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At least 19 recordsLinked to original sources
PubMed2005

A Bayesian Neural Network approach to estimating the Energy Equivalent Speed.

To reduce the number and the gravity of accidents, it is necessary to analyse and reconstruct them. Accident modelling requires the modelling of the impact which in turn requires the estimation of the deformation energy. There are several tools available to evaluate the deformation energy absorbed by a vehicle during an impact. However, there is a growing demand for more precise and more powerful tools. In this work, we express the deformation energy absorbed by a vehicle during a crash as a function of the Energy Equivalent Speed (EES). The latter is a difficult parameter to estimate because the structural response of the vehicle during an impact depends on parameters concerning the vehicle, but also parameters concerning the impact. The objective of our work is to design a model to estimate the EES by using an original approach combining Bayesian and Neural Network approaches. Both of these tools are complementary and offer significant advantages, such as the guarantee of finding the optimal model and the implementation of error bars on the computed output. In this paper, we present the procedure for implementing this Bayesian Neural Network approach and the results obtained for the modelling of the EES: our model is able to estimate the EES of the car with a mean error of 1.34 m s(-1). Furthermore, we built a sensitivity analysis to study the relevance of model's inputs.

Accidents, Traffic↗
PubMed2001

A statistical model to compare road mortality in OECD countries.

The objective of this paper is to compare safety levels and trends in OECD countries from 1980 to 1994 with the help of a statistical model and to launch international discussion and further research about international comparisons. Between 1980 and 1994, the annual number of fatalities decreased drastically in all the selected countries except Japan (+ 12%), Greece (+ 56%) and ex-East Germany (+ 50%). The highest decreases were observed in ex-West Germany (- 48%), Switzerland (- 44%), Australia (- 40%), and UK (- 39%). In France, the decrease in fatalities over the same period reached 34%. The fatality rate, an indicator of risk, decreased in the selected countries from 1980 to 1994 except in the east-European countries during the motorization boom in the late 1980s. As fatality rates are not sufficient for international comparisons, a statistical multiple regression model is set up to compare road safety levels in 21 OECD countries over 15 years. Data were collected from IRTAD (International Road Traffic and Accident Database) and other OECD statistical sources. The number of fatalities is explained by seven exogenous (to road safety) variables. The model, pooling cross-sectional and time series data, supplies estimates of elasticity to the fatalities for each variable: 0.96 for the population; 0.28 for the vehicle fleet per capita; -0.16 for the percentage of buses and coaches in the motorised vehicle fleet; 0.83 for the percentage of youngsters in the population; - 0.41 for the percentage of urban population; 0.39 for alcohol consumption per capita; and 0.39 for the percentage of employed people. The model also supplies a rough estimate of the safety performance of a country: the regression residuals are supposed to contain the effects of essentially endogenous and unobserved variables, independent to the exogenous variables. These endogenous variables are safety performance variables (safety actions, traffic safety policy, network improvements and social acceptance). A new indicator, better than the mortality rate, is then set upon the residuals. Mean estimates of this indicator for the years 1980-1982 and the years 1992-1994 rank the countries in the beginning and at the end of the study period. Countries showing the best ranks (and thus the best performance) in 1980 and 1994 are Sweden, the Netherlands and Norway. The UK and Switzerland reach the top 5 in 1994. Greece, Belgium, Portugal and Spain are the last countries in the classification along with, surprisingly, the USA. France was ranked 18th in 1980 and 15th in 1994 but is ranked amongst the five countries that most improved from 1980 to 1994. This model remains non definitive because it is not able to distinguish between safety performance and unobserved exogenous variables although these exogenous variables could explain more about the differences in levels and trends between the countries. More complex models, particularly highly sophisticated models regarding the number of fatalities with breakdowns by road users or road classes would be needed to give a precise and profound ranking of safety levels and safety improvements between countries.

Accidents, Traffic↗
PubMed2000

[Rapid diagnosis of the type of meningitis (bacterial or viral) by the assay of serum procalcitonin].

OBJECTIVE: It has been shown that serum procalcitonin (PCT) can be used to differentiate bacterial from viral meningitis in children in all cases. The aim of this study was to demonstrate the interest of PCT in the management of suspected meningitis in adults. PATIENTS AND METHODS: We conducted a prospective study including 179 consecutive patients admitted to the emergency department for suspected meningitis. All samples were taken at patient admission. The discriminant potential between bacterial and viral meningitis was studied for cerebrospinal fluid parameters (cytology, protein, glucose, lactate) and serum parameters (C reactive protein, PCT). RESULTS: Thirty-two patients had bacterial meningitis, 90 had viral meningitis and meningitis was ruled out in 57. Among all studied parameters, the most discriminant for distinguishing between bacterial and viral meningitis in 100% of the cases proved to be serum procalcitonin with a threshold value of 0.93 ng/ml. CONCLUSION: Serum procalcitonin is an interesting parameter in the emergency department for management of meningitis suspicion in adults.

Adenoviridae Infections↗
PubMed1999

Does bicarbonate therapy improve the management of severe diabetic ketoacidosis?

OBJECTIVE: The use of bicarbonates in the treatment of severe diabetic ketoacidosis remains controversial, especially regarding the benefit/risk ratio. The aim of this study was to assess the efficacy of bicarbonate therapy during severe diabetic ketoacidosis (pH <7.10). DESIGN: Retrospective study. SETTING: The emergency unit of a teaching hospital. PATIENTS: The records of 39 patients consecutively admitted for severe diabetic ketoacidosis were analyzed (pH <7.10). The patients were divided into two groups: group 1 (n = 24; patients with bicarbonate treatment) and group 2 (n = 15; patients without bicarbonate treatment). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We compared two groups of patients presenting with severe diabetic ketoacidosis (pH values between 6.83 and 7.08) treated with or without bicarbonate. A group of 24 patients received 120+/-40 mmol sodium bicarbonate. The two groups were similar at admission with regard to clinical and biological parameters. No difference could be demonstrated between the two groups concerning the clinical parameters or the normalization time of biochemical parameters. If the number of patients with hypokalemia was comparable between the two groups, the potassium supply was significantly more important in group 1 compared with group 2 (366+/-74 mmol/L vs. 188+/-109 mmol/L, respectively; p < .001). CONCLUSIONS: Data from the literature and this study are not in favor of the use of bicarbonate in the treatment of diabetic ketoacidosis with pH values between 6.90 and 7.10.

Adult↗
PubMed1999

[Diagnosis and development of heparin-induced thrombocytopenia. Biological and clinical aspects].

Two types of thrombocytopenia occur during treatment with heparin: type I and type II heparin-induced thrombocytopenia (HIT). Type I HIT is due to a direct interaction between heparin and platelets. They are asymptomatic, occur early, mild and transitory. Type II HIT which is immunoallergic in nature is the most important complication of this treatment. The thrombocytopenia has a different presentation, acute with a fall in platelets over 30 per cent and is often associated with the occurrence or worsening of a venous or arterial thrombotic episode. The major problems of this secondary type are threefold: its recognition, its confirmation and its management should be as early as possible to avoid the development of often dramatic complications which compromise the prognosis. Laboratory investigations are required by highly reliable specialist laboratories following a careful clinical history. The natural history of the platelet count should enable the difficult diagnosis of HIT to be made more accurately. The treatment of confirmed HIT and/or symptomatic HIT often requires a multidisciplinary approach from a specialized team involving clinicians and hematologists. Two therapies with the benefit of large experience have just been obtained in France with marketing approval (AMM) for the management of HIT: danaparoid (Orgaran) and recombinant hidurin, lepirudin (Refludan). A declaration to the regional drugs monitoring center should not be omitted. In addition, each patient should be given a certificate confirming the immunallergy thus avoiding any further exposure with potentially dramatic consequences.

Anticoagulants↗
PubMed1998

[Fatal voluntary poisoning with cibenzoline. Failure of conventional therapies].

BACKGROUND: Massive voluntary ingestion of cibenzoline causes major cardiotoxicity. We report on two cases where conventional treatments were ineffective. CASE REPORTS: Two patients were admitted to the intensive care unit of a University Hospital after massive voluntary intoxication with cibenzoline. Delay to admission after ingestion of cibenzoline was 1.5 and 4 hours. Circulatory impairment developed rapidly in both patients due to major atrioventricular and ventricular conduction disorders. Conventional intensive care procedures (sodium lactate and adrenaline) were performed but only provided temporary and incomplete efficacy. Outcome was fatal in both cases. DISCUSSION: The lethal potential of cibenzoline is very high. Extra-corporeal cardiocirculatory assistance might be an advisable measure if conventional therapy is unsuccessful. No clearly defined prognosis factors in cibenzoline intoxications have been reported.

Anti-Arrhythmia Agents↗
PubMed1998

A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. Prévention du Risque d'Embolie Pulmonaire par Interruption Cave Study Group.

BACKGROUND: The efficacy and safety of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis is still a matter of debate. METHODS: Using a two-by-two factorial design, we randomly assigned 400 patients with proximal deep-vein thrombosis who were at risk for pulmonary embolism to receive a vena caval filter (200 patients) or no filter (200 patients), and to receive low-molecular-weight heparin (enoxaparin, 195 patients) or unfractionated heparin (205 patients). The rates of recurrent venous thromboembolism, death, and major bleeding were analyzed at day 12 and at two years. RESULTS: At day 12, two patients assigned to receive filters (1.1 percent), as compared with nine patients assigned to receive no filters (4.8 percent), had had symptomatic or asymptomatic pulmonary embolism (odds ratio, 0.22; 95 percent confidence interval, 0.05 to 0.90). At two years, 37 patients assigned to the filter group (20.8 percent), as compared with 21 patients assigned to the no-filter group (11.6 percent), had had recurrent deep-vein thrombosis (odds ratio, 1.87; 95 percent confidence interval, 1.10 to 3.20). There were no significant differences in mortality or the other outcomes. At day 12, three patients assigned to low-molecular-weight heparin (1.6 percent), as compared with eight patients assigned to unfractionated heparin (4.2 percent), had had symptomatic or asymptomatic pulmonary embolism (odds ratio, 0.38; 95 percent confidence interval, 0.10 to 1.38). CONCLUSIONS: In high-risk patients with proximal deep-vein thrombosis, the initial beneficial effect of vena caval filters for the prevention of pulmonary embolism was counterbalanced by an excess of recurrent deep-vein thrombosis, without any difference in mortality. Our data also confirmed that low-molecular-weight heparin was as effective and safe as unfractionated heparin for the prevention of pulmonary embolism.

Aged↗
PubMed1998

Evaluation of D-dimer ELISA test in elderly patients with suspected pulmonary embolism.

STUDY OBJECTIVE: To determine the clinical usefulness of D-dimer ELISA test in elderly patients with clinically suspected pulmonary embolism (PE). DESIGN: Prospective cohort study. PATIENTS: Ninety-six consecutive outpatients older than 70 years with a duration of symptoms shorter than one week and without metastatic cancer or recent surgery, trauma, infection, stroke, myocardial infarction, deep vein thrombosis (DVT) or PE, or treatment with curative doses of heparin or oral anticoagulant. INTERVENTION: All patients underwent at least ventilation/perfusion scan and bilateral ultrasonic duplex scan and a blood sample collection within 24 hours of admission. When necessary a pulmonary angiography and/or a bilateral venography were also performed. Patients were classified as follows: (1) PE-positive: positive angiography or high probability V/Q scan and deep vein thrombosis (proven either by venography or by ultrasonic duplex scan) or non high probability V/Q scan and either DVT (proven at presentation by venography or by ultrasonic duplex scan) or symptomatic thromboembolic event within 3 months of follow-up; or (2) PE-negative; normal V/Q scan or normal angiography or non high probability V/Q scan and either negative ultrasonic duplex scan or normal venography and low clinical probability and absence of symptomatic thromboembolism within 3 months of follow-up. D-dimer measurements were performed using both a conventional and a single semi-quantitative ELISA test (Asserachrom D-di, Instant I.A.D-dimer). RESULTS: Using a cutoff value of 500 ng/ml, the conventional ELISA D-dimer test showed a sensitivity and a negative predictive value of 100% with poor specificity and positive predictive value of 14.3% and 45.5% respectively. The new rapid semi-quantitative D-dimer test displays worse results with sensitivity, negative predictive value, specificity and positive predictive value of 92.3%, 82.4%, 25% and 46% respectively. CONCLUSION: In a geriatric population, conventional ELISA D-dimer is a good marker to exclude PE but, due to the comorbid conditions, only a few patients presented with D-dimer values less than 500 ng/ml.

Aged↗
PubMed1997

A comparison of low-molecular-weight heparin with unfractionated heparin for acute pulmonary embolism. The THESEE Study Group. Tinzaparine ou Heparine Standard: Evaluations dans l'Embolie Pulmonaire.

BACKGROUND: Low-molecular-weight heparin appears to be at least as effective and safe as standard, unfractionated heparin for the treatment of deep-vein thrombosis, but only limited data are available on the use of low-molecular-weight heparin to treat acute symptomatic pulmonary embolism. METHODS: We randomly assigned 612 patients with symptomatic pulmonary embolism who did not require thrombolytic therapy or embolectomy to either subcutaneous low-molecular-weight heparin (tinzaparin) given once daily in a fixed dose or adjusted-dose, intravenous unfractionated heparin. Oral anticoagulant therapy was begun between the first and the third day and was given for at least three months. We compared the treatments at day 8 and day 90 with respect to a combined end point of recurrent thromboembolism, major bleeding, and death. RESULTS: In the first eight days of treatment, 9 of 308 patients assigned to receive unfractionated heparin (2.9 percent) reached at least one of the end points, as compared,with 9 of 304 patients assigned to low-molecular-weight heparin (3.0 percent; absolute difference, 0.1 percentage point; 95 percent confidence interval, -2.7 to 2.6). By day 90, 22 patients assigned to unfractionated heparin (7.1 percent) and 18 patients assigned to low-molecular-weight heparin (5.9 percent) had reached at least one end point (P=0.54; absolute difference, 1.2 percentage points; 95 percent confidence interval, -2.7 to 5.1). The risk of major bleeding was similar in the two treatment groups throughout the study. CONCLUSIONS: Under the conditions of this study, initial subcutaneous therapy with the low-molecular-weight heparin tinzaparin appeared to be as effective and safe as intravenous unfractionated heparin in patients with acute pulmonary embolism.

Acute Disease↗
PubMed1996

Effects of pentoxifylline on circulating cytokine concentrations and hemodynamics in patients with septic shock: results from a double-blind, randomized, placebo-controlled study.

OBJECTIVE: To determine whether a continuous intravenous infusion of pentoxifylline, a methylxanthine derivative, alters the serum cytokine concentrations and/or hemodynamic measurements in patients with septic shock. DESIGN: A prospective, randomized, double-blind, placebo-controlled study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: Sixteen patients with septic shock. INTERVENTIONS: Patients were randomly assigned to receive either pentoxifylline (1 mg/kg) followed by an infusion of 1.5 mg/kg/hr for 24 hrs (n = 8), or placebo (n = 8). MEASUREMENTS AND MAIN RESULTS: Tumor necrosis factor (TNF) and interleukin (IL)-6 concentrations were measured by radioimmunoassays; IL-8 concentrations by an enzyme-linked immunosorbent assay (ELISA) and pentoxifylline concentrations by high-performance liquid chromatography at 0, 3, 6, 12, 18, 24 and 48 hrs after study entry. Pulmonary artery catheter-derived hemodynamics were measured at 0, 0.75, 3, 6, 12, 18, and 24 hrs. In pentoxifylline-treated patients, at 24 hrs, serum concentrations of TNF were significantly lower compared with controls (12 +/- 2 vs. 42 +/- 12 pg/mL, respectively, p = .04). Serum concentrations of IL-6 and IL-8 did not differ between the two treatment groups. There were also no significant differences in any hemodynamic and oxygenation measurements comparing the two treatment groups. Pentoxifylline concentrations were 1,544 +/- 241 ng/mL after the initial dose, and 5,776 +/- 1,781 ng/mL at the end of the 24-hr infusion. Five patients in the pentoxifylline group and four patients in the placebo group died. CONCLUSIONS: Pentoxifylline is able to decrease serum TNF but not IL-6 or IL-8 serum concentrations during septic shock. Pentoxifylline was well tolerated by all eight patients with no adverse effect. Further studies are needed to determine if pentoxifylline's ability to lower circulating TNF concentration without altering hemodynamics will improve outcome in septic shock.

Adult↗
PubMed1996

Symptomatic inferior vena cava filter thrombosis: clinical study of 30 consecutive cases.

Inferior vena cava (IVC) filter thrombosis has not been described as a clinical entity. Thirty patients with IVC percutaneous filter thrombosis were assessed by cavography, computed tomographic (CT) scan and/or duplex ultrasonography. All patients had proximal venous thrombosis when the filter was placed, and the indication for filter placement was a contraindication to anticoagulant therapy in eight patients (27%). Filter thrombosis occurred within 6 months following filter placement in 15 patients (early filter thrombosis group). Among these patients, 10 were not treated with oral anticoagulant, and none of the other five received adjusted anticoagulation. No patients with late filter thrombosis received anticoagulant at the time of the diagnosis. Early filter thrombosis was mainly associated with LGM filters (12 of the 15 cases). Occlusion was revealed by recurrent venous thrombosis in 18 cases. A thrombus above the filter and pulmonary embolism was found in 10 patients (33%). Thrombolytic therapy failed in 5 out of 7 cases, and all but two patients were treated with anticoagulant therapy. In conclusion, early filter thrombosis appears to be due to intracaval extension of deep vein thrombosis, and this emphasizes the need for appropriate anticoagulation. In the case of temporary contraindication to anticoagulation at the time of the filter placement, anticoagulant should be reassessed later.

Adult↗
PubMed1995

[Justification of routine puncture of ascites in cirrhotic patients admitted to emergency hospital units].

OBJECTIVES: Spontaneous bacterial peritonitis (SBP) is a frequent, serious, recurrent complication, occurring in 10 to 30% of cirrhotic patients hospitalized with ascites. The key to diagnosis of SBP is ascites paracentesis and polymorphonuclear count in ascitic fluid. The purpose of our study was to evaluate sensitivity and specificity of clinical and biological criteria in diagnosis of 5 BP. METHODS: We prospectively reviewed 30 adult cirrhotic patients admitted in our emergency department with ascites. Ascites paracentesis was performed in each patient, and SBP diagnosis was based on either positive bacteriological culture or polymorphonuclear count above 250/mm3 in ascitic fluid. Classical criteria for SBP were recorded: blood pressure under 90 mm of Hg, abdominal pain, temperature above 38.5 or under 36.5, jaundice, encephalopathy, increased serum bilirubin or creatinine, leukocyte blood count about 12 G/l. We evaluated sensitivity and specificity of those criteria in SBP, and compared their frequency in patients with SBP or sterile ascitic fluid. RESULTS: Thirty patients were included in our series, and in 14 of them a SBP was diagnosed. A significant difference was observed between spontaneous bacterial peritonitis and sterile ascitic fluid for abdominal pain and temperature abnormalities, but specificity and sensitivity of these criteria were very low. Moreover, SBP was asymptomatic in 7%. CONCLUSION: Due to the high rate of mortality in patients with SBP we recommend diagnostic procedures for this frequent complication as soon as patient is admitted in emergency department. This diagnosis must be based on ascitic fluid paracentesis, which has to be performed, in the emergency department, in every cirrhotic patient admitted with ascites. Indeed, SBP is often asymptomatic, and no clinical or bacteriological criteria can be considered as completely reliable for the diagnosis of spontaneous bacterial peritonitis.

Ascites↗
PubMed1995

[Thrombotic thrombocytopenic purpura disclosing cancer: apropos of 2 cases].

Thrombotic thrombocytopenic purpura (TTP) causes severe haemolytic anaemia, thrombopenia, fever and neurological and renal involvement. Currently five large aetiologic groups have been identified: viral or bacterial infection, drugs, conjunctive tissue diseases, pregnancy and solid tumours. We observed two cases resulting from an adenocarcinoma. In the first case, a 71-year-old man with chronic silicosis, the presenting signs were asthenia, fever, epistaxis with diffus purpura and spontaneous haematomas of the lower limbs. Diagnosis of TTP was based on routine laboratory tests and the patient responded well to fresh frozen plasma. On the 5th day of treatment, haemoglobin level dropped sharply and melana occurred. Upper digestive tract endoscopy revealed a tumoural formation of the antrum-fundic junction and histology examination of the biopsy confirmed the diagnosis of adenocarcinoma. Ten months after gastrectomy the patient was in excellent health with no relapse of the TTP. In the second case, the presenting signs included spontaneous haematomas, rectorrhagia and low grade fever. Microscopic haematuria and renal failure were observed in addition to the biological syndrome of TTP. The patient responded poorly to fresh frozen plasma and packed cell transfusions. Plasma exchange was equally unsuccessful. The disease continued a fulminant course and the diagnosis of adenocarcinoma located in a pulmonary lymph nodes was made at autopsy. These rare cases of TTP caused by cancer emphasize the importance of a thorough aetiological research. Plasma exchange has been shown to be effective but mortality at 1 year approximately 85% in cancer related cases. Early diagnosis and specific anti-cancer therapy might improve prognosis. We report our personal experience with 16 other similar cases.

Adenocarcinoma↗
PubMed1995

Adult first generalized seizure: etiology, biological tests, EEG, CT scan, in an ED.

The purpose of this study was to evaluate adult first seizures in an emergency department by analyzing etiologic and epidemiological data and studying the usefulness of biological screening, electroencephalogram (EEG), and cerebral computed tomography (CT) scan. This was a retrospective study of a 3-year period during which 247 patients were admitted to an emergency department for a first generalized seizure. A CT scan had been performed in 247 patients and an EEG in 209. Etiologies were found to be (1) unknown, (2) alcohol abuse, (3) stroke, and (4) tumor. Early recurrence rate was 18.5%. EEG was of low interest in emergency. The rate of cerebral focal lesions on CT scan was significantly lower when both examination results and EEG were normal. The rate of metabolic abnormalities was 4.9%. It was concluded that (1) a short hospitalization is advisable because of recurrences, (2) recurrence rate does not increase significantly in patients with focal cerebral lesion, (3) metabolic screening is necessary, and (4) CT scan will be an outpatient procedure for most patients.

Adolescent↗