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Bertrand Souweine

Publications and source records attributed to Bertrand Souweine.

15 recordsLinked to original sources
PubMed2007

Mass spectrometry and scanning electron microscopy study of silicone tunneled dialysis catheter integrity after an exposure of 15 days to 60% ethanol solution.

Anti-infectious lock is an emerging therapeutic option for preventing and/or controlling catheter-associated infection. Ethanol has widespread bactericidal activity, limited side effects, and low risk of inducing antimicrobial resistance. However, concerns have been raised about ethanol-induced catheter structural degradation. In this study, silicone catheters were immersed at 37 degrees C in three different solvents: 0.9% sodium chloride, 60% ethanol, and 95% ethanol for 4 h, 15 days and 15 days after a first storage of 4 h. Scanning electron microscopy (magnification 1000-20 000 times) of the inner surface of the catheter revealed no damage to the lumen surfaces of catheters immersed in 95% ethanol for 15 days compared with the reference catheter. Gas chromatography/mass spectrometry (GC/MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis of the storage solutions revealed a significant release of polydimethylsiloxanes having a number of dimethylsiloxane units lower than 30 in the 95% ethanol solution and a structure highly consistent with a cyclic structure. Most release occurred within the first 4 h of exposure. In contrast, there was no difference in the small amounts of silicone released in 0.9% sodium chloride as reference and 60% ethanol solution, whatever the exposure time. These results should allow the development of clinical trials to assess the efficacy of the 60% ethanol lock technique in preventing or controlling the infectious complications of silicone dialysis catheters.

Anti-Infective Agents, Local↗
PubMed2006

Adrenal axis function does not appear to be associated with hemodynamic improvement in septic shock patients systematically receiving glucocorticoid therapy.

OBJECTIVE: There is mounting evidence showing the value of low-dose corticosteroids in patients with septic shock requiring vasopressor therapy. It remains unclear whether adrenal function tests should be carried out systematically to guide the decision on glucocorticoid therapy. METHODS: The retrospective study was conducted in 52 patients in three university hospital ICUs. We included consecutive patients with catecholamine-dependent septic shock who had not received ketoconazole, glucocorticoids, or etomidate in the 24 h before the ACTH test, and who had survived to day 3 after the shock onset. All patients had a 250-microg ACTH test before systematic glucocorticoid therapy was started. Various definitions of relative adrenal insufficiency were used (based on cortisol basal level and/or change in cortisol level after ACTH stimulation). We defined hemodynamic improvement as a 50% reduction in the vasoactive agent dose in the 3 days following the initiation of glucocorticoid treatment. The relationship between the hemodynamic improvement and the results of the adrenal function tests was analyzed. RESULTS: Hemodynamic improvement occurred in 29 patients (55.8%). Baseline characteristics, sites of infection, types of micro-organisms and antibiotic management did not differ between patients with and those without hemodynamic improvement. Relative adrenal insufficiency whatever the definition was not associated with hemodynamic improvement. CONCLUSION: In catecholamine-dependent septic shock patients managed with systematic glucocorticoid therapy the results of ACTH stimulation do not predict hemodynamic improvement.

Adrenal Glands↗
PubMed2006

Rapid gas chromatography/mass spectrometry quinine determination in plasma after automated solid-phase extraction.

The combined use of an automatic solid-phase extraction (SPE) apparatus with Oasis MCX cartridges and gas chromatography/mass spectrometry (GC/MS) to rapidly quantify quinine in biological samples with cyproheptadine as the internal standard is described. The selected ion monitoring mode, with the quantification ions m/z 136 and 287 (qualifier ions: m/z 261, 381 and 215, 96), allows the estimation of quinine levels, respectively. Separation was completed within 12.7 min. Excellent linearity was found up to 10 000 microg/L of plasma. The limit of detection (LOD) was 12.2 microg/L and the limit of quantification (LOQ) was 40.6 microg/L. High reproducibility (intra-assay CV range 1.9-4.3%, inter-assay CV range 2.2-11.3%) and accuracy values (intra-assay range 83.2-103.7%, inter-assay range 86.8-103.7%) were obtained. Recoveries were concentration-independent (97.2% and 89.8% for 4000 and 10 000 microg/L, respectively). This sensitive, simple assay for quinine in various matrices meets the current requirements for bioanalytical assays and may be used to monitor quinine levels in patients developing severe malaria with acute renal failure during hemofiltration. The optimal quinine dose in this situation is not really established and to improve clinical care, quinine concentrations might be explored to improve efficacy and minimise potential toxicity.

Gas Chromatography-Mass Spectrometry↗
PubMed2006

Catheter colonization in acute renal failure patients: comparison of central venous and dialysis catheters.

BACKGROUND: Little is known about vascular access infections in patients with acute renal failure. METHODS: We prospectively compared infection rates of dialysis catheters (DCs) and central venous catheters (CVCs) in patients in the intensive care unit treated with renal replacement therapy for acute renal failure. The same insertion and maintenance procedures were used for CVCs and DCs. To circumvent the allocation bias caused by severity of patient condition, only patients with both types of catheters were included. RESULTS: A total of 150 CVCs and 130 DCs were analyzed in 99 patients with a mean Simplified Acute Physiology Score II of 67 +/- 21. The major cause of acute renal failure was sepsis (62%). Hospital mortality was 62%. Mean catheter duration was shorter for DCs (6.7 +/- 4.4 days) than CVCs (7.8 +/- 4.9 days; P = 0.03). There was no difference between CVCs and DCs in cumulative incidence of catheter colonization (quantitative catheter cultures > or = 10(3) colony-forming units/mL; 4.7% versus 6.2%; P = 0.58) or incidence density of catheter colonization per 1,000 catheter days (5.9 versus 9.1; P = 0.44, respectively). There also was no difference between CVCs and DCs in cumulative incidence and incidence density regardless of whether catheters were placed at the internal jugular (P = 0.34 and P = 0.23) or femoral site (P = 0.57 and P = 0.80), respectively. Three cases of CVC-related bacteremia (the same microorganism responsible for both catheter colonization and blood culture result) were recorded, but none with DC use. CONCLUSION: When severity of patient condition is controlled for, epidemiological characteristics of colonization in CVCs and DCs are similar if similar infection control measures are used for insertion and maintenance.

Acute Kidney Injury↗
PubMed2006

A one-step and sensitive GC-MS assay for meprobamate determination in emergency situations.

A rapid, sensitive, and ready-to-use gas chromatography-mass spectrometry method for meprobamate assay using carisoprodol as internal standard is described. The method involves extracting a 0.2-mL sample with chloroform, previously acidified with HCl 0.2N. For the quantitative analysis, we used selected-ion monitoring mode, selecting the ion m/z 144 for quantification of meprobamate and m/z 245 for carisoprodol. Excellent linearity was found between 0 and 200 mg/L plasma. The limit of detection was 0.58 mg/L, and the limit of quantification was 1.93 mg/L. A high reproducibility [intra-assay coefficient of variation (CV) range of 2.3-4.3% and interassay CV range of 5.5-12.3%] and accuracy (intra-assay range of 96.8-112.3% and interassay range of 85.5-99.3%) were observed. Recoveries were concentration-independent (87.0%, 76.2%, and 81.2% for 20, 75 and 150 mg/L, respectively). No interference from endogenous compounds, other metabolites of meprobamate, or frequently coadministered drugs was detected. This sensitive, simple assay for meprobamate in plasma, whole blood, and urine meets the current requirements for bioanalytical assays in overdose cases.

Anti-Anxiety Agents↗
PubMed2006

Rapid decrease in plasma D-lactate as an early potential predictor of diminished 28-day mortality in critically ill septic shock patients.

BACKGROUND: Splanchnic ischemia plays a major role in the development of organ failure during septic shock. Plasma D-lactate has been proposed as a better marker of splanchnic hypoperfusion than L-lactate. We studied the prognostic ability of plasma D- and L-lactate levels. METHODS: A prospective study was performed in an intensive care unit and included patients with septic shock. Two samples for plasma D- and L-lactate determination were collected: the first within 6 h after the patient met the criteria for septic shock (day 1) and the second 24 h later (day 2). RESULTS: In univariate analysis, day 1 plasma D- and L-lactate values were associated with 28-day mortality. For plasma D- and L- lactate, the area under the receiver operating characteristic curve was 0.68+/-0.09 and 0.84+/-0.07 on day 1 (p=0.09), and 0.74+/-0.10 and 0.90+/-0.07 on day 2 (p=0.06), respectively. In survivors, D-lactate levels decreased between day 1 and day 2 (p=0.03), but L-lactate did not (p=0.29). In septic shock patients, plasma D- and L-lactate levels reliably discriminate between survivors and non-survivors. The prognostic ability of plasma L-lactate was better than that of plasma D-lactate. CONCLUSION: A rapid decrease in plasma D-lactate during the course of septic shock could indicate reduced 28-day mortality.

Aged↗
PubMed2005

Clinical features and outcome of chronic dialysis patients admitted to an intensive care unit.

BACKGROUND: Information about chronic dialysis (CD) patients admitted to intensive care units (ICU) is scant. This study sought to determine the epidemiology and outcome of CD patients in an ICU setting and to test the performance of the Simplified Acute Physiology Score (SAPS II) to predict hospital mortality in this population. METHODS: All consecutive CD patients admitted to an adult, 10 bed medical/surgical ICU at a university hospital between January 1996 and December 1999 were included in this prospective observational study. Demographics, characteristics of the underlying renal disease, admission diagnosis, the number of organ system failures (OSFs) excluding renal failure and SAPS II, both calculated 24 h after admission, the duration of mechanical ventilation, ICU survival and survival status at hospital discharge and 6 months after discharge were recorded. RESULTS: A total of 92 CD patients, 16 on peritoneal dialysis and 76 on haemodialysis, were included. The main reason for ICU admission was sepsis and the mean ICU length of stay 6.2+/-9.9 days. ICU mortality was 26/92 (28.3%) and was associated in multivariate analysis with SAPS II (P<0.001), duration of mechanical ventilation (P<0.01) and abnormal values of serum phosphorus (high or low; P<0.05). Hospital mortality was 35/92 (38.0%) and was accurately predicted by SAPS II [receiver operating characteristics curve: 0.86+/-0.04; goodness-of-fit test: C = 6.86, 5 degrees of freedom (df), P = 0.23 and H = 4.78, 5 df, P = 0.44]. The 6 month survival rate was 48/92 (52.2%). CONCLUSIONS: CD patients admitted to the ICU are a subgroup of patients with high mortality and SAPS II can be used to assess their probability of hospital mortality. The severity of the acute illness responsible for ICU admission and an abnormal value of serum phosphorus are determinants for ICU mortality.

Aged↗
PubMed2005

Prospective study of arterial and central venous catheter colonization and of arterial- and central venous catheter-related bacteremia in intensive care units.

OBJECTIVE: To compare the rates of positive quantitative culture (PQC) of arterial catheter (AC) and central venous catheter (CVC) tips and of CVC- and AC-related bacteremia in intensive care unit patients undergoing placement of both ACs and CVCs. DESIGN: Prospective, descriptive survey. To control for a difference in the severity of patients having an AC or CVC, only patients having both an AC and a CVC were included. SETTING: An adult, nine-bed medical/surgical intensive care unit at a university teaching hospital. SUBJECTS: The analysis included 308 CVCs and 299 ACs inserted in 212 severely ill patients, with a mean +/- sd Simplified Acute Physiology Score II of 52 +/- 22 and an intensive care unit mortality of 33% (69 of 212). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The same insertion and maintenance procedures were used for both types of catheter. A PQC was defined by a catheter tip culture yielding >/=10(3) colony forming units/mL. Catheter-related bacteremia was defined by a PQC and a blood culture positive for the same microorganism. The cumulative incidence (PQCs/number of catheters inserted) was 9.4% (29/308) for CVCs and 7.7% (23/299) for ACs (p = .44). Incidence density (PQCs/1,000 catheter days) was 12.0 for CVCs versus 9.3 for ACs. At the femoral site, there was no significant difference between CVCs and ACs in the cumulative incidences and incidence densities of PQCs. Two instances of catheter-related bacteremia were observed, one involving a CVC and one involving an AC. CONCLUSIONS: Among severely ill patients with both CVCs and ACs, the epidemiology of PQCs of CVCs and ACs is comparable when the same infection control measures are used for the insertion and maintenance of both types of catheters.

Aged↗
PubMed2005

Evolution of thrombin formation and fibrinolysis markers, including thrombin-activatable fibrinolysis inhibitor, during severe meningococcemia.

A 17-year-old girl presented with Neisseria meningitidis sepsis, with evidence of disseminated intravascular coagulation. Substitution therapy with both antithrombin and protein C concentrates was initiated, leading to clinical and biological improvement. Sequential dosages were performed for biological markers including thrombin-activatable fibrinolysis inhibitor (TAFI). Substitution therapy with both antithrombin and protein C concentrates led to a clinical and biological improvement. Biological markers showed a decrease in thrombin generation and in plasminogen activator inhibitor 1 (PAI-1) and a return of TAFI to a normal value. Discontinuation of substitutive treatment was marked by a clinical relapse at 24 h, with thrombin generation and increase in PAI-1, while TAFI remained unchanged. This report shows the evolution of hemostasis markers during septic shock and provides new data concerning the effects of a substitutive therapy.

Adolescent↗
PubMed2003

Ubiquitin-proteasome-dependent muscle proteolysis responds slowly to insulin release and refeeding in starved rats.

The central role of the ubiquitin-proteasome system in the loss of skeletal muscle protein in many wasting conditions has been well established. However, it is unclear what factors are responsible for the suppression of this system during periods of protein gain. Thus, the aim of these studies was to examine the short-term effects of insulin release and nutrients on skeletal muscle protein turnover in young rats starved for 48 h, and then infused intravenously with amino acids (AA), or fed an oral diet. Forty-eight hours of starvation (i.e. prolonged starvation in young rats) decreased muscle protein synthesis and increased proteasome-dependent proteolysis. Four-hour AA infusion and 4 h of refeeding increased plasma insulin release and AA concentrations, and stimulated muscle protein synthesis, but had no effect on either total or proteasome-dependent proteolysis, despite decreased plasma corticosterone concentrations. Both muscle proteasome-dependent proteolysis and the rate of ubiquitination of muscle proteins were not suppressed until 10 h of refeeding. The temporal response of these two measurements correlated with the normalised expression of the 14-kDa E2 (a critical enzyme in substrate ubiquitination in muscle) and the expression of the MSS1 subunit of the 19S regulatory complex of the 26S proteasome. In contrast, the starvation-induced increase in mRNA levels for 20S proteasome subunits was normalised by refeeding within 24 h in muscle, and 6 h in jejunum, respectively. In conclusion, unlike protein synthesis, skeletal muscle proteasome-dependent proteolysis is not acutely responsive in vivo to insulin, AA, and/or nutrient intake in refed starved rats. This suggests that distinct and perhaps independent mechanisms are responsible for the nutrient-dependent regulation of protein synthesis and ubiquitin-proteasome-dependent proteolysis following a prolonged period of catabolism. Furthermore, factors other than the expression of ubiquitin-proteasome pathway components appear to be responsible for the suppression of skeletal muscle proteasome-dependent proteolysis by nutrition.

Amino Acids↗
PubMed2003

Hand-cleansing during postanesthesia care.

BACKGROUND: Transmission of microorganisms from the hands of healthcare workers is the main source of cross-infection and can be prevented by hand-cleansing. The authors assessed the compliance rate with hand-cleansing practices in the postanesthesia care unit and investigated factors associated with noncompliance. METHODS: Patient care activities, indications for and compliance of postanesthesia care unit staff with hand-cleansing, defined as either washing hands with soap and water or rubbing hands with alcohol, were monitored at the time of patient admission and during their stay. Multivariate analysis identified predictors of noncompliance with hand-cleansing on admission after adjustment for confounders. RESULTS: A total of 3,143 patient care activities, including 1,091 opportunities for hand-cleansing at high or medium risk for cross-transmission, were recorded among 187 patients. The higher the workload, the higher the number of indications for hand-cleansing and the lower the compliance. Average compliance with hand-cleansing at postanesthesia care unit admission was 19.6%. Independent predictors for noncompliance included caring for patients older than 65 yr (odds ratio, 2.23; 95% confidence interval, 1.40-3.57) and those recovering from clean/clean-contaminated surgery (odds ratio, 2.27; 95% confidence interval, 1.11-4.76), as well as high intensity of patient care (odds ratio, 1.01 per patient care activity; 95% confidence interval, 1.0-1.02). Compliance with hand-cleansing for patients already admitted to the postanesthesia care unit was 12.5%. CONCLUSIONS: Failure to cleanse hands during patient care is common in the postanesthesia care unit and is associated with identifiable factors. The close relation between the intensity of patient care and noncompliance argues that hand-cleansing should not be viewed as a problematic individual behavior only, and system change must be considered in prevention strategies.

Adult↗
PubMed2002

ICU-acquired nosocomial infection: impact of delay of adequate antibiotic treatment.

In order to measure the impact on survival of the early introduction of adequate antibiotic treatment for nosocomial bacteremia and pneumonia, a retrospective, cohort study was carried out over a period of 17 months in a 6-bed respiratory ICU. All patients presenting with a first episode of ICU-acquired nosocomial bacteremic infection (Centers for Disease Control criteria) or pneumonia [BAL culture > or = 10(4) colony-forming units (CFU)/ml or protected specimen brush culture > or = 10(3) CFU/ml] were included. The organ failure score (Fagon criteria) was recorded on the day of diagnosis. Adequate antibiotic treatment was defined by the sensitivity of each etiologic organism to at least 1 prescribed antibiotic. A total of 25 patients (Simplified Acute Physiology Score II = 44) were included in the study with pneumonia (n = 17) or bacteremia (n = 8), on average 6.5 +/- 4.6 d after admission. At the time of diagnosis, 23 patients were receiving mechanical ventilation. The overall mortality rate was 48% and was significantly associated with the length of time without adequate antibiotic treatment (p = 0.011) and the number of organ failures on the day of diagnosis (p = 0.017). Adequate antibiotic treatment only had an impact on survival if it was started within the first 24 h after sampling (p < 0.02 on Day 0 and < 0.04 on Day 1). On the day of diagnosis, a failure score > 2 was associated with increased mortality (p = 0.009). After adjusting for the number of organ failures, the length of time without adequate antibiotic treatment remained associated with mortality (< or = 2 organ failures, p < 0.02; > 2 organ failures, p = 0.05). This study suggests that, during the course of nosocomial pneumonia and bacteremia, the time at which adequate antibiotic treatment is started is a key factor influencing survival.

Aged↗
PubMedDate not supplied

[Vancomycin-resistant Enterococcus in an epidemic situation: screening at admission for patients at risk of carriage].

OBJECTIVES: To evaluate a strategy based on screening and isolation at admission to a department of infectious diseases during an epidemic of vancomycin-resistant Enterococcus (VRE) at the University Hospital of Clermont-Ferrand. METHODS: Systematic screening for VRE by anal swabs began on November 15, 2004. Patients were isolated on admission if (a) they had been hospitalized more than 24 h in an at-risk department of our hospital or (b) they had received a course of wide-spectrum antimicrobial therapy for longer than 48 h in the three months preceding admission. Patients hospitalized in our department were screened weekly if they were treated with wide-spectrum antibiotics, had a urinary catheter left in place for one week, or were neutropenic. RESULTS: Through May 15, 2005, 12 (3.5%) of 341 swabs were found to be positive for VRE: eight were detected on admission and four during hospitalization. In all, 81 patients were isolated on admission. A case-control study confirmed that the criteria for patient isolation were indeed risk factors for VRE. Isolation was well accepted when it was clearly explained. No new case has been detected since March 2005. CONCLUSION: An isolation strategy based on known risk factors for VRE with systematic screening on admission appears to be an effective way to control an outbreak of VRE, perhaps in part because it helps to keep the medical staff alert to this problem. Isolation is well tolerated as long as it is explained clearly.

Aged↗