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Biomedical subjects

François Lemaire

Publications and source records attributed to François Lemaire.

At least 19 recordsLinked to original sources
PubMed2006

B-type natriuretic peptide and weaning from mechanical ventilation.

OBJECTIVE: Cardiac function and volume status could play a critical role in the setting of weaning failure. B-type natriuretic peptide (BNP) is a powerful marker of cardiac dysfunction. We assessed the value of BNP during the weaning process. DESIGN, SETTING AND PATIENTS: One hundred and two consecutive patients considered ready to undergo a 1-h weaning trial (T-piece or low-pressure support level) were prospectively included in a medical intensive care unit of a university hospital. Weaning was considered successful if the patient passed the trial and sustained spontaneous breathing for more than 48 h after extubation. INTERVENTIONS: Plasma BNP was measured just before the trial in all patients, and at the end of the trial in the first 60 patients. RESULTS: Overall, 42 patients (41.2%) failed the weaning process (37 patients failed the trial and 5 failed extubation). Logistic regression analysis identified high BNP level before the trial and the product of airway pressure and breathing frequency during ventilation as independent risk factors for weaning failure. BNP values were not different at the end of the trial. In nine of the patients in whom the weaning process failed, it succeeded on a later occasion after diuretic therapy. Their BNP level before weaning decreased between the two attempts (517 vs 226 pg/ml, p=0.01). In survivors, BNP level was significantly correlated to weaning duration (rho=0.52, p<0.01). CONCLUSIONS: Baseline plasma BNP level before the first weaning attempt is higher in patients with subsequent weaning failure and correlates to weaning duration.

Aged↗
PubMed2006

Effects of vertical positioning on gas exchange and lung volumes in acute respiratory distress syndrome.

OBJECTIVE: Supine position may contribute to the loss of aerated lung volume in patients with acute respiratory distress syndrome (ARDS). We hypothesized that verticalization increases lung volume and improves gas exchange by reducing the pressure surrounding lung bases. DESIGN AND SETTING: Prospective observational physiological study in a medical ICU. SUBJECTS AND INTERVENTION: In 16 patients with ARDS we measured arterial blood gases, pressure-volume curves of the respiratory system recorded from positive-end expiratory pressure (PEEP), and changes in lung volume in supine and vertical positions (trunk elevated at 45 degrees and legs down at 45 degrees ). MEASUREMENTS AND RESULTS: Vertical positioning increased PaO(2) significantly from 94+/-33 to 142+/-49 mmHg, with an increase higher than 40% in 11 responders. The volume at 20 cmH(2)O measured on the PV curve from PEEP increased using the vertical position only in responders (233+/-146 vs. -8+/-9 1ml in nonresponders); this change was correlated to oxygenation change (rho=0.55). End-expiratory lung volume variation from supine to vertical and 1 h later back to supine, measured in 12 patients showed a significant increase during the 1-h upright period in responders (n=7) but not in nonresponders (n=5; 215+/-220 vs. 10+/-22 ml), suggesting a time-dependent recruitment. CONCLUSIONS: Vertical positioning is a simple technique that may improve oxygenation and lung recruitment in ARDS patients.

Blood Gas Analysis↗
PubMed2005

[Terminal extubation in 5 end-of-life patients in intensive care units].

INTRODUCTION: Decisions to withhold or withdraw active life support treatment in situations with no hope of improvement remain difficult for critical-care specialists and families; they are not always well understood by the public. This report describes terminal extubation, a particular method of withdrawing ventilator support. METHODS: This retrospective analysis examines the records of patients who died in our intensive care unit after a decision to withdraw active life support by stopping artificial ventilation. Extubation was proposed for patients with irreversible neurological damage and was always performed only after a standardized collective decision-making process. This process included three stages. In the initial phase, withdrawal of ventilator support was discussed at a department staff meeting. The meeting's conclusions were transcribed into the medical file, and the possibility of extubation was raised with the family during a planned interview. At least a 24-hour period of reflection was necessary before a new interview, and any opposition, hesitation or lack of understanding by the family at this first interview resulted in suspending the decision. The technical procedures for terminal extubation were also standardized. RESULTS: In 5 cases (4 men and one woman, with a mean age of 65 +/- 4 years), terminal extubation was decided in cooperation with the family, following an average of 3 interviews, 16 days after admission. All patients died within 3 days. DISCUSSION: So-called "terminal" extubation, very common in the United States, but much less so in France, reinforces the transparency of end-of-life decisions in intensive care units and immediately makes tangible the end of the aggressive treatment for which critical-care specialists have been reproached. Since this first series of patients, extubation has been practiced in our department, principally in situations of irreversible neurological damage.

Aged↗
PubMed2005

[The mission of the Committee for Personal Protection (CPP) in France: neither ethical, nor scientific?].

In France, research on human beings was first organized (and legally authorized) in 1988 by a law (so called Huriet-Séruclat). Since then, the specific mission of research ethics committees (RECs) has been heavily disputed. The legislator explained that the role of RECs is neither ethic nor scientific. It is << to control that the research protocol has been drafted according to the law >>. Of course, this is clearly at odds with the common practice of RECs in France and abroad as well. The assessment of the benefit/risk balance and of the << pertinence >> of the protocol cannot be achieved without a clear understanding of its scientific rationale. Origin of this French << cultural exception >> is to be found in the historic context of the elaboration of the law, back in the mid Eighties.

Ethics, Medical↗
PubMed2005

Spirometer-dependence of vital capacity in ALS: validation of a portable device in 52 patients.

Since the evaluation of vital capacity (VC) needs to be carried out every three months in patients with amyotrophic lateral sclerosis (ALS), a portable spirometer would be of value in clinical practice. Over the follow-up of 52 ALS patients, we compared the values of slow vital capacity measured by two spirometers: a reference flow-metered spirometer based on a Hans-Rudolph pneumotachograph and a portable Venturi spirometer. The objectives were to analyse the overall concordance of the measurements from the two devices and determine a discordance cut-off. The correlation between measurements was high (r = 0.936) and significant (p<10(-20)). Bland and Altman analysis showed that the measurements were concordant at a statistical risk of 5%; nevertheless, on examination of the raw differences between the measurements, two sub-populations could be identified on either side of the 56% cut-off where the means of the differences were significantly different (p<0.0001). The 56% cut-off was also statistically significant in plotting differences against the coefficient of variations of the data pairs expressed as (100 x s/mean). The differences observed between the two spirometers could be explained by technical differences between the devices as well as by an increase in variability with progression of the disease. In conclusion, this study demonstrates that a portable spirometer can be used reliably at the bedside. For values of vital capacity below the discordance cut-off of 56%, vital capacity should be determined by operators trained in pulmonary function examinations.

Amyotrophic Lateral Sclerosis↗
PubMed2004

Peter Sjokvist.

Explore the source record for details and available documents.

Critical Care↗
PubMed2004

[Does clinical research provide any "direct individual benefit"?].

The European Commission and Parliament have promulgated a directive on clinical research (2001/20/CE) in April 2001. Its provisions have to be incorporated in all national laws by May 2004. Accordingly, the French " loi Huriet " (a law passed in 1988 organizing clinical research in France) had to be revised. During the process, it appeared that a key issue was the suppression of a distinction made by this law between research with and without " direct individual benefit ", a French specificity, as the directive recommends rather the assessment of the risk/benefit ratio. In order to harmonize the French legislation with the other European laws, and to suppress a set of provisions which have been repeatedly attacked during the last ten years, the French members of parliament have voted on October 2003 a new law which, among other important modifications, suppress that distinction.

Clinical Trials as Topic↗