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Biomedical subjects

Christian Brun-Buisson

Publications and source records attributed to Christian Brun-Buisson.

At least 19 recordsLinked to original sources

Prognostic value of anti-ADAMTS 13 antibody features (Ig isotype, titer, and inhibitory effect) in a cohort of 35 adult French patients undergoing a first episode of thrombotic microangiopathy with undetectable ADAMTS 13 activity.

To study both the pathophysiologic and the prognostic value of ADAMTS13 in thrombotic microangiopathies (TMAs), we enrolled a cohort of 35 adult patients combining a first acute episode of TMA, an undetectable (below 5%) ADAMTS13 activity in plasma, and no clinical background such as sepsis, cancer, HIV, and transplantation. All patients were treated by steroids and plasma exchange, and an 18-month follow-up was scheduled. Remission was obtained in 32 patients (91.4%), and 3 patients died (8.6%) after the first attack. At presentation, ADAMTS13 antigen was decreased in 32 patients (91.4%), an ADAMTS13 inhibitor was detectable in 31 patients (89%), and an anti-ADAMTS13 IgG/IgM/IgA was present in 33 patients (94%). The 3 decedent patients were characterized by the association of several anti-ADAMTS13 Ig isotypes, including very high IgA titers, while mortality was independent of the ADAMTS13 inhibitor titer. In survivors, ADAMTS13 activity in remission increased to levels above 15% in 19 patients (59%) but remained undetectable in 13 patients (41%). Six patients relapsed either once or twice (19%) during the follow-up. High levels of inhibitory anti-ADAMTS13 IgG at presentation were associated with the persistence of an undetectable ADAMTS13 activity in remission, the latter being predictive for relapses within an 18-month delay.

ADAM Proteins↗

Routine use of the Pneumonia Severity Index for guiding the site-of-treatment decision of patients with pneumonia in the emergency department: a multicenter, prospective, observational, controlled cohort study.

BACKGROUND: Although the Pneumonia Severity Index (PSI) has been extensively validated, little is known of the impact of its routine use as an aid to site-of-treatment decisions for patients with pneumonia who present to emergency departments (EDs). METHODS: A prospective, observational, controlled cohort study of patients with pneumonia was conducted in 8 EDs that used the PSI (PSI-user EDs) and 8 EDs that did not use the PSI (PSI-nonuser EDs) in France. The outcomes examined included the proportion of "low-risk" patients (PSI risk classes I-III) treated as outpatients, all-cause 28-day mortality, admission of inpatients to the intensive care unit, and subsequent hospitalization of outpatients. RESULTS: Of the 925 patients enrolled in the study, 472 (51.0%) were treated at PSI-user EDs, and 453 (49.0%) were treated at PSI-nonuser EDs; 449 (48.5%) of all patients were considered to be at low risk. In PSI-user EDs, 92 (42.8%) of 215 patients at low risk were treated as outpatients, compared with 56 (23.9%) of 234 patients at low risk in PSI-nonuser EDs. The adjusted odds ratios for outpatient treatment were higher for patients in PSI risk classes I and II who were treated in PSI-user EDs, compared with PSI-nonuser EDs (adjusted odds ratio, 7.0 [95% confidence interval, 2.0-25.0] and 4.6 [95% confidence interval, 1.3-16.2], respectively), whereas the adjusted odds ratio did not differ by PSI-user status among patients in risk class III or among patients at high risk. After adjusting for pneumonia severity, mortality was lower in patients who were treated in PSI-user EDs; other safety outcomes did not differ between patients treated in PSI-user and PSI-nonuser EDs. CONCLUSIONS: The routine use of the PSI was associated with a larger proportion of patients in PSI risk classes I and II who had pneumonia and who were treated in the outpatient environment without compromising their safety.

Aged↗

B-type natriuretic peptide and weaning from mechanical ventilation.

OBJECTIVE: Cardiac function and volume status could play a critical role in the setting of weaning failure. B-type natriuretic peptide (BNP) is a powerful marker of cardiac dysfunction. We assessed the value of BNP during the weaning process. DESIGN, SETTING AND PATIENTS: One hundred and two consecutive patients considered ready to undergo a 1-h weaning trial (T-piece or low-pressure support level) were prospectively included in a medical intensive care unit of a university hospital. Weaning was considered successful if the patient passed the trial and sustained spontaneous breathing for more than 48 h after extubation. INTERVENTIONS: Plasma BNP was measured just before the trial in all patients, and at the end of the trial in the first 60 patients. RESULTS: Overall, 42 patients (41.2%) failed the weaning process (37 patients failed the trial and 5 failed extubation). Logistic regression analysis identified high BNP level before the trial and the product of airway pressure and breathing frequency during ventilation as independent risk factors for weaning failure. BNP values were not different at the end of the trial. In nine of the patients in whom the weaning process failed, it succeeded on a later occasion after diuretic therapy. Their BNP level before weaning decreased between the two attempts (517 vs 226 pg/ml, p=0.01). In survivors, BNP level was significantly correlated to weaning duration (rho=0.52, p<0.01). CONCLUSIONS: Baseline plasma BNP level before the first weaning attempt is higher in patients with subsequent weaning failure and correlates to weaning duration.

Aged↗

Inappropriate prescribing of aminoglycosides: risk factors and impact of an antibiotic control team.

OBJECTIVES: Many factors are involved in the appropriate use of aminoglycosides, such as modalities of administration, drug levels monitoring and duration of treatment. We assessed prospectively the impact of an antibiotic control team on the appropriateness of prescriptions. METHODS: After a first observational audit assessing the appropriateness of prescriptions, and issuing updated recommendations, we performed an interventional audit, where an antibiotic control team provided counselling when prescriptions were considered inappropriate. Appropriateness of prescriptions, clinical outcomes of patients and medical costs were compared between the two periods. RESULTS: One hundred consecutive prescriptions were analysed in each period, and 32% of prescriptions were modified by the control team. As compared with the observational period, prescriptions in the intervention period were more appropriate with regard to treatment duration (73% versus 56%, P = 0.01) and drug levels monitoring (61% versus 40%, P = 0.05), and the median treatment duration was shorter (4 versus 6 days, P = 0.0002). Independent factors associated with appropriate treatment duration were hospitalization in intensive care unit [adjusted odds ratio (aOR), 4.46; 95% confidence interval (CI), 1.60-12.46], polymicrobial infection (aOR, 3.97; 1.32-11.92) and antibiotic control team intervention (aOR, 2.49; 1.27-4.87). The intervention period was associated with lower rate of nephrotoxicity (15% versus 4%, P = 0.01) and lower direct medical costs (4,039.4 Euros per 100 persons treated). CONCLUSIONS: Aminoglycoside use was frequently associated with excessive treatment duration and incorrect drug level monitoring. Reinforcing practice guidelines through direct counselling improved the appropriateness of prescriptions.

Aged↗

Validation of an algorithm based on direct examination of specimens in suspected ventilator-associated pneumonia.

BACKGROUND: The management of suspected ventilator-associated pneumonia (VAP) is traditionally based on either a clinical or a "bacteriological" approach. Direct examination of specimens may provide a valuable help to both approaches. OBJECTIVE: The objective was to test an algorithm for the management of suspected pneumonia based on severity criteria and Gram stains of specimens, including early treatment of patients with a positive Gram stain of a protected telescoping catheter specimen and awaiting culture results in patients with either Gram stains of endotracheal aspirate and protected specimen both being negative, or only positive endotracheal aspirate (EA), except in the presence of the severity criteria. METHODS: Observational study including 76 first episodes of suspected pneumonia in 4 units. We assessed the rates of correctly diagnosed episodes and of those treated empirically (i.e., ultimately confirmed pneumonia), or appropriately not receiving such therapy (non-confirmed pneumonia), based on protected specimen culture results. RESULTS: When adhered to, the algorithm allowed early appropriate management in 80% of patients, including 83% of those with confirmed pneumonia, and 74% of those without confirmed infection. The rate of appropriately managed episodes using this algorithm was significantly higher than that using a strategy based on the modified clinical pulmonary infection score (CPIS) alone (80 vs. 50%, p<0.001). The empiric regimen was adequate in 86% of confirmed episodes. CONCLUSION: A strategy based on severity criteria and Gram stain examination of respiratory tract specimens allows correct identification and appropriate management of more than 80% of mechanically ventilated patients who need or do not need therapy for suspected pneumonia.

Adult↗

Devic disease with brainstem lesions.

We describe a patient who suffered from an unusually severe form of neuromyelitis optica with a hyperacute time-course evolution requiring mechanical ventilation within 3 days. The patient died after 72 days and autopsy showed major spinal cord, optic nerve, and brainstem necrosis, and multifocal necrotic lesions on the cerebellum and cerebral white matter.

Acute Disease↗

[Epidemiology of severe sepsis].

Internationally recognized definitions of septic syndromes are available and make it possible to conduct more homogenous clinical trials. Nearly 15% of patients in intensive care have severe sepsis, and two thirds of them septic shock. In France, it is estimated that approximately 75,000 patients with severe sepsis are admitted to intensive care units, and the frequency of sepsis is increasing. Hospital mortality is 20% for simple sepsis and 40% and higher for cases of severe sepsis or septic shock; it has nonetheless been improving over the past decade. Prognosis depends on the severity of organ dysfunctions, in particular, of cardiovascular failure. Early identification of sepsis and of patients at risk of developing septic shock, together with rapid intervention aiming especially to correct hemodynamic disorders, is likely to improve prognosis.

Early Diagnosis↗

Bloodstream infection in adults with sickle cell disease: association with venous catheters, Staphylococcus aureus, and bone-joint infections.

Although well documented in children with sickle cell disease (SCD), the incidence, cause, and outcome of bloodstream infection (BSI) are poorly defined in adults with SCD. Through a 5-year retrospective analysis of a cohort of 900 patients followed at our institution, we identified 56 episodes of BSI in 47 patients. The incidence rate of BSI was 1.2 episodes per 100 patient-years. As compared to the patients followed in the cohort, those with BSI were more likely to be younger (p = 0.001), to have Hb-S disease (p = 0.008), severe disease (p = 0.001), or additional immunosuppression (p = 0.05). BSI was hospital-acquired in 46% of cases and mainly associated with venous catheters (41%) and Staphylococcus aureus (34%). Pneumococci were rarely identified (10.7%). Despite an adequate duration of antibiotic therapy, the course of BSI was marked by a high frequency of associated bone-joint infection. Bone-joint infection was noted in 18 patients (32% of episodes) and occurred either during the initial BSI episode (13 patients) or 1-6 months after BSI resolution (5 patients). Factors associated with the occurrence of bone-joint infection were previous osteonecrosis (relative risk, 2.5; 95% confidence interval, 1.2-5.3) and S. aureus infection (relative risk, 3.8; 95% confidence interval, 1.8-8.4). In conclusion, BSI is a rare event in adults with SCD compared to children. It mainly occurs in those with a severe underlying disease and a venous catheter. These patients have a high risk of associated bone-joint infection and therefore must be closely monitored.

Adult↗

Impact of humidification systems on ventilator-associated pneumonia: a randomized multicenter trial.

RATIONALE AND OBJECTIVES: The respective influence on the incidence of ventilator-associated pneumonia of currently available systems used for warming and humidifying the gases delivered to mechanically ventilated patients, that is, heated humidifiers and heat and moisture exchanger filters, remains controversial. METHODS: We addressed this question in a multicenter randomized study comparing heated humidifiers (with heated circuits) and filters in an unselected population of 369 intensive care patients receiving mechanical ventilation for more than 48 h. MAIN MEASUREMENTS AND RESULTS: The diagnosis of pneumonia was confirmed according to strict microbiologic criteria. There was no difference in pneumonia rate between the two groups (53 of 184 [28.8%] versus 47 of 185 [25.4%] for humidifiers versus filters; p = 0.48), or in the incidence density of pneumonia (27.4/1,000 ventilatory days versus 25.3/1,000 ventilatory days for humidifiers versus filters; p = 0.76). The mean duration of mechanical ventilation did not differ between the two groups (14.9 +/- 15.1 versus 13.5 +/- 16.3 days for humidifiers versus filters, p = 0.36). Endotracheal tube occlusion occurred, respectively, in five patients and one patient in the humidifier and filter groups (p = 0.12). Intensive care mortality was identical in the two groups (about 33%). CONCLUSION: These results suggest that both heated humidifiers and heat and moisture exchanger filters can be used with no significant impact on the incidence of ventilator-associated pneumonia and that other criteria may justify their choice.

Filtration↗

[Terminal extubation in 5 end-of-life patients in intensive care units].

INTRODUCTION: Decisions to withhold or withdraw active life support treatment in situations with no hope of improvement remain difficult for critical-care specialists and families; they are not always well understood by the public. This report describes terminal extubation, a particular method of withdrawing ventilator support. METHODS: This retrospective analysis examines the records of patients who died in our intensive care unit after a decision to withdraw active life support by stopping artificial ventilation. Extubation was proposed for patients with irreversible neurological damage and was always performed only after a standardized collective decision-making process. This process included three stages. In the initial phase, withdrawal of ventilator support was discussed at a department staff meeting. The meeting's conclusions were transcribed into the medical file, and the possibility of extubation was raised with the family during a planned interview. At least a 24-hour period of reflection was necessary before a new interview, and any opposition, hesitation or lack of understanding by the family at this first interview resulted in suspending the decision. The technical procedures for terminal extubation were also standardized. RESULTS: In 5 cases (4 men and one woman, with a mean age of 65 +/- 4 years), terminal extubation was decided in cooperation with the family, following an average of 3 interviews, 16 days after admission. All patients died within 3 days. DISCUSSION: So-called "terminal" extubation, very common in the United States, but much less so in France, reinforces the transparency of end-of-life decisions in intensive care units and immediately makes tangible the end of the aggressive treatment for which critical-care specialists have been reproached. Since this first series of patients, extubation has been practiced in our department, principally in situations of irreversible neurological damage.

Aged↗