the diagnosis of mucoviscidosis in the adult.

[Diagnostic use of oxygen consumption and gas exchange in exercise testing]. / Usage diagnostique de la consommation d'oxygène et des échanges gazeux au cours de l'épreuve d'exercice.

The interpretation of cardio-pulmonary exercise testing is usually performed on successive decisional organigrams which are based on the normality of two initial main branchpoints i.e., Vo2max and ventilatory threshold (VThr). This didactic approach leads however to a simplistic approach of exercise pathophysiology because the answer to the two original branchpoints (Vo2max and VThr) is mainly binary whereas the physiological meaning of these two parameters is multifactorial. Thus, we propose a methodic analytical approach which allows to integrate step by step the various informations concerning aerobic capacity, ventilatory and cardiocirculatory responses, and acidobasic status. After a purely descriptive analysis of data , a first synthesis describes the physiopathological behaviour during exercise and states the specificity of these informations excluding usual confounding factors. The comparison between the functional data and the clinical informations allows to propose some physiopathological hypothesis by confronting several complementary approaches: physiological, physiopathological and clinical ones. This method seems to be more adapted to the clinical diagnostic use of such a physiological investigation because it is sensitive, reproducible but not specific.

[Comparative study of magnetic resonance imaging and tomodensitometry in the diagnosis of locoregional extension in 61 patients with bronchial cancers]. / Etude comparative de l'imagerie par résonance magnétique et de la tomodensitométrie dans le diagnostic d'extension locorégionale de 61 patients porteurs de cancers bronchiques.

In order to assess the value of nuclear magnetic imagery NMR in the diagnosis of the extent of bronchial cancers, 61 patients with operable bronchial carcinoma had both a CT scan and an NMR scan pre-operatively. Fifty one mediastinoscopies were performed. Twelve times there were mediastinal glandular enlargement. Ten times the thoracotomy was performed straight away. After pathological studies of the biopsy, 24 patients were N2, 25 N1, 12 N0; the sensibility of NMR to foresee lymph node invasions was 83% (specificity 70%), for CT scanning 75% (specificity 81%). Thirteen patients presented with a direct mediastinal or parietal invasion. The sensibility of detecting these invasions was only 38% for NMR (specificity 94.5%) and for CT scanning 54% (specificity 94.5%). There is little difference in the results and no statistical difference. This leads us to conclude that at present, NMR does not give more information than TDM in the diagnosis of operability in bronchial cancers.

[Value of computed tomography in the diagnosis of the intrathoracic extension of bronchial cancer]. / Intérêt de la tomodensitométrie (TDM) pour le diagnostic d'extension intrathoracique du cancer bronchique.

In 76 patients the diagnosis of the mediastinal extension of a bronchial cancer, assessed by computed tomography (CT), was compared to histological specimens obtained by mediastinoscopy and surgery (58/76). The extension to mediastinal nodes was present in 26 subjects (34.2%) and yet was not recognised 15 times on CT. There were 15 false negatives (FN) and 3 false positives (FP). Sensitivity 43%, specificity 94%, predictive value for positives (VPP) 70%, predictive value for negatives (VPN) 75%. Extension was present in 18 patients. These were recognised 14 times by CT. There were no false positives. (Sensitivity 70%, specificity 100%, VPP 100%, VPN 94%). We conclude That CT is useful for diagnosing direct mediastinal extension and allows the juxta-hilar extension of the cancer to be assessed. CT has no place in the diagnosis of mediastinal gland involvement. Mediastinoscopy (5.2% FN; no FP) is better than TDM for the diagnosis of extension to the mediastinal nodes both for peripheral and central cancers.

[Primary alveolar hypoventilation. Clinical aspects and diagnostic problems. Apropos of a case]. / Hypoventilation alvéolaire primitive. Aspects cliniques et problèmes diagnostiques. A propos d'une observation.

Primary alveolar hypoventilation is a rare syndrome of unknown origin, characterized by a dysfunction of the automatic respiratory pattern in spite of normal lungs and in the absence of mechanical ventilatory defects. A reduction of the ventilatory response to CO2 is regularly found, and cardiac failure is common. The differential diagnosis mainly concerns the sleep apnoea syndrome. The usual treatments have little effectiveness.

[Rheumatic pelvispondylitis and non-tuberculous sclerotic lesions of the pulmonary apex]. / Pelvispondylite rhumatismale et lésions scléreuses non tuberculeuses des sommets.

Two new cases of rheumatic pelvispondylitis associated with bilateral fibrosis of the pulmonary apex are reported and published data are reviewed. The clinical, radiological, evolutive and diagnostic features of this probable pulmonary manifestation of rheumatic spondylitis are described, and the pathogenesis is discussed.

[Transparietal needle biopsy of pulmonary lesions with an image intensification system. Apropos of 82 biopsies]. / Ponction transpariétale de lésions pulmonaires, à l'aiguille sous amplificateur de brillance. A propos de 82 ponctions.

We report the results of 82 needle biopsies of pulmonary nodules, using a fine screw needle. Owing to the very small diameter of the needle (0.8 mm), very few complications were observed (minor pneumothorax 13%, major pneumothorax 2.5%). The screw needle provided samples adequate for both cytological and histological examination. Forty-eight out of 53 cancers were diagnosed by this method (sensitivity 83%, specificity 100%).

[Physiological significance and interpretation of plasma lactate concentration and pH in clinical exercise testing]. / Signification physiologique et interprétation clinique de la lactatémie et du pH au cours de l'EFX incrémentale.

According to a widely accepted model, based on the theory of the anaerobic threshold (AT), the increase in plasma lactate concentration which develops after the first ventilatory threshold (VT1, considered as an AT) is due to compensation for insufficient aerobic metabolism by anaerobic glycolysis, with accumulation of lactic acid resulting in a decrease in pH. Bicarbonate is the main buffer of protons (>90%) producing non-metabolic CO2 in muscle and thus increasing the CO2 flux to the lungs. This phenomenon, along with the low pH, triggers hyperventilation. Because of this model, great importance has been placed on plasma lactate and pH. We argue that this importance is excessive and these variables should be used with caution in the interpretation of clinical exercise testing, because the model based on AT is not valid: there is no aerobic failure above VT1 and, thus, there is no evidence of an AT; the increase in plasma lactate does not reflect anaerobiosis but is the marker of the increase in the error signal needed for the stimulation of mitochondrial respiration; bicarbonate is not the main buffer during exercise (these are proteins and phosphocreatine breakdown in the muscle; hemoglobin in the blood); non-metabolic CO2 is not produced in the muscle but in the lung because of the low pH and hyperventilation (the control of which remains unknown); and the flux of CO2 to the lung does not increase at faster rate after than before VT1.

[Cardiopulmonary exercise testing and dyspnea in patients with chronic respiratory diseases]. / Exploration fonctionnelle à l'exercice (EFX) et dyspnée au cours de maladies respiratoires chroniques.

Cardiopulmonary exercise testing (CPET) is the most comprehensive investigation for understanding the mechanisms responsible for dyspnea in patients with chronic respiratory disease. The two observations presented here illustrate how CPET can contribute to the management of patients with interstitial lung diseases. A 60-year-old woman had been followed for 20 years for non-progressive pulmonary sarcoidosis, untreated for many years. CPET led to the diagnosis of an atrial septal defect. A 76-year-old man was treated for idiopathic pulmonary fibrosis. Before pulmonary rehabilitation, CPET was performed which revealed significant aortic valve stenosis, which had been to that point asymptomatic. In these two observations, CPET determined the presence of an associated disease, distinct from the interstitial lung disease.

Breathing patterns during eccentric exercise.

Eccentric (ECC) work is interesting for rehabilitation purposes because it is more efficient than concentric (CON). This study assessed respiratory patterns and electromyographic activity (EMG) during ECC and CON cycling, both at similar power outputs and VO2 in eight healthy male subjects. Measurements include ventilation (VE), tidal volume (Vt), breathing frequency (Fb), arterial blood gases, and vastus lateralis (VL) and biceps brachii (BB) EMG. At the same mechanical power, VO2 and VE were fivefold lower in ECC as was VL EMG while BB EMG, Vd/Vt, PaO2 and PaCO2, were not different between modalities. At the same VO2, there was no difference in VE but Vt was lower and Fb higher in ECC. VL EMG was not different between modalities while BB EMG was higher in ECC. The latter observation suggests that ECC cycling may result in arm bracing and restricted chest expansion. Since hyperpnea is a known trigger of exaggerated dynamic hyperinflation, the prescription of ECC cycling for patient rehabilitation requires further assessment.

[From interpretation of cardiopulmonary exercise testing to medical decision]. / De l'interprétation de l'exploration fonctionnelle d'exercice (EFX) à la décision médicale.

Exercise is a situation that involves cardiovascular, respiratory and metabolic responses simultaneously. Thus, interpretating the results of the cardiopulmonary exercise testing (CPET) requires an integrated understanding of the pathophysiology of exercise intolerance which may result from lung, heart, pulmonary or peripheral circulation, muscles disturbances, or a combination of these functional disorders. In this paper, we offer a systematic method to assist clinicians in developing a pathophysiological reasoning from the functional competency of each component measured during incremental exercise. We propose to go through four steps: descriptive analysis, prioritization of the functional disorders, mechanistic proposals and diagnostic and/or therapeutic suggestions. The descriptive analysis step should answer seven key physiological questions, the prioritization step is based on the magnitude of the functional disorders and their relevance to the primary symptoms causing exercise intolerance, the mechanistic proposals step aims at suggesting different mechanisms and etiologies compatible with the scale of observed functional abnormalities, which will finally be tested by exploring specific diagnostic or therapeutic suggestions.