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F Brunet

Publications and source records attributed to F Brunet.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Artificial ventilation in acute respiratory distress syndrome in adults. Towards an individual optimization].

Artificial ventilation plays a key role in the treatment of acute respiratory distress syndrome (ARDS). Initially, the goal is to normalize gas exchange compromised by the lung disease. Positive pressure ventilation can however aggravate prior lesions of the pulmonary parenchyma, at least in areas of the lung accessible to ventilation. Computed tomography of the lung has given us a better understanding of the pathogenesis of these ventilation-induced lesions, leading to new ventilatory strategies aimed at assuring adequate oxygenation without damaging the parenchyma. These ventilatory modes may tolerate a certain degree of hypercapnia to avoid lung injury. Improved oxygenation relies on optimizing the ventilation/perfusion ratio, either with inhaled nitric oxide or a supine position to improve alveolar recruitment. In the most severe cases, extra-corporal gas exchange systems have shown their efficacy for patients whose lungs cannot be ventilated. Thus ventilation should be carefully adapted to each patient based on the severity of the ARDS and its clinical course. We present a practical protocol based on a hierarchy rationale for each ventilation mode and indicate the explorations required to adapt each mode to a specific patient.

Acute Disease↗
PubMed1996

The mariner transposable element in natural populations of Drosophila teissieri.

The mariner transposable elements of several natural populations of Drosophila teissieri, a rainforest species endemic to tropical Africa, were studied. Natural populations trapped along a transect from Zimbabwe to the Ivory Coast were analyzed by Southern blotting, in situ hybridization, cloning, and sequencing of PCR products. The Brazzaville population had some full-length elements, while the remaining populations had mainly deleted elements. The main class of deleted elements lacked a 500-bp segment. A mechanism is proposed that could generate such elements rapidly. In situ hybridizations showed that there are no mariner elements in pericentromeric heterochromatin. Finally, the phylogeny of the Mos1-like mariner full-length elements is consistent with vertical transmission from the ancestor of the melanogaster subgroup.

Africa↗
PubMed1995

Reduction of ventilator settings allowed by intravenous oxygenator (IVOX) in ARDS patients.

OBJECTIVE: To evaluate the possibility of reducing ventilator settings to "safe" levels by extrapulmonary gas exchange with IVOX in ARDS patients. DESIGN: Uncontrolled open clinical study. SETTING: Medical Intensive Care Unit of a University Hospital. PATIENTS: 6 patients with ARDS who entered into IVOX phase II clinical trials. INTERVENTIONS: The end-point of this study was to reduce ventilator settings from the initial values, recorded on the day of inclusion, to the following: peak inspiratory pressure < 40 cmH2O, mean airway pressure < 25 cmH2O and tidal volume < 10 ml/kg. Trials to achieve this goal were made on volume-controlled ventilation within the 24 h before and after IVOX insertion. Comparison of the results achieved during these trials used Wilcoxon test. RESULTS: Before IVOX implantation reduction of ventilator settings was not possible in the 6 patients, despite a non-significant increase in PaO2/FIO2 was achieved. IVOX permitted significant decrease in PaCO2 (from 60.5 +/- 15 to 52 +/- 11 mmHg; p = 0.02) before any modification of the ventilatory mode. After IVOX insertion, a significant decrease of the ventilator settings was performed: peak and mean airway pressures dropped from 44 +/- 10 to 36.8 +/- 6.7; p = 0.02 and from 26.3 +/- 5.6 to 22.5 +/- 3.9 cmH2O; p = 0.02, respectively. Concommitantly, PaCO2 remained unchanged and PaO2/FIO2 increased significantly from 93 +/- 28 to 117 +/- 52; p = 0.04. The interruption of oxygen flow on IVOX was associated with a slight decrease of the oxygen variables. Tolerance of IVOX was satisfactory. However, a significant decrease both in cardiac index and in pulmonary wedge pressures (from 4.5 +/- 1.2 to 3.4 +/- 9; p = 0.03 and from 16 +/- 5 to 11 +/- 2; p = 0.04, respectively) was observed. CONCLUSION: Gas exchange achieved by IVOX allowed reduction of ventilator settings in 6 ARDS patients in whom previous attempts have failed. CO2 removal by the device, may explain these results. Efficacy of IVOX on arterial oxygenation was uncertain.

Adult↗
PubMed1995

Effect of inhaled nitric oxide on right ventricular function in adult respiratory distress syndrome.

To determine whether inhaled nitric oxide (NO) affects pulmonary circulation, thereby improving right ventricular (RV) function in adult respiratory distress syndrome (ARDS), we studied 13 patients with both a lung injury severity score of 2.5 or more and a mean pulmonary artery pressure higher than 30 mm Hg. RV function was assessed by a thermodilution technique using a pulmonary artery catheter equipped with a rapid response thermistor before and 15 min after initiation of inhalation of NO (5 ppm). At baseline, stroke volumes were in a normal range (46 +/- 14 ml/m2), with a RV dilation (end-diastolic volume = 142 +/- 36 ml/m2). Inhaled NO was followed by an improvement in arterial oxygenation (PaO2/FIO2 = 103 +/- 47 versus 142 +/- 63, p < 0.05) and a drop in pulmonary artery pressure (36.1 +/- 4.5 versus 31.3 +/- 6.1 mm Hg, p < 0.01); stroke volumes and heart rates did not change. The resulting fall in pulmonary vascular resistance (211 +/- 43 versus 180 +/- 59 dyn-s/cm5, p < 0.05) was associated with an increase in RV, ejection fractions (32 +/- 5 versus 36 +/- 6%, p < 0.05), a trend toward decreased RV end-systolic (96 +/- 25 versus 85 +/- 19 ml/m2, NS) and end-diastolic (142 +/- 36 versus 131 +/- 27 ml/m2, NS) volumes, and a decrease in right atrial pressures (10.9 +/- 2.9 versus 9.6 +/- 3.2 mm Hg, p < 0.05). No relationship was seen between the improvement in arterial oxygenation and the decrease in pulmonary vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1995

Should mechanical ventilation be optimized to blood gases, lung mechanics, or thoracic CT scan?

This study was aimed at providing data for optimization of mechanical ventilation in patients with acute respiratory distress syndrome (ARDS). The effects of ventilation with positive end-expiratory pressure (PEEP) titrated to blood gases were studied by thoracic computed tomographic (CT) scans and lung mechanics measurements in eight patients. CT density histograms at end-expiration were used to investigate the effects of PEEP on three differently aerated zones. Static pressure-volume (P-V) curves were used to determine the deflection point above which baro-volotrauma (a combination of barotrauma and volotrauma) may occur. Peak pressures, plateau pressures, and lung volumes measured by Respitrace were compared with the deflection point. CT scan showed that PEEP increased "normally aerated" areas, decreased "nonaerated" areas, and did not change "poorly aerated" zones. No correlations were found between CT scan and either PaO2 or mechanical data. Pressure at the deflection point was lower than the usually recommended 35 to 40 cm H2O for peak pressure in four patients (range, 28 to 32 cm H2O). With regard to plateau pressures, only one patient was ventilated above the deflection point. However, monitoring of volumes showed that these four patients had an end-inspiratory volume above this point. We conclude that mechanical ventilation may be initially adjusted on the basis of blood gas values and then optimized on the basis of lung mechanics to limit the risk of baro-volotrauma.

Adolescent↗
PubMed1995

Is tracheal gas insufflation an alternative to extrapulmonary gas exchangers in severe ARDS?

Tracheal gas insufflation (TGI) of pure oxygen combined with mechanical ventilation decreases dead space and increases CO2 clearance. In the present study, TGI was used in six patients with ARDS who met extracorporeal membrane oxygenation criteria and who were severely hypoxemic and hypercapnic despite optimal pressure-controlled ventilation. This open clinical study aimed to investigate the effects of 4 L/min continuous flow of oxygen given via an intratracheal catheter. PaCO2 decreased from 108 +/- 32 to 84 +/- 26 mm Hg (p < 0.05), and no significant change in PaO2 (68 +/- 18 vs 96 +/- 43, p = 0.06). There was no change in airway pressures and hemodynamic variables. A slight increase in end-expiratory and end-inspiratory volumes with TGI possibly occurred, as seen on tracings from respiratory inductive plethysmography (Respitrace). We conclude that TGI improves tolerance of limited pressure ventilation by removing CO2, but it may induce changes in lung volumes that are not detected by ventilator measurements.

Adult↗
PubMed1995

Subjective psychological status of severely ill patients discharged from mechanical ventilation.

OBJECTIVE: To evaluate psychological status in consecutive survivors of ICU who needed mechanical ventilation (MV). DESIGN: Prospective study. SETTING: Twenty-four bed intensive care unit. PATIENTS: Fifty-four mechanically ventilated patients were considered for the study; 43 patients were included, but 11 refused or were unable to fill in the form. INTERVENTIONS: A 32-question form was filled out by the patients 48-96 hours after weaning from mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: The mean characteristics of the patients were: age 51.6 years, simplified acute physiologic score (SAPS) 14, organ system failure (OSF) 1.57, OMEGA score 277, length of stay 29 days, length of mechanical ventilation 14 days. Thirty-three required sedation, 30 analgesia, 20 paralysis. The results were as follows: Pain: 13 suffered intolerable pain with a mean intensity of pain during care of 3.5/10. Comfort: 25 felt an inability to communicate, 18 were bothered by noise and 15 by light, while nine feared to be abandoned by staff. Sleep disorders: 28 remember dreaming with a personal judgement about these dreams (0 = pleasant, 10 = nightmare) of 7.6/10; 17 noticed increasing sleep disorders during their stay. Anxiety: 22 felt diffuse anxiety disorder and 16 described intense fear of dying at least once. Mood: 38 felt physical depression and 18 intellectual depression. Delirium or confusion: 33 had delirium or a confused state at the time of weaning and nine suffered hallucinations. Nine correctly appreciated their length of stay and 18 knew the date when they were interviewed. CONCLUSIONS: These results showed that psychological status is poor in ventilated ICU patients, which should be considered in their care.

Adult↗
PubMed1994

Horizontal transmission versus ancient origin: mariner in the witness box.

The transposable element mariner has been found in many species of Drosophilidae, several groups of Arthropods, and more recently in Platyhelminthes as well as in a phytopathogenic fungus. In the family Drosophilidae, the distribution of mariner among species shows many gaps, and its geographical distribution among endemic species is restricted to Asia and Africa. Among mariner elements in species within and outside the Drosophilidae, the similarities in nucleotide sequence and the amino acid sequence of the putative transposase reveal many phylogenetic inconsistencies compared with the conventional phylogeny of the host species. This paper discusses the contrasting hypotheses of horizontal transfer versus ancestral origin proposed to explain these results.

Africa↗
PubMed1994

Accuracy assessment for three fiberoptic pulmonary artery catheters for SvO2 monitoring.

OBJECTIVE: To compare values of SvO2 obtained by reflectance spectrophotometry continuous monitoring with those obtained from blood samples measurements by transmission spectrophotometry (Co-Oximetry). DESIGN: Values of SvO2 recorded by three pulmonary artery catheters for continuous monitoring, SAT1, SAT2 and Oximetrix3 (OX3), were compared in a prospective manner to those measured on blood samples by a Co-Oximeter, using the statistical analysis of Bland and Altman. SETTING: Adult intensive care unit in an University Hospital. PATIENTS: 37 patients admitted for acute respiratory failure and/or shock who required hemodynamic monitoring. MAIN RESULTS: The bias (average under- or overestimation) was small for all comparative measurements: +1.3, -0.2 and +1.0 sat% for SAT1, SAT2 and OX3, respectively. However, limits of agreement were only acceptable for SAT2 (-8.3 to +7.9 sat%) and OX3 (-6.7 to +8.6 sat%), but not for SAT1 (-23.3 to +25.9 sat%). No significant drift during 24 h was found with the three catheters. However, in vitro calibration was only found acceptable for SAT2 and OX3. The results were not influenced by the numbers of wavelengths of the device (2 for SAT1 and SAT2, and 3 for OX3) nor did they correlate with any of the hemodynamic and biochemical variables tested. CONCLUSION: For usual monitoring in the ICU, SAT2 and OX3, gave SvO2 values which are in acceptable agreement with SvO2 measured on blood samples by Co-Oximetry.

Aged↗
PubMed1994

Teicoplanin: a well-tolerated and easily administered alternative to vancomycin for gram-positive infections in intensive care patients.

A prospective, randomized multicentre study was conducted in order to evaluate the potentially superior tolerability profile of teicoplanin plus netilmicin compared with vancomycin plus netilmicin in patients in ICUs. We considered that these glycopeptides have been shown to have comparable efficacy and that comparative tolerability is of paramount importance, particularly in severely ill patients. A total of 56 patients were enrolled into the study (36 males and 20 females). Twenty-four patients were included in the teicoplanin plus netilmicin group (15 males, 9 females: mean age 56.8 years). The mean simplified acute physiological score (SAPS) was 9.4 (range 4-20). Thirty-two patients were randomized to receive vancomycin plus netilmicin (21 males, 11 females; mean age 56.4 years). The mean SAPS was 9.3 (range 2-16). Septicaemia was the most common infection (14 cases in each group). Most infections were caused by Staphylococcus aureus or coagulase-negative staphylococci. The mean daily doses were: for teicoplanin, 457 mg (6.7 mg/kg); for vancomycin, 1678 mg (24.4 mg/kg); and for netilmicin 263.3 mg (3.9 mg/kg) in the teicoplanin group and 248 mg (3.8 mg/kg) in the vancomycin group. The trough levels of teicoplanin in the serum remained mostly between 7 and 10 mg/l, while more fluctuation was seen in patients receiving vancomycin. The mean trough levels of netilmicin in the serum were 1.2 (SD 0.9) mg/l in the teicoplanin group, compared with 1.7 (SD 1.4) mg/l in the vancomycin group (NS: p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The mariner transposable element in the Drosophilidae family.

The distribution of the mariner transposable element among Drosophilidae species was investigated using three different techniques, i.e. squash blots, Southern blots and PCR amplification, using two sets of primers (one corresponding to the Inverted Terminal Repeats and the other to two conserved regions of the putative transposase). Our results and those of others show that the distribution of mariner is not uniform and does not follow the phylogeny of the host species. An analysis of geographical distribution, based on endemic species, shows that mariner is mainly present in Asia and Africa. At least two hypotheses may be proposed to explain the specific and geographical distributions of this element. Firstly, they may be the results of several horizontal transmissions between Drosophila species and/or between Drosophila species and one or several donor species outside the Drosophilidae family. Secondly, these particular distributions may correspond to the evolution of the mariner element from an ancestral copy which was present in the ancestor of the Drosophilidae family.

Animals↗
PubMed1994

Permissive hypercapnia and intravascular oxygenator in the treatment of patients with ARDS.

This open clinical study was aimed at testing the hypothesis that an intravascular oxygenator (IVOX) may help to perform permissive hypoventilation in 10 patients with severe ARDS. After initial evaluation, we tried to reduce ventilator settings before and after IVOX implantation. Before IVOX, poor clinical tolerance and worsening oxygenation did not allow for a significant decrease in ventilator settings. With IVOX, peak inspiratory pressure (PIP) was reduced from 47 to 39 cm H2O (p = 0.005) and minute ventilation from 13 +/- 3.5 to 11 +/- 3 L/min. CO2 removal by IVOX allowed a significant decrease in PaCO2 from 66 +/- 15 to 59 +/- 13 mm Hg. Improvement of oxygenation with IVOX was not significant. Furthermore, interruption of oxygen flow through IVOX did not change oxygenation variables. Tolerance of the IVOX device was good, but insertion of the device was followed by a significant decrease in both cardiac index and pulmonary wedge pressure. In conclusion, IVOX improves tolerance of hypoventilation by limiting hypercapnia in ARDS patients. These preliminary results must be confirmed by a randomized controlled study.

Adult↗
PubMed1994

Extracorporeal carbon dioxide removal technique improves oxygenation without causing overinflation.

Extracorporeal CO2 removal combined with low frequency positive pressure ventilation (ECCO2R-LFPPV) improves gas exchange and decreases peak pressures, respiratory rates, and tidal volumes in animals and in humans. Recent evidence suggests that pulmonary barotrauma results from lung overinflation rather than from high pressures. This study was to test the hypothesis whether ECCO2R-LFPPV could improve gas exchange without causing lung overinflation, despite the use of higher levels of PEEP, when compared with conventional mechanical ventilation. Eleven patients with severe adult respiratory distress syndrome (ARDS) who failed to respond to different modes of mechanical ventilation were treated with ECCO2R-LFPPV. Risk of pulmonary barotrauma was evaluated by static pressure-volume (P-V) curves and dynamic changes in volumes monitored by respiratory inductive plethysmography (Respitrace). ECCO2R-LFPPV PaO2/FIO2 increased from 79 +/- 21 to 207 +/- 108 (p = 0.003). Risk of barotrauma, as shown by the shape of the P-V curve, was present in all patients receiving mechanical ventilation even though most of them were treated with permissive hypoventilation. By contrast, no evidence of persistent lung overinflation could be detected by either static P-V curves or dynamic measurements in nine of 11 patients who were treated by ECCO2R-LFPPV. The two remaining patients had severe airway obstruction because of bleeding, and they remained ventilated with persistent risk of barotrauma. We conclude that ECCO2R-LFPPV improves gas exchange without causing lung overinflation in a majority of patients with ARDS.

Adolescent↗
PubMed1994

Enoximone vs nicardipine during the early postoperative course of patients undergoing cardiac surgery. A prospective study of two therapeutic strategies.

The hemodynamic effects of enoximone and nicardipine were compared during the early postcardiac surgery period in 40 patients with systemic hypertension and moderate cardiac dysfunction. Patients were prospectively randomized into two groups. Mean right atrial pressure was maintained above 7 mm Hg. The drug infusion rate was adjusted to maintain mean systemic artery pressure (SAP) within the 65 to 80 mm Hg range. Complete hemodynamic evaluations were performed before any drug infusion and during the following 24 h with special attention to O2-related variables. Oxygen consumption, cardiac index, and stroke index improved significantly and similarly in the two groups. The SAP and systemic vascular resistance decreased more rapidly in the enoximone group but whole body lactate level increased after the second hour of infusion. Furthermore, this was paralleled by an arteriovenous O2 contents difference deficit. In our study, nicardipine was found superior over enoximone in terms of recovery from intraoperative tissue hypoxia. Furthermore, enoximone's inotropic effects were not found to be clinically relevant.

Cardiac Surgical Procedures↗