Search PubMed⌕ Search

Biomedical subjects

C Brun-Buisson

Publications and source records attributed to C Brun-Buisson.

At least 73 records · Page 4Linked to original sources
PubMed1998

[Methicillin-resistant Staphylococcus aureus: evolution and epidemiology, clinical impact, and prevention].

Methicillin-resistant Staphylococcus aureus (MRSA) strains have become endemic in hospitals in many countries. In most cases, epidemic clones emerge occasionally on the endemic background. Early institution of simple measures aimed at preventing hand-borne cross-contamination has resulted in low rates of MRSAs in a few countries of northern Europe. Although environmental contamination plays a role in some cases, colonized or infected patients are the main reservoir. Three significant problems have been identified in countries with high levels of endemicity, namely identification of the reservoir in the hospital, including detection of healthy carriers who are readmitted; notification of departments that receive healthy carriers transferred from another department in the same hospital or from another hospital; and the increasing and hard-to-control reservoir of resistant bacteria in extended-care facilities. These three problems are related to the current level of endemicity and to the risk of dissemination of resistant strains during hospital-to-hospital patient transfers. The technical responses to these problems vary with the environment and available means. They include detection of carriers in high-risk units, use of standardized reporting forms for patient transfers, and recording of the presence of MRSA in computerized medical records. Decontamination of carriers can help to prevent cross-contamination in some situations. It is of the utmost importance that all the facets of MRSA endemicity be taken into account at the level of the hospital as a whole and that all decision makers and health care providers make a commitment to reducing MRSA endemicity.

Cross Infection↗
PubMed1997

Reemergence of gentamicin-susceptible strains of methicillin-resistant Staphylococcus aureus: roles of an infection control program and changes in aminoglycoside use.

The spread of methicillin-resistant Staphylococcus aureus (MRSA) in our hospital in the 1980s correlated with increasing acquisition of resistance to antibiotics including gentamicin, rifampin, and fluoroquinolones. During the period 1993-1995, there was a major change in clinical MRSA isolates: the percentage of aminoglycoside-resistant MRSA isolates decreased from 75% to 52%, while the proportion of heterogeneous MRSA strains susceptible to gentamicin, rifampin, and tetracycline increased gradually from 4.9% to 27.5%. We used five epidemiological markers (i.e., antibiotyping, phage typing, pulsed-field gel electrophoresis, and restriction analysis of PCR amplified coagulase and protein A genes) to characterize recent isolates. With use of these techniques, we confirmed the persistence of the aminoglycoside-resistant MRSA clone and identified a clone of erythromycin-susceptible strains among the gentamicin-susceptible isolates and found that the remaining strains were diverse. These changes were due to the introduction of various MRSA strains from outside the hospital, while implementation of infection control measures in 1991 could have led to reduced transmission of the aminoglycoside-resistant MRSA strain. Changes in antibiotic prescribing patterns that resulted in reduced selective pressure from gentamicin may have contributed to the spread of gentamicin-susceptible MRSA strains.

Anti-Bacterial Agents↗
PubMed1997

Infection risk and cost-effectiveness of commercial bags or glass bottles for total parenteral nutrition.

OBJECTIVE: To determine whether the greater daily expense of administering total parenteral nutrition (TPN) via plastic bags changed once daily, compared to glass bottles changed thrice daily, could be offset by savings from a reduction in nosocomial infections. DESIGN: The costs and potential benefits of commercially available TPN bags and TPN in glass containers were compared. Costs were computed from the viewpoint of the hospital, first in a general model and then for two specific examples, Crohn's disease and intensive-care unit (ICU) patients. The extra cost of using bags was $20 per day. The total cost of nosocomial bacteremia was estimated at $6,000. The monetary benefits of using TPN bags were $6,000XT, where XT was the percentage of nosocomial infections averted. We also considered that reduction in intravenous (IV)-line manipulation could reduce bacteremia-related mortality and computed a cost-per-life-saved ratio. RESULTS: Modeling showed that TPN in bags could yield a net benefit when the absolute reduction in the daily risk of nosocomial bacteremia reached the threshold value of 0.3%. Such a reduction could not be attained in patients with Crohn's disease, and corresponded to a 50% to 60% reduction of infection rates in ICU patients. Varying the risk of mortality attributable to IV-line-related infection from 1% to 13% resulted in a cost effectiveness of using TPN bags ranging from $90,000 to $7,000 per life saved in ICU, assuming a two-thirds reduction in IV-line infections, and from $180,000 to $14,000 if the infection rate was reduced by one third. CONCLUSION: The baseline cost-minimization analysis concluded that the extra cost of TPN bags was not justified by the extra savings. The cost-effectiveness analysis, however, found that the cost per life saved fell within the accepted range of public health interventions, provided a large fraction of infections are averted using TPN bags.

Cost-Benefit Analysis↗
PubMed1997

Central venous catheter replacement strategies: a systematic review of the literature.

OBJECTIVE: To evaluate the effect of guidewire exchange and new-site replacement strategies on the frequency of catheter colonization and infection, catheter-related bacteremia, and mechanical complications in critically ill patients. DATA SOURCES: We searched for published and unpublished research by means of MEDLINE and Science Citation Index, manual searching of Index Medicus, citation review of relevant primary and review articles, review of personal files, and contact with primary investigators. STUDY SELECTION: From a pool of 151 randomized, controlled trials on central venous catheter management, we identified 12 relevant randomized trials of catheter replacement over a guidewire or at a new site. DATA EXTRACTION: In duplicate and independently, we abstracted data on the population, intervention, outcome, and methodologic quality. DATA SYNTHESIS: As compared with new-site replacement, guidewire exchange is associated with a trend toward a higher rate of catheter colonization (relative risk 1.26, 95% confidence interval 0.87 to 1.84), regardless of whether patients had a suspected infection. Guidewire exchange is also associated with trends toward a higher rate of catheter exit-site infection (relative risk 1.52, 95% confidence interval 0.34 to 6.73) and catheter-related bacteremia (relative risk 1.72, 95% confidence interval 0.89 to 3.33). However, guidewire exchange is associated with fewer mechanical complications (relative risk 0.48, 95% confidence interval 0.12 to 1.91) relative to new-site replacement. Exchanging catheters over guidewires or at new sites every 3 days is not beneficial in reducing infections, compared with catheter replacement on an as-needed basis. CONCLUSIONS: Guidewire exchange of central venous catheters may be associated with a greater risk of catheter-related infection but fewer mechanical complications than new-site replacement. More studies on scheduled vs. as-needed replacement strategies using both techniques are warranted. If guidewire exchange is used, meticulous aseptic technique is necessary.

Bacteremia↗
PubMed1997

How to use an article on therapy or prevention: pneumonia prevention using subglottic secretion drainage.

Evidence based critical care medicine involves integrating clinical experience, expertise, and patient preferences with explicit, systematic, and judicious use of current best evidence in making medical decisions. Published evidence has many sources: research from the basic sciences of medicine, and from patient-centered clinical research on the accuracy of diagnostic tests, the power of prognostic markers, and the effectiveness and safety of preventive, therapeutic, rehabilitative, and palliative interventions. When critically appraising a clinical article for potential use in intensive care unit (ICU) practice, the first question we ask ourselves is: Is this study valid? If examination of the study methods reveals that the design is rigorous, we can turn to the two other key questions: What are the results? and, Will the results help me care for my patients? This approach may aid in the interpretation of an article on therapy or prevention; in it we discuss a strategy designed to prevent ventilator associated pneumonia in critically ill patients.

Critical Care↗
PubMed1997

Gelatinases in epithelial lining fluid of patients with adult respiratory distress syndrome.

Gelatinases A and B are matrix metalloproteinases secreted as inactive pro forms and are capable of degrading basement membrane components after activation in the extracellular environment. To determine whether the presence of gelatinases A (noninflammatory cells) and B (inflammatory cells) in epithelial lining fluid (ELF) is associated with the adult respiratory distress syndrome (ARDS), we studied 28 patients divided into four groups based on the presence of ARDS and/or multiple organ failure (MOF). Gelatinase activities were quantified in ELF using zymography. ARDS patients had larger ELF volumes than non-ARDS patients: 9.2 +/- 8.5 ml/100 ml recovered lavage fluid (n = 18) vs. 1.9 +/- 1.7 ml/100 ml (n = 11), respectively (P < 0.001). The presence of activated gelatinase A in ELF was a sensitive (16 out of 18 ARDS patients, 89%) and specific (0 out of 11 non-ARDS patients with or without MOF) marker for ARDS. Activated gelatinase (A + B) activities per microliter ELF were correlated with albumin concentrations in ELF (P < 0.01), and activated gelatinase activities in ELF were correlated with the volume of ELF (P < 0.0005). This could suggest an involvement of these gelatinases in alveolar-capillary permeability increase.

Adult↗
PubMed1997

Alveolar neutrophils in endotoxin-induced and bacteria-induced acute lung injury in rats.

Polymorphonuclear neutrophils (PMNs) are thought to play a major role in the pathogenesis of adult respiratory distress syndrome. Because the alveolar epithelium is a decisive factor in alveolo-capillary wall permeability, a toxic effect of emigrated PMNs in alveolar spaces is conceivable. We evaluated alveolar PMN function in two rat models of acute lung injury induced by alveolar instillation of endotoxin [lipopolysaccharide (LPS)] or live Pseudomonas aeruginosa (PYO). Alveolar PMNs were isolated from bronchoalveolar lavage fluid 4 and 24 h after the challenge. Hypoxemia was assessed based on the ratio arterial partial pressure of O2 (PaO2)/fraction of inspired O2 (FIO2) during mechanical ventilation. The severity of lung injury in the two models was clearly different, since PaO2/FIO2 were approximately 400 mmHg in PYO- and LPS-induced injuries, respectively. Both contrast, alveolar neutrophil influx, unstimulated oxygen metabolite production, and proteinase (elastase, gelatinase B) secretions of ex vivo alveolar PMNs were not larger in the PYO model. Thus the difference in severity was not associated with variations in alveolar neutrophil recruitment or activation. Moreover, gelatinase and leukocyte elastase activities were absent in bronchoalveolar fluid, indicating effective antiproteinase defense in alveolar spaces. We conclude that alveolar neutrophils are not sufficient to create severe respiratory failure.

Animals↗
PubMed1997

Lower respiratory tract colonization and infection during severe acute respiratory distress syndrome: incidence and diagnosis.

Ventilator-associated pneumonia (VAP) is difficult to detect and is often unsuspected during adult respiratory distress syndrome (ARDS). We prospectively evaluated lower respiratory tract (LRT) colonization and infection in 30 patients with severe ARDS (PaO2/FIO2 ratio < 150 mm Hg), using repeated quantitative cultures of plugged telescopic catheter (PTC) specimens taken blindly via the endotracheal tube every 48 to 72 h after onset of ARDS. All patients except one were receiving antibiotics. When VAP was suspected on the presence of clinical criteria for infection, a repeated PTC and, when possible, a bronchoalveolar lavage (BAL) were obtained before any new antimicrobials were administered; samples growing > or = 10(3) cfu/ml (PTC) or > or = 10(4) cfu/ml (BAL) were considered diagnostic of infection. Twenty-four VAP episodes were diagnosed in 18 patients (60% of patients or 4.2/100 ventilator-days) a mean of 9.8+/-5.7 d after onset of ARDS. Eighteen LRT colonization episodes were recorded; 16 of 24 (66%) VAP episodes were preceded (by 2 to 6 d) by LRT colonization with the same organism(s), and only two episodes of colonization were not followed by VAP. We conclude that although VAP is of relatively late-onset during severe ARDS, its incidence is much higher than in other conditions and can be underestimated. Lower airways colonization is consistently followed by infection with the same organisms and precedes VAP in two thirds of episodes. Repeated protected specimens taken blindly may provide a useful means to predict infection and therefore allow early antimicrobial therapy in high-risk patients with diffuse lung injury.

Acute Disease↗
PubMed1996

Intrapleural administration of streptokinase in complicated purulent pleural effusion: a CT-guided strategy.

OBJECTIVE: To determine the usefulness and the results of a strategy using intrapleural streptokinase (SK) instillation guided by repeated computed tomography (CT) scan examinations in pleural empyemas unresponsive to chest tube drainage. DESIGN: A retrospective chart review. SETTING: The medical Intensive Care Unit and Department of Radiology, in a university hospital. PATIENTS: Sixteen patients with empyema who had a persistent pleural effusion despite drainage, among 37 patients with infectious pleural effusion. INTERVENTIONS: In the 16 patients, CT examination was performed before and at least once after SK. Intrapleural SK was instilled, either through the chest tube or via a needle puncture, according to the CT scan results. RESULTS: The first CT scan confirmed a persistent effusion in all, showing a multiloculated effusion in 13 patients, and an ectopic loculus in one. The first SK instillation resulted in a dramatic increase of fluid drained per day (from 68 +/- 28 ml to 567 +/- 262 ml; p < 0.001), leading to complete resolution in 11 patients, while the others required a second CT scan-guided procedure. In one, the chest tube was misplaced, while in two, transparietal injection was needed. Finally, a complete resolution was observed in 14 (87.5%) of the patients. Two patients had a poor initial response to SK and were eventually scheduled for video-thoracoscopy. A single episode of chills and fever was observed among 32 SK instillations. CONCLUSION: CT-guided SK instillation in pleural empyema appears to be safe, and allowed complete resolution in 87.5% of our patients.

Adult↗
PubMed1996

Use of the coagulase gene typing method for detection of carriers of methicillin-resistant Staphylococcus aureus.

Strains of Staphylococcus aureus can be typed on the basis of the polymorphism of the coagulase gene. DNA fragments generated after amplification by polymerase chain reaction (PCR) of the variable region of this gene and digested with the restriction enzyme HaeIII can be compared by their restriction fragment length polymorphism (RFLP). Seventy-nine of 86 (91.8%) methicillin-resistant S. aureus (MRSA) strains isolated in various hospitals had a characteristic RFLP pattern. This pattern differed from those of 32 methicillin-susceptible S. aureus (MSSA). Only one MSSA shared with MRSA the same RFLP pattern. After modification, we applied this method to the rapid detection of MRSA from 255 nasal swabs from patients hospitalized in intensive care units. When screened by plating on Chapman agar, 55 of these samples contained MRSA, whereas 40/55 yielded the expected restriction profile after amplification by PCR. No DNA was amplified by PCR in 9/55 samples and restriction profiles were uninterpretable in six cases. When compared to culture, the positive and negative predictive values of the PCR test were 100% and 93%, respectively. The specificity was 100% and the sensitivity was 72.7%. Since control of spread of MRSA strains in hospitals is based in part on rapid isolation of carriers, this method which allows detection of epidemic MRSA in nasal swabs within a day could be helpful, though culture would still be necessary to confirm the result.

Bacterial Typing Techniques↗
PubMed1996

Maximizing oxygen delivery in critically ill patients: a methodologic appraisal of the evidence.

OBJECTIVE: To systemically review the effect of interventions designed to achieve supraphysiologic values of cardiac index, oxygen delivery (DO2), and oxygen consumption (VO2) in critically ill patients. DATA SOURCES: Computerized bibliographic search of published research, citation review of relevant articles, and contact with primary investigators. STUDY SELECTION: We included all randomized clinical trials of adult intensive care unit (ICU) patients that evaluated interventions (fluids, inotropes, and vasoactive drugs) designed to achieve supraphysiologic values of cardiac index, DO2, and/or VO2. Independent review of 64 articles identified seven relevant studies of 1,016 patients. DATA EXTRACTION: We abstracted data on the population, interventions, outcomes, and methodologic quality of the studies by duplicate independent review. Agreement was high (weighed kappa 0.73); differences were resolved by consensus. DATA SYNTHESIS: Targeting therapy to achieve supraphysiologic end points in critically ill patients is associated with a nonstatistically significant trend toward decreased mortality rates (relative risk 0.86, 95% confidence intervals 0.62 to 1.20). For the two studies in which supraphysiologic goals were initiated preoperatively, the relative risk was 0.20 (95% confidence intervals 0.07 to 0.55). This value differed significantly from the combined estimate of the remaining studies, in which the intervention was started after ICU admission (relative risk 0.98, 95% confidence intervals 0.79 to 1.22; p<.01). However, there are several methodologic problems with the primary studies. In no trials were caregivers or outcome assessors blinded to treatment allocation. Only three of seven trials analyzed patients according to the group to which they were allocated. None adequately controlled for cointerventions, and there was considerable crossover between groups (patients in the control group achieved the goals of the intervention group and vice versa). CONCLUSIONS: Interventions designed to achieve supraphysiologic goals of cardiac index, DO2, and VO2 did not significantly reduce mortality rates in all critically ill patients. However, there may be a benefit in those patients in which the therapy is initiated preoperatively. Methodologic limitations weaken the inferences that can be drawn from these studies and preclude any evidence-based clinical recommendations.

Adult↗
PubMed1996

Prospective, randomized trial of two antiseptic solutions for prevention of central venous or arterial catheter colonization and infection in intensive care unit patients.

OBJECTIVES: To compare the efficacy of a newly available antiseptic solution (composed of 0.25% chlorhexidine gluconate, 0.025% benzalkonium chloride, and 4% benzyl alcohol), with 10% povidone iodine, on the prevention of central venous or arterial catheter colonization and infection. DESIGN: Prospective, randomized clinical trial. SETTING: Surgical-trauma intensive care unit (ICU) in a university hospital. PATIENTS: All patients admitted to the ICU and requiring the insertion of a central venous and/or an arterial catheter from July 1, 1992 to October 31, 1993. INTERVENTIONS: Patients were randomly assigned to one of two groups according to the antiseptic solution used for insertion and catheter care. The same solution was used for skin disinfection from the time of catheter insertion to the time of removal of each catheter. MEASUREMENTS AND MAIN RESULTS: Catheter distal tips were quantitatively cultured when catheters were no longer necessary, if there was a suspicion of catheter-related infection, and routinely after 7 days of use for arterial catheters, or after 15 days of use for central venous catheters. The rate of significant catheter colonization (i.e., > or = 10(3) colony-forming units [cfu]/mL by quantitative culture), and catheter-related sepsis (as defined by sepsis abating following catheter removal per 1,000 catheter-days), were significantly lower in the chlorhexidine group (12 vs. 31 [relative risk 0.4, 95% confidence interval 0.1 to 0.9, p < .01] and 6 vs. 16 [relative risk 0.4, 95% confidence interval 0.1 to 1, p = 0.5], respectively). The rate of central venous catheter colonization and central venous catheter-related sepsis per 1,000 catheter-days were also significantly lower in the chlorhexidine group (8 vs. 31 [relative risk 0.3, 95% confidence interval 0.1 to 1, p = .03] and 5 vs. 19 [relative risk 0.3, 95% confidence interval 0.1 to 1, p = .02], respectively). Finally, the rate of arterial catheter colonization per 1,000 catheter-days was significantly lower in the chlorhexidine group (15 vs. 32 [relative risk 0.5, 95% confidence interval 0.1 to 1, p = .05]), whereas the rate of arterial catheter-related sepsis per 1,000 catheter-days was similar for the two study groups (8 in the chlorhexidine group vs. 10 in the povidone iodine group [relative risk 0.8, 95% confidence interval 0.1 to 2.2, p = .6]). The 0.25% chlorhexidine solution was superior to the 10% povidone iodine solution in preventing catheter colonizations and catheter-related sepsis due to Gram-positive bacteria (5 vs. 20 [p < .001], and 2 vs. 10 [p < .001], respectively), whereas the activity of the 0.25% chlorhexidine solution was nonsignificantly superior in preventing Gram-negative infections (7 vs. 4 [p = .5], and 4 vs. 2 [p = .8], respectively). CONCLUSIONS: The 4% alcohol-based solution of 0.25% chlorhexidine gluconate and 0.025% benzalkonium chloride was more effective than 10% povidone iodine for insertion site care of short-term central venous and arterial catheters. This effect appeared related to a more efficacious prevention of infections with Gram-positive bacteria.

Adult↗
PubMed1996

Bronchoalveolar lavage in adult sickle cell patients with acute chest syndrome: value for diagnostic assessment of fat embolism.

Fat embolism of necrotic bone marrow could be a frequent cause of acute chest syndrome (ACS) in sickle cell syndromes (SC), as suggested by postmortem findings. To check this hypothesis in living patients, we evaluated the presence of fatty macrophages recovered by bronchoalveolar lavage (BAL) in ACS. We investigated 20 consecutive cases of ACS by BAL, and identification of alveolar cells containing fat droplets was performed using oil red O (ORO), a specific neutral fat stain. The specificity of the method was determined on control groups, including eight SC patients without acute chest syndrome and 15 non-SC patients. A cut-off of > 5% of alveolar macrophages containing fat droplets was determined from the control groups to assess the diagnosis of fat embolism. In 12 ACS episodes, BAL exhibited > 5% of fatty macrophages, ranging from 10% to 100% (median value 46.5%). In 11 cases, fat embolism was associated with proven (n = 8) or probable (n = 3) bone marrow infraction, which mostly predated ACS. Eight ACS episodes were associated with a low percentage (< or = 5%) of fatty alveolar macrophages and could be related to a cause other than fat embolism in six episodes, such as sepsis, in-situ thrombosis, or rib infarcts generating hypoventilation. This study supports the diagnostic yield of BAL for fat embolism, which can be incriminated in 60% of cases of ACS in this adult population.

Adolescent↗
PubMed1996

Bacteremia and severe sepsis in adults: a multicenter prospective survey in ICUs and wards of 24 hospitals. French Bacteremia-Sepsis Study Group.

To examine the relationships between bacteremia and severe sepsis and assess the influence of characteristics of infection on the risk of severe sepsis and outcome of bacteremia, we analyzed all clinically significant episodes of bacteremia occurring during a 2-mo prospective survey of 85,750 admissions to adult wards and intensive care units (ICUs) of 24 hospitals in France. Incidence rates of bacteremia and of bacteremic severe sepsis were 9.8 (95% CI: 9.2 to 10.5) and 2.6 (95% CI: 2.2 to 2.9), respectively, per 1,000 adult admissions; these rates were eight and 32 times higher in ICUs than in wards, respectively. Independent risk factors for severe sepsis during bacteremia included age (p < 0.001) and an intraabdominal (p < 0.001), pulmonary (p < 0.001), neuromeningeal (p = 0.004), or multiple (p < 0.001) source of bacteremia, but not categories of organisms involved. The probability of death at 28 d after bacteremia was 25% (95% CI: 23% to 29%), and was 54% (95% CI: 48% to 61%) in patients with bacteremic severe sepsis. The risk of death after bacteremia increased with age (p < 0.001), a rapidly or ultimately fatal underlying disease (p < 0.001), and the presence of severe sepsis (p < 0.001), shock (p = 0.03), and infection caused by gram-positive organisms other than coagulase-negative staphylococci, relative to other organisms (p < 0.001). A primary urinary tract source of infection was associated with a better prognosis (p = 0.03). We conclude that whereas sources of infection influence both the risk of severe sepsis and the outcome of bacteremia, the microbiologic characteristics of infection influence only the outcome, with gram-negative organisms and coagulase-negative staphylococci posing a lesser risk than other organisms.

Adult↗
PubMed1996

Prolonged remission of SLE-associated polyradiculoneuropathy after a single course of intravenous immunoglobulin.

Polyradiculoneuropathy is a rare and potentially severe complication of systemic lupus erythematosus (SLE). Treatment is not codified and response to corticosteroid is inconstant. We report the case of a patient with severe SLE-associated polyradiculoneuropathy and autoimmune thrombocytopenia. Dramatic neurologic improvement and correction of thrombocytopenia were observed after a single course of high-dose intravenous immunoglobulin infusions (IVIg, 2g/kg body weight). Our case suggests that IVIg may be effective in the treatment of this unusual condition.

Aged↗
PubMed1996

Could invasive diagnostic techniques for ventilator-associated pneumonia be associated with reduced antibiotic usage in the ICU?

ICUs are often viewed as the epicenter of bacterial resistance. Overuse of antibiotics is one factor associated with this characteristic; other such factors include overcrowding, suboptimal observance of hygienic practices, cross-transmission of resistant strains, and high susceptibility of patients housed in ICUs. Evidence is scarce that different approaches to diagnosing infections, especially of the lower respiratory tract, can influence overall patterns of antibiotic usage and resistance. However, it is likely that more antibiotics are being administered to patients with suspected respiratory tract infections when diagnosed using nonspecific techniques than when more specific techniques are being used routinely. Additionally, the evidence is mounting that prior antibiotic usage is associated with increased risk of lower respiratory tract infection (LRTI), and also of infection caused by high-risk antibiotic-resistant pathogens, which in turn are associated with higher risk of treatment failure and mortality than their susceptible counterparts. A logical approach that may partially resolve this problem is to use specific diagnostic techniques, which will result in avoiding overtreating patients with suspected LRTI.

Anti-Bacterial Agents↗