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Biomedical subjects

C Brun-Buisson

Publications and source records attributed to C Brun-Buisson.

At least 109 records · Page 6Linked to original sources
PubMed1993

Role of atrial natriuretic factor in impaired sodium excretion of normocapnic and hypercapnic patients with chronic obstructive lung disease.

To investigate the mechanisms of sodium retention in patients with chronic obstructive lung disease (COLD), we examined the renal and hormonal responses to volume expansion with isotonic saline and to infusion of atrial natriuretic factor (ANF) in 10 hypercapnic (PaCO2 52 +/- 2 mm Hg) and 12 normocapnic patients (PaCO2 39 +/- 1 mm Hg). Sodium excreted within 4 h of loading (expressed as % sodium load) was 23.5 +/- 2.5% (p < 0.05) in normocapnic and 8.5 +/- 1.5% (p < 0.001) in hypercapnic patients, compared with 32.5 +/- 3.0% in 11 age-matched control subjects. Sodium excretion and renal blood flow correlated negatively with arterial PCO2 and positively with FEV1. Basal plasma ANF concentrations were 72 +/- 5 pg/ml in controls, 100 +/- 14 pg/ml in normocapnic patients, and 230 +/- 52 pg/ml in hypercapnic patients (p < 0.001). Plasma renin activity and aldosterone did not differ between groups. In response to volume expansion, plasma ANF increased in both normocapnic and controls (with a greater increase in normocapnic patients) but remained unchanged in hypercapnic patients. Exogenous ANF increased glomerular filtration rate, renal plasma flow, natriuresis, and diuresis in both groups of patients. Patients with COLD have depressed renal function that appears unrelated to activation of the renin-angiotensin-aldosterone system. An increased secretory response of ANF to volume expansion may help to maintain volume homeostasis in normocapnic patients, while a blunted secretory response of ANF may contribute to sodium retention in hypercapnic patients.

Aged↗
PubMed1992

Severe pneumococcal sepsis and meningitis in human immunodeficiency virus-infected adults with sickle cell disease.

Pneumococcal infection is frequent in children with sickle-cell disease (SCD) but is less common in adults. Infection due to human immunodeficiency virus (HIV) is also a risk factor for pneumococcal infection. The purpose of this study was to determine the clinical course of HIV infection in adults with SCD. During a 6-year period, 283 adults suffering from SCD were screened for HIV type 1 and HIV type 2 infections. The clinical course of HIV infections in these patients was retrospectively analyzed at the term of the study. HIV type 1 infection was detected in eight patients. The mean follow-up period after diagnosis of HIV infection was 4.6 years. None of the patients had AIDS. Five episodes of severe pneumococcal infection were observed in four of these eight patients (septic shock in two patients and three episodes of meningitis in two patients); two patients died of meningitis. Only one severe pneumococcal infection (meningitis) was observed in the 275 non-HIV-infected patients with SCD (P = .000001). Our results show that pneumococcal infection appears to occur frequently and is often serious in HIV-infected adults with SCD.

Adult↗
PubMed1992

Evaluation of risk factors for laryngeal edema after tracheal extubation in adults and its prevention by dexamethasone. A placebo-controlled, double-blind, multicenter study.

Because laryngeal edema (LE) after tracheal extubation is likely to result from an exudative response, corticosteroids often are given routinely as a preventive treatment. No adequate controlled study supports this strategy, however. A prospective, randomized, placebo-controlled, double-blind, multicenter trial that included 700 consecutive patients requiring tracheal intubation and mechanical ventilation was conducted to determine risk factors for LE occurrence after tracheal extubation in adults and to evaluate the efficacy of corticosteroids in its prevention. One hour before extubation, patients were given either an intravenous bolus of 8 mg dexamethasone or a placebo. Patients were divided into two groups: 1) those in whom short-duration intubation (SDI, less than 36 h) was administered; and 2) those in whom long-duration intubation (LDI, more than 36 h) was administered. Minor LE was diagnosed when either stridor or laryngeal dyspnea, or both, occurred; major LE was diagnosed when reintubation due to LE was required, with LE evidenced during direct laryngoscopy. The overall incidence of LE was 4.2% and varied among the six participating centers from 2.3 to 6.9% (not significant). In only seven patients (1%), all with LDI, was tracheal reintubation required for LE. Laryngeal edema occurred more frequently after LDI than after SDI (7.2 vs. 0.9%; P less than 0.001). It also was more frequent in female than in male patients (20/284 vs. 8/379; P less than 0.05), irrespective of intubation duration and treatment. There was no association between LE and either difficulty/route of intubation or admission diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Bedside evaluation of the resistance of large and medium pulmonary veins in various lung diseases.

To evaluate the contribution of large and medium pulmonary veins to the total pulmonary vascular resistance in various human lung diseases, we compared in 64 patients the pulmonary arterial proximal wedge pressure (Ppw), obtained when the balloon of a 7F pulmonary artery catheter was inflated with 1.5 ml air, with the distal wedge pressure (Pdw), obtained after the tip of the catheter was advanced until wedged in a small artery without balloon inflation. Ppw, reflecting the pressure in a large pulmonary vein, approximates the left atrial pressure, whereas Pdw reflects the pressure in a smaller pulmonary vein. Pdw was greater than Ppw in all 64 patients. The Pdw-Ppw gradient was 1.1 +/- 0.5 mmHg in nine patients with normal lungs and was significantly higher in 13 patients with chronic congestive heart failure (3.8 +/- 0.8 mmHg, P less than 0.01) and in 22 patients with adult respiratory distress syndrome (3.8 +/- 0.8 mmHg; P less than 0.01), but not in 20 patients with chronic obstructive pulmonary disease (1.8 +/- 0.7 mmHg). The distribution of the pulmonary vascular resistance was clearly different among the four groups. The fraction of the total pulmonary vascular resistance attributable to large and medium pulmonary veins was significantly increased (P less than 0.01) in adult respiratory distress syndrome (27.5 +/- 12%) and cardiac patients (27.5 +/- 9%) compared with patients with chronic obstructive pulmonary disease (13 +/- 5%) and normal lungs (13.5 +/- 6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Modification of oxygen extraction ratio by change in oxygen transport in septic shock.

To help clarify the oxygen uptake/transport (VO2/TO2) relationship and because the oxygen extraction ratio (OER) and TO2 share no common variable such as cardiac index, we examined the changes in OER when TO2 was decreased in 12 patients with sepsis in whom a PEEP trial was performed. From zero end-expiratory pressure (ZEEP) to PEEP (12 +/- 3 cm H2O), a significant increase in OER from 30 +/- 10 percent to 38 +/- 12 percent (p less than 0.005) was observed, and individual percentage changes in OER were well correlated with individual percentage changes in TO2. The VO2 measured (VO2m) by respiratory gas analysis was unchanged, while VO2 calculated by the Fick equation (VO2f) decreased, suggesting a mathematical coupling between VO2f and TO2. Patients with hyperlactacidemia (n = 5) exhibited the same relationships between OER, VO2m, and TO2 as those without hyperlactacidemia. Our results suggest an adaptive response in the OER when TO2 is decreased in patients with established septic shock.

Adult↗
PubMed1991

Hormonal interactions and renal function during mechanical ventilation and ANF infusion in humans.

To investigate the influence of atrial natriuretic factor (ANF) on renal function during mechanical ventilation (MV), we examined the renal and hormonal responses to synthetic human ANF infusion in eight patients during MV with zero (ZEEP) or 10 cmH2O positive end-expiratory pressure (PEEP). Compared with ZEEP, MV with PEEP was associated with a reduction in diuresis (V) from 208 +/- 51 to 68 +/- 11 ml/h (P less than 0.02), in natriuresis (UNa) from 12.4 +/- 3.3 to 6.2 +/- 2.1 mmol/h (P less than 0.02), and in fractional excretion of sodium (FENa) from 1.07 +/- 0.02), 0.21 to 0.67 +/- 0.17% (P less than 0.02) and with an increase in plasma renin activity (PRA) from 4.83 +/- 1.53 to 7.85 +/- 3.02 ng.ml-1.h-1 (P less than 0.05). Plasma ANF levels markedly decreased during PEEP in four patients but showed only minor changes in the other four patients, and mean plasma ANF levels did not change (163 +/- 33 pg/ml during ZEEP and 126 +/- 30 pg/ml during PEEP). Glomerular filtration rate and renal plasma flow were unchanged. Infusion of ANF (5 ng.kg-1.min-1) during PEEP markedly increased V and UNa by 110 +/- 61 and 107 +/- 26%, respectively, whereas PRA decreased from 7.85 +/- 3.02 to 4.40 +/- 1.5 ng.ml-1.min-1 (P less than 0.05). In response to a 10 ng.kg-1.min-1 ANF infusion, V increased to 338 +/- 79 ml/h during ZEEP but only to 134 +/- 45 ml/h during PEEP (P less than 0.02), whereas UNa increased, respectively, to 23.8 +/- 5.3 and 11.3 +/- 3.3 mmol/h (P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Diagnosis of nosocomial pneumonia in mechanically ventilated patients. Comparison of a plugged telescoping catheter with the protected specimen brush.

Protected samples of lower respiratory tract secretions processed by quantitative culture techniques are recommended to diagnose nosocomial bacterial pneumonia in intubated, mechanically ventilated patients. To evaluate the accuracy of a simple and inexpensive sampling device in this setting, we compared quantitative cultures of paired single-sheathed plugged telescoping catheter (PTC) and protected specimen brush (PSB) samples in 55 patients during 78 suspected episodes of nosocomial pneumonia. PTC and PSB samples were taken in randomized order, and patients were also randomized to have PTC samples taken "blindly" or via a fiberoptic bronchoscope. Fifteen PSB and 27 PTC samples were culture positive (greater than or equal to 10(3) cfu/ml). The two sampling procedures gave similar results in 58 (74%) episodes. A major discrepancy occurred in 20 episodes, including six false negatives of PSB in episodes of proved pneumonia, four possible false positives of PSB, and 10 possible false positives of PTC (three of which rapidly evolved towards overt pneumonia). The sensitivity and specificity of PTC were 100 and 82.2%, and those of PSB were 64.7 and 93.5%, respectively. Blinded or directed PTC samples had similar concordance with PSB samples taken via bronchoscopy. We conclude that PTC is at least as accurate as PSB in the bacteriologic diagnosis of nosocomial pneumonia in intubated patients, and that its use can result in substantial cost savings, especially when fiberoptic bronchoscopy is not otherwise indicated.

Bacterial Infections↗
PubMed1990

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.

Acute Disease↗
PubMed1990

[Decontamination of the digestive tract during recovery from anesthesia].

Selective digestive tract decontamination is expected to decrease colonization and infection rate in intensive care patients. Its efficacy in this regards, when associated to systemic cefotaxime for the first few days of hospitalization, appears established in surgical patients. However, its superiority over established control and prophylactic measures remains unproven, in terms of reduced mortality, length of hospital stay, or overall use of antibiotics. Moreover, its long term effect on the risk of emergence of bacteria resistant to the regimens used remains to be proved.

Amphotericin B↗
PubMed1990

Organic arsenic-induced Guillain-Barré-like syndrome due to melarsoprol: a clinical, electrophysiological, and pathological study.

A young woman suffering from sleeping sickness was treated with melarsoprol. Thirty-eight days after the first administration of this organo-arsenic compound, myalgias, distal paresthesias and rapidly progressive weakness developed in all four limbs. Electrophysiological studies were misleading for Guillain-Barré syndrome. Neuropathological data included massive distal wallerian degeneration in peripheral nerves and abnormalities in dorsal ganglia and spinal cord where vacuolation of anterior horn cells and axonal neurofilamentous masses were observed. Very high concentrations of arsenic were found in the spinal cord, contrasting with undetectable levels in peripheral nerves. Our findings are consistent with an arsenic neuronopathy manifested by initial proximal demyelination and delayed distal axonal damage. Renal and hepatic dysfunctions, which were implicated in the toxic arsenic accumulation, should be systematically detected before administration of melarsoprol. The diagnosis of Guillain-Barré syndrome must be considered with caution in patients treated with this compound.

Adult↗
PubMed1990

Cardiac asthma presenting as status asthmaticus: deleterious effect of epinephrine therapy.

Epinephrine is a potent bronchodilator currently used to treat severe asthma, although there is no proven advantage of this drug over beta 2 adrenergic agonists. By contrast, as demonstrated here, the use of such a potent vasoconstrictor can worsen hemodynamic status when left ventricular dysfunction is associated with asthma or is the cause for dyspnea. We describe the case of a 60-year-old man with an history of chronic asthmatic bronchitis admitted for status asthmaticus. Bronchodilator therapy, including high dosages of intravenous epinephrine, failed to improve the patient and he was intubated and mechanically ventilated. Several hours later, a right heart catheterization revealed severe unexpected left heart dysfunction with a capillary wedge pressure of 45 mmHg and a cardiac index of 1.7 l/min/m2. Epinephrine was gradually stopped which resulted in a decrease in mean arterial blood pressure and an improvement of hemodynamic status. He was discharged on home mechanical ventilation. In this patient, ischemic left heart failure was revealed by a clinical picture mimicking status asthmaticus. Epinephrine, given as bronchodilator therapy on an empiric basis precipitated the patient into cardiogenic shock. Therefore this drug should not be recommended in face of the possibility of cardiac asthma or associated cardiac dysfunction.

Diagnosis, Differential↗
PubMed1990

Plasma levels of atrial natriuretic factor, renin activity, and aldosterone in patients with chronic obstructive pulmonary disease. Response to O2 removal and to hyperoxia.

To examine the interrelations between humoral systems involved in the circulatory and body fluid volume homeostasis of patients with chronic obstructive pulmonary disease (COPD), we measured plasma levels of renin activity (PRA), aldosterone (Aldo), and atrial natriuretic factor (ANF) in 14 patients with stable COPD who used continuous O2 therapy. Hemodynamics, blood gases, and plasma hormone levels were measured (1) while patients received supplemental O2; (2) after 30 min O2 discontinuation; and (3) after a 30-min period of 96% O2 breathing. Plasma immunoreactive ANF concentrations were 196 +/- 50 pg/ml during O2 breathing and were positively related to transmural pulmonary arterial wedge pressure (tPpaw, r = 0.90, p less than 0.001) and to PaCO2 (r = 0.57, p less than 0.02). Compared to normal subjects matched for age and sex, patients had higher plasma ANF levels (196 +/- 52 versus 72 +/- 6 pg/ml, p less than 0.01), similar PRA (2.1 +/- 0.5 versus 1.3 +/- 0.3 ng/ml/h, NS), and slightly lower plasma Aldo (98 +/- 17 versus 156 +/- 19 pg/ml, p less than 0.05). Discontinuation of O2 while decreasing PaO2 from 70 +/- 3 to 50 +/- 3 mm Hg resulted in a significant increase in pulmonary arterial pressure (Ppa) from 29 +/- 2 to 32.5 +/- 3 mm Hg (p less than 0.01) and cardiac index (Cl) from 3.6 +/- 0.1 to 3.9 +/- 0.1 L/min/m2 (p less than 0.01) and a decrease in systemic arterial pressure (Psa) from 96 +/- 3 to 91 +/- 2 mm Hg (p less than 0.05); transmural cardiac filling pressures and pulmonary vascular resistance (PVR) were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Infections of vascular catheters: diagnostic and incidence].

Catheter related infections may occur in up to 5% of patients at risk. Most infections are secondary to colonization of the subcutaneous tract of the catheter. The major risk factor for infection is the number of manipulations of the i.v. lines and sets. Semi-quantitative cultures of the catheter tip are necessary to differentiate colonization and contamination from true infection. Current studies attempt to evaluate new methods to predict infection before withdrawal of the catheter.

Bacterial Infections↗