Biomedical subjects

Brigitte Fauroux

Publications and source records attributed to Brigitte Fauroux.

28 records · Page 2Linked to original sources

PubMed2004

Burkholderia cepacia is associated with pulmonary hypertension and increased mortality among cystic fibrosis patients.

The aim of the study was to evaluate the impact of Burkholderia cepacia on cardiovascular status and mortality in cystic fibrosis. Seven patients infected with B. cepacia were matched with 31 patients not infected with this organism for gender, age, height, weight, genotype, and percent predicted forced expiratory volume in one second, partial arterial oxygen pressure, and pancreatic sufficiency status. The pulmonary artery systolic pressure, as assessed by transthoracic echocardiography, was significantly higher in patients infected with B. cepacia (61.3 +/- 17.2 mm Hg) than in controls (37.3 +/- 13.9 mm Hg; P = 0.02), and the mean acceleration time was significantly lower (77 +/- 33 ms versus 108 +/- 25 ms; P = 0.02). The 6-month mortality was significantly higher in patients infected with B. cepacia (57% versus 16%; P = 0.02). Six of the seven patients infected with B. cepacia harbored the same ribotype (genomovar II, B. multivorans). Pulmonary hypertension was significantly more frequent in patients infected by B. cepacia and could contribute to the increased mortality rate.

Adolescent↗

PubMed2004

The efficacy of premixed nitrous oxide and oxygen for fiberoptic bronchoscopy in pediatric patients: a randomized, double-blind, controlled study.

STUDY OBJECTIVE: s: The aim of the study was to evaluate the efficacy and safety of premixed 50% nitrous oxide and oxygen on the quality of sedation and pain control during fiberoptic bronchoscopy (FB) in children. DESIGN: A prospective, randomized, double-blind study. SETTING: Pediatric pulmonary department in a pediatric tertiary university hospital. PATIENTS: One hundred five children aged 1 month to 18 years. INTERVENTIONS: Patients inhaled after sedation and local anesthesia either premixed 50% nitrous oxide and oxygen (nitrous oxide group) or premixed 50% nitrogen and oxygen (control group) during FB. MEASUREMENT AND RESULTS: The rate of failure was significantly greater in the control group (62%) than in the nitrous oxide group (21%, p = 0.00003). The efficacy of premixed 50% nitrous oxide and oxygen was also demonstrated with higher satisfaction scores (p = 0.000001), lower Children's Hospital of Eastern Ontario Pain Scores (p = 0.002), better visual analog scale ratings (p = 0.03), and improved behavior scores. Side effects were minor and similar in both groups. CONCLUSIONS: This study demonstrates the improved efficacy of sedation, pain control, and safety of premixed 50% nitrous oxide and oxygen for FB in children.

Adolescent↗

PubMed2004

Assessing inspiratory muscle strength by sniff nasal inspiratory pressure.

The sniff nasal inspiratory pressure (SNIP) consists in the measurement of pressure through an occluded nostril during sniffs performed through the controlateral nostril. It is an accurate and noninvasive approximation of esophageal pressure swing during sniff maneuvers. However SNIP can underestimate esophageal pressure swing in subjects with nasal obstruction, patients with chronic obstructive pulmonary disease and severe neuromuscular patients. Nevertheless, since SNIP maneuver has predicted normal values, is noninvasive and is easier to perform than maximal inspiratory pressure (MIP) maneuver, it could be considered as the first simple test to use in order to assess inspiratory muscle weakness. In addition, because it is as reproducible as MIP, it can be suitable to follow inspiratory muscle function in chronic neuromuscular patients. Because, of the important limit of agreement between SNIP and MIP, these two methods are not interchangeable but complementary.

Forced Expiratory Volume↗

PubMed2003

Measurement of diaphragm loading during pressure support ventilation.

OBJECTIVE: The diaphragmatic pressure-time product (PTPdi) has been used to quantify the loading and unloading of the diaphragm. The validity of the relationship between PTPdi and diaphragm electrical activity (EMGdi) during pressure-support ventilation (PSV) is unclear. We examined this relationship. DESIGN AND SETTING: Physiological study in a physiology laboratory. SUBJECTS: Six healthy adults. INTERVENTIONS: Spontaneous breathing (SB) and two levels of PSV (6 and 12 cmH(2)O), breathing room air and incremental concentrations of carbon dioxide, sufficient to achieve an EMGdi signal of approximately 200% of baseline value. MEASUREMENTS AND RESULTS: We measured the electrical (EMGdi) and mechanical (PTPdi) activity of the diaphragm using oesophageal electrode and oesophageal and gastric balloon catheters. The relationship between EMGdi and PTPdi during SB was linear in five subjects and curvilinear in one. However, with PSV 12 cmH(2)O we observed that the relationship between EMGdi and PTPdi was 'left shifted'; specifically, for any given level of EMGdi the PTPdi was smaller with PSV 12 cmH(2)O than during SB. However, when PTPdi was converted to power (the product of pressure and flow) the tendency to left shift was largely reversed. CONCLUSIONS: We conclude that when assessing of diaphragm unloading during PSV flow measurements are required. Where flow is constant, PTPdi is a valid measure of diaphragm unloading, but if not these data may be used to make an appropriate correction.

Airway Resistance↗

PubMed2003

Effects of exhaustive incremental treadmill exercise on diaphragm and quadriceps motor potentials evoked by transcranial magnetic stimulation.

It is unknown whether changes in corticomotor excitability follow exercise in healthy humans. We hypothesized that a fall in the diaphragm and quadriceps motor-evoked potential (MEP) amplitude elicited by transcranial magnetic stimulation of the motor cortex would occur after an incremental exercise task. In 11 healthy subjects, we measured transdiaphragmatic pressure and isometric quadriceps tension in response to supramaximal peripheral magnetic nerve stimulation. MEPs were recorded from these muscles in response to transcranial magnetic stimulation. After baseline measurements, subjects performed a period of submaximal exercise (gentle walking). Measurements were repeated 5 and 20 min after this. The subjects then exercised on a treadmill with an incremental protocol to exhaustion. Transcranial magnetic stimulation was performed at baseline and at 5, 20, 40, and 60 min after exhaustive exercise, and force measurements were obtained at baseline, 20 min, and 60 min. Mean exercise duration was 18 +/- 4 min, and mean maximum heart rate was 172 +/- 10 beats/min. Twitch transdiaphragmatic pressure and twitch isometric quadriceps tension were not different from baseline after exercise, but a significant decrease was observed in diaphragm MEP amplitude 5 and 20 min after exercise (60 +/- 38 and 45 +/- 24%, respectively, of baseline, P = 0.0001). At the same times, the mean quadriceps MEPs were 59 +/- 39 and 74 +/- 32% of baseline (P < 0.0001 and P < 0.01, respectively). Studies using paired stimuli confirmed a likely intracortical mechanism for this depression. Our data confirm significant depression of both diaphragm and quadriceps MEPs after incremental treadmill exercise.

Adult↗

PubMed2003

[Protein repair therapy in cystic fibrosis].

In the past few years since the cloning of the gene defective in cystic fibrosis, much has been learned on the function of the protein cystic fibrosis transmembrane conductance regulator (CFTR) and on the mechanisms regulating its expression. Based on the current understanding of the processes involved in lung disease progression, a number of approaches have been developed using not only gene therapy, but also pharmacological agents. Several of these agents have been reported to restore function to CFTR with specific mutations.

Cystic Fibrosis↗

PubMed2003

Respiratory muscle testing in children.

The range of techniques available to assess respiratory muscles weakness has greatly expanded over recent years. Respiratory muscle tests can be divided into non-invasive tests, such as lung function parameters, maximal static pressures and sniff nasal pressure and invasive tests, such as transdiaphragmatic pressures during crying, maximal static pressures and magnetic stimulation of the phrenic nerves. Sniff nasal pressure and magnetic stimulation should have increasing relevance in children in the coming years. However, probably the most important message is to arrange for the evaluation of respiratory muscles in children with unexplained or disproportionate breathlessness such as in patients with neuromuscular diseases. Improvements are needed to evaluate respiratory muscle endurance in children, which is more difficult but complementary to the assessment of respiratory muscle strength.

Adolescent↗

PubMed2002

Changes in pulmonary mechanics with increasing disease severity in children and young adults with cystic fibrosis.

As forced expiratory volume in 1 second (FEV(1)) is a major predictor of outcome in patients with cystic fibrosis (CF), we investigated the effect of FEV(1) on pulmonary mechanics in children and young adults with CF. We measured respiratory rate; tidal volume; minute ventilation; arterial blood gases; sniff esophageal pressure; dynamic lung compliance; total pulmonary resistance; intrinsic positive end expiratory pressure; and total, elastic, and resistive work of breathing in 32 patients (FEV(1) range: 12-49% predicted). We observed correlations between FEV(1) and Pa(O(2)) (r = 0.76, p < 0.0001) and Pa(CO(2)) (r = -0.70, p < 0.0001), FEV(1) and respiratory rate/tidal volume (r = -0.41, p = 0.02), FEV(1) and dynamic lung compliance (r = 0.64, p < 0.0001), and FEV(1) and total work of breathing (r = -0.52, p = 0.002) and elastic work of breathing (r = -0.60. p = 0.0003). No correlations were observed between FEV(1) and sniff esophageal pressure (p = 0.5), minute ventilation (p = 0.9), total pulmonary resistance (p = 0.3), intrinsic positive end expiratory pressure (p = 0.3), or resistive work of breathing (p = 0.1). As FEV(1) declines in children and young adults with CF, there is an increase in the elastic load and work of breathing, resulting in a rapid shallow breathing pattern, that is associated with further impairment of gas exchange.

Adolescent↗

PubMed2002

Incidence of respiratory syncytial virus-related hospitalizations in high-risk children: follow-up of a national cohort of infants treated with Palivizumab as RSV prophylaxis.

The prophylactic administration of Palivizumab, a monoclonal antibody binding the respiratory syncytial virus (RSV) fusion protein, was recently shown to significantly decrease the incidence of RSV-related hospitalizations among high-risk children (IMpact-RSV trial). While awaiting marketing authorization in France and through a cohort of patients' name-based national program temporarily authorized by the French Drug Agency, a prospective register of all Palivizumab-treated patients in France was set up during the epidemic season 1999-2000. Based on this register, this study was carried out to evaluate the incidence of RSV-related hospitalizations and the safety of prophylaxis among a national cohort of children at high-risk of severe RSV disease. During the study period, guidelines issued by the French Pediatric Society recommended prophylaxis for children either aged less than 6 months at inclusion and born at less than 33 weeks of gestation with a history of bronchopulmonary dysplasia (BPD) at 28 days of life, or aged less than 2 years, born at less than 36 weeks of gestation, and having required treatment for BPD over the previous 6 months. Once included in the program, investigators were to prospectively report the clinical and demographic characteristics of children, all hospitalizations, and reasons for the hospitalizations. Five hundred and sixteen children were treated with 1-5 monthly doses. The median gestational age was 28 weeks, and children born at less than 33 weeks of gestation accounted for 88% of the cohort. The prevalence of BPD was 81%. Ninety children were hospitalized for respiratory illness. In 39 children, hospitalizations were attributed to RSV (7.6% of the total cohort). Among those 39 children, 10 (1.9% of the total cohort) required admission into an intensive care unit, and 4 required mechanical ventilation. No deaths or serious adverse events attributable to RSV infection or Palivizumab treatment were reported. We conclude that the RSV-related hospitalization rate in this high-risk cohort was comparable to the rate observed in the subgroup of Palivizumab-prophylaxed children with BPD in the IMpact-RSV trial.

Antibodies, Monoclonal↗

PubMed2002

Depression of diaphragm contractility by nitrous oxide in humans.

UNLABELLED: Nitrous oxide is widely used in anesthesia and critical care medicine. The effect of nitrous oxide on diaphragm contractility in humans is unknown. We evaluated the effect of a 50% nitrous oxide-50% oxygen mixture on diaphragm contractility in healthy adult volunteers. The sniff transdiaphragmatic pressure (Sn Pdi) and the twitch transdiaphragmatic pressure (Tw Pdi) elicited by bilateral supramaximal phrenic nerve stimulation were measured before during and after inhalation of a mixture of 50% nitrous oxide and 50% oxygen. Sn Pdi decreased by 15.4% during nitrous oxide inhalation, with a value of 136 +/- 21 cm H(2)O before nitrous oxide and a value of 115 +/- 27 cm H(2)O during nitrous oxide inhalation (P = 0.03). Similarly, Tw Pdi decreased from 21.2 +/- 1.8 cm H(2)O before nitrous oxide inhalation to 16.9 +/- 4.1 cm H(2)O during nitrous oxide inhalation (P = 0.03). The effect of nitrous oxide was totally abolished 20 min after its discontinuation. Nitrous oxide has a short-acting suppressant effect on the pressure generating capacity of the diaphragm in healthy humans. IMPLICATIONS: We investigated whether nitrous oxide (a common component of gas anesthesia) reduces diaphragm strength in humans. Diaphragm strength is reduced by nitrous oxide but the effect wears off within 20 min of administration. Caution is advised when using nitrous oxide without anesthesiologist supervision in patients at risk of ventilatory failure

Administration, Inhalation↗