Biomedical subjects
J Piquet
Publications and source records attributed to J Piquet.
Reversal of acute exacerbations of chronic obstructive lung disease by inspiratory assistance with a face mask.
BACKGROUND: Patients with acute exacerbations of chronic obstructive pulmonary disease may require endotracheal intubation with mechanical ventilation. We designed, and here report on the efficacy of, a noninvasive ventilatory-assistance apparatus to provide inspiratory-pressure support by means of a face mask. METHODS: We assessed the short-term (45-minute) physiologic effects of the apparatus in 11 patients with acute exacerbations of chronic obstructive pulmonary disease and evaluated its therapeutic efficacy in 13 such patients (including 3 of the 11 in the physiologic study) who were treated for several days and compared with 13 matched historical-control patients. RESULTS: In the physiologic study, after 45 minutes of inspiratory positive airway pressure by face mask, the mean (+/- SD) arterial pH rose from 7.31 +/- 0.08 to 7.38 +/- 0.07 (P less than 0.01), the partial pressure of carbon dioxide fell from 68 +/- 17 mm Hg to 55 +/- 15 mm Hg (P less than 0.01), and the partial pressure of oxygen rose from 52 +/- 12 mm Hg to 69 +/- 16 mm Hg (P less than 0.05). These changes were accompanied by marked reductions in respiratory rate (from 31 +/- 7 to 21 +/- 9 breaths per minute, P less than 0.01). Only 1 of the 13 patients treated with inspiratory positive airway pressure needed tracheal intubation and mechanical ventilation, as compared with 11 of the 13 historical controls (P less than 0.001). Two patients in each group died. As compared with the controls, the treated patients had a more transient need for ventilatory assistance (3 +/- 1 vs. 12 +/- 11 days, P less than 0.01) and a shorter stay in the intensive care unit (7 +/- 3 vs. 19 +/- 13 days, P less than 0.01). CONCLUSIONS: Inspiratory positive airway pressure delivered by a face mask can obviate the need for conventional mechanical ventilation in patients with acute exacerbations of chronic obstructive pulmonary disease.
[Environmental interstitial pneumonia caused by asbestos. Study of a Turkish family exposed to tremolite].
Environmental exposure to asbestos, as observed in Anatolia (Turkey), usually results in pleural pathology (plaques and mesothelioma). We report the case of a 50-year old woman who, until the age of 50, had lived in Eregli, central Anatolia, a region where inhalation of environmental asbestos is responsible for a high prevalence of pleural diseases. Radiology showed diffuse interstitial pneumonia without pleural involvement. Bronchoalveolar lavage brought back asbestos bodies (AB) in concentrations of 4,250 per millilitre. All were made of tremolite, a non-commercial variety of asbestos. The patient's family was investigated by chest radiography and search for AB in sputum. The husband, who came from the same town as his wife and had been exposed until the age of 45, had the classical response with bilateral pleural thickening but no parenchymal abnormalities; 2 AB were found in his sputum. The 3 sons, exposed for 10, 13 and 20 years respectively, had normal radiograms and no AB in their sputum, except for the older (3 AB) who had been exposed for 20 years. These cases illustrate the importance of environmental exposure to asbestos which may produce lesions similar to those observed in industrial exposure. Only mineralogical examinations can determine whether the asbestos is environmental or industrial.
[Apropos of 2 cases of hemolytic anemia in mycoplasma pneumonia].
The authors present 2 cases of mycoplasmal pneumonia associated with severe haemolysis. Haemolytic anaemia is a well-known and habitually mild complication of the disease. It is related to a peak of cold agglutinins, which are antibodies that agglutinate red blood cells usually at low temperatures but sometimes at 37 degrees C when they are present in high concentrations. The pathogenesis of cold agglutinins is thought to involve the secretion of peroxides by Mycoplasma pneumoniae with alteration of ed cell antigens which become immunogenic.
Effects of propranolol on pulmonary gas exchange in patients with cirrhosis.
Propranolol, a beta-blocking agent, has been proposed in the prevention of gastro-intestinal bleeding in cirrhotic patients, and is known for its bronchoconstrictive effects. Since hypoxemia is a frequent finding in patients with cirrhosis, this work was undertaken to study the effects of intravenous propranolol on pulmonary function and on gas exchange in these patients. The 10 patients studied had cirrhosis associated with an increase in the alveolar arterial O2 difference, (A-a)DO2, an index of arterial oxygenation impairment. Their 1-s forced expiratory volume/forced vital capacity (FEV1/FVC) was normal, but in most a reduction of the forced expiratory flow of 25-75% of vital capacity was observed (FEF 25-75), suggestive of some degree of small airway obstruction. Although propranolol induced a significant decrease of FEF 25-75 from 67.7 +/- 19.3% to 55.4 +/- 21.5% (P less than 0.01), suggesting a bronchoconstriction of the small airways, there was no significant decrease in mean arterial oxygen partial pressure (PaO2) (74.1 +/- 6.4 mmHg before and 77.0 +/- 6.5 mmHg after propranolol). Indeed, a slight but significant improvement of the (A-a)DO2 was observed, from 39.1 +/- 5.9 mmHg to 34.4 +/- 4.9 mmHg (P less than 0.02). Although the mechanism of this beneficial effect remains to be elucidated, we conclude that in spite of its bronchoconstrictive action, propranolol is not contra-indicated in cirrhotic patients with hypoxemia who have normal expiratory flow.
The ventilatory effect of external oscillation.
High frequency ventilation (HFV) may be achieved by external oscillation (external HFV) applied around the chest wall (HFCWO) in large animals and humans, or over the entire body (HFBSO) in small animals, instead of being applied via the trachea (internal HFV). We present a synthesis of the results obtained with external HFV in both normal and bronchoconstricted subjects. Whereas external and internal HFV were found to be equivalent in terms of gas exchange in normal rats, external HFV was found to have a beneficial effect in bronchoconstricted rabbits, but internal HFV did not. From the frequency-oscillatory tidal volume relationship determined in normocapnic rabbits, HFBSO at 5 Hz was found to be the optimal frequency at which to ventilate with tidal volumes close to the dead space volume, and which was also shown to be the optimal volume to obtain normocapnia. Moreover, 5 Hz oscillations (HFCWO) at 20 ml and 40 ml superimposed on tidal breathing accelerated nitrogen washout, i.e., gas exchange in normal humans. Unfortunately, only oscillations with much smaller volumes (5-10 ml) were obtainable in COPD patients. Nevertheless, they produced a clear change in breathing pattern associated with a slight improvement in gas exchange and a potentially positive effect on inspiratory muscle fatigue. These results support the concept that non-invasive external HFV technique may be of use in assisting ventilation in bronchoconstricted subjects and may possibly replace conventional controlled ventilation, at least in subjects with high lung compliance, such as babies, neonates and normal adults.
Atrial natriuretic factor in chronic obstructive lung disease with pulmonary hypertension. Physiological correlates and response to peptide infusion.
To investigate the physiological role of atrial natriuretic factor (ANF) in patients with hypoxic pulmonary hypertension secondary to chronic obstructive lung disease (COLD), we infused synthetic alpha-human ANF in seven such patients, and investigated the physiological correlates to circulating peptide levels in 24 patients with COLD. ANF infusion, at incremental rates of 0.01, 0.03, and 0.1 micrograms/kg.min, increased basal plasma immunoreactive (ir) ANF (136 +/- 38 pg/ml) by 3-, 10-, and 26-fold, respectively, and reduced pulmonary artery pressure (from 33 +/- 3 to 25 +/- 2 mmHg, P less than 0.001) and systemic arterial pressure (from 88 +/- 4 to 79 +/- 4 mmHg, P less than 0.001) in a dose-related fashion. Cardiac index increased by 13.5% (P less than 0.01) while heart rate was unchanged. Cardiac filling pressures decreased at 0.1 micrograms/kg.min ANF. Pulmonary and systemic vascular resistance fell by 37% (P less than 0.001) and 19% (P less than 0.001), respectively. Arterial oxygenation was impaired during ANF infusion, suggesting partial reversal of hypoxic pulmonary vasoconstriction. Plasma renin activity remained unchanged but aldosterone fell by 44% (P less than 0.01). The levels of plasma irANF in 24 patients correlated directly with the degree of hemoconcentration (r = 0.67, P less than 0.001), respiratory acidosis (r = -0.65, P less than 0.001), and pulmonary hypertension (r = 0.52, P less than 0.01). The results suggest that ANF may serve as a potent pulmonary vasodilator involved in the circulatory homeostasis of patients with COLD.
[Chronic bronchitis. Value of RU 41740].
Chronic bronchitis is responsible for 20,000 deaths per annum in France, i.e. 5 per cent of the overall mortality rate. Infection of the bronchi and lung tissue is a frequent cause of death in these patients. Acute on chronic bronchitis ranks fifth among the causes of disablement and admission to hospital. Pneumococci and Haemophilus influenza are the organisms most frequently isolated. the incidence and potential severity of acute episodes of infection account for the repeated use of antibiotics which carries a risk of promotion bacterial resistance. RU 41740 is a non-specific immunomodulator agent which reinforces the non-specific means of the respiratory tract against infections. Three double-blind, drug versus placebo and therefore reliable therapeutic trials have shown that the drug is effective in preventing airway infection. In patients with moderately advanced chronic bronchitis, RU 41740 reduces the number and duration of acute infectious episodes as well as antibiotic consumption. This positive effect persists in patients with chronic respiratory failure, including those who present with extensive bronchial dystrophy. RU 41740 is particularly effective in patients with numerous previous episodes of infection, but it also acts at all stages of chronic bronchitis.
The effects of urapidil therapy on hemodynamics and gas exchange in exercising patients with chronic obstructive pulmonary disease and pulmonary hypertension.
To examine the hemodynamic changes induced by vasodilator therapy with urapidil during exercise in patients with chronic obstructive pulmonary disease (COPD) and their potential impact on symptom-limited maximal oxygen consumption, we studied 12 clinically stable patients using a randomized, crossover design. Placebo or urapidil (60 mg orally thrice a day) was given during 48 h preceding each incremental maximal exercise testing. Urapidil compared to placebo consistently lowered the pulmonary artery pressure either at rest from 29 +/- 2.5 to 24 +/- 1.5 mm Hg (p less than 0.001) or during exercise from 55 +/- 3 to 46 +/- 2 mm Hg (p less than 0.01). At rest, the systemic arterial pressure was reduced from 97.5 +/- 4 to 88.5 +/- 3 mm Hg (p less than 0.001) with no significant difference in heart rate or cardiac index. During exercise, systemic arterial pressure decreased from 135 +/- 4 to 119 +/- 3 mm Hg (p less than 0.001). As compared to placebo, urapidil tended to increase the cardiac index from 6.1 +/- 0.4 to 6.6 +/- 0.4 L/min.m2 (NS) and to decrease heart rate, from 122 to 116 beats/min (NS); the resulting stroke volume index increased with urapidil from 49 +/- 3 to 57 +/- 4 ml/m2 (p less than 0.01); at rest, urapidil did not induce alteration in gas exchange, while during exercise, C(a-v)O2 decreased from 8.6 +/- 0.5 to 7.7 +/- 0.4 vol% (p less than 0.01), SVO2 increased from 39.5 +/- 2 to 44.5 +/- 1.5% (p less than 0.01), and SaO2 from 82 +/- 2 to 85 +/- 2% (p less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)
[Pleural effusion and yellow nails].
Explore the source record for details and available documents.
Atrial natriuretic peptide concentrations and pulmonary hemodynamics in patients with pulmonary artery hypertension.
To define the relationship between plasma levels of immunoreactive atrial natriuretic peptide (IR-ANP) and hemodynamic parameters in patients with chronic pulmonary artery hypertension, we measured plasma concentrations of the peptide in 15 patients during right heart catheterization. Eleven patients had chronic obstructive pulmonary disease and 4 had pulmonary vascular disease of diverse etiology. At rest, plasma concentrations of IR-ANP positively correlated with mean pulmonary artery pressure (r = 0.70, p less than 0.01) and pulmonary vascular resistance (r = 0.88, p less than 0.001), but not with right atrial pressure. Nine of these patients, all with chronic obstructive pulmonary disease, were also evaluated during exercise. Plasma concentrations of IR-ANP increased from 131 +/- 22 to 191 +/- 30 pg/ml (p less than 0.003) at maximal exercise, whereas pulmonary artery pressure increased from 29 +/- 1.5 to 56 +/- 2.5 mm Hg and right atrial pressure from 5 +/- 1 to 13 +/- 2 mm Hg. Increases of plasma IR-ANP concentrations correlated with changes in pulmonary artery pressure and right atrial pressure but not with changes in pulmonary capillary wedge pressure. These findings suggest that ANP is released in response to an increase in pulmonary artery pressure and are consistent with the hypothesis that ANP could modulate the pulmonary vascular tone in patients with pulmonary artery hypertension.
Effects of indomethacin on pulmonary hemodynamics and gas exchange in patients with pulmonary artery hypertension, interference with hydralazine.
To assess the ability of indomethacin (Indo) to influence pulmonary vascular tone in patients with chronic lung disease, we studied the hemodynamic and gas exchange alterations induced by a 50-mg indomethacin infusion in 10 patients suffering from varying degrees of pulmonary artery hypertension and hypoxemia. The most pronounced effects were observed 3 h after Indo administration. Mean systemic arterial pressure (Psa) increased from 76 +/- 4 to 86 +/- 4 mm Hg (p less than 0.01), whereas mean pulmonary arterial pressure (Ppa) was unchanged. The cardiac index (CI) decreased from 3.1 +/- 0.2 to 2.8 +/- 0.2 L/min/m2 (p less than 0.02) because of the reduced heart rate, which decreased from 86 +/- 5 to 80 +/- 4 beats/min (p less than 0.05). Systemic and pulmonary vascular resistance indexes increased, respectively, from 22 +/- 2 to 27.5 +/- 2 U/m2 (p less than 0.001) and from 11.9 +/- 2 to 13.4 +/- 2 U/m2 (p less than 0.05). We measured an increase in PaO2, from 49.5 +/- 4 to 57.5 +/- 4 mm Hg (p less than 0.001) simultaneously with a reduced venous admixture, from 39.5 +/- 4 to 30.5 +/- 3% (p less than 0.001). The calculated PO2 uptake was unchanged, but mixed venous O2 tension increased from 30.5 to 33.5 mm Hg (p less than 0.01). Because Indo may interfere with the hypotensive effect of hydralazine and because hydralazine has been proposed in the treatment of patients with pulmonary hypertension, 7 of these patients also received 0.35 mg/kg hydralazine and Indo plus hydralazine (Indo + H) injected simultaneously.(ABSTRACT TRUNCATED AT 250 WORDS)
High frequency chest wall oscillation in patients with chronic air-flow obstruction.
In order to assess high frequency chest wall oscillation (HFCWO) as a way to assist spontaneous breathing in obstructive lung disease, we studied 12 patients with severe and stable COPD. HFCWO at 5 Hz were applied by means of an inflatable vest. In order to avoid any discomfort, oscillations were applied only during the expiratory phase of the spontaneous breathing cycle. We compared gas exchange and pattern of breathing during control and HFCWO periods, each lasting 15 min. Minute ventilation did not change, but the pattern of breathing was markedly altered during HFCWO: breathing frequency decreased (p less than 0.001) from 18 +/- 6/min during control to 14 +/- 5/min, whereas tidal volume increased (p less than 0.01) from 600 +/- 200 ml during control to 860 +/- 400 ml. Secondary to this change in the pattern of breathing, arterial PO2 increased slightly (p less than 0.01) from 54 +/- 7 mm Hg during control to 57 +/- 8 mm Hg during HFCWO, and arterial PCO2 significantly (p less than 0.01) decreased from 46 +/- 6 mm Hg during control to 43 +/- 7 mm Hg during HFCWO. In addition, duty cycle (Ti/Ttot) decreased (p less than 0.001) from 0.37 +/- 0.03 s during control to 0.29 +/- 0.05 s during HFCWO. Such a decrease in duty cycle suggest that inspiratory muscle work was facilitated under HFCWO. In 8 patients, we obtained the tension-time index (TTdi), or the product of duty cycle and Pdi/Pdimax, and found that this index significantly decreased (p less than 0.05) from 0.06 +/- 0.03 during control to 0.04 +/- 0.02 during HFCWO.(ABSTRACT TRUNCATED AT 250 WORDS)
Hemodynamic effects of urapidil in patients with pulmonary hypertension. A comparative study with hydralazine.
Vasodilator therapy for pulmonary hypertension ideally should cause a proportionately greater reduction of resistance in the pulmonary vascular bed than in the systemic circulation. This should limit the occurrence of systemic hypotension, which can complicate the use of most vasodilator drugs. Urapidil is a new vasodilator that acts by postsynaptic alpha 1-blockade while inhibiting the aortic pressure baroreceptor reflex and reducing central sympathetic tone. We investigated and compared the short-term effects of Urapidil and hydralazine in 10 patients suffering varying degrees of pulmonary hypertension. Each patient received either 0.35 mg/kg hydralazine or 0.75 mg/kg Urapidil intravenously on 2 sequential days in a randomized order. The main effect of Urapidil was to decrease the mean pulmonary artery pressure in all 10 patients from 44 +/- 4 to 37 +/- 3.5 mm Hg (p less than 0.001). After Urapidil infusion, the mean decrease of resistance in the pulmonary vascular bed (32%) exceeded that in the systemic circulation (25%). In contrast, pulmonary artery pressure remained unchanged with hydralazine, and predominant systemic vasodilation occurred: systemic vascular resistance decreased by 45%, whereas pulmonary vascular resistance decreased by 25%. Hydralazine markedly increased the cardiac index and induced tachycardia. Urapidil maintained the heart rate nearly constant and only slightly increased the cardiac index, thereby fostering the diastolic emptying of the pulmonary circulation. No significant change in arterial oxygenation occurred with either drug, although arterial oxygen partial pressure tended to increase with hydralazine. Urapidil may be a promising drug in the treatment of patients with pulmonary hypertension.
High frequency transthoracic ventilation improves gas exchange during experimental bronchoconstriction in rabbits.
In order to evaluate the efficacy of ventilation by high frequency transthoracic oscillation in obstructive lung disease, we studied 10 anesthetized and paralyzed rabbits during experimental bronchoconstriction. In order to generate body surface oscillation, the animals were placed in a body-box connected to a piston pump. Two frequencies were successively applied in random order: 1 Hz, representing "conventional" ventilation, and 5 Hz for high frequency ventilation. During the control period, the magnitudes of the oscillation were adjusted such that the tidal volumes thus produced yielded normocapnia (PaCO2 = 40 +/- 2 mmHg) for at least 3 min at each frequency. The same tidal volumes were then used after a bronchoconstriction induced by aerosolized carbachol. We obtained a severe and stable bronchoconstriction and oscillated the animals at 1 and 5 Hz at identical tidal volumes as those used during the control period. Identical at the 2 frequencies of oscillation during the control period, the rate of CO2 elimination with bronchoconstriction was significantly higher (p less than 0.05) at 5 Hz (15.9 +/- 3.3 ml/min) than at 1 Hz (14.2 +/- 3.9 ml/min); PaCO2 was also significantly lower at 5 Hz than at 1 Hz. Mean arterial PO2 was significantly higher (p less than 0.01) at 5 Hz (58 +/- 4 mmHg) than at 1 Hz (46 +/- 12 mmHg) during bronchoconstriction. Mean alveolararterial O2 pressure difference was significantly lower (p less than 0.01) at 5 Hz (49 +/- 13 mmHg) than at 1 Hz (59 +/- 11 mmHg). Only a minor increase in lung volume was found during high frequency ventilation, and no significant hemodynamic changes occurred.(ABSTRACT TRUNCATED AT 250 WORDS)
[Evaluation of the efficacy of the surgical treatment of panlobular emphysema].
26 patients presenting with panlobular emphysema between 1978 and 1984 were submitted to a thoracotomy for surgical resection of their bullae. Pre-operative and post-operative evaluations of the following were made: The level of dyspnoea in 5 grades. The FEV1 (VEMS) the forced vital capacity (CVF) the functional residual capacity (CRF) measured plethysmographically, the residual volume (VR), the total lung capacity (CPT). Arterial blood gases. The presence of radiological signs of compression on pulmonary angiography and on plain chest radiographs: an index of compression rated 0 to 6 was defined at the outset. The subjects were split into 3 groups based on their post-operative respiratory function: Group 1: no improvement (n = 7). Group 2: moderate improvement of dyspnoea (n = 11). Group 3: a big improvement in dyspnoea (n = 7). These three groups were homogenous as regards their preoperative respiratory function. On the other hand, the compression caused by the bullae based on the pre-operative radiological data was much greater (p 0.01) in the group of patients who improved. In addition when the index of compression was equal or superior to 3 (n = 14) all the patients were improved (n = 6). The comparison of pre- and post-operative values shows the following results: The change in blood gases was very limited in all groups; the ventilatory parameters were unchanged in group 1; on the other hand in group 2 and 3 one notes an overall improvement in pulmonary function. The size of the improvement however, was very variable from one individual to another.(ABSTRACT TRUNCATED AT 250 WORDS)
[Heterogeneity of pulmonary ventilation/perfusion ratio: significance and measurement].
Explore the source record for details and available documents.
Immunoblastic lymphoma involving the bone marrow in a patient with alpha chain disease. Clinical and immunoelectron microscopic study.
A patient is reported who had disseminated immunoblastic proliferation that emerged during the course of alpha chain disease. This proliferation was characterized by overt marrow invasion together with osseous and neurologic manifestations. On immunoelectron microscopic study, the malignant immunoblasts displayed varying degrees of cytoplasmic maturation and constituted a morphologic spectrum of alpha-chain-synthesizing cells, ranging from immature blasts without endoplasmic reticulum development to relatively mature plasmablasts; alpha chain was not expressed at the surface of these cells. The general features of the overt malignant stage of alpha chain disease are reviewed in reference to this unusual case. The implications of the cellular findings are discussed with regard to the maturation stage of malignant immunoblasts.