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Biomedical subjects

F Leclerc

Publications and source records attributed to F Leclerc.

At least 37 records · Page 2Linked to original sources
PubMed2001

Overdistension in ventilated children.

Ventilating patients with acute respiratory failure according to standardized recommendations can lead to varying volume-pressure (V-P) relationships and overdistension. Young children may be more susceptible than adults to overdistension, and individual evaluation of the effects of ventilator settings is therefore required. Three studies have applied indices for the detection of overdistension to dynamic V-P curves in ventilated children. Two of those studies compared these indices to those obtained using a reference technique ([quasi]-static V-P curves), and suggested that the c coefficient of a second order polynomial equation (SOPE) and the ratio of the volume-dependent elastance to total dynamic elastance (%E2) were suitable indices for estimating overdistension.

Animals↗
PubMed2001

[Rehydration modalities for acute diarrhea in hospitalized infants. Impact of a permanent short-stay pediatric observation unit].

OBJECTIVE: To analyze hospital treatment of infants with acute gastroenteritis, especially the variations in modes of rehydration, hospitalization rates and lengths of stay, related to paediatrician permanency with a short-stay observation unit at their disposal. METHODS: This prospective multicentric study during two rotavirus epidemic periods included 1,187 infants (mean age 10 +/- 6 months) with acute gastroenteritis resulting or not in dehydration. During the first period, 12 volunteer hospitals were included. During the second period, we compared six (among the 12) hospitals where infants were admitted in emergency care or pediatric units without pediatric 24-h permanency, with a pediatric emergency care unit having pediatric permanency with a short-stay observation unit. RESULTS: During the first period, 32% were dehydrated and 6% had hypovolemic shock on admission. The hospitalization rate was 81%. Only 19% of dehydrated infants had exclusively oral rehydration, and 19% of normohydrated infants had intravenous rehydration. During the second period, the hospitalization rate was 42% in the pediatric emergency care unit (28% in the short-stay unit and 14% in hospitalization units) versus 77% in the six hospitals. In the pediatric emergency care unit as compared to the six hospitals, there were a reduction of 65% of hospitalization days, 58% of intravenous accesses, and 66% of laboratory tests. CONCLUSION: Our findings suggest that a paediatric permanency with a short-stay observation unit at their disposal improves quality of treatment and is cost-effective.

Cost-Benefit Analysis↗
PubMed2001

[Treatment of meningococcal purpura fulminans].

In France, the incidence of meningococcal infections is increasing. The most severe presentation, called purpura fulminans, has a death rate of 20-25%; 5 to 20% of the survivors need skin grafts and/or amputations. Diagnosis of invasive meningococcal infection is very difficult when purpura and "toxic" appearance are absent: one should take into account parents' impression of their ill child. This diagnosis must be evoked in any child presenting with febrile purpura (like in the United Kingdom, parents should be encouraged to use the "tumbler test" to identify a vasculitic rash); a fulminant form is to be suspected in the presence of only one ecchymosis and signs of infection, remembering that recognition of shock is difficult in children. Recently, the Health Authority has recommended to administer a third generation cephalosporin promptly (before biological investigations) for any child with signs of infection and a necrotic or ecchymotic purpura (> 3 mm of diameter), and then to refer the patient to the hospital. By grouping the patients from 7 studies, it can be observed that preadmission antibiotic administration has a protective effect on mortality (odds ratio: 0.36; 95% confidence interval: 0.23-0.56); a negative effect was observed in only one of these series. Children with purpura fulminans should be referred to a paediatric intensive care unit. Management includes antibiotics, steroids, fluid resuscitation and catecholamines (be aware of hypoglycaemia, particularly in infants, and hypocalcaemia). Treatment of cutaneous necrosis and distal ischemia is difficult and still controversial: antithrombin, protein C, tissue plasminogen activator and vasodilator infusion have no proven efficacy. Cases must be rapidly notified to the Public Health Service who will institute chemoprophylaxis for close contacts. Given the predominance of serogroup B in France, we hope that an efficient vaccine will soon become available.

Anti-Bacterial Agents↗
PubMed2001

Can generic scores (Pediatric Risk of Mortality and Pediatric Index of Mortality) replace specific scores in predicting the outcome of presumed meningococcal septic shock in children?

OBJECTIVE: To compare, in children with septic shock and purpura, the accuracy in predicting death of two specific scores (the MenOPP bedside clinical [MOC] score of Gedde Dahl and the score of Groupe Francophone de Réanimation Pédiatrique [GFRP]), the C-reactive protein (CRP) level, and the two pediatric generic scores (the Pediatric Risk of Mortality [PRISM] and Pediatric Index of Mortality [PIM] scores). DESIGN: Prospective, population-based study with analysis of previous comparative studies. SETTING: A 14-bed pediatric intensive care unit in a university hospital. PATIENTS: All children admitted consecutively to the pediatric intensive care unit with septic shock and purpura (n = 58, with 16 deaths [27.6%]) from January 1993 to May 2000. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The MOC and GFRP scores and the CRP level were prospectively determined at admission. The PRISM score was prospectively calculated within 24 hrs of admission or at the time of death, and the PIM score was calculated retrospectively between 1993 and 1997 and then prospectively from admission data. The nonparametric estimate of the area under the receiver operating characteristic curves (AUC) was calculated from the raw data using the Wilcoxon-Mann-Whitney two-sample statistic, and the standard error of the AUCs was calculated with DeLong's method. All the scores had an AUC >0.80, the PRISM probability of death having the best one (0.96 +/- 0.02). The PRISM value, which is easier to calculate, had an AUC of 0.95 +/- 0.02. The PRISM score performed significantly better than the PIM score (AUC, 0.83 +/- 0.06; p <.01) and the CRP level (AUC, 0.80 +/- 0.06; p <.01); however, there was no significant difference between the MOC (AUC, 0.91 +/- 0.04) and GFRP scores (AUC, 0.87 +/- 0.05). Analyzing literature and calculating AUCs from original data of previous studies, we observed that the superiority of the PRISM score had never been demonstrated in meningococcal diseases. CONCLUSIONS: The PRISM score performed better than the PIM score, and was not surpassed by specific scores. Thus, we propose its use for outcome prediction in children with septic shock and purpura. However, if the PRISM score is to be used as inclusion criterion for clinical trials, it should be evaluated within a few hours after admission.

Area Under Curve↗
PubMed2000

[Congenital hernia of the diaphragm. A retrospective study of 123 cases recorded in the Neonatal Medicine Department, URHC in Lille between 1985 and 1996].

BACKGROUND: During the last ten years, new therapeutic strategies have been used in order to improve the management of congenital diaphragmatic hernia (CDH). CDH is associated with pulmonary hypoplasia, abnormal pulmonary vascular reactivity and pulmonary immaturity. Between 1985 and 1990, mechanical hyperventilation and early surgery were provided systematically. Since 1991, the management of CDH in our institution has involved a preoperative stabilization with exogenous surfactant replacement, gentle ventilation, high-frequency oscillation, nitric oxide or extracorporeal membrane oxygenation. PURPOSE: To analyse the impact of the new therapeutic strategy on the survival and outcome of newborns with CDH. METHODS: Retrospective review of all infants with CDH admitted to our institution from 1985 through 1996. Mortality and morbidity were compared between period I (1985-1990) and period II (1991-1996). RESULTS: Between 1985 and 1996, 123 neonates were admitted to our Neonatal Department. Nine of them had another severe congenital malformation and were excluded from the study. Survival was 23% (12/52) in period I and 56% (35/62) in period II (p < 0.001). In period II, complications were more frequent among survivors in whom an extracorporeal membrane oxygenation was required (13 infants): bronchopulmonary dysplasia 77% (10/13), gastroesophageal reflux 61% (8/13), and hypotrophy 61% (8/13). CONCLUSION: These data demonstrate a significant improvement in survival in CDH since the implementation of new therapeutic modalities. Nevertheless, a significant morbidity exists among the infants who survive a severe respiratory failure.

Bronchopulmonary Dysplasia↗
PubMed2000

[Upper airway obstruction (foreign bodies excluded)].

Upper airway obstruction is a frequent cause of admission to the emergency department and the intensive care unit. Symptoms are mainly represented by dyspnea and stridor. Severity must be rapidly assessed to allow adapted treatment and avoid cardiac arrest and hypoxic encephalopathy. The possible etiologies are numerous, with acquired and congenital ones, but the majority is represented by laryngitis, lymphoid hypertrophy and laryngotracheomalacia. In case of respiratory failure, treatment must first establish airway patency with bag and mask ventilation, and then intubation. If vital prognosis is not threatened, biologic, radiologic or endoscopic examination can be performed to identify the cause of the obstruction and treat it.

Age Factors↗
PubMed2000

Valproic acid intoxication identified by 1H and 1H-(13)C correlated NMR spectroscopy of urine samples.

Analysis of biological fluids by proton and carbon nuclear magnetic resonance spectroscopy (1H and 13C NMR) is a promising tool in clinical biology. We used this method for rapid toxicological screening in the case of two suicide attempts. For each case, a urine sample was analysed at 300 MHz by 1D and 2D sequences (TOCSY and HMBC) in a short experimental time. Quantification was performed by peak integration on the 1D 1H NMR spectrum. For the two patients, results showed the same resonances of the major metabolite, valproyl-O-glucuronide at concentrations of 121 and 44 mmol/l.

Adolescent↗
PubMed2000

Do new strategies in meningococcemia produce better outcomes?

Meningococcal septic shock (MSS) has high mortality and morbidity rates. In addition to the traditional prompt antibiotics and respiratory and circulatory support, new treatment strategies have been proposed. AGAINST THE INFLAMMATORY CASCADE: Immunotherapy, such as antiserum to Escherichia coli J5 and human antilipid A monoclonal antibodies/centoxin (HA-1A), did not significantly alter the mortality rate of MSS; we are awaiting the results of the bactericidal/permeability-increasing protein multicenter trial. Two series reported the effects of hemofiltration and hemodiafiltration in MSS, but the true benefits remain unknown. TO TREAT HEMOSTATIC ABNORMALITIES: In MSS, heparin is still controversial and antithrombin concentrate use has been reported in only one child. Several case reports on protein C and recombinant tissue plasminogen activator have been published; the efficacy (improvement in shock and organ dysfunction and reduction in amputation rate) and safety (intracerebral hemorrhage with recombinant tissue plasminogen activator) of these treatments need further evaluation. Blood and plasma exchange appear to be safe and are supposed to reduce mortality, but it is difficult to draw firm conclusions from published studies. Finally, local application of medicinal leeches has been reported to improve purpuric lesions. TO INDUCE VASODILATION: Prostacyclin, or epoprostenol, infusion, sodium nitroprussiate infusion, sympathetic blockade, and topical nitroglycerin have been reported to improve distal perfusion; however, these reports are all anecdotal. OTHER STRATEGIES: Improvement in limb perfusion was achieved after hyperbaric oxygenation in patients with purpura fulminans caused by different pathogens. Most authors recommend monitoring of compartment pressures and performing fasciotomy as indicated. Finally, extracorporeal membrane oxygenation was recently proposed to support seven children with intractable MSS. CONCLUSIONS: There is no proof that unconventional treatments have a significant impact on outcome in MSS; prospective multicenter trials are needed. At present, early recognition of meningococcal sepsis and appropriate treatment seem to be the optimal methods of improving outcome. Efforts to find an effective meningococcal vaccine must be continued.

Bacteremia↗
PubMed2000

Ventilator-induced overdistension in children: dynamic versus low-flow inflation volume-pressure curves.

We applied to 20 paralyzed ventilated children (0.15 to 14.3 yr, six with acute respiratory distress syndrome [ARDS]) the low-flow inflation (LFI) technique providing quasi-static volume-pressure (V-P) curves and compared the assessment of overdistension (OD) on dynamic and LFI (reference) inspiratory V-P curves. Dynamic curves were obtained at the airway opening during regular constant flow ventilation (Servo 300). Then LFI curves were obtained. Two analyses were performed: First, the nonlinear coefficient c of a second order polynomial equation (SOPE) fitted to dynamic data obtained during constant flow was compared with the c of SOPE fitted to LFI curve (within tidal volume [VT]). Second, the dynamic C20/C (ratio of compliance of the last 20% of the curve (C20) to total compliance [C]) was compared with the determination of the upper inflection point (UIP) on the LFI curve. OD was defined as a negative value of c, a C20/C < 0.80, an UIP included within the VT range for that child during regular ventilation. Using LFI V-P curves as reference, SOPE offered a better detection of OD than dynamic C20/C or the determination of the UIP by graphical means. Indeed the first analysis showed a substantial agreement (kappa 0.75) between dynamic c and LFI c detection of OD whereas the second analysis showed a poor agreement (kappa 0.22) between C20/ C and LFI detection of the UIP. In conclusion, quasi-static V-P curves can easily be obtained in children with the LFI technique. SOPE offers a good detection of OD on dynamic and LFI V-P curves but the C20/C index seems to be an inadequate measure of OD.

Adolescent↗
PubMed1999

Comparison of four methods for measuring elevation of FRC in mechanically ventilated infants.

The aim of the study was to compare measurements of the elevation of functional residual capacity (FRC) above the relaxation volume obtained in 34 mechanically ventilated infants (median weight 2.6 kg, range 1.2-9) from four different methods: (1) direct measurement of the complete exhalation volume after brief disconnection from the ventilator, (2) calculated measurement from total positive end-expiratory pressure (PEEP) measured by end-expiratory occlusion of the breathing circuit, (3) extrapolated evaluation from the mathematical model of Brody, (4) extrapolated evaluation from the passive expiration method. We considered the direct measurement (1) as the "gold standard". Measurements obtained by total PEEP (2) and by the Brody's mathematical model (3) provided similar results than the direct measurement. Conversely, graphical extrapolation from the passive expiration method (4) underestimated the elevation of FRC. In conclusion, we suggest using the mathematical extrapolation from the Brody's model to evaluate the elevation of FRC in mechanically ventilated infants: this method is non-invasive, does not require disruption of gas flow, can be easily performed with all the neonatal ventilators, and allows continuous breath-by-breath measurements.

Airway Resistance↗