A Change in Nosocomial Infections among Surgical ICU Patients in the COVID-19 Era and MALDI-TOF Mass Spectrometry-A Cross-Sectional Study.

During the COVID-19 pandemic, changes occurred within the surgical patient population. An increase in the frequency of resistant Gram-negative bacteria has since been recorded worldwide. After the start of the COVID-19 pandemic, microbiological diagnostics in our institution was performed using MALDI-TOF mass spectrometry. With this study, we wanted to confirm whether it contributed to a greater number of pathogenic bacteria detected in surgical ICU patients. A total of 15,033 samples taken from 1781 surgical patients were compared during the period from 2016 to February 2020 and during the COVID-19 pandemic from March 2020 to February 2023. On patients' admission, pathogenic bacteria were mostly isolated from the respiratory system (43.1% and 44.9%), followed by urine cultures (18.4 vs. 15.4%) before and during the pandemic. After the onset of the COVID-19 pandemic, there was a significant increase in the frequency of isolation of Enterobacter spp. (5.4 before vs. 9%, p = 0.014) and other enterobacteria (6.9 vs. 10.8%, p = 0.017) on patients' admission to the ICU, respectively. Despite this change, mortality in the ICU during the post-COVID-19 period was reduced from 23 to 9.6% (p < 0.001). The frequency of bacterial isolation did not change with the application of MALDI-TOF technology. By identifying the microorganism while simultaneously recognizing some resistance genes, we were able to start targeted therapy earlier. With the application of other infection control methods, MALDI-TOF may have contributed to the reduction in mortality in surgical ICU patients during the COVID-19 pandemic.

Interpretation of results of PCR and B-D-glucan for the diagnosis of Pneumocystis Jirovecii Pneumonia in immunocompromised adults with acute respiratory failure.

BACKGROUND: The accuracy of a diagnostic test depends on its intrinsic characteristics and the disease incidence. This study aims to depict post-test probability of Pneumocystis pneumonia (PJP), according to results of PCR and Beta-D-Glucan (BDG) tests in patients with acute respiratory failure (ARF). MATERIALS AND METHODS: Diagnostic performance of PCR and BDG was extracted from literature. Incidence of Pneumocystis pneumonia was assessed in a dataset of 2243 non-HIV immunocompromised patients with ARF. Incidence of Pneumocystis pneumonia was simulated assuming a normal distribution in 5000 random incidence samples. Post-test probability was assessed using Bayes theorem. RESULTS: Incidence of PJP in non-HIV ARF patients was 4.1% (95%CI 3.3-5). Supervised classification identified 4 subgroups of interest with incidence ranging from 2.0% (No ground glass opacities; 95%CI 1.4-2.8) to 20.2% (hematopoietic cell transplantation, ground glass opacities and no PJP prophylaxis; 95%CI 14.1-27.7). In the overall population, positive post-test probability was 32.9% (95%CI 31.1-34.8) and 22.8% (95%CI 21.5-24.3) for PCR and BDG, respectively. Negative post-test probability of being infected was 0.10% (95%CI 0.09-0.11) and 0.23% (95%CI 0.21-0.25) for PCR and BDG, respectively. In the highest risk subgroup, positive predictive value was 74.5% (95%CI 72.0-76.7) and 63.8% (95%CI 60.8-65.8) for PCR and BDG, respectively. CONCLUSION: Although both tests yield a high intrinsic performance, the low incidence of PJP in this cohort resulted in a low positive post-test probability. We propose a method to illustrate pre and post-test probability relationship that may improve clinician perception of diagnostic test performance according to disease incidence in predefined clinical settings.

Intra-abdominal infection and sepsis in immunocompromised intensive care unit patients: Disease expression, microbial aetiology, and clinical outcomes.

We compared epidemiology of intra-abdominal infection (IAI) between immunocompromised and non-immunocompromised ICU patients and identified risk factors for mortality. We performed a secondary analysis on the "AbSeS" database, a prospective, observational study with IAI patients from 309 ICUs in 42 countries. Immunocompromised status was defined as either neutropenia or prolonged corticosteroids use, chemotherapy or radiotherapy in the past year, bone marrow or solid organ transplantation, congenital immunodeficiency, or immunosuppressive drugs use. Mortality was defined as ICU mortality at any time or 28-day mortality for those discharged earlier. Associations with mortality were assessed by logistic regression. The cohort included 2589 patients of which 239 immunocompromised (9.2 %), most with secondary peritonitis. Among immunocompromised patients, biliary tract infections were less frequent, typhlitis more frequent, and IAIs were more frequently healthcare-associated or early-onset hospital-acquired compared with immunocompetent patients. No difference existed in grade of anatomical disruption, disease severity, organ failure, pathogens, and resistance patterns. Septic shock was significantly more frequent in the immunocompromised population. Mortality was similar in both groups (31.1% vs. 28.9 %; p = 0.468). Immunocompromise was not a risk factor for mortality (OR 0.98, 95 % CI 0.66-1.43). Independent risk factors for mortality among immunocompromised patients included septic shock at presentation (OR 6.64, 95 % CI 1.27-55.72), and unsuccessful source control with persistent inflammation (OR 5.48, 95 % CI 2.29-12.57). In immunocompromised ICU patients with IAI, short-term mortality was similar to immunocompetent patients, despite the former presented more frequently with septic shock, and septic shock and persistent inflammation after source control were independent risk factors for death.

Intra-abdominal infections survival guide: a position statement by the Global Alliance For Infections In Surgery.

Intra-abdominal infections (IAIs) are an important cause of morbidity and mortality in hospital settings worldwide. The cornerstones of IAI management include rapid, accurate diagnostics; timely, adequate source control; appropriate, short-duration antimicrobial therapy administered according to the principles of pharmacokinetics/pharmacodynamics and antimicrobial stewardship; and hemodynamic and organ functional support with intravenous fluid and adjunctive vasopressor agents for critical illness (sepsis/organ dysfunction or septic shock after correction of hypovolemia). In patients with IAIs, a personalized approach is crucial to optimize outcomes and should be based on multiple aspects that require careful clinical assessment. The anatomic extent of infection, the presumed pathogens involved and risk factors for antimicrobial resistance, the origin and extent of the infection, the patient's clinical condition, and the host's immune status should be assessed continuously to optimize the management of patients with complicated IAIs.

Characteristics and outcomes of COVID-19 patients admitted to hospital with and without respiratory symptoms.

Background: COVID-19 is primarily known as a respiratory illness; however, many patients present to hospital without respiratory symptoms. The association between non-respiratory presentations of COVID-19 and outcomes remains unclear. We investigated risk factors and clinical outcomes in patients with no respiratory symptoms (NRS) and respiratory symptoms (RS) at hospital admission. Methods: This study describes clinical features, physiological parameters, and outcomes of hospitalised COVID-19 patients, stratified by the presence or absence of respiratory symptoms at hospital admission. RS patients had one or more of: cough, shortness of breath, sore throat, runny nose or wheezing; while NRS patients did not. Results: Of 178,640 patients in the study, 86.4 % presented with RS, while 13.6 % had NRS. NRS patients were older (median age: NRS: 74 vs RS: 65) and less likely to be admitted to the ICU (NRS: 36.7 % vs RS: 37.5 %). NRS patients had a higher crude in-hospital case-fatality ratio (NRS 41.1 % vs. RS 32.0 %), but a lower risk of death after adjusting for confounders (HR 0.88 [0.83-0.93]). Conclusion: Approximately one in seven COVID-19 patients presented at hospital admission without respiratory symptoms. These patients were older, had lower ICU admission rates, and had a lower risk of in-hospital mortality after adjusting for confounders.

Surveillance and prevention of healthcare-associated infections: best practices to prevent ventilator-associated events.

INTRODUCTION: Ventilator associated pneumonia (VAP) leads to an increase in morbidity, mortality, and healthcare costs. In addition to increased evidence from the latest European and American guidelines (published in 2017 and 2022, respectively), in the last two years, several important clinical experiences have added new prevention tools to be included to improve the management of VAP. AREAS COVERED: This paper is a narrative review of new evidence on VAP prevention. We divided VAP prevention measures into pharmacological, non-pharmacological, and ventilator care bundles. EXPERT OPINION: Most of the effective strategies that have been shown to decrease the incidence of complications are easy to implement and inexpensive. The implementation of care bundles, accompanied by educational measures and a multidisciplinary team should be part of optimal management. In addition to ventilator care bundles for the prevention of VAP, it could possibly be beneficial to use ventilator care bundles for the prevention of noninfectious ventilator associated events.

Severe Legionnaires' disease.

BACKGROUND: Legionnaires' disease (LD) is a common but under-diagnosed cause of community-acquired pneumonia (CAP), although rapid detection of urine antigen testing (UAT) and advances in molecular testing have improved the diagnosis. LD entails intensive care unit (ICU) admission in almost one-third of cases, and the mortality rate ranges from 4% to 40%. This review aims to discuss recent advances in the study of this condition and to provide an update on the diagnosis, pathogenesis and management of severe LD. RESULTS: The overall incidence of LD has increased worldwide in recent years due to the higher number of patients with risk factors, especially immunosuppression, and to improvements in diagnostic methods. Although LD is responsible for only around 5% of all-cause CAP, it is one of the three most common causes of CAP requiring ICU admission. Mortality in ICU patients, immunocompromised patients or patients with a nosocomial source of LD can reach 40% despite appropriate antimicrobial therapy. Regarding pathogenesis, no Legionella-specific virulence factors have been associated with severity; however, recent reports have found high pulmonary Legionella DNA loads, and impairments in immune response and lung microbiome in the most severe cases. The clinical picture includes severe lung injury requiring respiratory and/or hemodynamic support, extrapulmonary symptoms and non-specific laboratory findings. LD diagnostic methods have improved due to the broad use of UAT and the development of molecular methods allowing the detection of all Lp serogroups. Therapy is currently based on macrolides, quinolones, or a combination of the two, with prolonged treatment in severe cases. CONCLUSIONS: Numerous factors influence the mortality rate of LD, such as ICU admission, the underlying immune status, and the nosocomial source of the infection. The host immune response (hyperinflammation and/or immunoparalysis) may also be associated with increased severity. Given that the incidence of LD is rising, studies on specific biomarkers of severity may be of great interest. Further assessments comparing different regimens and/or evaluating host-directed therapies are nowadays needed.

Ventilator-associated events in adults: A secondary analysis assessing the impact of monitoring ventilator settings on outcomes.

BACKGROUND: Ventilator-associated events (VAE) is a tier implemented for surveillance by the CDC in the USA. Implementation usefulness for clinical decisions is unknown. METHODS: We conducted a secondary analysis from a prospective, multicentre, international study, to assess the impact on outcomes of using tiers with shorter follow-up (VAE24), lower oxygenation requirements (light-VAE) or both (light VAE24). RESULTS: A cohort of 261 adults with 2706 ventilator-days were included. The median (IQR) duration of mechanical ventilation (MV) was 9 days (5-21), and the median (IQR) length of stay in the intensive care unit (ICU) was 14 days (8-26). A VAE tier was associated with a trend to increase from 32% to 44% in the ICU mortality rates. VAE Incidence was 24 per 1,000 ventilator-days, being increased when reduced the oxygenation settings requirement (35 per 1,000 ventilator-days), follow-up (41 per 1,000 ventilator-days) or both (55 per 1,000 ventilator-days). A VAE tier was associated with 13 extra (21 vs. 8) days of ventilation, 11 (23 vs. 12) ICU days and 7 (31 vs. 14) hospitalization days, outperforming the modified tiers' performance. CONCLUSIONS: The modification of ventilator settings (consistent with ventilator-associated events) was associated with worse outcomes among adults with prolonged mechanical ventilation. Monitoring ventilator-associated events at the bedside represents a new tool for quality improvement.

Outcomes associated with ventilator-associated events (VAE), respiratory infections (VARI), pneumonia (VAP) and tracheobronchitis (VAT) in ventilated pediatric ICU patients: A multicentre prospective cohort study.

OBJECTIVES: An objective categorization of respiratory infections based on outcomes is an unmet clinical need. Ventilator-associated pneumonia and tracheobronchitis remain used in clinical practice, whereas ventilator-associated events (VAE) are limited to surveillance purposes. RESEARCH METHODOLOGY/DESIGN: This was a secondary analysis from a multicentre observational prospective cohort study. VAE were defined as a sustained increase in minimum Oxygen inspired fraction (FiO2) and/or Positive end-expiratory pressures (PEEP) of ≥ 0.2/2 cm H2O respectively, or an increase of 0.15 FiO2 + 1 cm H20 positive end-expiratory pressures for ≥ 1 calendar-day. SETTING: 15 Paediatric Intensive Care Units. MAIN OUTCOME MEASURES: Mechanical ventilation duration, intensive care and hospital length of stay; (LOS) and mortality. RESULTS: A cohort of 391 ventilated children with an age (median, [Interquartile Ranges]) of 1 year[0.2-5.3] and 7 days[5-10] of mechanical ventilation were included. Intensive care and hospital stays were 11 [7-19] and 21 [14-39] days, respectively. Mortality was 5.9 %. Fifty-eight ventilator-associated respiratory infections were documented among 57 patients: Seventeen (29.3 %) qualified as ventilator-associated pneumonia (VAP) and 41 (70.7 %) as ventilator-associated tracheobronchitis (VAT). Eight pneumonias and 16 tracheobronchitis (47 % vs 39 %,P = 0.571) required positive end-expiratory pressure or oxygen increases consistent with ventilator-associated criteria. Pneumonias did not significantly impact on outcomes when compared to tracheobronchitis. In contrast, infections (pneumonia or tracheobronchitis) following VAEs criteria were associated with > 6, 8 and 15 extra-days of ventilation (16 vs 9.5, P = 0.001), intensive care stay (23.5 vs 15; P = 0.004) and hospital stay (39 vs 24; P = 0.015), respectively. CONCLUSION: When assessing ventilated children with respiratory infections, VAE apparently is associated with higher ventilator-dependency and LOS compared with pneumonia or tracheobronchitis. IMPLICATIONS FOR PRACTICE: Incorporating the modification of ventilatory settings for further categorization of the respiratory infections may facilitate therapeutic management among ventilated patients.

Invasive Fungal Diseases in Adult Patients in Intensive Care Unit (FUNDICU): 2024 consensus definitions from ESGCIP, EFISG, ESICM, ECMM, MSGERC, ISAC, and ISHAM.

PURPOSE: The aim of this document was to develop standardized research definitions of invasive fungal diseases (IFD) in non-neutropenic, adult patients without classical host factors for IFD, admitted to intensive care units (ICUs). METHODS: After a systematic assessment of the diagnostic performance for IFD in the target population of already existing definitions and laboratory tests, consensus definitions were developed by a panel of experts using the RAND/UCLA appropriateness method. RESULTS: Standardized research definitions were developed for proven invasive candidiasis, probable deep-seated candidiasis, proven invasive aspergillosis, probable invasive pulmonary aspergillosis, and probable tracheobronchial aspergillosis. The limited evidence on the performance of existing definitions and laboratory tests for the diagnosis of IFD other than candidiasis and aspergillosis precluded the development of dedicated definitions, at least pending further data. The standardized definitions provided in the present document are aimed to speed-up the design, and increase the feasibility, of future comparative research studies.

Challenges of antimicrobial stewardship among older adults.

Older adults hospitalized in internal medicine wards or long-term care facilities (LTCF) are progressively increasing. Older adults with multimorbidity are more susceptible to infections, as well as to more vulnerable to adverse effects (and interactions) of antibiotics, resulting in a need for effective and safer strategies for antimicrobial stewardship (ASM), both in hospitalization wards and long-term care facilities. Studies on antimicrobial stewardship in older patients are scarce and guidelines are required. Given the peculiarities of the optimization of antimicrobial prescription in individual older adults for common infections, tactics to overcome barriers need an update. The use of rapid diagnosis tests, biomarkers, de-escalation and switching from intravenous to oral/subcutaneous therapy strategies are examples of successful AMS interventions. AMS interventions are associated with reduced side effects, lower mortality, shorter hospital stays, and reduced costs. The proposed AMS framework in LTCF should focus on five domains: strategic vision, team, interventions, patient-centred care and awareness. Internists can partner with geriatrists, pharmacists and infectious disease specialists to address barriers and to improve patient care.

Epidemiology and risk factors for mortality in critically ill patients with pancreatic infection.

Background: The AbSeS-classification defines specific phenotypes of patients with intra-abdominal infection based on the (1) setting of infection onset (community-acquired, early onset, or late-onset hospital-acquired), (2) presence or absence of either localized or diffuse peritonitis, and (3) severity of disease expression (infection, sepsis, or septic shock). This classification system demonstrated reliable risk stratification in intensive care unit (ICU) patients with intra-abdominal infection. This study aimed to describe the epidemiology of ICU patients with pancreatic infection and assess the relationship between the components of the AbSeS-classification and mortality. Methods: This was a secondary analysis of an international observational study ("AbSeS") investigating ICU patients with intra-abdominal infection. Only patients with pancreatic infection were included in this analysis (n=165). Mortality was defined as ICU mortality within 28 days of observation for patients discharged earlier from the ICU. Relationships with mortality were assessed using logistic regression analysis and reported as odds ratio (OR) and 95% confidence interval (CI). Results: The overall mortality was 35.2% (n=58). The independent risk factors for mortality included older age (OR=1.03, 95% CI: 1.0 to 1.1 P=0.023), localized peritonitis (OR=4.4, 95% CI: 1.4 to 13.9 P=0.011), and persistent signs of inflammation at day 7 (OR=9.5, 95% CI: 3.8 to 23.9, P<0.001) or after the implementation of additional source control interventions within the first week (OR=4.0, 95% CI: 1.3 to 12.2, P=0.013). Gram-negative bacteria were most frequently isolated (n=58, 49.2%) without clinically relevant differences in microbial etiology between survivors and non-survivors. Conclusions: In pancreatic infection, a challenging source/damage control and ongoing pancreatic inflammation appear to be the strongest contributors to an unfavorable short-term outcome. In this limited series, essentials of the AbSeS-classification, such as the setting of infection onset, diffuse peritonitis, and severity of disease expression, were not associated with an increased mortality risk.ClinicalTrials.gov number: NCT03270345.

Impact of antimicrobial stewardship in organisms causing nosocomial infection among COVID-19 critically ill adults.

OBJECTIVE: To evaluate the implementation of an antibiotic stewardship program in critically ill COVID-19 patients and to establish risk factors for coinfection. Secondary objective was to analyze the evolution of the etiology of respiratory nosocomial infections. METHODS: Single-center observational cohort study of consecutive patients admitted to ICU due to COVID-19 pneumonia from March 2020 to October 2022. An antibiotic stewardship program was implemented at the end of the second wave. RESULTS: A total of 878 patients were included during 6 pandemic waves. Empirical antibiotic consumption decreased from the 96% of the patients during the first pandemic wave, mainly in combination (90%) to the 30% of the patients in the 6th pandemic wave most in monotherapy (90%). There were not differences in ICU and Hospital mortality between the different pandemic periods. In multivariate analysis, SOFA at admission was the only independent risk factor for coinfection in critically ill COVID-19 patients (OR 1,23 95%CI 1,14 to 1,35). Differences in bacterial etiology of first nosocomial respiratory infection were observed. There was a progressive reduction in Enterobacteriaceae and non- fermentative Gram Negative Bacilli as responsible pathogens, while methicillin-sensitive Staphylococcus aureus increased during pandemic waves. In the last wave, however, a trend to increase of potentially resistant pathogens was observed. CONCLUSIONS: Implementation of an antibiotic stewardship program was safe and not associated with worse clinical outcomes, being severity at admission the main risk factor for bacterial coinfection in covid-19 patients. A decline in potentially resistant pathogens was documented throughout the pandemic.

Legionella pneumonia in hospitalized adults with respiratory failure: Quinolones or macrolides?

The optimal antimicrobial regimen for adults with respiratory failure due to Legionella pneumonia remains controversial. A systematic review was performed to assess the impact on outcomes comparing quinolones versus macrolides. A literature search was conducted in PubMed, Cochrane Library and Web of Science between 2012 and 2022. It yielded 124 potentially articles and ten observational studies met the inclusion criteria. A total of 4271 patients were included, 2879 (67 %) were male. A total of 1797 (42 %) subjects required intensive care unit (ICU) admission and 942 (52 %) mechanical ventilation. Fluoroquinolones and macrolides alone were administered in 1397 (33 %) and 1500 (35 %) subjects, respectively; combined therapy in 204 (4.8 %) patients. Overall mortality was 7.4 % (319 patients), with no difference between antibiotics. When data from the three studies with severe pneumonia were pooled together, mortality with fluoroquinolones alone was statistically superior to macrolides alone (72.8 % vs 30.8 %, p value 0.027). Hospital length of stay and complications were comparable. Our findings suggest that macrolides and quinolones were comparable for hospitalized Legionella pneumonia. However, in severe pneumonia, a randomized clinical trial is an unmet clinical need. PROSPERO registration number: CRD42023389308.

Infection in ECMO patients: Changes in epidemiology, diagnosis and prevention.

Patients with prolonged duration of extracorporeal membrane oxygenation support (ECMO) are a vulnerable population for sepsis, particularly ventilator-associated pneumonia and bloodstream infections. Rates differ between venous-arterial and venous-venous ECMO patients and according to the cannulation technique used. The presence of particular organisms depends on local epidemiology, antibiotic exposure, and the duration of the intervention; patients undergoing ECMO for more than three weeks present a high risk of persistent candidemia. Recognizing predisposing factors, and establishing the best preventive interventions and therapeutic choices are critical to optimizing the management of these complications. Infection control practices, including shortening the period of the indwelling devices, and reducing antibiotic exposure, must be followed meticulously. Innovations in oxygenator membranes require an updated approach. Hand hygiene and avoiding breaking the circuit-oxygenator sterility are cornerstones. ECMO management would benefit from clearer definitions, optimization of infection control strategies, and updated infectious clinical practice guidelines.

Early prediction of ventilator-associated pneumonia with machine learning models: A systematic review and meta-analysis of prediction model performance✰.

BACKGROUND: Machine learning-based prediction models can catalog, classify, and correlate large amounts of multimodal data to aid clinicians at diagnostic, prognostic, and therapeutic levels. Early prediction of ventilator-associated pneumonia (VAP) may accelerate the diagnosis and guide preventive interventions. The performance of a variety of machine learning-based prediction models were analyzed among adults undergoing invasive mechanical ventilation. METHODS: This systematic review and meta-analysis was conducted in accordance with the Cochrane Collaboration. Machine learning-based prediction models were identified from a search of nine multi-disciplinary databases. Two authors independently selected and extracted data using predefined criteria and data extraction forms. The predictive performance, the interpretability, the technological readiness level, and the risk of bias of the included studies were evaluated. RESULTS: Final analysis included 10 static prediction models using supervised learning. The pooled area under the receiver operating characteristics curve, sensitivity, and specificity for VAP were 0.88 (95 % CI 0.82-0.94, I2 98.4 %), 0.72 (95 % CI 0.45-0.98, I2 97.4 %) and 0.90 (95 % CI 0.85-0.94, I2 97.9 %), respectively. All included studies had either a high or unclear risk of bias without significant improvements in applicability. The care-related risk factors for the best performing models were the duration of mechanical ventilation, the length of ICU stay, blood transfusion, nutrition strategy, and the presence of antibiotics. CONCLUSION: A variety of the prediction models, prediction intervals, and prediction windows were identified to facilitate timely diagnosis. In addition, care-related risk factors susceptible for preventive interventions were identified. In future, there is a need for dynamic machine learning models using time-depended predictors in conjunction with feature importance of the models to predict real-time risk of VAP and related outcomes to optimize bundled care.