Pierre-Emmanuel Charles

A clinical algorithm to diagnose invasive pulmonary aspergillosis in critically ill patients.

RATIONALE The clinical relevance of Aspergillus-positive endotracheal aspirates in critically ill patients is difficult to assess. OBJECTIVES We externally validate a clinical algorithm to discriminate Aspergillus colonization from putative invasive pulmonary aspergillosis in this patient group. METHODS We performed a multicenter (n = 30) observational study including critically ill patients with one or more Aspergillus-positive endotracheal aspirate cultures (n = 524). The diagnostic accuracy of this algorithm was evaluated using 115 patients with histopathologic data, considered the gold standard. Subsequently, the diagnostic workout of the algorithm was compared on the total cohort (n = 524), with the categorization based on the diagnostic criteria of the European Organization for the Research and Treatment of Cancer/Mycoses Study Group. MEASUREMENTS AND MAIN RESULTS Among 115 histopathology-controlled patients, 79 had proven aspergillosis. The algorithm judged 86 of 115 cases to have putative aspergillosis. This diagnosis was confirmed in 72 and rejected in 14 patients. The algorithm judged 29 patients to have Aspergillus colonization. This was confirmed in 22 and rejected in 7 patients. The algorithm had a specificity of 61% and a sensitivity of 92%. The positive and negative predictive values were 61 and 92%, respectively. In the total cohort (n = 524), 79 patients had proven invasive pulmonary aspergillosis (15.1%). According to the European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria, 32 patients had probable aspergillosis (6.1%) and 413 patients were not classifiable (78.8%). The algorithm judged 199 patients to have putative aspergillosis (38.0%) and 246 to have Aspergillus colonization (46.9%). CONCLUSIONS The algorithm demonstrated favorable operating characteristics to discriminate Aspergillus respiratory tract colonization from invasive pulmonary aspergillosis in critically ill patients.

Effect of Statin Therapy on Mortality in Patients With Ventilator-AssociatedPneumonia: A Randomized Clinical Trial

IMPORTANCE Observational studies have reported that statin use may be associated with improved outcomes of various infections. Ventilator-associated pneumonia (VAP) is the most common infection in the intensive care unit (ICU) and is associated with substantial mortality. OBJECTIVE To determine whether statin therapy can decrease day-28 mortality in patients with VAP. DESIGN, SETTING, AND PARTICIPANTS Randomized, placebo-controlled, double-blind, parallel-group, multicenter trial performed in 26 intensive care units in France from January 2010 to March 2013. For power to detect an 8% absolute reduction in the day-28 mortality rate, we planned to enroll 1002 patients requiring invasive mechanical ventilation for more than 2 days and having suspected VAP, defined as a modified Clinical Pulmonary Infection Score of 5 or greater. The futility stopping rules were an absolute increase in day-28 mortality of at least 2.7% with simvastatin compared with placebo after enrollment of the first 251 patients. INTERVENTIONS Participants were randomized to receive simvastatin (60 mg) or placebo, started on the same day as antibiotic therapy and given until ICU discharge, death, or day 28, whichever occurred first. MAIN OUTCOMES AND MEASURES Primary outcome was day-28 mortality. Day-14, ICU, and hospital mortality rates were determined, as well as duration of mechanical ventilation and Sequential Organ Failure Assessment (SOFA) scores on days 3, 7, and 14. RESULTS The study was stopped for futility at the first scheduled interim analysis after enrollment of 300 patients, of whom all but 7% in the simvastatin group and 11% in the placebo group were naive to statin therapy at ICU admission. Day-28 mortality was not lower in the simvastatin group (21.2% [95% CI, 15.4% to 28.6%) than in the placebo group (15.2% [95% CI, 10.2% to 22.1%]; P = .10; hazard ratio, 1.45 [95% CI, 0.83 to 2.51]); the between-group difference was 6.0% (95% CI, -3.0% to 14.9%). In statin-naive patients, day-28 mortality was 21.5% (95% CI, 15.4% to 29.1%) with simvastatin and 13.8% (95% CI, 8.8% to 21.0%) with placebo (P = .054) (between-group difference, 7.7% [95%CI, -1.8% to 16.8%). There were no significant differences regarding day-14, ICU, or hospital mortality rates; duration of mechanical ventilation; or changes in SOFA score. CONCLUSIONS AND RELEVANCE In adults with suspected VAP, adjunctive simvastatin therapy compared with placebo did not improve day-28 survival. These findings do not support the use of statins with the goal of improving VAP outcomes. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01057758.

Mutant Selection Window in Levofloxacin and Moxifloxacin Treatments of Experimental Pneumococcal Pneumonia in a Rabbit Model of Human Therapy

ABSTRACT For some pneumococci the fluoroquinolone MICs are low but the mutant prevention concentrations (MPCs) are high; this difference defines in vitro the mutant selection window (MSW). We investigated in vivo the bacterial reduction and the occurrence of resistant mutants with moxifloxacin (MFX; 400 mg once daily) or levofloxacin (LVX; 500 mg twice daily) in treatments similar to those in humans with experimental pneumonia due to pneumococci (expPP) exhibiting various MICs and MPCs. The MIC/MPC for MFX and LVX and genotypes were as follows: strain 16089, 0.125/0.125 and 0.5/0.5 (wild type); strain MS1A, 0.25/0.25 and 1/2 (efflux); strain MS2A, 0.25/4 and 1.75/28 (parC79); strain MR3B4, 0.25/4 and 2/32 (parC79); strain M16, 0.5/2 and 8/32 (parC83); strain Gyr-1207, 1.5/3 and 8/16 (gyrA); and strain MQ3A, 4/4 and 16/64 (parC and gyrA). Both drugs were efficient with wild type-expPP, but only MFX was efficient with efflux-expPP. No bacterial reduction was observed for parC-expPPs due to mutants observed in 18 to 100% of animals, depending on the strain and the drug tested. These mutants showed unbound area under the concentration-time curve and MICs of from 50 to 164 for MFX. The in vivo pharmacodynamic boundaries of the MSW were different for MFX and LVX. We conclude that, after LVX or MFX treatment, mutants occur in vivo if there is a preexisting parC mutation, since the drug concentrations fall below the MPCs of these strains. Since the MPC determination cannot be routinely determined, these phenotypes or genotypes should be detected by simple tests to guide the therapeutic options.

Effect of Low-Level Resistance on Subsequent Enrichment of Fluoroquinolone-Resistant Streptococcus pneumoniae in Rabbits

BACKGROUND We measured the effect of low-level fluoroquinolone resistance in Streptococcus pneumoniae on the development of high-level resistance within the context of the mutant selection window. METHODS Rabbits infected with S. pneumoniae were treated with ciprofloxacin or moxifloxacin concentrations that simulated pharmacokinetics in treated humans; bacteria obtained from lungs were examined for fluoroquinolone susceptibility. RESULTS Ciprofloxacin enriched resistant mutants from a wild-type strain; moxifloxacin did not. However, moxifloxacin enriched resistant mutants from a parC mutant; the drug concentration at the top of the selection window was determined. CONCLUSIONS A parC resistance mutation facilitates the enrichment of high-level resistance, as was predicted by in vitro measurements.

Role of biomarkers in the management of antibiotic therapy: an expert panel review II: clinical use of biomarkers for initiation or discontinuation of antibiotic therapy

Biomarker-guided initiation of antibiotic therapy has been studied in four conditions: acute pancreatitis, lower respiratory tract infection (LRTI), meningitis, and sepsis in the ICU. In pancreatitis with suspected infected necrosis, initiating antibiotics best relies on fine-needle aspiration and demonstration of infected material. We suggest that PCT be measured to help predict infection; however, available data are insufficient to decide on initiating antibiotics based on PCT levels. In adult patients suspected of community-acquired LRTI, we suggest withholding antibiotic therapy when the serum PCT level is low (<0.25 ng/mL); in patients having nosocomial LRTI, data are insufficient to recommend initiating therapy based on a single PCT level or even repeated measurements. For children with suspected bacterial meningitis, we recommend using a decision rule as an aid to therapeutic decisions, such as the Bacterial Meningitis Score or the Meningitest®; a single PCT level ≥0.5 ng/mL also may be used, but false-negatives may occur. In adults with suspected bacterial meningitis, we suggest integrating serum PCT measurements in a clinical decision rule to help distinguish between viral and bacterial meningitis, using a 0.5 ng/mL threshold. For ICU patients suspected of community-acquired infection, we do not recommend using a threshold serum PCT value to help the decision to initiate antibiotic therapy; data are insufficient to recommend using PCT serum kinetics for the decision to initiate antibiotic therapy in patients suspected of ICU-acquired infection. In children, CRP can probably be used to help discontinue therapy, although the evidence is limited. In adults, antibiotic discontinuation can be based on an algorithm using repeated PCT measurements. In non-immunocompromised out- or in- patients treated for RTI, antibiotics can be discontinued if the PCT level at day 3 is < 0.25 ng/mL or has decreased by >80-90%, whether or not microbiological documentation has been obtained. For ICU patients who have nonbacteremic sepsis from a known site of infection, antibiotics can be stopped if the PCT level at day 3 is < 0.5 ng/mL or has decreased by >80% relative to the highest level recorded, irrespective of the severity of the infectious episode; in bacteremic patients, a minimal duration of therapy of 5 days is recommended.

Ceftaroline versus Ceftriaxone in a Highly Penicillin-Resistant Pneumococcal Pneumonia Rabbit Model Using Simulated Human Dosing

ABSTRACT Ceftaroline (CPT) is a new cephalosporin exhibiting bactericidal activity against Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Streptococcus pneumoniae (MDRSP), as well as common Gram-negative pathogens. This study investigated the in vivo efficacy of a 48-hour simulated human dose regimen of CPT compared with ceftriaxone (CRO) against isolates of S. pneumoniae with different susceptibilities to penicillin in a rabbit pneumonia model. Three S. pneumoniae strains were used: CRO-susceptible penicillin-susceptible S. pneumoniae (CRO-S PSSP), CRO-susceptible penicillin-intermediate S. pneumoniae (CRO-S PISP), and CRO-resistant penicillin-resistant S. pneumoniae (CRO-R PRSP). Animals were randomized to the control group (no treatment) (n = 22) or to a group given intravenous (IV) CPT human equivalent (HE) dosage (600 mg/12 h; n = 19) or IV CRO HE dosage (1 g/24 h; n = 19). The total doses needed to achieve the HE dosage were 71 and 82 mg/kg of body weight/24 h for CRO and CPT, respectively. One group of rabbits infected with the CRO-R PRSP strain received intramuscular (IM) administration of CPT (5 or 20 mg/kg twice daily; n = 5 for each). Evaluation of efficacy was based on bacterial counts in the lungs and spleen. For IV CPT and IV CRO, the mean areas under the concentration-time curves from 0 to 24 h (AUC0–24s) were 155 and 938 mg · h/liter, respectively, the maximum concentrations in serum (Cmaxs) were 20 and 158 mg/liter, respectively, and the minimum concentrations in serum (Cmins) were 1.3 and 6 mg/liter, respectively. Both agents effectively treated pulmonary infections caused by CRO-S PSSP or CRO-S PISP with complete bacterial eradication in the lungs and spleen after 2 days of treatment. Against PRSP, CPT demonstrated excellent bactericidal activity, reducing bacterial counts in the lungs and spleen by approximately 8 and 4 log units, respectively (P < 0.001); CRO treatment resulted in a 2-log-unit reduction in the bacterial counts in lungs that did not reach statistical significance. Twice-daily IM CPT (5 mg/kg) reduced the bacterial burden by approximately 6 log units in the lungs and 3 log units in the spleen, and the 20-mg/kg dosage effectively eradicated PRSP infection. These findings further validate the in vivo bactericidal activity of CPT against pneumococci.

Incidence and Predictors of New-Onset Atrial Fibrillation in Septic Shock Patients in a Medical ICU: Data from 7-Day Holter ECG Monitoring

Purpose We investigated incidence, risk factors for new-onset atrial fibrillation (NAF), and prognostic impact during septic shock in medical Intensive Care Unit (ICU) patients. Methods Prospective, observational study in a university hospital. Consecutive patients from 03/2011 to 05/2013 with septic shock were eligible. Exclusion criteria were age <18 years, history of AF, transfer with prior septic shock. Included patients were equipped with long-duration (7 days) Holter ECG monitoring. NAF was defined as an AF episode lasting >30 seconds. Patient characteristics, infection criteria, cardiovascular parameters, severity of illness, support therapies were recorded. Results Among 66 patients, 29(44%) developed NAF; 10 (34%) would not have been diagnosed without Holter ECG monitoring. NAF patients were older, with more markers of heart failure (troponin and NT-pro-BNP), lower left ventricular ejection fraction (LVEF), longer QRS duration and more nonsustained supra ventricular arrhythmias (<30s) on day 1 than patients who maintained sinus rhythm. By multivariate analysis, age (OR: 1.06; p = 0.01) and LVEF<45% (OR: 13.01, p = 0.03) were associated with NAF. NAF did not predict 28 or 90 day mortality. Conclusions NAF is common, especially in older patients, and is associated with low ejection fraction. We did not find NAF to be independently associated with higher mortality.

Mild-stretch mechanical ventilation upregulates toll-like receptor 2 and sensitizes the lung to bacterial lipopeptide

IntroductionMechanical ventilation (MV) could prime the lung toward an inflammatory response if exposed to another insult such as bacterial invasion. The underlying mechanisms are not so far clear. Toll-like receptors (TLRs) allow the host to recognize selectively bacterial pathogens and in turn to trigger an immune response. We therefore hypothesized that MV modulates TLR2 expression and in turn modifies responsiveness to agonists such as bacterial lipopeptide (BLP).MethodBoth in vitro and in vivo experiments were conducted. First, TLR2 expression and protein were measured in the A549 pulmonary epithelial cell line submitted to 8-hour cyclic stretch (20% elongation; 20/minute rate). After a 24-hour period of cyclic stretch, the inflammatory response of the A549 cells to the synthetic BLP, Pam3CSK4, was tested after 8 hours of exposure. In a second set of experiments, healthy anesthetized and paralyzed rabbits were submitted to 8-hour MV (tidal volume = 12 ml/kg, zero end-expiratory pressure; FIO2 = 50%; respiratory rate = 20/minute) before being sacrificed for TLR2 lung expression assessment. The lung inflammatory response to BLP was then tested in animals submitted to 24-hour MV before being sacrificed 8 hours after the tracheal instillation of Pam3CSK4.ResultsCyclic stretch of human pulmonary epithelial cell lines increased both TLR2 mRNA and protein expression. Cells submitted to cyclic stretch also increased IL-6 and IL-8 secretion in response to Pam3CSK4, a classical TLR2 ligand. A mild-stretch MV protocol induced a 60-fold increase of TLR2 mRNA expression in lung tissue when compared with spontaneously breathing controls. Moreover, the combination of MV and airway exposure to Pam3CSK4 acted synergistically in causing lung inflammation and injury.ConclusionsMild-stretch MV increases lung expression of TLR2 and sensitizes the lung to bacterial TLR2 ligands. This may account for the propensity of mechanically ventilated patients to develop acute lung injury in the context of airway bacterial colonization/infection.

Cerebral aspergillosis in adult critically ill patients: a descriptive report of 10 patients from the AspICU cohort.

An unexpectedly high incidence of invasive pulmonary aspergillosis (IPA) has been reported in non-neutropenic intensive care unit (ICU) patients. After the respiratory tract, the brain is most often affected by invasive aspergillosis. However, little is known about brain involvement by Aspergillus in critically ill patients. In this study, demographics, risk profile, diagnosis, treatment and outcome of proven cases of invasive cerebral aspergillosis (ICA) taken from a cohort of 563 adult patients with evidenced Aspergillus involvement during their ICU stay were reviewed. Ten patients with central nervous system aspergillosis were identified. All had one or more host factors predisposing for invasive aspergillosis. The clinical and radiological presentation was non-specific and exclusively pulmonary-related. All but one patient had proven or probable/putative IPA. On cerebral computed tomography, lesions appeared as either solitary and hyperdense or were multiple and randomly distributed throughout the brain. One patient presented with sole meningeal infestation. Aspergillus infection was confirmed by brain biopsy in three subjects. Voriconazole was used as primary treatment in only one-half of the patients. Mortality was 90%. ICA is not frequently observed in adult ICU patients. Diagnosis must be considered in patients at risk presenting with proven or probable/putative IPA in association with suggestive neuroradiological findings. The brain is most likely affected through haematogenous dissemination from the lungs. Current treatment recommendations are not always applied and outcome remains dismal.

Impact of prior statin therapy on the outcome of patients with suspected ventilator-associated pneumonia: an observational study.

IntroductionVentilator-associated pneumonia (VAP) is the most commonly acquired infection in intensive care units (ICU). Its outcome is related, at least in part, to the host’s response. Statins have anti-inflammatory effects and may thus improve the outcome. We aimed to assess the impact of prior statin use in the setting of VAP.MethodsA six-year cohort study was conducted in a French ICU at a teaching hospital. All of the patients with suspected VAP were included. Baseline characteristics, outcomes, statin exposure, and the description of suspected episodes were collected prospectively. The primary endpoint was 30-day mortality. Patients who were taking statins before admission to the ICU whether or not treatment was continued thereafter (‘previous users’ group) were compared to those without prior statin therapy (‘statin-naive’ group). A survival analysis using a Cox model was conducted in the whole cohort and in the subgroup of prior statin users.ResultsAmong the 349 patients included, 93 (26.6%) had taken statins. At baseline, these patients were at higher risk of complications than statin-naive ones (for example, older, more likely to be men and to have underlying diseases, greater simplified acute physiology score II (SAPS II)). There was, however, no difference regarding severity at the time VAP was suspected (sequential organ failure assessment (SOFA): 9.0 (4.0 to 16.0) versus 8.0 (4.0 to 17.0); P = 0.11). Nonetheless, 30-day mortality in statin users was not different from that in statin-naive patients (35.5% versus 26.2%, respectively; adjusted hazard ratio (HR) = 1.23 (0.79 to 1.90) 95% confidence interval (CI); P = 0.36). In contrast, after limiting analysis to prior statin users and adjusting for potential confounders, those who continued the treatment had better survival than those who did not (HR = 0.47; (0.22 to 0.97) 95% CI; P = 0.04).ConclusionsStatin continuation in prior users could provide protective effects in patients with suspected VAP.