Convalescent Plasma for Covid-19-Induced ARDS in Mechanically Ventilated Patients.

BACKGROUND: Passive immunization with plasma collected from convalescent patients has been regularly used to treat coronavirus disease 2019 (Covid-19). Minimal data are available regarding the use of convalescent plasma in patients with Covid-19-induced acute respiratory distress syndrome (ARDS). METHODS: In this open-label trial, we randomly assigned adult patients with Covid-19-induced ARDS who had been receiving invasive mechanical ventilation for less than 5 days in a 1:1 ratio to receive either convalescent plasma with a neutralizing antibody titer of at least 1:320 or standard care alone. Randomization was stratified according to the time from tracheal intubation to inclusion. The primary outcome was death by day 28. RESULTS: A total of 475 patients underwent randomization from September 2020 through March 2022. Overall, 237 patients were assigned to receive convalescent plasma and 238 to receive standard care. Owing to a shortage of convalescent plasma, a neutralizing antibody titer of 1:160 was administered to 17.7% of the patients in the convalescent-plasma group. Glucocorticoids were administered to 466 patients (98.1%). At day 28, mortality was 35.4% in the convalescent-plasma group and 45.0% in the standard-care group (P = 0.03). In a prespecified analysis, this effect was observed mainly in patients who underwent randomization 48 hours or less after the initiation of invasive mechanical ventilation. Serious adverse events did not differ substantially between the two groups. CONCLUSIONS: The administration of plasma collected from convalescent donors with a neutralizing antibody titer of at least 1:160 to patients with Covid-19-induced ARDS within 5 days after the initiation of invasive mechanical ventilation significantly reduced mortality at day 28. This effect was mainly observed in patients who underwent randomization 48 hours or less after ventilation initiation. (Funded by the Belgian Health Care Knowledge Center; ClinicalTrials.gov number, NCT04558476.).

Critically Ill Patients with Visceral Nocardia Infection, France and Belgium, 2004-2023.

We studied 50 patients with invasive nocardiosis treated during 2004-2023 in intensive care centers in France and Belgium. Most (65%) died in the intensive care unit or in the year after admission. Nocardia infections should be included in the differential diagnoses for patients in the intensive care setting.

A reactive monocyte subset characterized by low expression of CD91 is expanded during sterile and septic inflammation.

OBJECTIVES: This study was undertaken to assess CD91 expression on monocytes and changes in monocyte subset distribution during acute tissue damage and bloodstream infection (BSI). METHODS: We investigated blood specimens from healthy individuals, trauma and cardiac surgery patients as a model of tissue damage, and patients with BSI, by flow cytometry using a panel of antibodies comprising CD45, HLA-DR, CD14, CD16 and CD91 for the identification of monocyte subsets. RESULTS: While infrequent in healthy subjects, CD91low/neg monocyte levels were markedly high in BSI, trauma and after cardiac surgery. This monocyte subset expanded up to 15-fold in both patient cohorts, whereas CD14+CD16+ inflammatory monocytes were multiplied by a factor of 5 only. CD14+CD91low monocytes displayed a significantly lower density of HLA-DR and markedly reduced expression of CD300e, compared to the other subsets. They also expressed high levels of myeloperoxidase and showed robust phagocytic and oxidative burst activity. CONCLUSIONS: Expansion of CD91low monocytes is a sensitive marker of acute inflammatory states of infectious and non-infectious etiology.

[Does a rapid antibiotic susceptibility test optimize antibiotic therapy of patients with bacteremia ?] / Un antibiogramme rapide optimise-t-il la prise en charge thérapeutique des patients présentant une bactériémie ?

BACKGROUND: We evaluated the contribution of a rapid antibiotic susceptibility test performed directly from a positive blood culture (PBC), the dRAST™, in the management of patients with bacteremia. METHODS: We retrospectively compared the time from sampling to availability of antibiotic susceptibility test (AST) results («time-to-result¼, TTR) between dRAST™ and classic AST (Vitek®2), in 150 patients with bacteremia. The antibiotic treatment of these 150 patients was classified into three categories (optimal, suboptimal, ineffective) according to the time of availability of AST results. RESULTS: Adaptation of antibiotic treatment to optimal therapy following AST results occurred in 46/100 (46 %) of Gram-negative PBC and in 4/50 (2 %) of Gram-positive HP. TTR was significantly lower with dRAST™ compared with classic AST (29:35 (± 08:48) hours versus 50:55 (± 12:45) hours, p < 0.001). CONCLUSION: For patients with bacteremia requiring adjustment of empirical antibiotic therapy based on AST, dRAST™ could allow a faster administration of optimal therapy.

CONTEXTE: Nous avons évalué la contribution d'un antibiogramme rapide réalisé directement à partir d'une hémoculture positive (HP), le dRAST™, dans la prise en charge des patients présentant une bactériémie. Méthodes: Nous avons comparé, rétrospectivement, le délai entre le prélèvement et la disponibilité des résultats d'antibiogramme («temps-pour-résultats¼, TPR) entre le dRAST™ et l'antibiogramme classique (Vitek®2), auprès de 150 patients présentant une bactériémie. Les antibiothérapies de ces 150 patients ont été classés en trois catégories (optimale, suboptimale, inefficace) en fonction du moment d'obtention des résultats de l'antibiogramme. Résultats : L'adaptation du traitement antibiotique en thérapie optimale suite au résultat de l'antibiogramme est survenue chez 46/100 (46 %) des HP à Gram négatif et chez 4/50 (2 %) des HP à Gram positif. Le TPR était significativement plus faible avec le dRAST™ par rapport à l'antibiogramme classique (29:35 (± 08:48) heures versus 50:55 (± 12:45) heures, p < 0,001). CONCLUSION: Pour les patients avec bactériémie nécessitant une adaptation de l'antibiothérapie empirique basée sur l'antibiogramme, le dRAST™ permettrait une administration plus rapide du traitement optimal.

Prospective flow cytometry analysis of leucocyte subsets in critically ill patients who develop sepsis: a pilot study.

PURPOSE: Sepsis in critically ill patients with injury bears a high morbidity and mortality. Extensive phenotypic monitoring of leucocyte subsets in critically ill patients at ICU admission and during sepsis development is still scarce. The main objective of this study was to identify early changes in leukocyte phenotype which would correlate with later development of sepsis. METHODS: Patients who were admitted in a tertiary ICU for organ support after severe injury (elective cardiac surgery, trauma, necessity of prolonged ventilation or stroke) were sampled on admission (T1) and 48-72 h later (T2) for phenotyping of leukocyte subsets by flow cytometry and cytokines measurements. Those who developed secondary sepsis or septic shock were sampled again on the day of sepsis diagnosis (Tx). RESULTS: Ninety-nine patients were included in the final analysis. Nineteen (19.2%) patients developed secondary sepsis or septic shock. They presented significantly higher absolute monocyte counts and CRP at T1 compared to non-septic patients (1030/µl versus 550/µl, p = 0.013 and 5.1 mg/ml versus 2.5 mg/ml, p = 0.046, respectively). They also presented elevated levels of monocytes with low expression of L-selectin (CD62Lneg monocytes) (OR[95%CI] 4.5 (1.4-14.5), p = 0.01) and higher SOFA score (p < 0.0001) at T1 and low mHLA-DR at T2 (OR[95%CI] 0.003 (0.00-0.17), p = 0.049). Stepwise logistic regression analysis showed that both monocyte markers and high SOFA score (> 8) were independently associated with nosocomial sepsis occurrence. No other leucocyte count or surface marker nor any cytokine measurement correlated with sepsis occurrence. CONCLUSION: Monocyte counts and change of phenotype are associated with secondary sepsis occurrence in critically ill patients with injury.

Duration of antibiotic treatment using procalcitonin-guided treatment algorithms in older patients: a patient-level meta-analysis from randomized controlled trials.

BACKGROUND: Older patients have a less pronounced immune response to infection, which may also influence infection biomarkers. There is currently insufficient data regarding clinical effects of procalcitonin (PCT) to guide antibiotic treatment in older patients. OBJECTIVE AND DESIGN: We performed an individual patient data meta-analysis to investigate the association of age on effects of PCT-guided antibiotic stewardship regarding antibiotic use and outcome. SUBJECTS AND METHODS: We had access to 9,421 individual infection patients from 28 randomized controlled trials comparing PCT-guided antibiotic therapy (intervention group) or standard care. We stratified patients according to age in four groups (<75 years [n = 7,079], 75-80 years [n = 1,034], 81-85 years [n = 803] and >85 years [n = 505]). The primary endpoint was the duration of antibiotic treatment and the secondary endpoints were 30-day mortality and length of stay. RESULTS: Compared to control patients, mean duration of antibiotic therapy in PCT-guided patients was significantly reduced by 24, 22, 26 and 24% in the four age groups corresponding to adjusted differences in antibiotic days of -1.99 (95% confidence interval [CI] -2.36 to -1.62), -1.98 (95% CI -2.94 to -1.02), -2.20 (95% CI -3.15 to -1.25) and - 2.10 (95% CI -3.29 to -0.91) with no differences among age groups. There was no increase in the risk for mortality in any of the age groups. Effects were similar in subgroups by infection type, blood culture result and clinical setting (P interaction >0.05). CONCLUSIONS: This large individual patient data meta-analysis confirms that, similar to younger patients, PCT-guided antibiotic treatment in older patients is associated with significantly reduced antibiotic exposures and no increase in mortality.

Prevention of ventilator-associated pneumonia and ventilator-associated conditions: a randomized controlled trial with subglottic secretion suctioning.

OBJECTIVES: Ventilator-associated pneumonia diagnosis remains a debatable topic. New definitions of ventilator-associated conditions involving worsening oxygenation have been recently proposed to make surveillance of events possibly linked to ventilator-associated pneumonia as objective as possible. The objective of the study was to confirm the effect of subglottic secretion suctioning on ventilator-associated pneumonia prevalence and to assess its concomitant impact on ventilator-associated conditions and antibiotic use. DESIGN: Randomized controlled clinical trial conducted in five ICUs of the same hospital. PATIENTS: Three hundred fifty-two adult patients intubated with a tracheal tube allowing subglottic secretion suctioning were randomly assigned to undergo suctioning (n = 170, group 1) or not (n = 182, group 2). MAIN RESULTS: During ventilation, microbiologically confirmed ventilator-associated pneumonia occurred in 15 patients (8.8%) of group 1 and 32 patients (17.6%) of group 2 (p = 0.018). In terms of ventilatory days, ventilator-associated pneumonia rates were 9.6 of 1,000 ventilatory days and 19.8 of 1,000 ventilatory days, respectively (p = 0.0076). Ventilator-associated condition prevalence was 21.8% in group 1 and 22.5% in group 2 (p = 0.84). Among the 47 patients with ventilator-associated pneumonia, 25 (58.2%) experienced a ventilator-associated condition. Neither length of ICU stay nor mortality differed between groups; only ventilator-associated condition was associated with increased mortality. The total number of antibiotic days was 1,696 in group 1, representing 61.6% of the 2,754 ICU days, and 1,965 in group 2, representing 68.5% of the 2,868 ICU days (p < 0.0001). CONCLUSIONS: Subglottic secretion suctioning resulted in a significant reduction of ventilator-associated pneumonia prevalence associated with a significant decrease in antibiotic use. By contrast, ventilator-associated condition occurrence did not differ between groups and appeared more related to other medical features than ventilator-associated pneumonia.

Modelled target attainment after meropenem infusion in patients with severe nosocomial pneumonia: the PROMESSE study.

OBJECTIVES: The objective of this study was to propose an optimal treatment regimen of meropenem in critically ill patients with severe nosocomial pneumonia. PATIENTS AND METHODS: Among 55 patients in intensive care treated with 1 g of meropenem every 8 h for severe nosocomial pneumonia, 30 were assigned to intermittent infusion (II; over 0.5 h) and 25 to extended infusion (EI; over 3 h) groups. Based on plasma and epithelial lining fluid (ELF) concentrations determined at steady-state, pharmacokinetic modelling and Monte Carlo simulations were undertaken to assess the probability of attaining drug concentrations above the MIC for 40%-100% of the time between doses (%T > 1-fold and 4-fold MIC), for 1 or 2 g administered by either method. RESULTS: Penetration ratio, measured by the ELF/plasma ratio of AUCs, was statistically higher in the EI group than in the II group (mean ± SEM: 0.29 ± 0.030 versus 0.20 ± 0.033, P = 0.047). Considering a maximum susceptibility breakpoint of 2 mg/L, all dosages and modes of infusions achieved 40%-100% T > 1-fold MIC in plasma, but none did so in ELF, and only the 2 g dose over EI achieved 40%-100% T > 4-fold MIC in plasma. CONCLUSIONS: The optimum regimen to treat severe nosocomial pneumonia was 2 g of meropenem infused over 3 h every 8 h. This regimen achieved the highest pharmacodynamic targets both in plasma and in ELF.

Saccharomyces cerevisiae fungemias: how heterogenous is their management?

Saccharomyces cerevisiae is a yeast used mainly as a probiotic for prevention or treatment of diarrhoea. However, the prevalence of S. cerevisiae fungemia has risen over the past years, notably among patients with predisposing factors. This retrospective study presents 21 cases of S. cerevisiae fungemia at the University Hospital of Liege from 2000 to 2022, their clinical relevance and therapeutic management. Each patient presented one or several risk factors prior to fungemia. The isolated strains presented high minimal inhibitory concentration for fluconazole, while MICs for amphotericin B, voriconazole and echinocandins were low. Some patients received antifungal therapy, while for others only central and peripheral lines were removed and probiotics discontinued. The MICs obtained for voriconazole and echinocandins makes them an alternative treatment to fluconazole and amphotericin B as reported in other studies. Since a S. cerevisiae fungemia can induce the same complications as candidemia, follow-up blood cultures should be collected and metastatic foci should be looked for. This study showed an important discrepancy in the clinical management of infections due to S. cerevisiae and highlights the need for guidelines.

A dose-adjusted, open-label, pilot study of the safety, tolerability, and pharmacokinetics of STC3141 in critically ill patients with sepsis.

Increased circulating histones correlate with sepsis severity and are a potential therapeutic target. Pre-clinical studies showed benefit with a histone-neutralizing polyanion molecule (STC3141). We aimed to investigate the safety, tolerability, and pharmacokinetics of STC3141 in critically ill patients with sepsis. We studied 26 patients with sepsis divided into four cohorts of one, five, ten, and ten subjects, respectively. We conducted a dose-adjusted, open-label study to determine the safety, tolerability, and pharmacokinetics of STC3141 administered as an IV infusion for up to 72 h, with rate adjusted to estimated creatinine clearance. Four steady-state concentrations were targeted. Twenty of the 26 subjects (77%) in the study experienced at least one adverse event (AE). The most frequently reported study drug-related AE was a mildly prolonged aPTT (four events). Only one AE (pulmonary hemorrhage) led to discontinuation of the drug. After excluding patients receiving renal replacement therapy (RRT) patients, clearance ranged from 3.3 to 4.2 L/h across cohorts and was essentially completely renal in nature. Half-life values ranged from 5 to 7 h. The mean (±SD) terminal half-life for non-RRT subjects and for whom it was possible to calculate was approximately 9 (±4.77) h but increased to 19 (±7.94) h for subjects on RRT. Overall, 18 (69.2%) patients completed the study to day eight in the ICU, and 22 (84.6%) survived to 28 days. STC3141 administration appeared to have an acceptable degree of safety and tolerability and expected pharmacokinetics. Cautious, larger randomized efficacy trials in sepsis appear justified.

Immunological sub-phenotypes and response to convalescent plasma in COVID-19 induced ARDS: a secondary analysis of the CONFIDENT trial.

BACKGROUND: Convalescent plasma (CP) reduced the mortality in COVID-19 induced ARDS (C-ARDS) patients treated in the CONFIDENT trial. As patients are immunologically heterogeneous, we hypothesized that clusters may differ in their treatment responses to CP. METHODS: We measured 20 cytokines, chemokines and cell adhesion markers using a multiplex technique at the time of inclusion in the CONFIDENT trial in patients of centers having accepted to participate in this secondary study. We performed descriptive statistics, unsupervised hierarchical cluster analysis, and examined the association between the clusters and CP effect on day-28 mortality. RESULTS: Of the 475 patients included in CONFIDENT, 391 (82%) were sampled, and 196/391 (50.1%) had been assigned to CP. We identified four sub-phenotypes representing 89 (22.8%), 178 (45.5%), 38 (9.7%), and 86 (22.0%) patients. The most contributing biomarkers in the principal component analysis were IL-1ß, IL-12p70, IL-6, IFN-α, IL-17A, IFN-γ, IL-13, TFN-α, total IgG, and CXCL10. Sub-phenotype-1 displayed a lower immune response, sub-phenotype-2 a higher adaptive response, sub-phenotype-3 the highest innate antiviral, pro and anti-inflammatory response, and adhesion molecule activation, and sub-phenotype-4 a higher pro and anti-inflammatory response, migration protein and adhesion molecule activation. Sub-phenotype-2 and sub-phenotype-4 had higher severity at the time of inclusion. The effect of CP treatment on mortality appeared higher than standard care in each sub-phenotype, without heterogeneity between sub-phenotypes (p = 0.97). CONCLUSION: In patients with C-ARDS, we identified 4 sub-phenotypes based on their immune response. These sub-phenotypes were associated with different clinical profiles. The response to CP was similar across the 4 sub-phenotypes. TRIAL REGISTRATION: Ethics Committee of the University Hospital of Liège CE 2020/239. CLINICALTRIALS: gov NCT04558476. Registered 2020-09-11, https://www. CLINICALTRIALS: gov/study/NCT04558476 .

Clinical and molecular epidemiological features of critically ill patients with invasive group A Streptococcus infections: a Belgian multicenter case-series.

BACKGROUND: Recent alerts have highlighted an increase in group A streptococcal (GAS) infections since 2022 in Europe and the United States. Streptococcus pyogenes can cause limited skin or mucosal disease, but can also present as severe invasive disease necessitating critical care. We performed a multicenter retrospective study of patients with GAS infections recently admitted to Belgian intensive care units (ICUs) since January 2022. We describe patient characteristics and investigate the molecular epidemiology of the S. pyogenes strains involved. RESULTS: Between January 2022 and May 2023, a total of 86 cases (56 adults, 30 children) with GAS disease were admitted to critical care in the university hospitals of Leuven, Antwerp and Liège. We noted a strikingly high incidence of severe community-acquired pneumonia (sCAP) (45% of adults, 77% of children) complicated with empyema in 45% and 83% of adult and pediatric cases, respectively. Two-thirds of patients with S. pyogenes pneumonia had viral co-infection, with influenza (13 adults, 5 children) predominating. Other disease presentations included necrotizing fasciitis (23% of adults), other severe skin/soft tissue infections (16% of adults, 13% of children) and ear/nose/throat infections (13% of adults, 13% of children). Cardiogenic shock was frequent (36% of adults, 20% of children). Fifty-six patients (65%) had toxic shock syndrome. Organ support requirements were high and included invasive mechanical ventilation (77% of adults, 50% of children), renal replacement therapy (29% of adults, 3% of children) and extracorporeal membrane oxygenation (20% of adults, 7% of children). Mortality was 21% in adults and 3% in children. Genomic analysis of S. pyogenes strains from 55 out of 86 patients showed a predominance of emm1 strains (73%), with a replacement of the M1global lineage by the toxigenic M1UK lineage (83% of emm1 strains were M1UK). CONCLUSIONS: The recent rise of severe GAS infections (2022-23) is associated with introduction of the M1UK lineage in Belgium, but other factors may be at play-including intense circulation of respiratory viruses and potentially an immune debt after the COVID pandemic. Importantly, critical care physicians should include S. pyogenes as causative pathogen in the differential diagnosis of sCAP.

Procalcitonin usefulness for the initiation of antibiotic treatment in intensive care unit patients.

OBJECTIVES: To test the usefulness of procalcitonin serum level for the reduction of antibiotic consumption in intensive care unit patients. DESIGN: Single-center, prospective, randomized controlled study. SETTING: Five intensive care units from a tertiary teaching hospital. PATIENTS: All consecutive adult patients hospitalized for >48 hrs in the intensive care unit during a 9-month period. INTERVENTIONS: Procalcitonin serum level was obtained for all consecutive patients suspected of developing infection either on admission or during intensive care unit stay. The use of antibiotics was more or less strongly discouraged or recommended according to the Muller classification. Patients were randomized into two groups: one using the procalcitonin results (procalcitonin group) and one being blinded to the procalcitonin results (control group). The primary end point was the reduction of antibiotic use expressed as a proportion of treatment days and of daily defined dose per 100 intensive care unit days using a procalcitonin-guided approach. Secondary end points included: a posteriori assessment of the accuracy of the infectious diagnosis when using procalcitonin in the intensive care unit and of the diagnostic concordance between the intensive care unit physician and the infectious-disease specialist. MEASUREMENTS AND MAIN RESULTS: There were 258 patients in the procalcitonin group and 251 patients in the control group. A significantly higher amount of withheld treatment was observed in the procalcitonin group of patients classified by the intensive care unit clinicians as having possible infection. This, however, did not result in a reduction of antibiotic consumption. The treatment days represented 62.6±34.4% and 57.7±34.4% of the intensive care unit stays in the procalcitonin and control groups, respectively (p=.11). According to the infectious-disease specialist, 33.8% of the cases in which no infection was confirmed, had a procalcitonin value>1µg/L and 14.9% of the cases with confirmed infection had procalcitonin levels<0.25 µg/L. The ability of procalcitonin to differentiate between certain or probable infection and possible or no infection, upon initiation of antibiotic treatment was low, as confirmed by the receiving operating curve analysis (area under the curve=0.69). Finally, procalcitonin did not help improve concordance between the diagnostic confidence of the infectious-disease specialist and the ICU physician. CONCLUSIONS: Procalcitonin measuring for the initiation of antimicrobials did not appear to be helpful in a strategy aiming at decreasing the antibiotic consumption in intensive care unit patients.

Bone Marrow-Derived Mesenchymal Stromal Cell Therapy in Severe COVID-19: Preliminary Results of a Phase I/II Clinical Trial.

Background: Treatment of acute respiratory distress syndrome (ARDS) associated with COronaVIrus Disease-2019 (COVID-19) currently relies on dexamethasone and supportive mechanical ventilation, and remains associated with high mortality. Given their ability to limit inflammation, induce immune cells into a regulatory phenotype and stimulate tissue repair, mesenchymal stromal cells (MSCs) represent a promising therapy for severe and critical COVID-19 disease, which is associated with an uncontrolled immune-mediated inflammatory response. Methods: In this phase I-II trial, we aimed to evaluate the safety and efficacy of 3 intravenous infusions of bone marrow (BM)-derived MSCs at 3-day intervals in patients with severe COVID-19. All patients also received dexamethasone and standard supportive therapy. Between June 2020 and September 2021, 8 intensive care unit patients requiring supplemental oxygen (high-flow nasal oxygen in 7 patients, invasive mechanical ventilation in 1 patient) were treated with BM-MSCs. We retrospectively compared the outcomes of these MSC-treated patients with those of 24 matched control patients. Groups were compared by paired statistical tests. Results: MSC infusions were well tolerated, and no adverse effect related to MSC infusions were reported (one patient had an ischemic stroke related to aortic endocarditis). Overall, 3 patients required invasive mechanical ventilation, including one who required extracorporeal membrane oxygenation, but all patients ultimately had a favorable outcome. Survival was significantly higher in the MSC group, both at 28 and 60 days (100% vs 79.2%, p = 0.025 and 100% vs 70.8%, p = 0.0082, respectively), while no significant difference was observed in the need for mechanical ventilation nor in the number of invasive ventilation-free days, high flow nasal oxygenation-free days, oxygen support-free days and ICU-free days. MSC-treated patients also had a significantly lower day-7 D-dimer value compared to control patients (median 821.0 µg/L [IQR 362.0-1305.0] vs 3553 µg/L [IQR 1155.0-6433.5], p = 0.0085). Conclusions: BM-MSC therapy is safe and shows very promising efficacy in severe COVID-19, with a higher survival in our MSC cohort compared to matched control patients. These observations need to be confirmed in a randomized controlled trial designed to demonstrate the efficacy of BM-MSCs in COVID-19 ARDS. Clinical Trial Registration: (www.ClinicalTrials.gov), identifier NCT04445454.

Overall Survival Rate in Allogeneic Stem Cell Transplanted Patients Requiring Intensive Care Can Be Predicted by the Prognostic Index for Critically Ill Allogeneic Transplantation Patients (PICAT) and the Sequential Organ Failure Assessment (SOFA) Scores.

Background. Allogeneic hematopoietic stem cell transplantation (allo-HCT) recipients requiring intensive care unit (ICU) have high mortality rates. Methods. In the current study, we retrospectively assessed whether the Prognostic Index for Critically Ill Allogeneic Transplantation patients (PICAT) score predicted overall survival in a cohort of 111 consecutive allo-HCT recipients requiring ICU. Results. Survival rates at 30 days and 1 year after ICU admission were 57.7% and 31.5%, respectively, and were significantly associated with PICAT scores (p = 0.036). Specifically, survival at 30-day for low, intermediate, and high PICAT scores was 64.1%, 58.1%, and 31.3%, respectively. At one-year, the figures were 37.5%, 29%, and 12.5%, respectively. In multivariate analyses, high PICAT score (HR = 2.23, p = 0.008) and relapse prior to ICU admission (HR = 2.98, p = 0.0001) predicted higher mortality. We next compared the ability of the PICAT and the Sequential Organ Failure Assessment (SOFA) scores to predict mortality in our patients using c-statistics. C statistics for the PICAT and the SOFA scores were 0.5687 and 0.6777, respectively. Conclusions. This study shows that while the PICAT score is associated with early and late mortality in allo-HCT recipients requiring ICU, it is outperformed by the SOFA score to predict their risk of mortality.

Continuous infusion, therapeutic drug monitoring and outpatient parenteral antimicrobial therapy with ceftazidime/avibactam: a retrospective cohort study.

OBJECTIVES: Based on recent pharmacokinetic/pharmacodynamic (PK/PD) evidence, continuous-infusion (CI) ß-lactam administration is increasingly recommended for serious infections. Since 2016, the combination ceftazidime/avibactam (CAZ/AVI) is administered as per the manufacturer's instructions as an intermittent infusion of 2.5 g every 8 h. Thus, CI has not yet been evaluated in clinical trials. METHODS: We aimed to evaluate the use of CI of CAZ/AVI in a retrospective case series from December 2016 to October 2019. All isolates displayed in vitro susceptibility to CAZ/AVI according to EUCAST definitions. Patients were initially given CAZ/AVI as CI of 5 g every 12 h, and dosages were adjusted according to therapeutic drug monitoring of ceftazidime with a therapeutic goal of ≥4-5 × MIC in plasma and/or at the site of infection. RESULTS: CAZ/AVI was administered by CI in 10 patients with infections mainly caused by multidrug-resistant Pseudomonas aeruginosa (54.5%) and Klebsiella pneumoniae (36.4%). Bacteraemia occurred in 30% of cases. Sepsis or septic shock was present in 20% of cases. CAZ/AVI was used as monotherapy in 60% of cases. Clinical cure and microbiological eradication were achieved in 80% and 90% of cases, respectively. The 30-day mortality after CAZ/AVI treatment onset was 10%. The therapeutic goals of ≥4-5 × MIC in plasma and/or at the site of infection were achieved in 100% and 87.5% of cases, respectively, without adverse events. CONCLUSION: Despite a limited number of patients, CI of CAZ/AVI provided promising results after optimisation of PK/PD parameters both in plasma and at the site of infection.

Machine learning identification of specific changes in myeloid cell phenotype during bloodstream infections.

The early identification of bacteremia is critical for ensuring appropriate treatment of nosocomial infections in intensive care unit (ICU) patients. The aim of this study was to use flow cytometric data of myeloid cells as a biomarker of bloodstream infection (BSI). An eight-color antibody panel was used to identify seven monocyte and two dendritic cell subsets. In the learning cohort, immunophenotyping was applied to (1) control subjects, (2) postoperative heart surgery patients, as a model of noninfectious inflammatory responses, and (3) blood culture-positive patients. Of the complex changes in the myeloid cell phenotype, a decrease in myeloid and plasmacytoid dendritic cell numbers, increase in CD14+CD16+ inflammatory monocyte numbers, and upregulation of neutrophils CD64 and CD123 expression were prominent in BSI patients. An extreme gradient boosting (XGBoost) algorithm called the "infection detection and ranging score" (iDAR), ranging from 0 to 100, was developed to identify infection-specific changes in 101 phenotypic variables related to neutrophils, monocytes and dendritic cells. The tenfold cross-validation achieved an area under the receiver operating characteristic (AUROC) of 0.988 (95% CI 0.985-1) for the detection of bacteremic patients. In an out-of-sample, in-house validation, iDAR achieved an AUROC of 0.85 (95% CI 0.71-0.98) in differentiating localized from bloodstream infection and 0.95 (95% CI 0.89-1) in discriminating infected from noninfected ICU patients. In conclusion, a machine learning approach was used to translate the changes in myeloid cell phenotype in response to infection into a score that could identify bacteremia with high specificity in ICU patients.