A comprehensive, predictive mortality score for patients with bloodstream infections (PROBAC): a prospective, multicentre cohort study.

OBJECTIVES: Bloodstream infections (BSI) are an important cause of mortality, although they show heterogeneity depending on patients and aetiological factors. Comprehensive and specific mortality scores for BSI are scarce. The objective of this study was to develop a mortality predictive score in BSI based on a multicentre prospective cohort. METHODS: A prospective cohort including consecutive adults with bacteraemia recruited between October 2016 and March 2017 in 26 Spanish hospitals was randomly divided into a derivation cohort (DC) and a validation cohort (VC). The outcome was all-cause 30-day mortality. Predictors were assessed the day of blood culture growth. A logistic regression model and score were developed in the DC for mortality predictors; the model was applied to the VC. RESULTS: Overall, 4102 patients formed the DC and 2009 the VC. Mortality was 11.8% in the DC and 12.34% in the CV; the patients and aetiological features were similar for both cohorts. The mortality predictors selected in the final multivariate model in the DC were age, cancer, liver cirrhosis, fatal McCabe underlying condition, polymicrobial bacteraemia, high-risk aetiologies, high-risk source of infection, recent use of broad-spectrum antibiotics, stupor or coma, mean blood pressure <70 mmHg and PaO2/FiO2 ≤ 300 or equivalent. Mortality in the DC was <2% for ≤2 points, 6%-14% for 3-7 points, 26%-45% for 8-12 points and ≥60% for ≥13 points. The predictive score had areas under the receiving operating curves of 0.81 (95% CI 0.79-0.83) in the DC and 0.80 (0.78-0.83) in the VC. CONCLUSIONS: A 30 day mortality predictive score in BSI with good discrimination ability was developed and internally validated.

Differences in clinical outcomes of bloodstream infections caused by Klebsiella aerogenes, Klebsiella pneumoniae and Enterobacter cloacae: a multicentre cohort study.

BACKGROUND: Klebsiella aerogenes has been reclassified from Enterobacter to Klebsiella genus due to its phenotypic and genotypic similarities with Klebsiella pneumoniae. It is unclear if clinical outcomes are also more similar. This study aims to assess clinical outcomes of bloodstreams infections (BSI) caused by K. aerogenes, K. pneumoniae and Enterobacter cloacae, through secondary data analysis, nested in PRO-BAC cohort study. METHODS: Hospitalized patients between October 2016 and March 2017 with monomicrobial BSI due to K. aerogenes, K. pneumoniae or E. cloacae were included. Primary outcome was a composite clinical outcome including all-cause mortality or recurrence until 30 days follow-up. Secondary outcomes were fever ≥ 72 h, persistent bacteraemia, and secondary device infection. Multilevel mixed-effect Poisson regression was used to estimate the association between microorganisms and outcome. RESULTS: Overall, 29 K. aerogenes, 77 E. cloacae and 337 K. pneumoniae BSI episodes were included. Mortality or recurrence was less frequent in K. aerogenes (6.9%) than in E. cloacae (20.8%) or K. pneumoniae (19.0%), but statistical difference was not observed (rate ratio (RR) 0.35, 95% CI 0.08 to 1.55; RR 0.42, 95% CI 0.10 to 1.71, respectively). Fever ≥ 72 h and device infection were more common in K. aerogenes group. In the multivariate analysis, adjusted for confounders (age, sex, BSI source, hospital ward, Charlson score and active antibiotic therapy), the estimates and direction of effect were similar to crude results. CONCLUSIONS: Results suggest that BSI caused by K. aerogenes may have a better prognosis than E. cloacae or K. pneumoniae BSI.

Clostridium paraputrificum bacteremia in a 64-year-old woman with colon carcinoma.

Here we report a case of bacteremia caused by Clostridium paraputrificum in a 64-year-old woman with colon carcinoma and gastrointestinal disease. Using the new EUCAST 2022 clinical breakpoints for Clostridium perfringens, the isolate was susceptible to metronidazole and vancomycin, but resistant to benzylpenicillin, meropenem, and clindamycin. Thus, treatment with metronidazole should be considered in all patients with Clostridium bacteremia until antibiotic susceptibility is determined to minimize the risk of treatment failure.

Clinical Course of Migraine during Strict Quarantine due to SARS-CoV-2: Effect of Psychiatric Comorbidities in a Clinical Cohort.

OBJECTIVE: During the SARS-CoV-2 pandemic, there has been a significant increase in the prevalence of anxiety and depression. This study sought to establish the probability of migraine progression by comparing data from week 0 with week 12 of quarantine. METHODS: A retrospective cohort study. Three hundred ten patients were included, 238 with episodic migraine and 33 with chronic migraine; they all completed a self-administered questionnaire with demographic, clinical, and psychiatric symptom information. A multivariate statistical analysis was conducted to identify factors associated with the progression of migraine. RESULTS: This study demonstrated a 22.5% progression probability from episodic migraine to chronic migraine with an RR 2.7 and CI (1.92-3.95, p < 0.001). The increase in depression scores (p < 0.005), anxiety (p < 0.001), and alteration in sleep quality (p < 0.003) were associated with the worsening of migraine. CONCLUSION: During the SARS-CoV-2 pandemic, depression, anxiety, and the deterioration of sleep quality influenced the probability of progression from episodic migraine to chronic migraine.

New strategies to optimize renal haemodynamics.

PURPOSE OF REVIEW: This review discusses the macrocirculatory and microcirculatory aspects of renal perfusion, as well as novel methods by which to measure renal blood flow. Finally, therapeutic options are briefly discussed, including renal-specific microcirculatory effects. RECENT FINDINGS: The optimal mean arterial pressure (MAP) needed for preservation of renal function has been debated but is most likely a MAP of 60-80 mmHg. In addition, attention should be paid to renal outflow pressure, typically central venous pressure. Heterogeneity in microcirculation can exist and may be mitigated through appropriate use of vasopressors with unique microcirculatory effects. Excessive catecholamines have been shown to be harmful and should be avoided. Both angiotensin II and vasopressin may improve glomerular flow through a number of mechanisms. Macrocirculatory and microcirculatory blood flow can be measured through a number of bedside ultrasound modalities, sublingual microscopy and urinary oxygen measurement, SUMMARY: Acute kidney injury (AKI) is a common manifestation of organ failure in shock, and avoidance of hemodynamic instability can mitigate this risk. Measurement of renal haemodynamics is not routinely performed but may help to guide therapeutic goals. A thorough understanding of pathophysiology, measurement techniques and therapeutic options may allow for a personalized approach to blood pressure management in patients with septic shock and may ultimately mitigate AKI.

Racial Disparities in Nephrology Consultation and Disease Progression among Veterans with CKD: An Observational Cohort Study.

BACKGROUND: Incident rates of ESRD are much higher among black and Hispanic patients than white patients. Access to nephrology care before progression to ESRD is associated with better clinical outcomes among patients with CKD. However, it is unknown whether black or Hispanic patients with CKD experience lower pre-ESRD nephrology consultation rates compared with their white counterparts, or whether such a disparity contributes to worse outcomes among minorities. METHODS: We assembled a retrospective cohort of patients with CKD who received care through the Veterans Health Administration from 2003 to 2015, focusing on individuals with incident CKD stage 4 who had an initial eGFR≥60 ml/min per 1.73 m2 followed by two consecutive eGFRs<30 ml/min per 1.73 m2. We repeated analyses among individuals with incident CKD stage 3. Outcomes included nephrology provider referral, nephrology provider visit, progression to CKD stage 5, and mortality. RESULTS: We identified 56,767 veterans with CKD stage 4 and 640,704 with CKD stage 3. In both cohorts, rates of nephrology referral and visits were significantly higher among black and Hispanic veterans than among non-Hispanic white veterans. Despite this, both black and Hispanic patients experienced faster progression to CKD stage 5 compared with white patients. Black patients with CKD stage 4 experienced slightly lower mortality than white patients, whereas black patients with CKD stage 3 had a small increased risk of death. CONCLUSIONS: Black or Hispanic veterans with CKD are more likely than white patients to see a nephrologist, yet are also more likely to suffer disease progression. Biologic and environmental factors may play a bigger role than nephrology consultation in driving racial disparities in CKD progression.

Auritidibacter ignavus in ear discharge of paediatric patients: Two cases reports and literature review.

INTRODUCTION: The development and research of new technologies for identifying microorganisms, has allowed the identification of hitherto unknown bacteria. Auritidibacter ignavus is a newly described Gram-positive rod possibly associated with otitis, although its role as an etiologic agent in otitis is currently controversial. METHODS: We report two cases of recurrent otitis in paediatric patients in which A. ignavus was isolated and review the previous cases reported in the literature. RESULTS: All the isolates were identified as A. ignavus by proteomic and genomic methods. Both patients recovered from their symptoms. CONCLUSION: A. ignavus was recovered from ear discharges of paedriatic patients with chronic ear problems. All the cases previously reported in the literature were adults. More evidence is needed for the association between A. ignavus and otitis, since data regarding this species are still scarce.

Association of microbiological factors with mortality in Escherichia coli bacteraemia presenting with sepsis/septic shock: a prospective cohort study.

OBJECTIVES: This study aimed to determine the association of Escherichia coli microbiological factors with 30-day mortality in patients with bloodstream infection (BSI) presenting with a dysregulated response to infection (i.e. sepsis or septic shock). METHODS: Whole-genome sequencing was performed on 224 E coli isolates of patients with sepsis/septic shock, from 22 Spanish hospitals. Phylogroup, sequence type, virulence, antibiotic resistance, and pathogenicity islands were assessed. A multivariable model for 30-day mortality including clinical and epidemiological variables was built, to which microbiological variables were hierarchically added. The predictive capacity of the models was estimated by the area under the receiver operating characteristic curve (AUROC) with 95% confidence intervals (CI). RESULTS: Mortality at day 30 was 31% (69 patients). The clinical model for mortality included (adjusted OR; 95% CI) age (1.04; 1.02-1.07), Charlson index ≥3 (1.78; 0.95-3.32), urinary BSI source (0.30; 0.16-0.57), and active empirical treatment (0.36; 0.11-1.14) with an AUROC of 0.73 (95% CI, 0.67-0.80). Addition of microbiological factors selected clone ST95 (3.64; 0.94-14.04), eilA gene (2.62; 1.14-6.02), and astA gene (2.39; 0.87-6.59) as associated with mortality, with an AUROC of 0.76 (0.69-0.82). DISCUSSION: Despite having a modest overall contribution, some microbiological factors were associated with increased odds of death and deserve to be studied as potential therapeutic or preventive targets.

Whole-genome characterisation of Escherichia coli isolates from patients with bacteraemia presenting with sepsis or septic shock in Spain: a multicentre cross-sectional study.

BACKGROUND: Escherichia coli is the most frequent cause of bloodstream infections (BSIs). About one-third of patients with BSIs due to E coli develop sepsis or shock. The objective of this study is to characterise the microbiological features of E coli blood isolates causing sepsis or septic shock to provide exploratory information for future diagnostic, preventive, or therapeutic interventions. METHODS: E coli blood isolates from a multicentre cross-sectional study of patients older than 14 years presenting with sepsis or septic shock (according to the Third International Consensus Definitions for Sepsis and Septic Shock criteria) from hospitals in Spain between Oct 4, 2016, and Oct 15, 2017, were studied by whole-genome sequencing. Phylogroups, sequence types (STs), serotype, FimH types, antimicrobial resistance (AMR) genes, pathogenicity islands, and virulence factors were identified. Susceptibility testing was performed by broth microdilution. The main outcome of this study was the characterisation of the E coli blood isolates in terms of population structure by phylogroups, groups (group 1: phylogroups B2, F, and G; group 2: A, B1, and C; group 3: D), and STs and distribution by geographical location and bloodstream infection source. Other outcomes were virulence score and prevalence of virulence-associated genes, pathogenicity islands, AMR, and AMR-associated genes. Frequencies were compared using χ² or Fisher's exact tests, and continuous variables using the Mann-Whitney test, with Bonferroni correction for multiple comparisons. FINDINGS: We analysed 224 isolates: 140 isolates (63%) were included in phylogenetic group 1, 52 (23%) in group 2, and 32 (14%) in group 3. 85 STs were identified, with four comprising 44% (n=98) of the isolates: ST131 (38 [17%]), ST73 (25 [11%]), ST69 (23 [10%]), and ST95 (12 [5%]). No significant differences in phylogroup or ST distribution were found according to geographical areas or source of bloodstream infection, except for ST95, which was more frequent in urinary tract infections than in other sources (11 [9%] of 116 vs 1 [1%] of 108, p=0·0045). Median virulence score was higher in group 1 (median 25·0 [IQR 20·5-29·0) than in group 2 (median 14·5 [9·0-20·0]; p<0·0001) and group 3 (median 21 [16·5-23·0]; p<0·0001); prevalence of several pathogenicity islands was higher in group 1. No significant differences were found between phylogenetic groups in proportions of resistance to antibiotics. ST73 had higher median virulence score (32 [IQR 29-35]) than the other predominant clones (median range 21-28). Some virulence genes and pathogenicity islands were significantly associated with each ST. ST131 isolates had higher prevalence of AMR and a higher proportion of AMR genes, notably blaCTX-M-15 and blaOXA-1. INTERPRETATION: In this exploratory study, the population structure of E coli causing sepsis or shock was similar to previous studies that included all bacteraemic isolates. Virulence genes, pathogenicity islands, and AMR genes were not randomly distributed among phylogroups or STs. These results provide a comprehensive characterisation of invasive E coli isolates causing severe response syndrome. Future studies are required to determine the contribution of these microbiological factors to severe clinical presentation and worse outcomes in patients with E coli bloodstream infection. FUNDING: Instituto de Salud Carlos III.

A Pilot Study Examining the Use of Ultrasound to Measure Intravascular Volume Status in Agricultural Workers in a Field-Based Research Setting.

OBJECTIVE: The aim of this pilot study was to explore if internal jugular vein (IJV) ultrasound studies on agricultural workers in a field-based research setting could assess volume status during a hydration intervention. METHODS: We performed pre- and post-work shift IJV ultrasound images on 30 agricultural workers. The IJV collapsibility index values were <39% (euvolemic) or ≥39% (hypovolemic). RESULTS: Of the water group, 13% (2/15) had an IJV collapsibility index ≥39%, and this increased to 19% (3/16) by the end of the work shifts. The electrolyte group did not have any workers start the work shift with an IJV collapsibility index ≥39%; however, at the postshift assessment, 15% (2/13) were hypovolemic. CONCLUSION: Internal jugular vein ultrasounds may have the potential to be a useful tool to determine volume status in field-based research settings. Further investigation is needed to confirm these findings.

Q fever, a rare cause of secondary hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome in which Coxiella burnetii is a very infrequent etiology. We present the case of a 62-year-old male with progressive pulmonary infiltrates, fever, hepatitis, and bicytopenia despite broad spectrum antibiotics. A thorough clinical evaluation led to a high suspicion of Coxiella burnetii infection, subsequently confirmed through a positive serum polymerase chain reaction (PCR) analysis. HLH diagnosis was established based on the fulfillment of 5/8 diagnostic criteria, obviating the need for a bone marrow biopsy. Targeted antibiotic treatment and dexamethasone led to full recovery within two weeks, eliminating the need for stronger immunosuppressive therapy.

Clinical and Microbiological Risk Factors for 30-Day Mortality of Bloodstream Infections Caused by OXA-48-Producing Klebsiella pneumoniae.

Bloodstream infections (BSI) caused by carbapenem-resistant Klebsiella pneumoniae are associated with high morbidity and mortality, and the therapy options available for their treatment are frequently scarce. The aim of this study was to analyze risk factors for 30-day mortality in patients with BSI caused by OXA-48-producing K. pneumoniae. The clinical and treatment features of the patients, who attended a single hospital over a five-year period, were retrospectively reviewed. The microbiological features, including the sequence types (ST) and the somatic (O) and capsular (K) antigens, as well as their resistance properties, comprising phenotypes and genetic background, were also considered. To identify the risk factors for 30-day mortality, uni- and multivariate statistical analyses were performed. The univariate analysis revealed statistically significant correlations for age, male gender, lower respiratory system infection, infection by ST147 isolates, and infection by isolates expressing the K64 antigen. The multivariate analysis, applied to variables yielding p-values close to or lower than 0.05 in the univariate analysis, confirmed gender, lower respiratory system infection, and infection with ST147 isolates, but not age or infection with K64 isolates, as risk factors for 30-day mortality. Moreover, the multivariate analysis showed that patients suffering from hematological malignancies or having been treated with inappropriate therapy, both having p-values slightly higher than 0.05 in the univariate analysis, exhibited significantly poorer outcomes in the multivariant analysis. The association of the ST147 clone with an increased risk of mortality is a novel finding that deserves further attention. Studies like the one presented here can certainly benefit the management of patients with nosocomial BSI caused by carbapenemase-producing K. pneumoniae.

Clinical Utility of the FilmArray® Blood Culture Identification (BCID) Panel for the Diagnosis of Neonatal Sepsis.

This prospective single-center study was designed to assess the clinical utility of the FilmArray® blood culture identification (BCID) panel for improving the diagnostic accuracy in neonatal sepsis. Results obtained using the FilmArray® BCID panel were correlated with results of blood culture in all consecutive neonates with suspicion of early-onset (EOS) and late-onset sepsis (LOS) attended in our service over a two-year period. A total of 102 blood cultures from 92 neonates were included, 69 (67.5%) in cases of EOS and 33 (32.3%) in LOS. The FilmArray® BCID panel was performed in negative culture bottles at a median of 10 h of blood culture incubation (IQR 8-20), without differences by the type of sepsis. The FilmArray® BCID panel showed a 66.7% sensitivity, 100% specificity, 100% positive predictive value, and 95.7% negative predictive value. There were four false-negative cases, three of which were Streptococcus epidermidis in neonates with LOS, and there was one case of Granulicatella adiacens in one neonate with EOS. We conclude that the use of the FilmArray® BCID panel in negative blood cultures from neonates with clinical suspicion of sepsis is useful in decision-making of starting or early withdrawal of empirical antimicrobials because of the high specificity and negative predictive values of this assay.

Conventional Hospitalization versus Sequential Outpatient Parenteral Antibiotic Therapy for Staphylococcus aureus Bacteremia: Post-Hoc Analysis of a Multicenter Observational Cohort.

It is not known whether sequential outpatient parenteral antimicrobial (OPAT) is as safe and effective as conventional hospitalization in patients with S. aureus bacteremia (SAB). A post-hoc analysis of the comparative effectiveness of conventional hospitalization versus sequential OPAT was performed in two prospective Spanish cohorts of patients with S. aureus bacteremia. The PROBAC cohort is a national, multicenter, prospective observational cohort of patients diagnosed in 22 Spanish hospitals between October 2016 and March 2017. The DOMUS OPAT cohort is a prospective observational cohort including patients from two university hospitals in Seville, Spain from 2012 to 2021. Multivariate regression was performed, including a propensity score (PS) for receiving OPAT, stratified analysis according to PS quartiles, and matched pair analyses based on PS. Four hundred and thirteen patients were included in the analysis: 150 in sequential OPAT and 263 in the full hospitalization therapy group. In multivariate analysis, including PS and center effect as covariates, 60-day treatment failure was lower in the OPAT group than in the full hospitalization group (p < 0.001; OR 0.275, 95%CI 0.129−0.584). In the PS-based matched analyses, sequential treatment under OPAT was not associated with higher 60-day treatment failure (p = 0.253; adjusted OR 0.660; % CI 0.324−1.345). OPAT is a safe and effective alternative to conventional in-patient therapy for completion of treatment in well-selected patients with SAB, mainly those associated with a low-risk source and without end-stage kidney disease.

POCUS in Intensive Care Nephrology.

Acute kidney injury (AKI) is a significant problem for patients admitted to the intensive care unit (ICU), both due to the high incidence and associated mortality with rates of AKI requiring renal replacement therapy (RRT) of over 5%, and mortality rates with AKI of over 60% 1, 2.Ultrasound can be used to identify those at risk for AKI and assist with AKI management. Risk factors for AKI in the ICU not only include hypoperfusion but also venous congestion and volume overload. Volume overload and vascular congestion are associated with multi-organ dysfunction and worse renal outcomes. Daily and overall fluid balance, daily weights, and physical examination for edema can be inaccurate and belie true systemic venous pressure 3, 4, 5. Bedside ultrasound allows providers to evaluate vascular flow patterns and obtain a more reliable evaluation of volume status to guide and individualize therapies. Cardiac, lung, and vascular patterns on ultrasound can identify preload responsiveness, which should be assessed to safely manage ongoing fluid resuscitation and assess for signs of fluid intolerance. Here we present an overview in the use of point of care ultrasound with particular emphasis on nephro-centric strategies, namely in the identification of the type of renal injury, renal vascular flow assessment, the static measure of volume status, as well as dynamic evaluation for volume optimization in critically ill patients.

Hydration Interventions Among Agricultural Workers: A Pilot Study.

OBJECTIVE: To estimate the impact of hydration interventions on postworkday hydration status and incidence of acute kidney injury (AKI). METHODS: Thirty agricultural workers were first monitored on a workday without any interventions. On the intervention workday, the same workers were randomized to one of two groups: 169 ounces (oz) (5 L) of plain water (n = 16) or 169 oz (5L) of water with electrolytes (n = 14). RESULTS: No participants in the electrolyte group had an estimate glomerular filtration rate (eGFR) at the end of the workday of less than 90 mL/min/1.73 m2 or met the criteria for AKI in comparison to the water group (eGFR < 90: 15%; AKI: 23%) or the control group (eGFR < 90: 28%; AKI: 18%). CONCLUSION: The study showed that drinking water with electrolytes may lower the risk for development of AKI among agricultural workers.

Ureaplasma parvum Septic Arthritis, a Clinic Challenge.

Ureaplasma parvum is usually part of the normal genital microbiota. Rarely, it can cause invasive infections such as septic arthritis or meningitis. A case of a 74-year-old woman with follicular lymphoma who developed cellulitis followed by elbow arthritis with negative routine bacterial cultures is described. U. parvum was identified in the synovial fluid using a broad-range 16S ribosomal RNA gene polymerase chain reaction (PCR) and also in vaginal fluid by a targeted PCR (Anyplex™ II STI-7). Multilocus Sequence Typing (MLST) revealed that isolates from both sources belonged to ST4, a worldwide distributed clone. Treatment consisted of surgery and targeted antibiotic therapy with doxycycline and azithromycin. Evolution showed initial clinical improvement in arthritis despite functional sequelae. Ureaplasma arthritis should be considered as a rare cause of arthritis in negative culture, especially in immunosuppressed patients. In these cases, the treatment is not well established, but according to this and previous works, patients could improve with doxycycline, azithromycin or fluoroquinolone therapy on a prolonged basis.

Evaluation and Clinical Impact of Biofire FilmArray Pneumonia Panel Plus in ICU-Hospitalized COVID-19 Patients.

Microbiological diagnosis by using commercial multiplex quantitative PCR systems provides great advantages over the conventional culture. In this work, the Biofire FilmArray Pneumonia Panel Plus (FAPP+) was used to test 144 low respiratory tract samples from 105 COVID-19 patients admitted to an Intensive Care Unit (ICU), detecting 78 pathogens in 59 (41%) samples. The molecular panel was evaluated by using the conventional culture (CC) as comparator, which isolated 42 pathogens in 40 (27.7%) samples. The overall percentage of agreement was 82.6%. Values of sensitivity (93%), specificity (62%), positive predictive value (50%), and negative predictive value (96%) were obtained. The mean time elapsed from sample extraction to modification of antibiotic treatment was 7.6 h. A change in antimicrobial treatment after the FAPP+ results was performed in 27% of patients. The FAPP+ is a highly sensitive diagnostic method that can be used to significantly reduce diagnostic time and that allows an early optimization of antimicrobial treatment.

Pseudomonas aeruginosa Community-Onset Bloodstream Infections: Characterization, Diagnostic Predictors, and Predictive Score Development-Results from the PRO-BAC Cohort.

Community-onset bloodstream infections (CO-BSI) caused by gram-negative bacilli are common and associated with significant mortality; those caused by Pseudomonas aeruginosa are associated with worse prognosis and higher rates of inadequateempirical antibiotic treatment. The aims of this study were to describe the characteristics of patients with CO-BSI caused by P. aeruginosa, to identify predictors, and to develop a predictive score for P. aeruginosa CO-BSI. Materials/methods: PROBAC is a prospective cohort including patients >14 years with BSI from 26 Spanish hospitals between October 2016 and May 2017. Patients with monomicrobial P. aeruginosa CO-BSI and monomicrobial Enterobacterales CO-BSI were included. Variables of interest were collected. Independent predictors of Pseudomonas aeruginosa CO-BSI were identified by logistic regression and a prediction score was developed. Results: A total of 78patients with P. aeruginosa CO-BSI and 2572 with Enterobacterales CO-BSI were included. Patients with P. aeruginosa had a median age of 70 years (IQR 60−79), 68.8% were male, median Charlson score was 5 (IQR 3−7), and 30-daymortality was 18.5%. Multivariate analysis identified the following predictors of CO-BSI-PA [adjusted OR (95% CI)]: male gender [1.89 (1.14−3.12)], haematological malignancy [2.45 (1.20−4.99)], obstructive uropathy [2.86 (1.13−3.02)], source of infection other than urinary tract, biliary tract or intra-abdominal [6.69 (4.10−10.92)] and healthcare-associated BSI [1.85 (1.13−3.02)]. Anindex predictive of CO-BSI-PA was developed; scores ≥ 3.5 showed a negative predictive value of 89% and an area under the receiver operator curve (ROC) of 0.66. Conclusions: We did not find a good predictive score of P. aeruginosa CO-BSI due to its relatively low incidence in the overall population. Our model includes variables that are easy to collect in real clinical practice and could be useful to detect patients with very low risk of P. aeruginosa CO-BSI.