Search PubMed⌕ Search

Biomedical subjects

E Weitzenblum

Publications and source records attributed to E Weitzenblum.

At least 19 recordsLinked to original sources
PubMed1992

[Long-term oxygen therapy in chronic respiratory insufficiency. Usefulness, indications, modes of administration].

Long-term oxygen therapy improves the life expectancy of hypoxaemic patients with chronic obstructive pulmonary disease (COPD), provided the hypoxaemia is sufficiently pronounced under stable conditions (PaO2 less than 55 mmHg) and oxygen is given for more than 16 out of 24 hours. By extension, the same indications are applicable to hypoxaemia due to other causes (diffuse fibrosis, pneumoconiosis, cystic fibrosis, etc.). Long-term oxygen therapy improves the patients' quality of life and also has favourable effects on oxygen transport, neuropsychological status, polycythaemia and pulmonary hypertension. It is usually delivered by means of O2 extractors, to which may be added small flasks of O2 gas for walking and moving about. Liquid O2 is a good solution for subjects who are motivated and are obliged to do a great deal of walking. The O2 flow rate administered must be such that it rises the PaO2 level above 60 mmHg. Oxygen therapy is only a symptomatic treatment and cannot replace other types of therapy, such as bronchodilators, physiotherapy, etc. It gives satisfactory results but it has not transformed the prognosis of severe hypoxaemic COPD.

Blood Gas Analysis↗
PubMed1992

Benefit from long-term O2 therapy in chronic obstructive pulmonary disease patients.

The Nocturnal Oxygen Therapy Trial (NOTT) and Medical Research Council (MRC) trial have clearly indicated that long-term oxygen therapy (LTO) improved survival in patients with hypoxemic chronic obstructive pulmonary disease (COPD), but the mechanisms accounting for this improved survival could not be established. In particular, there was no link between survival and changes in pulmonary hemodynamics. More recent studies have shown even better results of survival in patients under LTO after at least 5 years. LTO improves the quality of life in these patients by improving their neuropsychological condition, by increasing their walking distance, and by reducing the time spent in hospital. Whether LTO improves pulmonary hemodynamics and right ventricular function is still debated. No significant changes in mean pulmonary artery pressure (PAP) were observed in the MRC study in patients receiving O2 during greater than 15 h/day, whereas a modest but significant fall in PAP was noticed after 6 months in the NOTT patients receiving O2 during greater than 18 h/day. In our own study, confirmed by more recent data from our laboratory, a reversal in the progression of pulmonary hypertension was observed in patients receiving O2 during greater than 16 h/day, but it is not possible to say whether a rather small decrease in PAP and pulmonary vascular resistance will have favorable effects on life expectancy. Presently, we do not know whether LTO can reverse, at least partially, the structural changes in the pulmonary vessels possibly induced by chronic alveolar hypoxia, and we need to perform further studies in this field.

Clinical Trials as Topic↗
PubMed1992

Frequency and correlates of the saw-tooth pattern of flow-volume curves in an epidemiological survey.

The object of this report was to assess the possibility of identifying saw-tooth patterns on flow-volume curves in men aged 28 to 58 years. We studied the frequency of these patterns and their relationships with two indirect signs of UAO increase in FEV1/PEF and FEF50%/FIF50% ratios--as well as with clinical and functional data. Twenty-six of the 360 subjects surveyed, ie, 7.2 percent, had flow oscillations in the inspiratory and/or expiratory part of flow-volume curves, corresponding to the definition of the saw-tooth pattern. We observed significant relationships between the saw-tooth pattern and the mean FEV1/PEF ratio. In 97 subjects, the proportion of those with saw-tooth patterns was 13.4 percent, and the mean FEF50%/FIF50% ratio was 1.53 in those with the pattern vs 1.07 in those without it. These results show that the saw-tooth pattern was not rare in these men.

Adult↗
PubMed1992

Chronic obstructive pulmonary disease and sleep apnea syndrome.

The term "overlap syndrome" was introduced by Flenley to describe the association of sleep apnea syndrome (SAS) with chronic obstructive pulmonary disease (COPD). Epidemiologic data on the prevalence of the overlap syndrome are not available, but the frequency of an associated COPD in SAS patients has been emphasized in almost all the studies analyzing the development of respiratory insufficiency in SAS patients. In a large series (n = 264) of unselected SAS patients who had undergone detailed pulmonary function tests, we observed an obstructive ventilatory defect (FEV1/VC < 60%) in 30 of 264 patients (11%). These patients had lower daytime PaO2 and higher PaCO2 than the other patients and they had higher resting and exercising pulmonary artery mean pressure (right heart catheterization was performed in 215 of 264 patients). We conclude that the risk of developing respiratory insufficiency and cor pulmonale is higher in overlap patients.

Adult↗
PubMed1992

[Sequential administration of a reduced dose of almitrine to patients with chronic obstructive bronchopneumopathies. A controlled multicenter study].

Recent multi-centre studies have shown that high doses of Almitrine (100-200 mg per day), lead to a significant improvement in the hypoxaemia of patients presenting with chronic airflow obstruction, but that a high blood level (greater than 500 ng/ml) is often seen after 1 year, sometimes associated with signs of peripheral neuropathy. In order to maintain Almitrine blood levels in the range 200-300 ng/ml we have used an intermittent regime (with a "window" of 1 month every 3 months) and a dose limited to 100 mg per day. 102 hypoxic patients with chronic airflow obstruction, who were in a stable state were included. 65 patients were in the Almitrine group (A) and 37 patients in the placebo group (P). The treatment lasted for 1 year. In addition there was a 3 monthly follow up with arterial blood gases and spirometry, a clinical neurological examination and also electrophysiology, initially and after 6 and 12 months. 43% of patients in group A and 32% of patients in group P, left the study, most often due to poor cooperation, but sometimes as a result of side effects. After 12 months the PaO2 rose significantly in group A from 59.1 +/- 0.7 to 65.8 +/- 1.6 mmHg (p less than 0.001) whilst it was not changed in group P. The PaCO2 did not change in either group. On the other hand there was a significant fall in the subgroup of patients with hypercapnia in group A (p less than 0.001). The outcome of the neurological and electrophysiological assessments did not show any significant difference between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Sleep-related oxygen desaturation and daytime pulmonary haemodynamics in COPD patients.

It has been hypothesized that in chronic obstructive pulmonary disease (COPD), sleep-related hypoxaemia could lead to pulmonary hypertension (PH) and cor pulmonale, even in patients with only mild daytime hypoxaemia. We investigated the relationships between sleep variables and daytime pulmonary haemodynamics in 40 COPD patients with daytime arterial oxygen tension (PaO2) between 60-70 mmHg (8-9.3 kPa). Patients were considered as desaturators if they spent at least 30% of the sleep recording time with a transcutaneous O2 saturation (StcO2) less than 90%. Daytime arterial blood gases and pulmonary volumes could not discriminate desaturators "D" (n = 18) from non-desaturators "ND" (n = 22), but awake baseline StcO2, measured just prior to the onset of sleep, was lower in group D. Pulmonary artery mean pressure was significantly higher in group D (19.1 +/- 4.7 vs 16.8 +/- 1.9 mmHg, p less than 0.05) and all patients with PH (6 out of 40) belonged to group D. PH was observed in 6 of the 15 patients whose mean nocturnal StcO2 was less than 90% but in none of the 25 with a mean nocturnal StcO2 greater than 90%. The PH patients (n = 6), all desaturators, differed from the desaturators with no PH (n = 12), and from ND (n = 22) in having higher numbers of desaturation dips, longer durations of dips, and lower mean nocturnal arterial oxygen saturation (SaO2). We conclude that a causal relation between nocturnal desaturation and permanent PH is very likely. Further studies are needed to see whether oxygen therapy can prevent PH in these patients.

Blood Gas Monitoring, Transcutaneous↗
PubMed1991

Evolution of physiological variables in patients with chronic obstructive pulmonary disease before and during long-term oxygen therapy.

In 24 patients with severe chronic obstructive pulmonary disease (COPD), we investigated the evolution of pulmonary volumes, arterial blood gases (ABG) and mean pulmonary artery pressure (PAP), before (T0-T1) and during (T1-T2) long-term oxygen therapy (LTO). LTO was initiated at T1 on usual criteria (PaO2 persistently less than or equal to 55 mm Hg) and was given during greater than or equal to 16 h/day. The T0-T1 period ranged from 12 to 186 months (mean 53 +/- 41 months) and the T1-T2 period from 12 to 120 months (mean 44 +/- 30 months). There was a significant worsening of the obstructive pattern (FEV1 decreasing from 1,084 +/- 326 to 879 +/- 318 ml, p less than 0.005) and of ABG (PaO2 decreasing from 58.2 +/- 9.2 to 51.6 +/- 6.5 mm Hg, p less than 0.01) before the onset of LTO, whereas there was a rather good stability of ABG during LTO and the changes in pulmonary volumes were modest and statistically nonsignificant (FEV1 decreased from 879 +/- 318 to 809 +/- 247 ml). PAP tended to increase from T0 to T1 and to decrease from T1 to T2, but these changes only reached the level of statistical significance when they were expressed as changes per year (+1.0 +/- 2.7 vs. -1.3 +/- 4.5 mm Hg, p less than 0.05). The evolution of physiological variables was nearly identical in subgroups of patients who had died (n = 13) or were still alive (n = 11) at the time of data collection (T3) and this held particularly true for PAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1991

Pulmonary hemodynamics in chronic obstructive pulmonary disease of the emphysematous type.

Pulmonary hemodynamics have been extensively investigated in patients with chronic bronchitis or in 'mixed' patients (chronic bronchitis + emphysema) but rarely in patients with markedly predominant emphysema. We have investigated a large series (n = 151) of such patients, emphysema having been assessed on radiological, clinical and functional grounds. The mean age was 58 +/- 10 years; vital capacity (VC, % of predicted) = 81 +/- 19; forced expiratory volume in 1 s (FEV1) = 1,198 +/- 589 ml; FEV1/VC = 38 +/- 12%; PaO2 = 72 +/- 11 mm Hg; PaCO2 = 37.5 mm Hg. Pulmonary hypertension (PH), defined by a resting pulmonary artery pressure (PAP) of greater than or equal to 20 mm Hg, was present in only 31 of 151 patients. During steady-state exercise (40 W or less) an abnormally high PAP (greater than or equal to 30 mm Hg) was observed in 99 of 151 patients. Resting and exercising PAP were poorly correlated with resting PaO2 and PaCO2, but were better correlated with the amplitude of the respiratory pressure swings, FEV1, the transfer factor and exercising PaO2. Patients with PH (n = 31) showed significantly more obstruction and pulmonary distension than the remainder, but they did not differ from the non-PH patients with regard to resting PaO2. It is concluded that: (1) resting PH is not the rule in diffuse emphysema but exercising hypertension is frequent (2 of 3 patients), and (2) hypoxemia is not a determining factor of hemodynamic abnormalities in emphysema.

Adult↗
PubMed1991

One year treatment with almitrine improves hypoxaemia but does not increase pulmonary artery pressure in COPD patients.

Almitrine bismesylate, a chemoreceptor agonist, improves hypoxaemia in a high percentage of chronic obstructive pulmonary disease (COPD) patients and its long-term use may thus be of interest in these patients. The course of pulmonary haemodynamics during a one year treatment was investigated in severe COPD patients (forced expiratory volume in one second FEV1 = 1,040 +/- 80 SEM ml) with persistent hypoxaemia (initial arterial oxygen tension (PaO2) in the range 6.6-8.6 kPa (50-65 mmHg]. Patients were given either almitrine (A, n = 27), 100 mg.day-1, during two consecutive months per quarter followed by a one month wash-out period (intermittent "schedule"), or placebo (P, n = 18) with the same schedule. Eleven patients in group A and 8 in group P could not complete the one year study because of lack of compliance, worsening of respiratory insufficiency, or for other reasons. In the remaining patients, PaO2 significantly increased in group A (n = 16) from 7.6 +/- 0.1 to 8.3 +/- 0.2 kPa (56.9 +/- 1.0 to 62.7 +/- 1.7 mmHg) (p less than 0.001) but not in group P (n = 10) from 7.5 +/- 0.3 to 7.9 +/- 0.3 kPa (56.1 +/- 2.3 to 59.1 +/- 2.1 mmHg). PaCO2 did not significantly change in either group. Pulmonary artery mean pressure (PAP) was stable in both groups: from 26.8 +/- 2.1 to 25.4 +/- 1.9 mmHg in group A, and from 20.6 +/- 1.1 to 20.9 +/- 1.5 mmHg in group P.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1979

Radionuclide computerized ventilation studies.

Studies of regional lung function have developed rapidly in the last few years. Xenon -133 is the most frequently used isotope because of its physiocochemical and biologic properties. Fixed counters are being replaced by the scintillation camera interfaced to a computer allowing easy acquisition and interpretation of results and numerical data. The use of isotopes other than 133Xe, such as 81mKr, is less widespread. In this article, a method is described for studying regional ventilation in which the isotope used is 133Xe, the radioactivity is recorded by a scintillation camera, interfaced to a computer andsix (or 12) regions for both lungs are selected and investigated. The regional ventilation is expressed as an absolute value in ml/min/ml of ventilated volume as well as the relative contribution in percent of each zone to the total ventilation and volume. To illustrate this method, the results are reported for healthy subjects and for patients with chronic bronchitis and emphysema. Scintigraphs of individual cases are presented. Certain theoretic problems related to calculation of regional ventilation are discussed.

Bronchitis↗
PubMed1979

Course of pulmonary hemodynamics in patients with chronic obstructive pulmonary disease.

Eighty-five patients with chronic obstructive pulmonary disease, mainly chronic bronchitis (71 patients), who had arterial hypoxemia and moderate to severe obstruction of the airways underwent at least two right cardiac catheterizations in a clinical steady state, with a delay of three years or more between the first and the last catheterization. The average delay was 60 +/- 19 months (range, 36 to 119 months). Patients were regularly examined (quarterly clinical and functional checkups). The changes in pulmonary hemodynamic data were small. In the group of 53 patients with an initial mean pulmonary arterial pressure of 20 mm Hg or less, this pressure varied from 15.4 +/- 3.1 to 18.3 +/- 6.6 mm Hg (P less than 0.001); in the group of 32 patients with an initial mean pulmonary arterial pressure greater than 20 mm Hg, this pressure varied from 27.7 +/- 6.0 to 31.0 +/- 9.3 mm Hg (P less than 0.05). The mean pulmonary arterial pressure increased by 5 mm Hg or more in only 28 patients. In these patients with hemodynamic "worsening," the final arterial oxygen pressure (PaO2) was lower and the final arterial carbon dioxide tension was higher than in the remaining patients. A significant negative correlation (r = -0.39; P less than 0.001) was observed between changes in PaO2 and mean pulmonary arterial pressure. There was a generally good agreement between the course of pulmonary hemodynamics (mean pulmonary arterial pressure), on the one hand, and the clinical, radiologic (transverse diameter of the heart), and electrocardiographic evolution, on the other hand. In the 33 patients who died, a relatively long survival was observed after the first episode of right-sided heart failure or after ascertaining pulmonary hypertension.

Adult↗
PubMed1978

[The regional exploration of pulmonary function using xenon 133. Value of the gamma camera connected to a computer (author's transl)].

Regional isotopic exploration of ventilation and pulmonary perfusion is not yet widely applied in clinical practice, by virtue of the complexity of the equipment required, but also because of the complicated and lengthy analysis of the results. In this respect, connection of the scintillation camera to a computer represents a major advance which other authors have already emphasized. Our own experience in this area and our method of exploration are described. The results of regional exploration in a group of 43 cases of chronic obstructive lung disease (33 patients of the chronic bronchitis type, 10 patients with emphysema) are analysed and discussed. The results indicate the following : in chronic bronchitis, a very marked fall in ventilation of the bases with inversion of the normal vertical ventilation gradient, and a fall in the ventilation/perfusion ratio of the bases; in emphysema, a fall in ventilation, but also and above all in regional perfusion of all territories with preservation of normal or even increased regional ventilation/perfusion ratios. Regional exploration may also be of value in the detection of early stages of obstructive lung disease, and in pre-operative assessment in thoracic surgery.

Bronchitis↗
PubMed1977

Regional pulmonary function in sarcoidosis.

In 26 subjects with a confirmed histological diagnosis of thoracic sarcoidosis regional lung function was studied with Xenon 133. All subjects also underwent overall lung function studies including CO steady state (TCO SS) and single breath (TCO SB) diffusing capacity. Regional ventilation (Vr) was on the average increased in stages I (isolated hilar adenopathies) and II (pulmonary infiltration) and appeared normal in stage III (pulmonary fibrosis). Regional perfusion (Qr) was on the average normal in stages I and II and decreased in stage III. There were no appreciable differences between average values in stages I and II. Abnormalities of Vr and Qr were frequently found in individual cases. A distinction was made between the total number of abnormalities and deficiency abnormalities. The total number of abnormalties was high in all three stages. Deficiency abnormalities were relatively rare in stages I and II, and frequent in stage III. The correlation between radiological and regional functional abnormalities was low. TCO SB/VA was found significantly lower (P less than 0.005) in subjects with regional deficiency abnormalities (mostly perfusion abnormalities). These data probably indicate that a lowered diffusing capacity may be due to the loss of pulmonary capillaries and not only to ventilation - perfusion disparities.

Adolescent↗