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Biomedical subjects

S Chevret

Publications and source records attributed to S Chevret.

At least 91 records · Page 5Linked to original sources
PubMed1999

Use of tunneled femoral catheters to prevent catheter-related infection. A randomized, controlled trial.

BACKGROUND: The risk for catheter-related infection seems higher with femoral catheters than with catheters inserted at other sites. OBJECTIVE: To evaluate the effect of catheter tunneling on femoral catheter-related infection in critically ill patients. DESIGN: Randomized, controlled trial. SETTING: Three intensive care units at academic hospitals in Paris, France. PATIENTS: 345 adult patients requiring a femoral venous catheter for more than 48 hours. INTERVENTION: Tunneled or nontunneled femoral catheters. MEASUREMENTS: Time to occurrence of systemic catheter-related sepsis, catheter-related bloodstream infection, and quantitative catheter tip culture with a cutoff of 10(3) colony-forming units/mL. RESULTS: Of 345 randomly assigned patients, 336 were evaluable. Probable systemic catheter-related sepsis occurred in 15 of 168 patients who received a nontunneled femoral catheter (controls) and in 5 of 168 patients who received a tunneled femoral catheter (estimated absolute risk reduction, 6% [95% CI, 0.9% to 11%]). Time to occurrence of catheter-related bloodstream infection was not significantly modified (relative risk, 0.28 [CI, 0.03 to 1.92]; P = 0.18); 3 events occurred in the control group and 1 event occurred in the tunneled-catheter group. After stratification by treatment center and adjustment for variables that were prognostic (use of broad-spectrum antimicrobial agents at catheter insertion) or imbalanced between both groups (mechanical ventilation at insertion), tunnelized catheterization reduced the proportion of patients who developed systemic catheter-related sepsis (relative risk, 0.25 [CI, 0.09 to 0.72]; P = 0.005) and positive quantitative culture of the catheter tip (relative risk, 0.48 [CI, 0.23 to 0.99]; P = 0.045). CONCLUSION: The incidence of femoral catheter-related infections in critically ill patients can be reduced by using subcutaneous tunneling.

Catheterization, Peripheral↗
PubMed1999

Hepatocellular carcinoma without cirrhosis in the West: epidemiological factors and histopathology of the non-tumorous liver. Groupe d'Etude et de Traitement du Carcinome Hépatocellulaire.

BACKGROUND/AIM: In the West, hepatocellular carcinoma rarely occurs in patients without cirrhosis. In these patients, epidemiological factors and the histopathology of the non-neoplastic liver are not well known. The aim of this study was to clarify these points. METHODS: We studied 30 patients (26 men, 28-87 years) with hepatocellular carcinoma and histologically-proven non-cirrhotic livers. Serological markers of HBV and HCV infection, as well as alcohol and tobacco consumption were evaluated. Pathological changes in the non-tumorous liver (fibrosis, inflammation, steatosis, alcoholic hepatitis lesions, iron overload, and large cell dysplasia) were systematically assessed using semi-quantitative scores. RESULTS: Twenty patients had alcohol intake > or =30 g/d and 16 were smokers. Serological HBV or HCV markers were positive in 10 patients. Only four patients had no exposure to alcohol or tobacco and no serological markers of HBV or HCV Histological examination showed that all livers had pathological changes. Seventeen patients (57%) had clearly-identified chronic liver disease: chronic hepatitis (n = 10) or alcoholic liver disease (n = 7). Non-specific and moderate pathological changes were observed in the 13 other patients (43%), with different degrees of fibrosis, activity, steatosis, and iron overload. Large cell dysplasia was present in 12 patients (40%). CONCLUSIONS: In our study, all patients with hepatocellular carcinoma and non-cirrhotic livers had non-tumorous pathological liver changes, especially iron overload and large cell dysplasia. These results suggest that hepatocellular carcinoma originates from an abnormal histological background, even in non-cirrhotic liver.

Adult↗
PubMed1999

A new prognostic classification for predicting survival in patients with hepatocellular carcinoma. Groupe d'Etude et de Traitement du Carcinome Hépatocellulaire.

BACKGROUND/AIMS: In patients with hepatocellular carcinoma, prediction of survival is difficult. The aim of this prospective study was to provide a simple classification for predicting survival of patients with hepatocellular carcinoma, based on a multivariable Cox model. METHODS: Seven hundred and sixty-one patients who presented with hepatocellular carcinoma from 24 Western medical centers were enrolled over a 30-month period. Patients were randomly assigned to either a training sample (n=506, with 418 deaths) from which a classification system was established, or a test sample (n=255, with 200 deaths) for validating its prognostic significance. RESULTS: Five prognostic factors were selected at the 0.0001 level: Karnofsky index <80% (relative risk of death=2.2, 95% confidence interval: 1.7-2.7), serum bilirubin >50 micromol/l (relative risk=2.1, 95% confidence interval: 1.7-2.6), serum alkaline phosphatase at least twice the upper limit of normal range (relative risk=1.6, 95% confidence interval: 1.3-2.0), serum alpha-fetoprotein >35 microg/l (relative risk=1.7, 95% confidence interval: 1.4-2.1), and ultrasonographic portal obstruction (relative risk=1.3, 95% confidence interval: 1.1-1.7). Three risk groups with different 1-year survival rates (72%, 34%, 7%) were derived, and independently validated in the test sample (79%, 31%, 4%). CONCLUSION: This classification could be useful in the assessment of prognosis from homogeneous groups of patients with respect to their expected outcome.

Adult↗
PubMed1999

Prognostic value of the soluble interleukin-2 receptor in chronic hepatitis C treated with interferon-alfa. Multicenter GER-CYT 04 Group.

BACKGROUND/AIMS: High serum levels of the soluble interleukin 2 receptor (sIL-2R) have been reported in patients with chronic hepatitis C. The aims of this study were to determine the evolution of sIL-2R considered as an indicator of activation of T cells in patients with hepatitis C virus (HCV) treated with IFN-alpha and to correlate sIL-2R serum levels with parameters reflecting ongoing liver disease and with outcome of interferon treatment. METHODS: In a case-control study, we studied patients enrolled in a multicenter randomized clinical trial which had demonstrated the benefit of a reinforced regimen of interferon alpha. Each of the 26 sustained virological responders (SVR) was paired for treatment regimen with two non-responders (NR). RESULTS: Prior to treatment, higher levels of sIL-2R were found in the sera of 78 patients compared with healthy controls (3791+/-210 pg/ml versus 956+/-88 pg/ml (p<0.001)). In the 78 patients after 4 weeks of treatment, the levels of sIL-2R were higher than pretreatment levels (4308+/-206 pg/ml (p<0.01)). In the NR, levels of sIL-2R increased significantly after 4 weeks of treatment compared with pretreatment levels (p<0.01), and levels of sIL-2R at week 72 were not significantly different from those at pretreatment. Conversely, in the SVR, levels of sIL-2R at week 4 did not significantly increase compared to pretreatment values, and thereafter gradually decreased. At week 72, levels of sIL-2R were significantly lower than before treatment (p<0.001). The difference between levels of sIL-2R at week 4 and before initiation of treatment (delta s IL-2R) was smaller in the SVR than in the NR (142+/-219 pg/ml versus 704+/-107 pg/ml (p<0.02). The disappearance of HCV RNA from the serum at week 4 showed a sensitivity of 92% (95% confidence interval 86-98) and a specificity of 60% (95% confidence interval 49-71), delta sIL-2R had a sensitivity of 42% (95% confidence interval 31-53) and a specificity of 81% (95% confidence interval 79-90) for the prediction of a sustained virological response 6 months after stopping treatment. The disappearance of HCV RNA from serum at week 4 and delta sIL-2R were independent and early predictive factors for a sustained virological response 6 months after stopping treatment. CONCLUSIONS: At week 4, delta sIL-2R may be a more specific parameter than the disappearance of HCV RNA for assessing total, and hence more sustained, elimination of HCV infection 6 months after stopping treatment.

Adult↗
PubMed1999

Treatment of the adult Guillain-Barré syndrome: indications for plasma exchange.

The Guillain-Barré syndrome is the most common cause of acute flaccid paralysis. Currently, 5% of patients die and 10% are left with severe motor sequelae at one year. Multidisciplinary teams, trained to specific treatments, are required to manage these patients. Oral and intravenous steroid treatment of GBS has been disappointing. Two large randomized clinical trials comparing plasma exchange (PE) to standard supportive treatment have shown a short-term and a one-year benefit of PE. Appropriate number of exchanges and indications of PE are now more precisely known. Patients with mild forms of the disease (able to walk) should receive two PEs, while a further two exchanges should be done in case of deterioration or in advanced forms (loss of walking ability, mechanical ventilation). A greater number of exchanges does not appeared beneficial. More recently, two randomized trials produced some evidence that intravenous immune globulin (IVIg, 0.4 g/kg daily for five days) and PE had equivalent efficiency in advanced forms. The combination of PE with IVIg did not yield a significant advantage, but did increase cost and risk. In advanced forms, the choice between PE and IVIg depends on the contraindications of each treatment.

Guillain-Barre Syndrome↗
PubMed1999

A short induction regimen of interferon-alpha is not effective for treatment of relapse in chronic hepatitis C: a randomized trial. For the multicentre GER-CYT-01 group.

The aim of this work was to assess the effect of a high-dose (10 million units, MU) short-duration (14 weeks) interferon-alpha2b (IFN-alpha2b) regimen in relapsers compared with the standard IFN regimen of 3 MU three times weekly (t.i.w.) for 6 months. Fifty-eight non-cirrhotic patients (who had relapsed after previous treatment with IFN) with chronic hepatitis were randomized: 29 to the high-dose, short-duration regimen and 29 to the standard regimen. By the end of IFN therapy, in the high-dose, short-duration group alanine aminotransferase (ALT) normalization was observed in 23 (79%) of 29 patients, and undetectable hepatitis C virus (HCV) RNA in eight (28%) vs 25 (86%) and 11 (38%) of the 29 patients in the standard group, respectively (P = NS). At the end of the 72-week follow-up, in the high-dose, short-duration group a sustained ALT normalization was observed in two (7%) patients, and undetectable HCV RNA in 0 (0%) vs five (17%) and four (14%) patients in the standard group (P = NS). There was less fibrosis improvement in the high-dose, short-duration group (two of 26 patients, 8%) than in the standard group (eight of 25 patients, 32%) (P = 0.04). Tolerance to IFN was good and similar in the two groups. In conclusion, in IFN relapsers, high-dose, short-duration treatment with IFN-alpha has no advantage when compared to a 6-month treatment with 3 MU IFN t.i.w.

Adult↗
PubMed1999

Attributable morbidity and mortality of catheter-related septicemia in critically ill patients: a matched, risk-adjusted, cohort study.

OBJECTIVE: To determine the attributable risk of death due to catheter-related septicemia (CRS) in critically ill patients when taking into account severity of illness during the intensive-care unit (ICU) stay but before CRS. DESIGN: Pairwise-matched (1:2) exposed-unexposed study. SETTING: 10-bed medical-surgical ICU and an 18-bed medical ICU. PATIENTS: Patients admitted to either ICU between January 1, 1990, and December 31, 1995, were eligible. Exposed patients were defined as patients with CRS; unexposed controls were selected according to matching variables. METHODS: Matching variables were diagnosis at ICU admission, length of central catheterization before the infection, McCabe Score, Simplified Acute Physiologic Score (SAPS) II at admission, age, and gender. Severity scores (SAPS II, Organ System Failure Score, Organ Dysfunction and Infection Score, and Logistic Organ Dysfunction System) were calculated four times for each patient: the day of ICU admission, the day of CRS onset, and 3 and 7 days before CRS. Matching was successful for 38 exposed patients. Statistical analysis was based on nonparametric tests for epidemiological data and on Cox's models for the exposed-unexposed study, with adjustment on matching variables and prognostic factors of mortality. RESULTS: CRS complicated 1.17 per 100 ICU admissions during the study period. Twenty (53%) of the CRS cases were associated with septic shock. CRS was associated with a 28% increase in SAPS II. Crude ICU mortality rates from exposed and unexposed patients were 50% and 21%, respectively. CRS remained associated with mortality even when adjusted on other prognostic factors at ICU admission (relative risk [RR], 2.01; 95% confidence interval [CI95], 1.08-3.73; P=.03). However, after adjustment on severity scores calculated between ICU admission and 1 week before CRS, the increased mortality was no longer significant (RR, 1.41; CI95, 0.76-2.61; P=.27). CONCLUSION: CRS is associated with subsequent morbidity and mortality in the ICU, even when adjusted on severity factors at ICU admission. However, after adjustment on severity factors during the ICU stay and before the event, there was only a trend toward CRS-attributable mortality. The evolution of patient severity should be taken into account when evaluating excess mortality induced by nosocomial events in ICU patients.

APACHE↗
PubMed1999

Usefulness of the cytomegalovirus (CMV) antigenemia assay for predicting the occurrence of CMV disease and death in patients with AIDS.

A cohort study of 214 human immunodeficiency virus (HIV)-infected patients was performed to assess the usefulness of the cytomegalovirus (CMV) antigenemia assay for predicting the occurrence of CMV disease and death. Multivariate analysis revealed that only positive baseline CMV antigenemia assays (relative risk [RR], 7.2; 95% confidence interval [CI], 3.7-14.2; P = .0001) and CD4 cell counts (RR, 0.98; 95% CI, 0.97-0.99; P = .009) were associated with CMV disease. A positive baseline CMV antigenemia assay was also associated with death by multivariate analysis (RR, 2.2; 95% CI, 1.5-3.4; P = .0003). Increasing levels of CMV antigenemia during follow-up were associated with increased risks of CMV disease and death. A positive CMV antigenemia assay that showed > 10 cells per 2 x 10(5) polymorphonuclear leukocytes during follow-up was 91% sensitive and 84% specific for predicting a diagnosis of CMV disease; the negative predictive value for this positive test was high (97%). Therefore, the CMV antigenemia assay appears to be a simple, rapid, and inexpensive test for predicting the occurrence of CMV disease and death in patients with advanced HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed1999

Pneumocystis carinii pneumonia requiring intensive care management: survival and prognostic study in 110 patients with human immunodeficiency virus.

OBJECTIVE: To perform a descriptive study of patients with acute respiratory failure secondary to acquired immunodeficiency syndrome-related Pneumocystis carinii pneumonia and to identify variables that are predictive of death within 3 months. DESIGN: Case series study. SETTING: Infectious disease intensive care unit (ICU) in a university hospital. PATIENTS: Detailed clinical, laboratory, and ventilatory data were collected prospectively within 48 hrs of admission and during the ICU stay in 110 consecutive human immunodeficiency virus-infected patients requiring ICU management with or without mechanical ventilation for P. carinii pneumonia-related acute respiratory failure. MEASUREMENTS AND MAIN RESULTS: Continuous positive airway pressure was used initially in 66 (60%) patients. Among the 34 patients (31%) who required mechanical ventilation, including 12 at admission and 22 after failure of continuous positive airway pressure, 76% died. The 3-month mortality rate after ICU admission was estimated at 34.6% (95% confidence interval [CI], 25%-44%). The 1-yr survival rate was estimated at 47% (95% CI, 36%-58%). With successive multiple logistic regression models analyzing the relative prognostic importance of baseline clinical and laboratory tests variables, ventilation variables, and events in the ICU, only delayed mechanical ventilation after 3 days (odd ratio [OR], 6.7; 95% CI, 1.9-23.9), duration of mechanical ventilation of > or = 5 days (OR, 2.8; 95% CI, 1.1-6.9), nosocomial infection (OR, 5.2; 95% CI, 2.1-12.9), and pneumothorax (OR, 5; 95% CI, 1.7-14.7) were predictive of death within 3 months of ICU admission. Among patients with delayed mechanical ventilation on day 3 or later and with a pneumothorax associated or not associated with a nosocomial infection, the predicted probability of 3-month death was close to 100%. CONCLUSIONS: Our data suggest that the most significant predictive factors of death were identifiable during the course of P. carinii pneumonia-related acute respiratory failure rather than at admission and can help in bedside decisions to withdraw intensive care support in such patients.

AIDS-Related Opportunistic Infections↗
PubMed1999

Estimating regression parameters and degree of dependence for multivariate failure time data.

Multivariate failure time data are frequently encountered in longitudinal studies when subjects may experience several events or when there is a grouping of individuals into a cluster. To take into account the dependence of the failure times within the unit (the individual or the cluster) as well as censoring, two multivariate generalizations of the Cox proportional hazards model are commonly used. The marginal hazard model is used when the purpose is to estimate mean regression parameters, while the frailty model is retained when the purpose is to assess the degree of dependence within the unit. We propose a new approach based on the combination of the two aforementioned models to estimate both these quantities. This two-step estimation procedure is quicker and more simple to implement than the EM algorithm used in frailty models estimation. Simulation results are provided to illustrate robustness, consistency, and large-sample properties of estimators. Finally, this method is exemplified on a diabetic retinopathy study in order to assess the effect of photocoagulation in delaying the onset of blindness as well as the dependence between the two eyes blindness times of a patient.

Biometry↗
PubMed1999

Is early noninvasive mechanical ventilation of first choice in stable restrictive patients with chronic respiratory failure?

Noninvasive long-term ventilation is consensually advocated when daytime hypercapnia > 6 kPa at steady state in chronic restrictive pulmonary syndromes. Several mechanisms can cause the occurrence of hypercapnia in these diseases. They may involve impairment of lung mechanics or airway function and cough, ventilation-perfusion mismatching, blunted central ventilatory drive or respiratory muscle fatigue. These abnormalities may occur while awake or during sleep. From a practical point of view, imperative ventilation, a palliative technique that aims to supply respiratory muscle weakness, and preventive ventilation, aimed at delaying respiratory handicap, should be distinguished between. The latter is offered to patients who do not fulfil any criteria for mechanical ventilation. Otherwise, the underlying disease markedly influences both pathophysiology and outcome. This implies that the available modes of ventilatory support should be assessed in each disease. Several findings have been published about Duchenne's muscular dystrophy. Mechanical ventilation, usually using noninvasive methods, is offered to patients with either hypercapnia or a forced vital capacity < 20% of the predicted value. Nevertheless, based on our experience, deterioration of the restrictive syndrome should be followed by a tracheostomy. By contrast, early ventilation, offered to patients free of symptoms and whose forced vital capacity are within 20-50% pred and with normal arterial blood gas levels, achieves no benefit.

Humans↗
PubMed1999

[Severe community-acquired bacterial pneumonia from Streptococcus pneumonia in HIV-infected patients: epidemiology and prognostic features of mortality].

In HIV-infected patients, community-acquired pneumonia due to Streptococcus pneumoniae is more common, more often associated with bacteremia, and more likely to recur. The epidemiology of this condition is discussed based on a literature review. Factors predictive of mortality in severe cases managed in intensive care units are analyzed.

AIDS-Related Opportunistic Infections↗
PubMed1998

High-dose therapy and autologous peripheral blood stem cell transplantation in multiple myeloma: up-front or rescue treatment? Results of a multicenter sequential randomized clinical trial.

Results to date indicate that high-dose therapy (HDT) with autologous stem cell support improves survival of patients with symptomatic multiple myeloma (MM). We performed a multicenter, sequential, randomized trial designed to assess the optimal timing of HDT and autotransplantation. Among 202 enrolled patients who were up to 56 years old, 185 were randomly assigned to receive HDT and peripheral blood stem cell (PBSC) autotransplantation (early HDT group, n = 91) or a conventional-dose chemotherapy (CCT) regimen (late HDT group, n = 94). In the late HDT group, HDT and transplantation were performed as rescue treament, in case of primary resistance to CCT or at relapse in responders. PBSC were collected before randomization, after mobilization by chemotherapy, and, in the two groups, HDT was preceded by three or four treatments with vincristine, doxorubicin, and methylprednisolone. Data were analyzed on an intent-to-treat basis using a sequential design. Within a median follow-up of 58 months, estimated median overall survival (OS) was 64.6 months in the early HDT group and 64 months in the late group. Survival curves were not different (P = .92, log-rank test). Median event-free survival (EFS) was 39 months in the early HDT group whereas median time between randomization and CCT failure was 13 months in the late group. Average time without symptoms, treatment, and treatment toxicity (TWiSTT) were 27.8 months (95% confidence interval [CI]; range, 23.8 to 31.8) and 22.3 months (range, 16.0 to 28.6) in the two groups, respectively. HDT with PBSC transplantation obtained a median OS exceeding 5 years in young patients with symptomatic MM, whether performed early, as first-line therapy, or late, as rescue treatment. Early HDT may be preferred because it is associated with a shorter period of chemotherapy.

Adult↗
PubMed1998

Predictive factors for late toxicity after endobronchial brachytherapy: a multivariate analysis.

PURPOSE: To determine the predictive factors associated with hemoptysis and radiation bronchitis after endobronchial brachytherapy by univariate and multivariate analyses METHODS AND MATERIALS: One hundred forty-nine patients underwent endobronchial brachytherapy and were divided into three therapeutic groups: group 1: patients treated with palliative intent (n=47); group 2: patients treated with curative intent (small endobronchial tumors without mediastinal or general dissemination: n=73); group 3: patients also receiving external irradiation (n=29). One hundred twelve patients had previously received external irradiation. Brachytherapy was delivered with a dose per fraction ranging from 4 to 7 Gy and a prescription point between 0.5 and 1.5 cm, usually 1 cm from the source center. Two to six fractions were delivered according to the therapeutic group and clinical situation. The influence of the following variables on the incidence of hemoptysis or radiation bronchitis was studied: age, sex, Karnofsky score, therapeutic group, histologic type, endoscopic tumor length, dose per fraction, total brachytherapy dose, total external beam irradiation dose, total dose (brachytherapy dose plus external irradiation dose), volumes of the 100% and 200% isodoses, and volumes of the 7 and 14 Gy isodoses. RESULTS: We observed 11 hemoptyses (7.4%), 10 were lethal. All but one occurred in patients with progressive disease. Two clinical factors were significantly associated with hemoptysis by univariate analysis: palliative group (p=0.009) and endobronchial tumor length (p=0.004). No technical factors seem to be implicated in the occurrence of hemoptysis. Only endobronchial tumor length remained in the multivariate model (p=0.02). Radiation bronchitis was observed in 13 cases (8.7%). By univariate analysis, a good Karnofsky score (p=0.02), curative treatment (p=0.02), and tumor location on trachea and main stem bronchus (p=0.002) were significantly associated with this complication. Two technical factors were also incriminated: the total dose (p=0.04) and the 100% isodose volume (p=0.02). By multivariate analysis, only the tumor location retained statistical significance (p=0.009). CONCLUSION: Hemoptysis is most likely due to disease progression, with the bleeding being facilitated by brachytherapy. Some rare cases could be a direct complication of brachytherapy itself, particularly when tumors are located in the upper lobes. In contrast, radiation bronchitis occurred more frequently in patients with controlled disease, and was significantly influenced by tumor location and technical factors (dose and volumes treated). Technical improvements should increase the therapeutic ratio.

Analysis of Variance↗
PubMed1998

Reinforced regimen of interferon alfa-2a reduces the incidence of cirrhosis in patients with chronic hepatitis C: a multicentre randomised trial. Multicentre GER-CYT-04 Group.

BACKGROUND/AIMS: Our aim was to assess and compare the long-term effect of interferon at standard (6 months) and reinforced dose and duration regimens in chronic hepatitis C. METHODS: A multicentre institutional trial included 244 previously untreated patients with chronic hepatitis C, without cirrhosis, who were randomly allocated to either standard (3 MU thrice a week for 24 weeks; n=120) or reinforced (6 MU daily for 12 days, 6 MU thrice a week for 22 weeks, 3 MU thrice a week for 24 weeks; n=124) regimens. The main endpoint was sustained ALT response at 72 weeks (18 months); secondary end-points were virological (branched DNA and PCR) and histological responses (incidence of cirrhosis) at month 18. RESULTS: Sustained ALT response was observed in five patients (4%, 95% confidence interval 0-8%) in the standard group and in 21 patients (18%, 95% confidence interval 11-25%), from the reinforced group (p=0.002), in agreement with virological response in 21 (81%) patients. Cirrhosis at month 18 was observed in ten (10%) patients in the standard group and one (1%) in the reinforced group (p=0.004). CONCLUSIONS: The standard regimen of interferon, in chronic hepatitis C, confers a minimal sustained response rate at 18 months and may not prevent the occurrence of cirrhosis. Reinforced regimens allow sustained response to be reached in a limited number of patients and reduce the risk of cirrhosis during 18 months of follow-up.

Adult↗