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Biomedical subjects

Christian Brun-Buisson

Publications and source records attributed to Christian Brun-Buisson.

At least 55 records · Page 3Linked to original sources

The costs of septic syndromes in the intensive care unit and influence of hospital-acquired sepsis.

OBJECTIVE: To document the costs and outcomes of the various forms of the septic syndromes [systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, septic shock), particularly those associated with infection acquired in an intensive care unit (ICU). DESIGN: Prospective data collection for all septic patients admitted to a medical ICU during a 1-year period. Costs were computed from the viewpoint of the hospital. RESULTS: Mean total hospital costs were Euro 26,256, Euro 35,185, and Euro 27,083 for patients with sepsis, severe sepsis, and septic shock, respectively. Total costs varied slightly according to the site of infection and the severity of sepsis but were influenced mostly by its mode of acquisition: patients having sepsis associated with ICU-acquired infection incurred total costs about three times those of patients presenting with infection and sepsis on ICU admission (from Euro 39,908 in patients with ICU acquired sepsis to Euro 44,851 in patients with ICU-acquired septic shock). Stratifying patients by the presence of ICU-acquired infection also showed that a first episode of infection complicated by ICU-acquired sepsis incurred at least 2.5 times more costs than a single episode of sepsis. CONCLUSIONS: In this series the medical costs of sepsis were not markedly influenced by its severity but by its mode of acquisition. Due to wide variations in ICU costs cost-effectiveness analyses of treatments for sepsis should document the case-mix of patients and the contribution to this of nosocomial infections.

Costs and Cost Analysis↗

Diagnosing pneumonia during mechanical ventilation: the clinical pulmonary infection score revisited.

The clinical pulmonary infection score-original or modified-has been proposed for the diagnosis and management of ventilator-associated pneumonia. In 79 episodes of suspected pneumonia, we prospectively assessed the diagnostic accuracy of the physicians' clinical assessment of probability and of the modified clinical pulmonary infection score, both measured before (pretest) and after (post-test) incorporating gram stains results, using bronchoalveolar lavage fluid culture as the reference test. The pretest clinical estimate was inaccurate (sensitivity 50%, specificity 58%); the mean clinical pulmonary infection score at baseline was 6.5 +/- 1.3 (range, 3-9) and 5.9 +/- 1.7 (range, 3-9), respectively, for the 40 confirmed and the 39 nonconfirmed episodes (p = 0.07), and only slightly more accurate (sensitivity 60%, specificity 59%) than the clinical prediction. Incorporating the gram stain results of either directed or blind protected sampling increased the diagnostic accuracy (sensitivity and specificity of 85% and 49% and 78% and 56%, respectively) of the clinical score and increased the likelihood ratio for pneumonia of a score of more than six from 1.46 to 1.67 and 1.77. The clinical pulmonary infection score has low diagnostic accuracy; however, incorporating gram stains results into the score may help clinical decision making in patients with clinically suspected pneumonia.

Bronchoalveolar Lavage Fluid↗

Influence of systemic inflammatory response syndrome and sepsis on outcome of critically ill infected patients.

The clinical significance of the systemic inflammatory response in infected patients remains unclear. We examined risk factors for hospital mortality in 3,608 intensive care unit patients included in the European Sepsis Study. Patients were categorized as having infection without or with (i.e., sepsis) systemic inflammatory response, severe sepsis, and septic shock, on the first day of infection. Hospital mortality varied from 25 to 60% according to sepsis stage, but did not differ between the first two categories (hazard ratio, 0.94; p = 0.55), whereas there was a grading of severity from sepsis to severe sepsis (1.53, p < 10-4) and septic shock (2.64, p < 10-4). Within each stage, mortality was unaffected by the number of inflammatory response criteria. Prognostic factors identified by Cox regression included comorbid conditions, severity of acute illness and acute organ dysfunction, shock, nosocomial infection, and infection caused by aerobic gram-negative bacilli, enterobacteria, Staphylococcus aureus, and infection from a digestive or unknown source. We conclude that whereas the categorization of infection by the presence of organ dysfunction or shock has strong prognostic significance, infection and sepsis have similar outcomes, unaffected by the presence or number of inflammatory response criteria. Refinement of risk stratification of patients presenting with infection and no organ dysfunction is needed.

Aged↗

Discrepancies between perceptions by physicians and nursing staff of intensive care unit end-of-life decisions.

Several studies have pointed out ethical shortcomings in the decision-making process for withholding or withdrawing life-supporting treatments. We conducted a study to evaluate the perceptions of all caregivers involved in this process in the intensive care unit. A closed-ended questionnaire was completed by 3,156 nursing staff members and 521 physicians from 133 French intensive care units (participation rate, 42%). Decision-making processes were perceived as satisfactory by 73% of physicians and by only 33% of the nursing staff. More than 90% of caregivers believed that decision-making should be collaborative, but 50% of physicians and only 27% of nursing staff members believed that the nursing staff was actually involved (p < 0.001). Fear of litigation was a reason given by physicians for modifying information given to competent patients, families, and nursing staff. Perceptions by nursing staff may be a reliable indicator of the quality of medical decision-making processes and may serve as a simple and effective tool for evaluating everyday practice. Recommendations and legislation may help to build consensus and avoid conflicts among caregivers at each step of the decision-making process.

Attitude of Health Personnel↗

Bactericidal activity response of blood neutrophils from critically ill patients to in vitro granulocyte colony-stimulating factor stimulation.

OBJECTIVE: Neutrophil function impairment is common in nonneutropenic critically ill patients. Whether granulocyte colony-stimulating factor (G-CSF) may be useful for preventing nosocomial infection in these patients is debated. The response of blood neutrophils from critically ill patients to G-CSF was investigated in vitro. DESIGN AND SETTING: Prospective study, laboratory investigation in two intensive care units. PATIENTS: 52 critically ill patients without immunosuppression. MEASUREMENTS: Neutrophils obtained from 52 patients on the 5th day of their intensive care unit stay were incubated with and without G-CSF (1, 10, 100 ng/ml). Reactive oxygen species (ROS) release and bactericidal activity against Staphylococcus aureus and Pseudomonas aeruginosa were evaluated. Plasma cytokines (interleukin 10, tumor necrosis factor alpha, and G-CSF) were measured. RESULTS: Median values (25th-75th percentiles) indicated no stimulatory effect of G-CSF on neutrophil bactericidal activity against either organism: S. aureus, 100% (95-109) of the unstimulated condition with 1 ng/ml G-CSF, and P. aeruginosa, 102% (98-109) with 1 ng/ml G-CSF. However, wide interindividual variability was found, ranging from marked inhibition to marked stimulation. Similar variability was found for ROS release. No correlations were found between ROS release and bactericidal activities against either bacterial strain. Inhibition of neutrophil bactericidal activity by G-CSF was associated with significantly higher plasma interleukin 10 concentrations. Plasma G-CSF levels were significantly higher in patients whose neutrophil bactericidal activity was unresponsive to G-CSF, suggesting G-CSF receptor downregulation. CONCLUSIONS: The effect of G-CSF on in vitro neutrophil bactericidal activity varied widely, depending on endogenous levels of G-CSF and was not predictable based on severity scores.

Adult↗

Prevention of venous thromboembolism in critically ill medical patients: a Franco-Canadian cross-sectional study.

BACKGROUND: Medical intensive care unit (ICU) patients are at moderate risk of venous thromboembolism (VTE) and prophylaxis against VTE is recommended. OBJECTIVES: To observe the range and frequency of VTE prophylaxis administered to medical ICU patients and to determine factors associated with different strategies in French and Canadian ICUs. DESIGN: Prospective cross-sectional observational study. RESULTS: 113/251 (45.0%) French and 29/30 (96.6%) Canadian ICUs agreed to participate. Of 1,222 critically ill medical patients, most were mechanically ventilated (62.5%). Overall, heparin VTE prophylaxis was administered to 63.9% patients, similarly between the 2 countries. Excluding patients with contraindications to heparin and those receiving therapeutic anticoagulation, 91.7% of medical ICU patients appropriately received either low dose unfractionated heparin (UFH) or low molecular weight heparin (LMWH) prophylaxis. Independent predictors of heparin prophylaxis were invasive mechanical ventilation (odds ratio [OR]; 95%CI, 2.4 (1.4-4.3) and obesity (OR 3.1; 1.1-8.8). LMWH was less likely to be prescribed for patients with renal failure (OR 0.1; 0.0009-0.9), or receiving antiembolic stockings (OR 0.4, 0.1-0.9), and much more likely to be prescribed in French ICUs (OR 9.2; 5.0-16.9); however, among patients receiving LMWH, high doses were more likely to be prescribed in Canadian ICUs (OR 8.7; 2.0-37.6). Patients who were pregnant or postpartum (OR 7.7, 1.3-44.3), had neurologic failure (OR 2.1, 1.3-3.4), or were Canadian (OR 3.0, 2.1-4.4) were most likely to receive mechanical VTE prophylaxis (with antiembolic stockings or pneumatic compression devices), whereas those who were already receiving heparin were less likely to receive mechanical prophylaxis (OR 0.5, 0.3-0.7). CONCLUSIONS: In this binational cross-sectional observational study of medical ICU patients, we found that 92% of eligible patients received either UFH or LWMH for VTE prophylaxis. Differences in prescribing between countries include significantly greater use of LMWH in France, but use of lower doses than in Canada, and greater use of mechanical VTE prophylaxis in Canada. More randomized trials of VTE prophylaxis in critically ill medical patients would better inform practice.

Anticoagulants↗

An intranet-based automated system for the surveillance of nosocomial infections: prospective validation compared with physicians' self-reports.

OBJECTIVE: To examine the reliability of the data produced by an automated system for the surveillance of nosocomial infections. SETTING: A 906-bed, tertiary-care teaching hospital. DESIGN: Three surveillance techniques were concurrently performed in seven high-risk units during an 11-week period: automated surveillance (AS) based on the prospective processing of computerized medical records; laboratory-based ward surveillance (LBWS) based on the retrospective verification by ward clinicians of weekly reports of positive bacteriologic results; and a reference standard (RS) consisting of the infection control team reviewing case records of patients with positive bacteriology results. Bacteremia, urinary tract infections, and catheter-related infections were recorded for all inpatients. The performances (sensitivity, specificity, and time consumption) of AS and LBWS were compared with those of RS. RESULTS: Of 548 positive bacteriology samples included during the study period, 229 (42%) were classified as nosocomial infections. The overall sensitivity was 91% and 59% for AS and LBWS, respectively. The two methods had the same overall specificity value (91%). Kappa measures of agreement were 0.81 and 0.54 for AS and LBWS, respectively. AS required less time to collect data (54 seconds per week per unit) compared with LBWS (7 minutes and 43 seconds per week per unit) and RS (37 minutes and 15 seconds per week per unit). CONCLUSION: Our results confirm that the retrospective review of charts and laboratory data by physicians lacks sensitivity for the surveillance of nosocomial infections. The intranet-based automated method developed for this purpose was more accurate and less time-consuming than the weekly, retrospective LBWS method.

Automation↗

Exacerbation with granulocyte colony-stimulating factor of prior acute lung injury during neutropenia recovery in rats.

OBJECTIVE: Neutropenia recovery may be associated with an increased risk of respiratory function deterioration. A history of pneumonia complicating neutropenia has been identified as the leading cause of adult respiratory distress syndrome during neutropenia recovery in patients receiving anticancer chemotherapy, suggesting that neutropenia recovery may worsen prior lung injury. DESIGN: Controlled animal study. SETTING: Research laboratory of an academic institution. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: We studied the effect of recovery from cyclophosphamide-induced neutropenia on endotoxin (lipopolysaccharide)- or hydrochloric acid-induced acute lung injury in rats. We also studied the effects of adding granulocyte colony-stimulating factor. MEASUREMENTS AND MAIN RESULTS: Compared with noncyclophosphamide-treated rats, rats undergoing neutropenia recovery had a higher wet/dry lung weight ratio after hydrochloric acid-induced but not lipopolysaccharide-induced acute lung injury. Granulocyte colony-stimulating factor significantly increased both alveolar cell recruitment (bronchoalveolar lavage fluid counts) and pulmonary edema (wet/dry lung ratio) in both acute lung injury models during neutropenia recovery. Furthermore, in an experiment in hydrochloric acid-instilled rats, exacerbation by granulocyte colony-stimulating factor of hydrochloric acid-induced acute lung injury was inhibited by lidocaine, which prevents adhesion of neutrophils to endothelial cells. Tumor necrosis factor-alpha and interleukin-1 beta concentrations in supernatants of lipopolysaccharide-stimulated alveolar macrophages from rats undergoing neutropenia recovery with granulocyte colony-stimulating factor treatment were significantly increased compared with rats undergoing neutropenia recovery without granulocyte colony-stimulating factor. CONCLUSION: Neutropenia recovery can worsen acute lung injury, and this effect is exacerbated by granulocyte colony-stimulating factor.

Animals↗

Nosocomial infections occurring during receipt of circulatory support with the paracorporeal ventricular assist system.

This retrospective study sought to report the spectrum of infections in a homogenous group of 39 patients who underwent implantation of the Thoratec paracorporeal ventricular assist device system (Thoratec Laboratories) in an emergency setting. Thirty-one of the 39 patients developed a total of 99 nosocomial infections (attack rate, 79.5%; incidence, 4.9 per 100 support-days). The lungs were the most frequently involved site (31.3%), and coagulase-negative Staphylococcus species were the pathogens most frequently isolated (16.2%). Infected patients required more transfusions and chest surgical revisions, as well as a longer duration of mechanical ventilation and a longer stay in the intensive care unit, compared with uninfected patients. Cox regression analysis revealed that chest surgical revision was the only independent risk factor for infection at any site (odds ratio, 2.6; 95% confidence interval, 1.2-5.7). There was no significant effect of infection on heart transplantation rate and overall survival.

Adult↗

Efficacy of handrubbing with alcohol based solution versus standard handwashing with antiseptic soap: randomised clinical trial.

OBJECTIVE: To compare the efficacy of handrubbing with an alcohol based solution versus conventional handwashing with antiseptic soap in reducing hand contamination during routine patient care. DESIGN: Randomised controlled trial during daily nursing sessions of 2 to 3 hours. SETTING: Three intensive care units in a French university hospital. PARTICIPANTS: 23 healthcare workers. INTERVENTIONS: Handrubbing with alcohol based solution (n=12) or handwashing with antiseptic soap (n=11) when hand hygiene was indicated before and after patient care. Imprints taken of fingertips and palm of dominant hand before and after hand hygiene procedure. Bacterial counts quantified blindly. MAIN OUTCOME MEASURES: Bacterial reduction of hand contamination. RESULTS: With handrubbing the median percentage reduction in bacterial contamination was significantly higher than with handwashing (83% v 58%, P=0.012), with a median difference in the percentage reduction of 26% (95% confidence interval 8% to 44%). The median duration of hand hygiene was 30 seconds in each group. CONCLUSIONS: During routine patient care handrubbing with an alcohol based solution is significantly more efficient in reducing hand contamination than handwashing with antiseptic soap.

Alcohols↗

Guidelines for treatment of hospital-acquired pneumonia.

In the past decade, much information has been gained on the diagnostic and therapeutic strategies in patients suspected of having hospital-acquired pneumonia. The key to an effective therapeutic approach is the diagnostic strategy used, and timely administration of appropriate antibiotic therapy. Many patients, but not all, need early appropriate empiric therapy. This decision and the selection of the initial regimen is based on local epidemiological and surveillance data, the clinical presentation, and the recent history of the individual patient; direct examination of reliable respiratory tract samples can provide a valuable help, but cannot be relied on solely. Whenever possible, the timely performance of such samples (i.e., before instituting therapy) is of paramount importance because this will bear heavily on their interpretation and the conduct of subsequent and definitive therapy. Hospitals are now plagued with infection caused by increasingly multidrug-resistant organisms; this is especially the case in intensive care units (ICUs), where nosocomial respiratory tract infection is the primary reason for prescribing antibiotics. Although many questions remain unanswered regarding the optimal choices and duration of therapy, reversing this trend will require continuous and prolonged efforts to strictly adhere to a rigorous approach for antibiotic prescribing in nosocomial respiratory tract infection.

Journal Article↗

Impairment of polymorphonuclear neutrophil functions precedes nosocomial infections in critically ill patients.

OBJECTIVE: A postinjury immunodepression involving neutrophil functions has been described in critically ill patients. The aim of this prospective study was to search for a relationship between an impairment of neutrophil functions and the subsequent development of nosocomial infection. DESIGN: Twenty-one severely ill (simplified acute physiology score II >20 on admission), nonimmunosuppressed patients who were receiving no antibiotics active against methicillin-resistant Staphylococcus aureus and highly resistant Pseudomonas aeruginosa were included. Twelve healthy subjects constituted a control group. MEASUREMENTS: Neutrophil functions (phagocytosis and bactericidal activity toward S. aureus and P. aeruginosa in homologous plasma, reactive oxygen species secretion) were studied at day 4 +/- 1 after admission, and occurrence of nosocomial infection was prospectively recorded over the following 5 days. Interleukin-10 concentration was assessed by enzyme-linked immunosorbent assay. Results are expressed as median (25th-75th percentiles). MAIN RESULTS: Six out of the 21 patients acquired a nosocomial infection during the 5 days after blood sampling (infected group). Compared with the patients who did not acquire nosocomial infection (noninfected group, n = 15), the neutrophils of the infected group demonstrated a higher percentage of intracellular bacterial survival (17% [2% to 67%] vs. infected: 62% [22% to 100%], p <.05), leading to an impairment of S. aureus killing in homologous plasma (killed bacteria: 4.93 log(10) colony forming units/mL [4.24-5.29] vs. infected: 3.62 log(10) colony forming units/mL [0.00-4.58], p <.05). Interleukin-10 plasma concentration was higher in infected patients (78 pg/mL [60-83]) compared with noninfected patients (22 pg/mL [14-58], p <.05). By contrast, P. aeruginosa killing was similar in patients whether or not they acquired a nosocomial infection. CONCLUSION: A decrease in S. aureus killing capabilities of neutrophils can be evidenced within the days before occurrence of a nosocomial infection.

Adult↗

Beneficial effects of nitric oxide inhalation on pulmonary bacterial clearance.

OBJECTIVE: The beneficial effects of nitric oxide inhalation on oxygenation during acute respiratory distress syndrome are well described. In contrast, the effects of nitric oxide on pulmonary inflammatory response are much less known in vivo. The objectives of this study were to evaluate the effects of nitric oxide inhalation on bacterial clearance during bacterial pneumonia and on alveolar neutrophil functions. DESIGN: Controlled animal study. SETTING: Research laboratory of an academic institution. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Severe pneumonia was induced by alveolar instillation of live Pseudomonas aeruginosa (1.5 x 10(8) colony-forming units/kg) in rats. After instillation, rats were exposed to oxygen alone (FIO(2) 100%) or to oxygen (FIO(2) approximately 100%) plus nitric oxide (10 ppm) during 24 hrs. MEASUREMENTS AND MAIN RESULTS: Oxygen plus nitric oxide inhalation compared with oxygen alone increased recruitment of alveolar neutrophils (32.5 +/- 4.6 x 10(6) cells/mL vs. 23.4 +/- 1.9 x 10(6) cells/mL, p <.05) and improved bacterial clearance in the bronchoalveolar lavage fluid (8.1 +/- 4.2 x 10(2) vs. 1.6 +/- 1.0 x 10(5) colony-forming units/mL, p <.05) and in the pulmonary parenchyma (1.7 +/- 1.14 x 10(7) vs. 3.4 +/- 1.5 x 10(8) colony-forming units/mL, p <.05). However, neither protein concentration in the bronchoalveolar lavage fluid nor mortality rates were modified by nitric oxide inhalation. The ex vivo alveolar neutrophil functions were similar regardless of whether rats previously inhaled nitric oxide. In vitro experiments demonstrated that nitric oxide donor had a direct bactericidal effect against P. aeruginosa and did not modify alveolar neutrophil functions. CONCLUSIONS: These results suggest a beneficial effect of nitric oxide inhalation on bacterial clearance of P. aeruginosa attributable to both a direct bactericidal effect and an influx of alveolar neutrophils with preserved functions.

Administration, Inhalation↗

Granulocyte colony-stimulating factor enhances host defenses against bacterial pneumonia following peritonitis in nonneutropenic rats.

OBJECTIVE: Polymorphonuclear cell functions frequently are impaired in critically ill patients, and restoration of normal functions could help to prevent nosocomial infections. The aim of this study was to evaluate the effects of pretreatment with granulocyte colony-stimulating factor (G-CSF) on bacterial pneumonia induced 48 hrs after peritonitis (cecal ligation and puncture [CLP]) in rats. DESIGN: Controlled animal study. SETTING: Research laboratory of an academic institution. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: First, the CLP model was characterized. Second, alveolar endotoxin instillation allowed us to evaluate the ability of neutrophils to migrate to airspaces after CLP was assessed. In the last set of experiments, CLP was followed by G-CSF treatment as a preventive therapy for subsequent bacterial superinfection induced by alveolar instillation. MEASUREMENTS AND MAIN RESULTS: CLP induced a brief increase in proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta) at the 6th hr followed by a longer-lived anti-inflammatory response (interleukin-10 increase from days 1 to 3) in plasma, compared with healthy rats. Impaired neutrophil migration to alveolar spaces denoting immunoparalysis was evidenced after endotracheal endotoxin instillation following CLP, compared with non-CLP rats challenged with endotoxin. No such impairment was found when G-CSF (100 microg/kg: glycosylated recombinant human G-CSF, Lenograstim) was given before endotoxin. G-CSF (100 microg/kg 24 and 48 hrs after CLP) given before endotracheal instillation increased bacterial clearance, as shown by counts in both bronchoalveolar lavage (8.9 x 10 +/- 2.8 x 10 colony-forming units/mL vs. 3.3 x 10 +/- 1.5 x 10 colony-forming units/mL with saline) and lung tissue (4.2 x 10 +/- 1.0 x 10 colony-forming units/g vs. 1.5 x 10 +/- 0.6 x 10 colony-forming units/g with saline). Furthermore, G-CSF pretreatment kept clearance in CLP rats similar to that in non-CLP rats challenged with. CONCLUSION: These results suggest that G-CSF (Lenograstim) may enhance host defenses in rats with peritonitis and immunoparalysis.

Animals↗