Sepsis-associated acute kidney injury in patients with chronic kidney disease: Patient characteristics, prevalence, timing, trajectory, treatment and associated outcomes.

AIM: The features and outcomes of sepsis-associated acute kidney injury (SA-AKI) may be affected by chronic kidney disease (CKD). Accordingly, we aimed to compare SA-AKI in patients with or without CKD. METHODS: Retrospective cohort study in 12 intensive care units (ICU). We studied the prevalence, patient characteristics, timing, trajectory, treatment and outcomes of SA-AKI with and without CKD. RESULTS: Of 84 240 admissions, 7255 (8.6%) involved patients with CKD. SA-AKI was more common in patients with CKD (21% vs 14%; p < .001). CKD patients were older (70 vs. 60 years; p < .001), had a higher median Charlson co-morbidity index (5 vs. 3; p < .001) and acute physiology and chronic health evaluation (APACHE) III score (78 vs. 60; p < .001) and were more likely to receive renal replacement therapy (RRT) (25% vs. 17%; p < .001). They had less complete return to baseline function at ICU discharge (48% vs. 60%; p < .001), higher major adverse kidney events at day 30 (MAKE-30) (38% vs. 27%; p < .001), and higher hospital and 90-day mortality (21% vs. 13%; p < .001, and 27% vs. 16%; p < .001, respectively). After adjustment for patient characteristics and severity of illness, however, CKD was not an independent risk factor for increased 90-day mortality (OR 0.88; 95% CI 0.76-1.02; p = .08) or MAKE-30 (OR 0.98; 95% CI 0.80-1.09; p = .4). CONCLUSION: SA-AKI is more common in patients with CKD. Such patients are older, more co-morbid, have higher disease severity, receive different ICU therapies and have different trajectories of renal recovery and greater unadjusted mortality. However, after adjustment day-90 mortality and MAKE-30 risk were not increased by CKD.

Variability in forgoing life-sustaining treatment practices in critically Ill patients with hospital-acquired bloodstream infections: a secondary analysis of the EUROBACT-2 international cohort.

BACKGROUND: The decision to forgo life-sustaining treatment in intensive care units (ICUs) is influenced by ethical, cultural, and medical factors. This study focuses on a population of patients with hospital-acquired bloodstream infections (HABSI) to investigate the association between patient, pathogen, center and country-level factors and these decisions. METHODS: We analyzed data from the EUROBACT-2 study (June 2019-January 2021) from 265 centers worldwide, focusing on non-COVID-19 patients who died in the hospital or within 28 days after HABSI. We assessed whether death was preceded by a decision to forgo life-sustaining treatment, examining country, center, patient, and pathogen variables. To assess the association of each potentially important variable with the decision to forgo life-sustaining treatment, univariable mixed logistic regression models with a random center effect were performed. RESULTS: Among 1589 non-COVID-19 patients, 519 (32.7%) died, with 191 (36.8%) following a decision to forgo life-sustaining treatment. Significant geographical differences were observed, with no reported decisions to forgo life-sustaining treatment in African countries and fewer in the Middle East compared to Western Europe, Australia, and Asia. Once a center effect was considered, only health expenditure (Odds ratio 1.79, 95%CI: 1.45-2.21, p < 0.01) and age (Odds ratio 1.02, 95%CI: 1.002-1.05, p = 0.03) were significantly associated with decisions to forgo life-sustaining treatment, while other patient and pathogen factors were not. CONCLUSION: Economic and regional disparities significantly impact end-of-life decision-making in ICUs. Global policies should consider these disparities to ensure equitable end-of-life care practices.

The Impact of Prescription Time Limits on Phosphate Administration in the Intensive Care Unit: A Before-After Quality Improvement Study.

(1) Background: We aim to examine and improve phosphate prescribing as part of a quality assurance program by examining the change in the proportion of patients receiving phosphate with normal or high preceding serum phosphate concentrations before and after the introduction of the 24 h time limit to default phosphate prescription. (2) Methods: This was a quality assurance study conducted across three Australian adult intensive care units (ICUs). All adult patients with ICU lengths of stay greater than or equal to 48 h who had their serum phosphate concentrations measured were included. A 24 h time limit was introduced to the protocolised prescription in the electronic clinical information system for enteral and intravenous phosphate at participating ICUs. Patient characteristics, phosphate administration, and outcomes were compared before and after this time limit was introduced. The primary outcome was the proportion of patients to whom phosphate was prescribed after measurement of a normal or high serum phosphate level. Secondary outcomes were ICU length of stay, mortality, and discharge destination. (3) Results: A total of 1192 patients were included from three ICUs over the two periods. The proportion of patients with a normal or high measured phosphate level who then received phosphate supplementation was significantly lower in the second study period (30.3% vs. 9.9%; p < 0.001). This difference persisted when adjusted for potential confounders in a mixed-effects logistic regression model (an adjusted odds ratio for receiving phosphate with normal or high serum concentration 0.214, 95% confidence interval of 0.132-0.347; p < 0.001). No significant difference was seen in the typical ICU length of stay, in-hospital case-fatality rate, and hospital discharge destination between these groups. (4) Conclusions: This multicentre before-after study has demonstrated that the introduction of a 24 h limit on electronic phosphate prescriptions resulted in significantly fewer patients receiving phosphate when their serum phosphate concentration was normal or high, without any adverse impact on patient outcomes.

Epidemiology of Hypophosphatemia in Critical Illness: A Multicentre, Retrospective Cohort Study.

INTRODUCTION: Hypophosphatemia is common in critically ill patients. We have described the epidemiology of hypophosphatemia in patients admitted to the Intensive Care Units. METHODS: A multicentre, retrospective cohort study of 12 ICUs in Queensland, Australia from January 1st, 2015, to December 31st, 2021. Exclusions included readmissions, renal replacement therapy, end-stage renal disease, and palliative intent admissions and transfers from other ICUs. Patients were classified into four groups based on the severity of the first episode of low serum phosphate (PO4): "None" (PO4: ≥ 0.81 mmol/L, ``Mild" (PO4: ≥ 0.50 & < 0.81 mmol/L) "Moderate" (PO4: ≥ 0.30 & < 0.50 mmol/L) and "Severe" (PO4: < 0.30 mmol/L). A mixed-effect logistic regression model, including hospital as a random effect, was developed to examine factors associated with 90-day case fatality. RESULTS: Of the 89,776 patients admitted, 68,699 patients were included in this study, with 23,485 (34.2%) having hypophosphatemia with onset mostly on Day 2 of ICU admission and correcting to normal 3 days after hypophosphatemia was identified. There was substantial variation among participating ICUs in phosphate replacement; the threshold, and the route by which it was replaced. Day-90 case fatality increased with severity of hypophosphatemia (None: 3,974 (8.8%), Mild: 2,306 (11%), Moderate: 377 (14%); Severe: 108 (21%) (p < 0.001)). Multivariable regression analysis showed that compared to those without hypophosphatemia, patients with moderate (odds ratio (OR) 1.24; 95% confidence intervals (CI) 1.07-1.44; p = 0.004) or severe (OR 1.49; 95% CI 1.13-1.97; p = 0.005) hypophosphatemia had increased risk of 90-day case fatality. CONCLUSION: Hypophosphatemia was common, and mostly occurred on day 2 with early correction of serum phosphate. Phosphate replacement practices were variable among ICUs. Moderate and severe hypophosphatemia was associated with increased 90-day case fatality.

Integrating omics techniques and culture-independent systems may improve the detection of persistent candidemia: data from an observational study.

INTRODUCTION: Blood cultures have low sensitivity for candidemia. Sensitivity can be improved by the culture-independent system T2 Magnetic Resonance (T2). SeptiCyte RAPID is a host response assay quantifying the risk of infection-related inflammation through a scoring system (SeptiScore). We investigate the performance of SeptiScore in detecting persistent candidemia as defined by conventional cultures and T2. METHODS: This is a prospective multicentre observational study on patients with candidemia. Blood cultures and blood samples for assessment by T2 and SeptiCyte were collected for 4 consecutive days after the index culture. The performance of SeptiScore was explored to predict persistent candidemia as defined by (1) positive follow-up blood culture (2) either positive follow-up blood culture or T2 sample. RESULTS: 10 patients were enrolled including 34 blood collections assessed with the 3 methods. Overall, 4/34 (12%) follow-up blood cultures and 6/34 (18%) T2 samples were positive. A mixed model showed significantly higher SeptiScores associated with persistent candidemia when this was defined as either a positive follow-up blood culture or T2 sample (0.82, 95%CI 0.06 to 1.58) but not when this was defined as a positive follow-up blood culture only (-0.57, 95%CI -1.28 to 0.14). ROC curve for detection of persistent candidemia by SeptiScore at day 1 follow-up showed an AUC of 0.85 (95%CI 0.52-1.00) when candidemia was defined by positive follow-up blood culture, and an AUC of 1.00 (95%CI 1.00-1.00) when candidemia was defined according to both methods. CONCLUSION: Integrating transcriptome profiling with culture-independent systems and conventional cultures may increase our ability to diagnose persistent candidemia.

Associations between Late Lactate Clearance and Clinical Outcomes in Adults with Hyperlactataemia in the Setting of Diabetic Ketoacidosis.

Objective: This study aimed to determine the associations between lactate clearance in hyperlactataemic patients with diabetic ketoacidosis (DKA) and intensive care unit (ICU), hospital length of stay (LOS), and case-fatality. Methods: A retrospective, multicentre, cohort study of adult patients admitted to ICU with hyperlactataemia and a primary diagnosis of DKA from twelve sites in Queensland, Australia was conducted utilising pre-existing datasets that were linked for research purposes. The patients were divided into early and late lactate clearance groups; the early lactate clearance group included patients whose lactate returned to <2.0 mmol/L within 12 h, and the remainder were classified as late lactate clearance group. Results: The final dataset included 511 patients, 427 in the early lactate clearance group and 84 in the late lactate clearance group. Late lactate clearance was associated with increasing ICU LOS (ß = +15.82, 95% CI +0.05 to +31.59, p < 0.049), increasing hospital LOS (ß = +7.24, 95% CI +0.11 to 14.37, p = 0.048) and increasing Acute Physiology and Chronic Health Evaluation(APACHE) III score (ICU LOS outcome variable ß = +1.05, 95% CI +0.88 to +1.22, p < 0.001; hospital LOS outcome variable ß = +3.40, 95% CI +2.22 to 4.57, p < 0.001). Hospital case-fatality was not significantly different (2.2% in the early clearance group vs. 1.7% in the late clearance group, p = 0.496). Conclusions: In hyperlactataemic patients with DKA, late lactate clearance was associated with a statistically significant increase in both ICU and hospital LOS, though the clinical significance in both is minor.

Presentation, management, and outcomes of older compared to younger adults with hospital-acquired bloodstream infections in the intensive care unit: a multicenter cohort study.

PURPOSE: Older adults admitted to the intensive care unit (ICU) usually have fair baseline functional capacity, yet their age and frailty may compromise their management. We compared the characteristics and management of older (≥ 75 years) versus younger adults hospitalized in ICU with hospital-acquired bloodstream infection (HA-BSI). METHODS: Nested cohort study within the EUROBACT-2 database, a multinational prospective cohort study including adults (≥ 18 years) hospitalized in the ICU during 2019-2021. We compared older versus younger adults in terms of infection characteristics (clinical signs and symptoms, source, and microbiological data), management (imaging, source control, antimicrobial therapy), and outcomes (28-day mortality and hospital discharge). RESULTS: Among 2111 individuals hospitalized in 219 ICUs with HA-BSI, 563 (27%) were ≥ 75 years old. Compared to younger patients, these individuals had higher comorbidity score and lower functional capacity; presented more often with a pulmonary, urinary, or unknown HA-BSI source; and had lower heart rate, blood pressure and temperature at presentation. Pathogens and resistance rates were similar in both groups. Differences in management included mainly lower rates of effective source control achievement among aged individuals. Older adults also had significantly higher day-28 mortality (50% versus 34%, p < 0.001), and lower rates of discharge from hospital (12% versus 20%, p < 0.001) by this time. CONCLUSIONS: Older adults with HA-BSI hospitalized in ICU have different baseline characteristics and source of infection compared to younger patients. Management of older adults differs mainly by lower probability to achieve source control. This should be targeted to improve outcomes among older ICU patients.

Antimicrobial therapeutic drug monitoring in critically ill adult patients - An international perspective on access, utilisation, and barriers.

BACKGROUND: Therapeutic drug monitoring (TDM) is an effective method for individualising antimicrobial therapy in critically ill patients. The 2021 ADMIN-intensive care unit survey studied a wide range of intensive care unit clinicians worldwide to gain their perspectives on antimicrobial TDM. This article reports the responses from this survey relating to TDM access, utilisation, and barriers. METHODS: An online survey consisted of multiple-choice questions and 5-point Likert scales. The survey examined respondent's access to minimum inhibitory concentration (MIC) results, drug assays, and dosing software, as well as barriers to TDM. RESULTS: The survey included 538 clinicians from 409 hospitals in 45 countries, with 71% physicians and 29% pharmacists. Despite most respondents having access to assays, 21% and 26% of respondents lacked access to vancomycin and aminoglycosides, respectively. In lower-income countries, almost 40% reported no access. Delayed drug assay turnaround time was the most significant barrier to TDM, particularly in lower-income countries. Routine access to MIC results was unavailable for 41% of respondents, with 25% of lower-income country respondents having no access to MIC or susceptibility reports. CONCLUSIONS: This global survey indicated that consistent TDM usage is hindered by assay access in some sites and the timeliness of assay results in others. Addressing barriers to TDM, particularly in low-income countries, should be a priority to ensure equitable access to affordable TDM.

Hospital-acquired bloodstream infections in critically ill cirrhotic patients: a post-hoc analysis of the EUROBACT-2 international cohort study.

BACKGROUND: Hospital-acquired bloodstream infections are common in the intensive care unit (ICU) and have a high mortality rate. Patients with cirrhosis are especially susceptible to infections, yet there is a knowledge gap in the epidemiological distinctions in hospital-acquired bloodstream infections between cirrhotic and non-cirrhotic patients in the ICU. It has been suggested that cirrhotic patients, present a trend towards more gram-positive infections, and especially enterococcal infections. This study aims to describe epidemiological differences in hospital-acquired bloodstream infections between cirrhotic and non-cirrhotic patients hospitalized in the ICU regarding infection sources, microorganisms and mortality. METHODS: Using prospective Eurobact-2 international cohort study data, we compared hospital-acquired bloodstream infections sources and microorganisms in cirrhotic and non-cirrhotic patients. The association between Enterococcus faecium and cirrhosis was studied using a multivariable mixed logistic regression. The association between cirrhosis and mortality was assessed by a multivariable frailty Cox model. RESULTS: Among the 1059 hospital-acquired bloodstream infections patients included from 101 centers, 160 had cirrhosis. Hospital-acquired bloodstream infection source in cirrhotic patients was primarily abdominal (35.6%), while it was pulmonary (18.9%) for non-cirrhotic (p < 0.01). Gram-positive hospital-acquired bloodstream infections accounted for 42.3% in cirrhotic patients compared to 33.2% in non-cirrhotic patients (p = 0.02). Hospital-acquired bloodstream infections in cirrhotic patients were most frequently caused by Klebsiella spp (16.5%), coagulase-negative Staphylococci (13.7%) and E. faecium (11.5%). E. faecium bacteremia was more frequent in cirrhotic patients (11.5% versus 4.5%, p < 0.01). After adjusting for possible confounding factors, cirrhosis was associated with higher E. faecium hospital-acquired bloodstream infections risk (Odds ratio 2.5, 95% CI 1.3-4.5, p < 0.01). Cirrhotic patients had increased mortality compared to non-cirrhotic patients (Hazard Ratio 1.3, 95% CI 1.01-1.7, p = 0.045). CONCLUSIONS: Critically ill cirrhotic patients with hospital-acquired bloodstream infections exhibit distinct epidemiology, with more Gram-positive infections and particularly Enterococcus faecium.

Randomised, controlled, feasibility trial comparing vasopressor infusion administered via peripheral cannula versus central venous catheter for critically ill adults: A study protocol.

BACKGROUND: When clinicians need to administer a vasopressor infusion, they are faced with the choice of administration via either peripheral intravenous catheter (PIVC) or central venous catheter (CVC). Vasopressor infusions have traditionally been administered via central venous catheters (CVC) rather than Peripheral Intra Venous Catheters (PIVC), primarily due to concerns of extravasation and resultant tissue injury. This practice is not guided by contemporary randomised controlled trial (RCT) evidence. Observational data suggests safety of vasopressor infusion via PIVC. To address this evidence gap, we have designed the "Vasopressors Infused via Peripheral or Central Access" (VIPCA) RCT. METHODS: The VIPCA trial is a single-centre, feasibility, parallel-group RCT. Eligible critically ill patients requiring a vasopressor infusion will be identified by emergency department (ED) or intensive care unit (ICU) staff and randomised to receive vasopressor infusion via either PIVC or CVC. Primary outcome is feasibility, a composite of recruitment rate, proportion of eligible patients randomised, protocol fidelity, retention and missing data. Primary clinical outcome is days alive and out of hospital up to day-30. Secondary outcomes will include safety and other clinical outcomes, and process and cost measures. Specific aspects of safety related to vasopressor infusions such as extravasation, leakage, device failure, tissue injury and infection will be assessed. DISCUSSION: VIPCA is a feasibility RCT whose outcomes will inform the feasibility and design of a multicentre Phase-3 trial comparing routes of vasopressor delivery. The exploratory economic analysis will provide input data for the full health economic analysis which will accompany any future Phase-3 RCT.

Interventions to improve patient admission and discharge practices in adult intensive care units: A systematic review.

OBJECTIVES: To identify and synthesise interventions and implementation strategies to optimise patient flow, addressing admission delays, discharge delays, and after-hours discharges in adult intensive care units. METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Five electronic databases, including CINAHL, PubMed, Emcare, Scopus, and the Cochrane Library, were searched from 2007 to 2023 to identify articles describing interventions to enhance patient flow practices in adult intensive care units. The Critical Appraisal Skills Program (CASP) tool assessed the methodological quality of the included studies. All data was synthesised using a narrative approach. SETTING: Adult intensive care units. RESULTS: Eight studies met the inclusion criteria, mainly comprising quality improvement projects (n = 3) or before-and-after studies (n = 4). Intervention types included changing workflow processes, introducing decision support tools, publishing quality indicator data, utilising outreach nursing services, and promoting multidisciplinary communication. Various implementation strategies were used, including one-on-one training, in-person knowledge transfer, digital communication, and digital data synthesis and display. Most studies (n = 6) reported a significant improvement in at least one intensive care process-related outcome, although fewer studies specifically reported improvements in admission delays (0/0), discharge delays (1/2), and after-hours discharge (2/4). Two out of six studies reported significant improvements in patient-related outcomes after implementing the intervention. CONCLUSION: Organisational-level strategies, such as protocols and alert systems, were frequently employed to improve patient flow within ICUs, while healthcare professional-level strategies to enhance communication were less commonly used. While most studies improved ICU processes, only half succeeded in significantly reducing discharge delays and/or after-hours discharges, and only a third reported improved patient outcomes, highlighting the need for more effective interventions. IMPLICATIONS FOR CLINICAL PRACTICE: The findings of this review can guide the development of evidence-based, targeted, and tailored interventions aimed at improving patient and organisational outcomes.

The role of centre and country factors on process and outcome indicators in critically ill patients with hospital-acquired bloodstream infections.

PURPOSE: The primary objective of this study was to evaluate the associations between centre/country-based factors and two important process and outcome indicators in patients with hospital-acquired bloodstream infections (HABSI). METHODS: We used data on HABSI from the prospective EUROBACT-2 study to evaluate the associations between centre/country factors on a process or an outcome indicator: adequacy of antimicrobial therapy within the first 24 h or 28-day mortality, respectively. Mixed logistical models with clustering by centre identified factors associated with both indicators. RESULTS: Two thousand two hundred nine patients from two hundred one intensive care units (ICUs) were included in forty-seven countries. Overall, 51% (n = 1128) of patients received an adequate antimicrobial therapy and the 28-day mortality was 38% (n = 839). The availability of therapeutic drug monitoring (TDM) for aminoglycosides everyday [odds ratio (OR) 1.48, 95% confidence interval (CI) 1.03-2.14] or within a few hours (OR 1.79, 95% CI 1.34-2.38), surveillance cultures for multidrug-resistant organism carriage performed weekly (OR 1.45, 95% CI 1.09-1.93), and increasing Human Development Index (HDI) values were associated with adequate antimicrobial therapy. The presence of intermediate care beds (OR 0.63, 95% CI 0.47-0.84), TDM for aminoglycoside available everyday (OR 0.66, 95% CI 0.44-1.00) or within a few hours (OR 0.51, 95% CI 0.37-0.70), 24/7 consultation of clinical pharmacists (OR 0.67, 95% CI 0.47-0.95), percentage of vancomycin-resistant enterococci (VRE) between 10% and 25% in the ICU (OR 1.67, 95% CI 1.00-2.80), and decreasing HDI values were associated with 28-day mortality. CONCLUSION: Centre/country factors should be targeted for future interventions to improve management strategies and outcome of HABSI in ICU patients.

Time in ICU and post-intensive care syndrome: how long is long enough?

BACKGROUND: Our understanding of post-ICU recovery is influenced by which patients are selected to study and treat. Many studies currently list an ICU length of stay of at least 24, 48, or 72 h as an inclusion criterion. This may be driven by established evidence that prolonged time in an ICU bed and prolonged ventilation can complicate post-ICU rehabilitation. However, recovery after short ICU stays still needs to be explored. METHODS: This is a secondary analysis from the tracking outcomes post-intensive care (TOPIC) study. One hundred and thirty-two participants were assessed 6-months post-ICU discharge using standardised and validated self-report tools for physical function, cognitive function, anxiety, depression and post-traumatic stress disorder (with clinically significant impairment on any tool being considered a complicated recovery). Routinely collected data relating to the ICU stay were retrospectively accessed, including length of stay and duration of mechanical ventilation. Patients with short ICU stays were intentionally included, with 77 (58%) participants having an ICU length of stay < 72 h. RESULTS: Of 132 participants, 40 (30%) had at least one identified post-ICU impairment 6 months after leaving ICU, 22 (17%) of whom had an ICU length of stay < 72 h. CONCLUSION: Many patients with an ICU length of stay < 72 h are reporting post-ICU impairment 6 months after leaving ICU. This is a population often excluded from studies and interventions. Future research should further explore post-ICU impairment among shorter stays.

Determinants of 90-day case fatality among older patients admitted to intensive care units: A retrospective cohort study.

BACKGROUND: A recent systematic review identified highly variable case-fatality rates among studies of older patients admitted to intensive care units (ICUs). However, structural and process determinants including patient resident status, tertiary ICU status, and treatment limitations were unavailable. OBJECTIVE: The objective of this study was to evaluate the role of determinants such as resident status, tertiary ICU, and treatment limitations on 90-day case fatality among older ICU patients. METHODS: A retrospective cohort of all Queensland residents aged 75 years and older admitted to four ICUs within the Metro North Hospital and Health Service was included. The impact of Metro North Hospital and Health Service resident status, tertiary ICU, treatment limitations, and other known determinants on 90-day all-cause case fatality (case-fatality) was assessed. RESULTS: Of the 2144 eligible first admissions included, 1365 were residents, and 893 were nonelective admissions. The case-fatality rates were higher in residents (21% vs 12%, p < 0.001), nonelective admissions (32% vs 7%, p < 0.001), and non-tertiary ICU admissions (27% vs 16%, p < 0.001). The case fatality increased progressively with age, being highest (29.6%) in the >90 years age-group. Multivariable mixedeffects logistic regression modelling demonstrated that presence of treatment limitations was strongly associated with case fatality, but neither resident status nor the tertiary ICU was associated. CONCLUSION: The presence of treatment limitations should be considered when evaluating variations in case fatality among cohorts of older ICU patients, in addition to variables with well-established association with case fatality such as comorbidities and illness severity.

Persistence of Detectable Pathogens by Culture-Independent Systems (T2 Magnetic Resonance) in Patients With Bloodstream Infection: Prognostic Role and Possible Clinical Implications.

BACKGROUND: Persistent Staphylococcus aureus bacteremia is associated with metastatic infection and adverse outcomes, whereas gram-negative bacteremia is normally transient and shorter course therapy is increasingly advocated for affected patients. Whether the prolonged detection of pathogen DNA in blood by culture-independent systems could have prognostic value and guide management decisions is unknown. METHODS: We performed a multicenter, prospective, observational study on 102 patients with bloodstream infection (BSI) to compare time to bloodstream clearance according to T2 magnetic resonance and blood cultures over a 4-day follow-up. We also explored the association between duration of detectable pathogens according to T2 magnetic resonance (magnetic resonance-DNAemia [MR-DNAemia]) and clinical outcomes. RESULTS: Time to bloodstream clearance according to T2 magnetic resonance was significantly longer than blood culture clearance (HR, .54; 95% CI, .39-.75) and did not differ according to the causative pathogen (P = .5). Each additional day of MR-DNAemia increased the odds of persistent infection (defined as metastatic infection or delayed source control) both in the overall population (OR, 1.98; 95% CI, 1.45-2.70) and in S. aureus (OR, 1.92; 95% CI, 1.12-3.29) and gram-negative bacteremia (OR, 2.21; 95% CI, 1.35-3.60). MR-DNAemia duration was also associated with no improvement in Sequential Organ Failure Assessment score at day 7 from infection onset (OR, 1.76; 95% CI, 1.21-2.56). CONCLUSIONS: T2 magnetic resonance may help diagnose BSI in patients on antimicrobials with negative blood cultures as well as to identify patients with metastatic infection, source control failure, or adverse short-term outcome. Future studies may inform its usefulness within the setting of antimicrobial stewardship programs.

Host response signature trends in persistent bacteraemia and metastatic infection due to Staphylococcus aureus and Gram-negative bacilli: a prospective multicentre observational study.

BACKGROUND: A prompt diagnosis of bacteraemia and sepsis is essential. Markers to predict the risk of persistent bacteraemia and metastatic infection are lacking. SeptiCyte RAPID is a host response assay stratifying patients according to the risk of infectious vs sterile inflammation through a scoring system (SeptiScore). In this study we explore the association between SeptiScore and persistent bacteraemia as well as metastatic and persistent infection in the context of a proven bacteraemia episode. METHODS: This is a prospective multicentre observational 14-month study on patients with proven bacteraemia caused by Staphylococcus aureus or Gram-negative bacilli. Samples for assessment by SeptiCyte were collected with paired blood cultures for 4 consecutive days after the index blood culture. RESULTS: We included 86 patients in the study, 40 with S. aureus and 46 with Gram-negative bacilli bacteraemia. SeptiScores over the follow-up were higher in patients with Gram-negative compared to S. aureus bacteraemia (median 6.4, IQR 5.5-7.4 vs 5.6 IQR 5.1-6.2, p = 0.002). Higher SeptiScores were found to be associated with positive blood cultures at follow-up (AUC = 0.86, 95%CI 0.68-1.00) and with a diagnosis of metastatic infection at day 1 and 2 of follow-up (AUC = 0.79, 95%CI 0.57-1.00 and AUC = 0.82, 95%CI 0.63-1.00 respectively) in the context of Gram-negative bacteraemia while no association between SeptiScore and the outcomes of interest was observed in S. aureus bacteraemia. Mixed models confirmed the association of SeptiScore with positive blood cultures at follow-up (p = 0.04) and metastatic infection (p = 0.03) in the context of Gram-negative bacteraemia but not S. aureus bacteraemia after adjusting for confounders. CONCLUSIONS: SeptiScores differ in the follow-up of S. aureus and Gram-negative bacteraemia. In the setting of Gram-negative bacteraemia SeptiScore demonstrated a good negative predictive value for the outcomes of interest and might help rule out the persistence of infection defined as metastatic spread, lack of source control or persistent bacteraemia.