Abdominal infections in the intensive care unit: characteristics, treatment and determinants of outcome

11β hydroxysteroid dehydrogenase type 1 transgenic mesenchymal stem cells attenuate inflammation in models of sepsis

Background

Human bone marrow mesenchymal stem cell (MSC) administration reduces inflammation in pre-clinical models of sepsis and sepsis-related lung injury, however clinical efficacy in patients has not yet been demonstrated. We previously showed that Alveolar Macrophage (AM) 11β-hydroxysteroid dehydrogenase type-1 (HSD-1) autocrine signalling is impaired in critically ill sepsis patients, which promotes inflammatory injury. Administration of transgenic MSCs (tMSCs) which overexpress HSD-1 may enhance the anti-inflammatory effects of local glucocorticoids and be more effective at reducing inflammation in sepsis than cellular therapy alone.

Methods

MSCs were transfected using a recombinant lentiviral vector containing the HSD-1 and GPF transgenes under the control of a tetracycline promoter. Thin layer chromatography assessed HSD-1 reductase activity in tMSCs. Mesenchymal stem cell phenotype was assessed by flow cytometry and bi-lineage differentiation. HSD-1 tMSCs were co-cultured with LPS-stimulated monocyte-derived macrophages (MDMs) from healthy volunteers prior to assessment of pro-inflammatory cytokine release. HSD-1 tMSCs were administered intravenously to mice undergoing caecal ligation and puncture (CLP).

Results

MSCs were transfected with an efficiency of 91.1%, and maintained an MSC phenotype. Functional HSD-1 activity was demonstrated in tMSCs, with predominant reductase cortisol activation (peak 8.23 pM/hour/100,000 cells). HSD-1 tMSC co-culture with LPS-stimulated MDMs suppressed TNFα and IL-6 release. Administration of transgene activated HSD-1 tMSCs in a murine model of CLP attenuated neutrophilic inflammation more effectively than transgene inactive tMSCs (medians 0.403 v 1.36 × 106/ml, p = 0.033).

Conclusion

The synergistic impact of HSD-1 transgene expression and MSC therapy attenuated neutrophilic inflammation in a mouse model of peritoneal sepsis more effectively than MSC therapy alone. Future studies investigating the anti-inflammatory capacity of HSD-1 tMSCs in models of sepsis-related direct lung injury and inflammatory diseases are required.

Empirical antifungal therapy for health care-associated intra-abdominal infection: a retrospective, multicentre and comparative study

BACKGROUND

Current guidelines recommend using antifungals for selected patients with health care-associated intra-abdominal infection (HC-IAI), but this recommendation is based on a weak evidence. This study aimed to assess the association between early empirical use of antifungals and outcomes in intensive care unit (ICU) adult patients requiring re-intervention after abdominal surgery.

METHODS

A retrospective, multicentre cohort study with overlap propensity score weighting was conducted in three ICUs located in three medical institutions in France. Patients treated with early empirical antifungals for HC-IAI after abdominal surgery were compared with controls who did not receive such antifungals. The primary endpoint was the death rate at 90 days, and the secondary endpoints were the death rate at 1 year and composite criteria evaluated at 30 days following the HC-IAI diagnosis, including the need for re-intervention, inappropriate antimicrobial therapy and death, whichever occurred first.

RESULTS

At 90 days, the death rate was significantly decreased in the patients treated with empirical antifungals compared with the control group (11.4% and 20.7%, respectively, p = 0.02). No differences were reported for the secondary outcomes.

CONCLUSION

The use of early empirical antifungal therapy was associated with a decreased death rate at 90 days, with no effect on the death rate at 1 year, the death rate at 30 days, the rate of re-intervention, the need for drainage, and empirical antibiotic and antifungal therapy failure at 30 days.

Risk factors of acute respiratory distress syndrome in sepsis caused by intra-abdominal infections: A retrospective study

BACKGROUND

Intra-abdominal infections are frequently associated with acute respiratory distress syndrome, which significantly affects patient prognosis. However, little is known about the specific risk factors of acute respiratory distress syndrome in sepsis caused by intra-abdominal infections.

METHODS

This retrospective study included adult patients with intra-abdominal sepsis admitted to the intensive care unit of a tertiary teaching hospital in China between June 2017 and June 2022. Patients were categorized based on the presence or absence of acute respiratory distress syndrome. Data, including vital signs, laboratory values, and severity scores collected within 24 hours of sepsis diagnosis, as well as outcomes within 90 days, were analyzed. Multivariable logistic regression was used to identify independent risk factors associated with acute respiratory distress syndrome.

RESULTS

A total of 738 patients were included, of whom 218 (29.5%) developed acute respiratory distress syndrome. Patients with acute respiratory distress syndrome were younger, had a higher body mass index and disease severity scores, and exhibited higher proportions of septic shock and hospital-acquired intra-abdominal infections. The mortalities in the intensive care unit and at 28 and 90 days were higher in the acute respiratory distress syndrome group. In the multivariate logistic regression model, age under 65 years (odds ratio [95% confidence interval]: 1.571 [1.093-2.259]), elevated body mass index (2.070 [1.382-3.101] for overweight, 6.994 [3.207-15.255]) for obesity, septic shock (2.043 [1.400-2.980]), procalcitonin (1.009 [1.004-1.015]), hospital-acquired intra-abdominal infections (2.528[1.373-4.657]), and source of intra-abdominal infections (2.170 [1.140-4.128] for biliary tract infection, 0.443 [0.217-0.904] for gastroduodenal perforation) were independently associated with acute respiratory distress syndrome.

CONCLUSION

In patients with intra-abdominal sepsis, age under 65 years, higher body mass index and procalcitonin, septic shock, hospital-acquired intra-abdominal infections, and biliary tract infection were risk factors for acute respiratory distress syndrome.

Kinetics of Different Blood Biomarkers during Polymyxin-B Extracorporeal Hemoperfusion in Abdominal Sepsis

INTRODUCTION

Comparison of the marker kinetics procalcitonin, presepsin, and endotoxin during extracorporeal hemoperfusion with polymyxin-B adsorbing cartridge (PMX-HA) has never been described in abdominal sepsis. We aimed to compare the trend of three biomarkers in septic post-surgical abdominal patients in intensive care unit (ICU) treated with PMX-HA and their prognostic value.

METHODS

Ninety abdominal post-surgical patients were enrolled into different groups according to the evidence of postoperative sepsis or not. Non-septic patients admitted in the surgical ward were included in C group (control group). ICU septic shock patients with endotoxin levels <0.6 EAA receiving conventional therapy were addressed in S group and those with endotoxin levels ≥0.6 EAA receiving treatment with PMX-HA, besides conventional therapy, were included in SPB group. Presepsin, procalcitonin, endotoxin and other clinical data were recorded at 24 h (T0), 72 h (T1) and 7 days (T2) after surgery. Clinical follow-up was performed on day 30.

RESULTS

SPB group showed reduced levels of the three biomarkers on T2 versus T0 (p < 0.001); presepsin, procalcitonin and endotoxin levels decreased, respectively, by 25%, 11%, and 2% on T1 versus T0, and 40%, 41%, and 26% on T2 versus T0. All patients in C group, 73% of patients in SPB group versus 37% of patients in S group survived at follow-up. Moreover, procalcitonin had the highest predictive value for mortality at 30 days, followed by presepsin.

CONCLUSION

The present study showed the reliability of presepsin in monitoring PMX-HA treatment in septic shock patients. Procalcitonin showed better predicting power for the mortality riSsk.

Utility of paired plasma and drainage fluid mNGS in diagnosing acute intra-abdominal infections with sepsis

BACKGROUND

Metagenomic next-generation sequencing (mNGS) has been increasingly applied in sepsis. We aimed to evaluate the diagnostic and therapeutic utility of mNGS of paired plasma and peritoneal drainage (PD) fluid samples in comparison to culture-based microbiological tests (CMTs) among critically ill patients with suspected acute intra-abdominal infections (IAIs).

METHODS

We conducted a prospective study from October 2021 to December 2022 enrolling septic patients with suspected IAIs (n = 111). Pairwise CMTs and mNGS of plasma and PD fluid were sent for pathogen detection. The mNGS group underwent therapeutic regimen adjustment based on mNGS results for better treatment. The microbial community structure, clinical features, antibiotic use and prognoses of the patients were analyzed.

RESULTS

Higher positivity rates were observed with mNGS versus CMTs for both PD fluid (90.0% vs. 48.3%, p < 0.005) and plasma (76.7% vs. 1.6%, p < 0.005). 90% of enrolled patients had clues of suspected pathogens combining mNGS and CMT methods. Gram-negative pathogens consist of most intra-abdominal pathogens, including a great variety of anaerobes represented by Bacteroides and Clostridium. Patients with matched plasma- and PD-mNGS results had higher mortality and sepsis severity. Reduced usage of carbapenem (30.0% vs. 49.4%, p < 0.05) and duration of anti-MRSA treatment (5.1 ± 3.3 vs. 7.0 ± 8.4 days, p < 0.05) was shown in the mNGS group in our study.

CONCLUSIONS

Pairwise plasma and PD fluid mNGS improves microbiological diagnosis compared to CMTs for acute IAI. Combining plasma and PD mNGS could predict poor prognosis. mNGS may enable optimize empirical antibiotic use.

Optimized Treatment of Nosocomial Peritonitis

This comprehensive review aims to provide a practical guide for intensivists, focusing on enhancing patient care associated with nosocomial peritonitis (NP). It explores the epidemiology, diagnosis, and management of NP, a significant contributor to the mortality of surgical patients worldwide. NP is, per definition, a hospital-acquired condition and a consequence of gastrointestinal surgery or a complication of other diseases. NP, one of the most prevalent causes of sepsis in surgical Intensive Care Units (ICUs), is often associated with multi-drug resistant (MDR) bacteria and high mortality rates. Early clinical suspicion and the utilization of various diagnostic tools like biomarkers and imaging are of great importance. Microbiology is often complex, with antimicrobial resistance escalating in many parts of the world. Fungal peritonitis and its risk factors, diagnostic hurdles, and effective management approaches are particularly relevant in patients with NP. Contemporary antimicrobial strategies for treating NP are discussed, including drug resistance challenges and empirical antibiotic regimens. The importance of source control in intra-abdominal infection management, including surgical and non-surgical interventions, is also emphasized. A deeper exploration into the role of open abdomen treatment as a potential option for selected patients is proposed, indicating an area for further investigation. This review underscores the need for more research to advance the best treatment strategies for NP.

Identification of Risk Factors for Intra-Abdominal Candidiasis

Background: Intra-abdominal candidiasis (IAC) is associated with substantial morbidity and mortality in hospitalized patients. Identifying high-risk populations may facilitate early and selective directed therapy in appropriate patients and avoid unwarranted treatment and any associated adverse effects in those who are low risk. Patients and Methods: This retrospective, case-control study included patients >18 years of age admitted from July 1, 2010 to July 1, 2021 who had a microbiologically confirmed intra-abdominal infection (gastrointestinal culture positive for either a Candida spp. [cases] or bacterial isolate [controls] collected intra-operatively or from a drain placed within 24 hours). Patients receiving peritoneal dialysis treatment or with a peritoneal dialysis catheter in place or treated at an outside hospital were excluded. Multivariable regression was utilized to identify independent risk factors for the development of IAC. Results: Five hundred twenty-three patients were screened, and 250 met inclusion criteria (125 per cohort). Multivariable analysis identified exposure to corticosteroids (odds ratio [OR], 5.79; 95% confidence interval [CI], 2.52-13.32; p < 0.0001), upper gastrointestinal tract surgery (OR, 3.51; 95% CI, 1.25-9.87; p = 0.017), and mechanical ventilation (OR, 3.09; 95% CI 1.5-6.37; p = 0.002) were independently associated with IAC. The area under the receiver operating characteristic (AUROC) and goodness of fit were 0.7813 and p = 0.5024, respectively. Conclusions: Exposure to corticosteroids, upper gastrointestinal tract surgery, and mechanical ventilation are independent risk factors for the development of microbiologically confirmed IAC suggesting these factors may help identify high-risk individuals requiring antifungal therapy.

Combination of serum and peritoneal 1.3-beta-D-glucan can rule out intra-abdominal candidiasis in surgical critically ill patients: a multicenter prospective study

BACKGROUND

Intra-abdominal candidiasis (IAC) is difficult to predict in critically ill patients with intra-abdominal infection, leading to the overuse of antifungal treatments. Serum and peritoneal 1.3-beta-D-glucan (sBDG and pBDG) have been proposed to confirm or invalidate the diagnosis of IAC, but clinical studies have reported inconsistent results, notably because of heterogeneous populations with a low IAC prevalence. This study aimed to identify a high-risk IAC population and evaluate pBDG and sBDG in diagnosing IAC.

METHODS

This prospective multicenter noninterventional French study included consecutive critically ill patients undergoing abdominal surgery for abdominal sepsis. The primary objective was to establish the IAC prevalence. The secondary objective was to explore whether sBDG and pBDG could be used to diagnose IAC. Wako® beta-glucan test (WT, Fujifilm Wako Chemicals Europe, Neuss, Germany) was used for pBDG measurements. WT and Fungitell® beta-D-glucan assay (FA, Associate of Cape Cod, East Falmouth, USA) were used for sBDG measurements.

RESULTS

Between 1 January 2020 and 31 December 2022, 199 patients were included. Patients were predominantly male (63%), with a median age of 66 [54-72] years. The IAC prevalence was 44% (87/199). The main IAC type was secondary peritonitis. Septic shock occurred in 63% of cases. After multivariate analysis, a nosocomial origin was associated with more IAC cases (P = 0.0399). The median pBDG level was significantly elevated in IAC (448 [107.5-1578.0] pg/ml) compared to non-IAC patients (133 [16.0-831.0] pg/ml), P = 0.0021. For a pBDG threshold of 45 pg/ml, the negative predictive value in assessing IAC was 82.3%. The median sBDG level with WT (n = 42) at day 1 was higher in IAC (5 [3.0-9.0] pg/ml) than in non-IAC patients (3 [3.0-3.0] pg/ml), P = 0.012. Similarly, median sBDG level with FA (n = 140) at day 1 was higher in IAC (104 [38.0-211.0] pg/ml) than in non-IAC patients (50 [23.0-141.0] pg/ml), P = 0.009. Combining a peritonitis score < 3, sBDG < 3.3 pg/ml (WT) and pBDG < 45 pg/ml (WT) yielded a negative predictive value of 100%.

CONCLUSION

In critically ill patients with intra-abdominal infection requiring surgery, the IAC prevalence was 44%. Combining low sBDG and pBDG with a low peritonitis score effectively excluded IAC and could limit unnecessary antifungal agent exposure.

TRIAL REGISTRATION

The study was registered with ClinicalTrials.gov (ID number 03997929, first registered on June 24, 2019).

Predictive nomogram for in-hospital mortality among older patients with intra-abdominal sepsis incorporating skeletal muscle mass

BACKGROUND

Studies on prognostic factors for older patients with intra-abdominal sepsis are scarce, and the association between skeletal muscle mass and prognosis among such patients remains unclear.

AIMS

To develop a nomogram to predict in-hospital mortality among older patients with intra-abdominal sepsis.

METHODS

Older patients with intra-abdominal sepsis were prospectively recruited. Their demographics, clinical features, laboratory results, abdominal computed tomography-derived muscle mass, and in-hospital mortality were recorded. The predictors of mortality were selected via least absolute shrinkage and selection operator and multivariable logistic regression analyses, and a nomogram was developed. The nomogram was assessed and compared with Sequential Organ Failure Assessment score, Acute Physiology and Chronic Health Evaluation II score, and Simplified Acute Physiology Score II.

RESULTS

In total, 464 patients were included, of whom 104 (22.4%) died. Six independent risk factors (skeletal muscle index, cognitive impairment, frailty, heart rate, red blood cell distribution width, and blood urea nitrogen) were incorporated into the nomogram. The Hosmer-Lemeshow goodness-of-fit test and calibration plot revealed a good consistency between the predicted and observed probabilities. The area under the receiver operating characteristic curve was 0.875 (95% confidence interval = 0.838-0.912), which was significantly higher than those of commonly used scoring systems. The decision curve analysis indicated the nomogram had good predictive performance.

DISCUSSION

Our nomogram, which is predictive of in-hospital mortality among older patients with intra-abdominal sepsis, incorporates muscle mass, a factor that warrants consideration by clinicians. The model has a high prognostic ability and might be applied in clinical practice after external validation.

Timing of surgical operation for patients with intra-abdominal infection: A systematic review and meta-analysis

BACKGROUND

Intra-abdominal infections (IAIs) is the most common type of surgical infection, with high associated morbidity and mortality rates. In recent years, due to the use of antibiotics, various drug-resistant bacteria have emerged, making the treatment of abdominal infections more challenging. Early surgical exploration can reduce the mortality of patients with abdominal infection and the occurrence of complications. However, available evidence regarding the optimal timing of IAI surgery is still weak. In study, we compared the effects of operation time on patients with abdominal cavity infection and tried to confirm the best timing of surgery.

AIM

To assess the efficacy of early vs delayed surgical exploration in the treatment of IAI, in terms of overall mortality.

METHODS

A systematic literature search was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Ovid, and ScienceDirect. The systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses method. Based on the timing of the surgical operation, we divided the literature into two groups: Early surgery and delayed surgery. For the early and delayed surgery groups, the intervention was performed with and after 12 h of the initial surgical intervention, respectively. The main outcome measure was the mortality rate. The literature search was performed from May 5 to 20, 2021. We also searched the World Health Organization International Clinical Trials Registry Platform search portal and ClinicalTrials.gov on May 20, 2021, for ongoing trials. This study was registered with the International Prospective Register of Systematic Reviews.

RESULTS

We identified nine eligible trial comparisons. Early surgical exploration of patients with IAIs (performed within 12 h) has significantly reduced the mortality and complications of patients, improved the survival rate, and shortened the hospital stay.

CONCLUSION

Early surgical exploration within 12 h may be more effective for the treatment of IAIs relative to a delayed operation.

Severe infections caused by difficult-to-treat Gram-negative bacteria

PURPOSE OF REVIEW

Antimicrobial resistance (AMR) in Gram-negative bacteria (GNB) poses a significant global health concern, contributing to increased infections, mortality rates, and healthcare costs. This review discusses the main clinical manifestations, therapeutic options, and recent findings in managing antibiotic-resistant GNB, with a focus on difficult-to-treat infections.

RECENT FINDINGS

Difficult-to-treat resistance (DTR) is a novel classification that identifies GNB exhibiting intermediate or resistant phenotypes to first-line agents in the carbapenem, beta-lactam, and fluoroquinolone categories. The main pathogens implicated in severe infections include DTR Enterobacterales, DTR Pseudomonas aeruginosa , and DTR Acinetobacter baumannii. Although the clinical implications of DTR strains are still under investigation, certain studies have linked them to prolonged hospital stays and poor patient outcomes.

SUMMARY

Severe infections caused by DTR-GNB pose a formidable challenge for healthcare providers and represent a growing global health issue. The proper administration and optimization of novel antibiotics at our disposal are of paramount importance for combating bacterial resistance and improving patient prognosis.

Reappraisal of intra-abdominal candidiasis: insights from peritoneal fluid analysis

BACKGROUND

The understanding of high mortality associated with intra-abdominal candidiasis (IAC) remains limited. While Candida is considered a harmless colonizer in the digestive tract, its role as a true pathogen in IAC is still debated. Evidence regarding Candida virulence in the human peritoneal fluid are lacking. We hypothesized that during IAC, Candida albicans develops virulence factors to survive to new environmental conditions. The objective of this observational exploratory monocentric study is to investigate the influence of peritoneal fluid (PF) on the expression of C. albicans virulence using a multimodal approach.

MATERIALS AND METHODS

A standardized inoculum of a C. albicans (3.106 UFC/mL) reference strain (SC5314) was introduced in vitro into various PF samples obtained from critically ill patients with intra-abdominal infection. Ascitic fluids (AFs) and Sabouraud medium (SBD) were used as control groups. Optical microscopy and conventional culture techniques were employed to assess the morphological changes and growth of C. albicans. Reverse transcriptase qPCR was utilized to quantify the expression levels of five virulence genes. The metabolic production of C. albicans was measured using the calScreener™ technology.

RESULTS

A total of 26 PF samples from patients with secondary peritonitis were included in the study. Critically ill patients were mostly male (73%) with a median age of 58 years admitted for urgent surgery (78%). Peritonitis was mostly hospital-acquired (81%), including 13 post-operative peritonitis (50%). The infected PF samples predominantly exhibited polymicrobial composition. The findings revealed substantial variability in C. albicans growth and morphological changes in the PF compared to ascitic fluid. Virulence gene expression and metabolic production were dependent on the specific PF sample and the presence of bacterial coinfection.

CONCLUSIONS

This study provides evidence of C. albicans virulence expression in the peritoneal fluid. The observed variability in virulence expression suggests that it is influenced by the composition of PF and the presence of bacterial coinfection. These findings contribute to a better understanding of the complex dynamics of intra-abdominal candidiasis and advocate for personalized approach for IAC patients. Trial registration https://clinicaltrials.gov/ (NCT05264571; February 22, 2022).

Acute gastrointestinal injury and altered gut microbiota are related to sepsis-induced cholestasis in patients with intra-abdominal infection: a retrospective and prospective observational study

Background

Sepsis-associated liver dysfunction (SALD) has high incidence and mortality in patients with intra-abdominal infection (IAI). The associations between acute gastrointestinal injury (AGI), gut microbiota, and SALD were evaluated in patients with IAI.

Methods

A retrospective study was conducted to assess the relationship between AGI and SALD in patients with IAI. Patients were divided into non-SALD and sepsis-induced cholestasis (SIC) groups, which is a subtype of SALD. SIC was defined as total bilirubin >2 mg/dL. AGI incidences between the two groups were compared using Chi-square test. Subsequently, a prospective study was conducted to investigate the gut microbiota differences between patients without SALD and those with SIC. Fecal samples were collected on days 1, 3, and 7 after admission to analyze changes in gut microbiota using 16S ribosomal ribonucleic acid sequencing.

Results

One hundred thirty-four patients with IAI were included retrospectively, with 77 SALD and 57 non-SALD cases. Among patients with SALD, 71 were diagnosed with SIC. Patients with SIC had a higher incidence of AGI compared to those without SALD (28.07% vs. 56.34%, p < 0.05), and a severity-dependent relationship was found between AGI grade and SIC occurrence. Subsequently, 20 patients with IAI were recruited prospectively, with 10 patients each assigned to the non-SALD and SIC groups. Patients with SIC had a more severe gut microbiota disorder on day 7 than those without SALD, including lower microbiota diversities, decreased abundance of Firmicutes and Bacteroidetes, and increased abundance of Proteobacteria and Actinobacteria at the phylum level. Furthermore, Burkholderia - Caballeronia - Paraburkholderia and Delftia, the two most abundant genera, were significantly higher in the SIC group than in the non-SALD group. Functional prediction analysis showed that the top three KEGG pathways were ribosome, pyrimidine metabolism, and the two-component system. During the first week, the abundance of Proteobacteria decreased significantly, whereas Cyanobacteria increased in the non-SALD group; however, the phyla taxa did not change significantly in the SIC group.

Conclusion

There exists a severity-dependent relationship between AGI grade and SIC occurrence in adult patients with IAI. A severe gut microbiota disorder was discovered in SIC during the first week of the intensive care unit stay.

ENDOTHELIAL GLYCOCALYX SHEDDING IN INTRA-ABDOMINAL SEPSIS: A FEASIBILITY STUDY

ABSTRACT

Background: The endothelial glycocalyx layer (EGL) is a complex meshwork of glycosaminoglycans and proteoglycans that protect the vascular endothelium. Cleavage or shedding of EGL-specific biomarkers, such as hyaluronic acid (HA) and syndecan-1 (SDC-1, CD138) in plasma, have been shown to be associated with poor clinical outcomes. However, it is unclear whether levels of circulating EGL biomarkers are representative of the EGL injury within the tissues. The objective of the present feasibility study was to describe a pathway for plasma and tissue procurement to quantify EGL components in a cohort of surgical patients with intra-abdominal sepsis. We sought to compare differences between tissue and plasma EGL biomarkers and to determine whether EGL shedding within the circulation and/or tissues correlated with clinical outcomes. Methods: This was a prospective, observational, single-center feasibility study of adult patients (N = 15) with intra-abdominal sepsis, conducted under an approved institutional review boards. Blood and resected tissue (pathologic specimen and unaffected peritoneum) samples were collected from consented subjects at the time of operation and 24-48 hours after surgery. Endothelial glycocalyx layer biomarkers (i.e., HA and SDC-1) were quantified in both tissue and plasma samples using a CD138 stain and ELISA kit, respectively. Pairwise comparisons were made between plasma and tissue levels. In addition, we tested the relationships between measured EGL biomarkers and clinical status and patient outcomes. Results: Fifteen patients with intra-abdominal sepsis were enrolled in the study. Elevations in EGL-specific circulating biomarkers (HA, SDC-1) were positively correlated with postoperative SOFA scores and weakly associated with resuscitative volumes at 24 hours. Syndecan-1 levels from resected pathologic tissue significantly correlated with SOFA scores at all time points ( R = 0.69 and P < 0.0001) and positively correlated with resuscitation volumes at 24 hours ( R = 0.41 and P = 0.15 for t = 24 hours). Tissue and circulating HA and SDC-1 positively correlated with SOFA >6. Conclusions: Elevations in both circulating and tissue EGL biomarkers were positively correlated with postoperative SOFA scores at 24 hours, with resected pathologic tissue EGL levels displaying significant correlations with SOFA scores at all time points. Tissue and circulating EGL biomarkers were positively correlated at higher SOFA scores (SOFA > 6) and could be used as indicators of resuscitative needs within 24 hours of surgery. The present study demonstrates the feasibility of tissue and plasma procurement in the operating room, although larger studies are needed to evaluate the predictive value of these EGL biomarkers for patients with intra-abdominal sepsis.

Novel Aspects of the Immune Response Involved in the Peritoneal Damage in Chronic Kidney Disease Patients under Dialysis

Chronic kidney disease (CKD) incidence is growing worldwide, with a significant percentage of CKD patients reaching end-stage renal disease (ESRD) and requiring kidney replacement therapies (KRT). Peritoneal dialysis (PD) is a convenient KRT presenting benefices as home therapy. In PD patients, the peritoneum is chronically exposed to PD fluids containing supraphysiologic concentrations of glucose or other osmotic agents, leading to the activation of cellular and molecular processes of damage, including inflammation and fibrosis. Importantly, peritonitis episodes enhance peritoneum inflammation status and accelerate peritoneal injury. Here, we review the role of immune cells in the damage of the peritoneal membrane (PM) by repeated exposure to PD fluids during KRT as well as by bacterial or viral infections. We also discuss the anti-inflammatory properties of current clinical treatments of CKD patients in KRT and their potential effect on preserving PM integrity. Finally, given the current importance of coronavirus disease 2019 (COVID-19) disease, we also analyze here the implications of this disease in CKD and KRT.

circFLNA promotes intestinal injury during abdominal sepsis through Fas-mediated apoptosis pathway by sponging miR-766-3p

BACKGROUND

Intra-abdominal infections are the second most common cause of sepsis in the intensive care unit. Intestinal epithelial injury due to abdominal sepsis results in a variety of pathological changes, such as intestinal bacteria and toxins entering the blood, leading to persistent systemic inflammation and multiple organ dysfunction. The increased apoptosis of intestinal epithelial cells induced by sepsis further exacerbates the progression of sepsis. Although several studies have revealed that circRNAs are involved in intestinal epithelial injury in sepsis, few studies have identified the roles of circRNAs in intestinal epithelial apoptosis.

METHODS

We used laser capture microdissection to obtain purified epithelial cells located in intestinal crypts from four patients with abdominal sepsis induced by intestinal perforation and four samples from age and sex-matched non-septic patients. Microarray analysis of circRNAs was conducted to assess differentially expressed circRNAs between patients with and without sepsis. Lastly, in vitro and in vivo assays were performed to study the mechanism of circFLNA in intestinal epithelial apoptosis during sepsis.

RESULTS

circFLNA was upregulated in the intestinal epithelium after abdominal sepsis induced by intestinal perforation. Inhibition of miR-766-3p impaired si-circFLNA-mediated inhibition of apoptosis and inflammation factor levels in lipopolysaccharide (LPS)-treated HIEC-6 cells. circFLNA aggravated apoptosis and inflammation through the Fas-mediated apoptosis pathway in both LPS-treated HIEC-6 cells and a mouse cecal ligation and puncture model.

CONCLUSION

Our findings showed that circFLNA promotes intestinal injury in abdominal sepsis through the Fas-mediated apoptosis pathway by sponging miR-766-3p. The circFLNA/miR-766-3p/Fas axis has potential as a novel therapeutic target for treating intestinal injury in sepsis.

Analysis of Manheim Peritonitis Index Scoring in Predicting Outcome in Patients with Perforation Peritonitis

Scoring systems are essential to calibrate the severity of abdominal sepsis for adequate management. Disease specific scoring system based on easy to handle clinical parameters can help the cause. Objective: To study the role of Manheim peritonitis index scoring in predicting outcome and prognosis in patients with perforation peritonitis. Methods: This prospective study was carried out in Surgical Unit 1, Nishtar Hospital, Multan from 20th of August 2019 to 31st of December, 2019. It includes both sexes aged 20 years and above diagnosed at laparotomy after confirmation of peritonitis due to perforated viscus regardless of the etiology. Data were analyzed using SPSS version 19.0 Software. The outcome (death vs discharge) was compared separately to different predictors using Chi-square test. Fischer Exact test was used where assumptions of Chi-square were not met. Results: Advance age, female gender, colonic perforation, organ failure and fecal contamination were associated with high mortality. The mean MPI Score was 25.06 ± 4.96. The lowest score was 16 and the highest was 37. Overall, the in-hospital mortality rate was 14.3% in patients with MPI ≥26 compared to 6.4% in patients with MPI <26, implying over a twofold higher risk in the former group. For a score of 26 or greater as a predictor of mortality, the sensitivity was 75.0%, specificity was 38.2% at an accuracy of 94%. Conclusion: MPI enables us to categorize patients into different groups so as to tailor management according to individual needs

Effectiveness of Five Antibiotic Regimens for the Treatment of Intra-Abdominal Infection in Bogotá

Background: Intra-abdominal infection (IAI) results in prolonged in-hospital length-of-stay, critical care unit requirements, and multiple surgical procedures. Several antimicrobial agents are available for treatment of IAI. In Colombia, there are no data on the comparative effectiveness of the different regimens used. Patients and Methods: A multicenter retrospective cohort study was completed in four third-level hospitals by comparing treatment effectiveness of five different antibiotic protocols (ampicillin-sulbactam, clindamycin-amikacin, piperacillin-tazobactam, amikacin-metronidazole, and cefuroxime-metronidazole) in patients with a diagnosis of IAI. Analysis was based on a composed outcome of therapeutic failure (change of antibiotic because of no clinical improvement, requirement of surgical re-intervention, post-operative infection, change of antibiotic because of antimicrobial resistance, and in-hospital mortality). Association of each antibiotic protocol to therapeutic failure was assessed through logistic regression analysis. Results: Five hundred ninety-three individuals were included. Two hundred twenty-nine were prescribed ampicillin-sulbactam; 170, clindamycin-amikacin; 77, amikacin-metronidazole; 83, piperacillin-tazobactam; and 34, cefuroxime-metronidazole. Therapeutic failure rate was 22%. Multivariable analysis showed none of the evaluated antibiotic protocols had an association with the primary outcome. Variables having an association for higher risk were age >70 years old (odds ratio [OR], 2.08; 95% confidence interval [CI], 1.04-4.18); complicated IAI (OR, 3.36; 95% CI, 1.4-8.07); and World Society of Emergency Surgery (WSES) Sepsis Severity Score (OR, 1.31; 95% CI, 1.18-1.45). Adequate source control (OR, 0.16; 95% CI, 0.05-0.45) and hospitalization at Health Center 2 (OR, 0.30; 95% CI, 0.14-0.63) were identified as protective factors. Conclusions: There are no differences between the rate of therapeutic failure among the different antibiotic protocols evaluated. This outcome depends heavily on risk factors related to disease severity when surgical intervention occurs.

Korean Guidelines for Use of Antibiotics for Intra-abdominal Infections in Adults

The guidelines are intended to provide practical information for the correct use of antibiotics for intra-abdominal infections in Korea. With the aim of realizing evidence-based treatment, these guidelines for the use of antibiotics were written to help clinicians find answers to key clinical questions that arise in the course of patient care, using the latest research results based on systematic literature review. The guidelines were prepared in consideration of the data on the causative pathogens of intra-abdominal infections in Korea, the antibiotic susceptibility of the causative pathogens, and the antibiotics available in Korea.

A Literature Overview of Secondary Peritonitis Due to Carbapenem-Resistant Enterobacterales (CRE) in Intensive Care Unit (ICU) Patients

This comprehensive review of the recently published literature offers an overview of a very topical and complex healthcare problem: secondary peritonitis from multidrug-resistant pathogens, especially carbapenem-resistant Enterobacterales (CRE). Spontaneous secondary peritonitis and postsurgical secondary peritonitis are among the major causes of community- and healthcare- acquired sepsis, respectively. A large number of patients enter ICUs with a diagnosis of secondary peritonitis, and a high number of them reveal infection by CRE, P. aeruginosa or A. baumannii. For this reason, we conceived the idea to create a synthetic report on this topic including updated epidemiology data, a description of CRE resistance patterns, current strategies of antimicrobial treatment, and future perspectives. From this update it is clear that antimicrobial stewardship and precision medicine are becoming essential to fight the emergence of antimicrobial resistance and that even if there are new drugs effective against CRE causing secondary peritonitis, these drugs have to be used carefully especially in empirical therapy.

Combining T2Bacteria and T2Candida Panels for Diagnosing Intra-Abdominal Infections: A Prospective Multicenter Study

The T2Bacteria panel is a direct-from-blood assay that delivers rapid results, targeting E. coli, S. aureus, K. pneumoniae, A. baumanii, P. aeruginosa, and E. faecium (ESKAPE pathogens). In this study, T2Bacteria and T2Candida (targeting C. albicans/C. tropicalis, C. glabrata/C. krusei, and C. parapsilosis) were evaluated in parallel with blood cultures in 101 consecutive surgical patients with suspected intra-abdominal infection admitted to the intensive care unit or high dependency unit. Fifteen patients had bacteremia, with T2Bacteria correctly identifying all on-panel (n = 8) pathogens. T2Bacteria was positive in 19 additional patients, 11 of whom had supportive cultures from other normally sterile sites (newly inserted drains, perioperative cultures or blood cultures) within seven days. Six of these eleven patients (55%) received broad-spectrum antibiotics at the sampling time. T2Candida identified the two cases of blood-culture-positive candidemia and was positive in seven additional patients, three of whom were confirmed to have intra-abdominal candidiasis. Of four patients with concurrent T2Bacteria and T2Candida positivity, only one patient had positive blood cultures (candidemia), while three out of four patients had supporting microbiological evidence of a mixed infection. T2Bacteria and T2Candida were fast and accurate in diagnosing on-panel bloodstream infections, and T2Bacteria was able to detect culture-negative intra-abdominal infections.

Population Pharmacokinetics of Temocillin Administered by Continuous Infusion in Patients with Septic Shock Associated with Intra-Abdominal Infection and Ascitic Fluid Effusion

Temocillin is active against Gram-negative bacteria, including many extended-spectrum β-lactamase (ESBL)-producing Enterobacterales. We studied its pharmacokinetics in plasma and ascitic fluid after intravenous administration of a loading dose of 2 g over 30 min, followed by continuous infusion of 6 g/24 h, to 19 critically-ill patients with septic shock associated with complicated intra-abdominal infection. We established a pharmacokinetic model describing unbound temocillin concentrations in plasma and ascitic fluid and performed Monte-Carlo simulations to evaluate the probability of target attainment (PTA) of unbound concentrations (100% fT > MIC, i.e., unbound concentrations remaining above the MIC during 100% of the time) for the applied and hypothetical dosing regimens. The temocillin AUC in ascitic fluid was 46% of the plasma AUC. Plasma unbound concentrations were best described by a two-compartment model, and an additional compartment was added to describe unbound concentration in ascitic fluid, with renal clearance as a covariate. Dosing simulations showed that 90% PTA was achieved in the plasma with the current dosing regimen for MIC ≤ 16 mg/L (EUCAST susceptibility breakpoint) but not in the ascitic fluid if renal clearance was ≥40 mL/min. Hypothetical dosing with a higher (a) loading dose or (b) infused dose allowed to reach target concentrations in ascitic fluid (a) more rapidly or (b) sustainably, but these simulations need to be evaluated in the clinics for safety and efficacy.

Healthcare-associated infections in adult intensive care unit patients: Changes in epidemiology, diagnosis, prevention and contributions of new technologies

Patients in intensive care units (ICUs) are at high risk for healthcare-acquired infections (HAI) due to the high prevalence of invasive procedures and devices, induced immunosuppression, comorbidity, frailty and increased age. Over the past decade we have seen a successful reduction in the incidence of HAI related to invasive procedures and devices. However, the rate of ICU-acquired infections remains high. Within this context, the ongoing emergence of new pathogens, further complicates treatment and threatens patient outcomes. Additionally, the SARS-CoV-2 (COVID-19) pandemic highlighted the challenge that an emerging pathogen provides in adapting prevention measures regarding both the risk of exposure to caregivers and the need to maintain quality of care. ICU nurses hold a special place in the prevention and management of HAI as they are involved in basic hygienic care, steering and implementing quality improvement initiatives, correct microbiological sampling, and aspects antibiotic stewardship. The emergence of more sensitive microbiological techniques and our increased knowledge about interactions between critically ill patients and their microbiota are leading us to rethink how we define HAIs and best strategies to diagnose, treat and prevent these infections in the ICU. This multidisciplinary expert review, focused on the ICU setting, will summarise the recent epidemiology of ICU-HAI, discuss the place of modern microbiological techniques in their diagnosis, review operational and epidemiological definitions and redefine the place of several controversial preventive measures including antimicrobial-impregnated medical devices, chlorhexidine-impregnated washcloths, catheter dressings and chlorhexidine-based mouthwashes. Finally, general guidance is suggested that may reduce HAI incidence and especially outbreaks in ICUs.

Time to source control and outcome in community-acquired intra-abdominal infections: The multicentre observational PERICOM study

BACKGROUND

Optimal management of community-acquired intra-abdominal infections (IAI) requires timely surgical source control and adequate anti-infective treatment.

OBJECTIVE

To describe the initial management of community-acquired IAI admitted to the emergency department and assess the association between the length of time to either diagnosis or therapeutic procedures and patient outcomes.

DESIGN

A prospective, multicentre, observational study.

SETTING

Thirteen teaching hospitals in France between April 2018 and February 2019.

PATIENTS

Two hundred and five patients aged at least 18 years diagnosed with community-acquired IAI.

MAIN OUTCOME MEASURES

The primary outcome was hospital length of stay. The secondary outcome was hospital mortality.

RESULTS

Patients had a mean age of 56 (± 21) years and a median [interquartile] SAPS II of 26 [17 to 34]. Among the study cohort, 18% were postoperatively transferred to intensive care unit and 7% had died by day 28. Median [IQR] time to imaging, antibiotic therapy and surgery were 4 [2 to 6], 7.5 [4 to 12.5] and 9 [5.5 to 17] hours, respectively. The length of time to surgical source control [0.99, 95% confidence interval (CI), 0.98 to 0.99], SOFA greater than 2 [0.36 (95% CI, 0.26 to 0.651)], age greater than 60 years [0.65 (95% CI, 0.45 to 0.94)], generalized peritonitis [0.7 (95% CI, 0.56 to 0.89)] and laparotomy surgery [0.657 (95% CI, 0.42 to 0.78)] were associated with longer hospital length of stay. The duration of time to surgical source control [1.02 (95% CI, 1.01 to 1.04)], generalized peritonitis [2.41 (95% CI, 1.27 to 4.61)], and SOFA score greater than 2 [6.14 (95% CI, 1.40 to 26.88)] were identified as independent risk factors for 28-day mortality.

CONCLUSION

This multicentre observational study revealed that the time to surgical source control, patient severity and generalized peritonitis were identified as independent risk factors for increased hospital LOS and mortality in community-acquired IAI. Organisational strategies to reduce the time to surgical management of intra-abdominal infections should be further evaluated.

STUDY REGISTRATION

ClinicalTrials.gov on 1 April 2018, NCT03544203.

Comparison of Duration and Empiric Antibiotic Choice of Post-Operative Treatment in Abdominal Sepsis

Background: Although abdominal foci are the second most common source of sepsis, only few studies focus on the optimal length of post-operative antibiotic therapy in critically ill patients with abdominal sepsis. The aim of this study was to compare the outcomes of short versus long antibiotic therapy as well as broad-spectrum penicillin versus carbapenem in patients with abdominal sepsis. Patients and Methods: We performed a single center retrospective study in patients with abdominal sepsis who underwent emergency surgery. The study was conducted in a tertiary hospital in Germany during 2016-2018. We reviewed the duration of post-operative antibiotic therapy and the initially used agent, comparing patients treated shorter or longer than seven days with or without source control. Depending on the empirically given antibiotic, a subgroup analysis was conducted comparing patients treated with piperacillin-tazobactam versus carbapenems. Results: Longer duration of post-operative antibacterial treatment (>7 days) was not substantially advantageous. The group with a longer course of antibiotic therapy had more severe post-operative complications (82.4% [n = 61] vs. 62.5% [n = 20]; p = 0.01) requiring longer critical care support (18 days vs. 11 days; p = 0.027), prolonging the length of stay (28 days vs. 20 days; p = 0.044). Surgical re-interventions were more frequent in the long-course arm (70.3% vs. 40.6%; p = 0.004). The subgroup analysis comparing piperacillin-tazobactam versus carbapenems confirmed more severe complications (86.3% vs. 67.5%; p = 0.04) for the carbapenem arm. Conclusions: Post-surgical continuation of antibiotic agents beyond seven days was observed with more post-operative complications and delayed recovery. Piperacillin-tazobactam seems to be a potent alternative for patients with abdominal sepsis.

Is ß-d-glucan Relevant for the Diagnosis and Follow-Up of Intensive Care Patients with Yeast-Complicated Intra-Abdominal Infection?

The usefulness of (1,3)-ß-d-glucan (BDG) detection for the diagnosis of intra-abdominal candidiasis and treatment monitoring is unknown. A prospective, single-center study of consecutive patients admitted to an ICU with complicated intra-abdominal infection (IAI) over a 2-year period was conducted. BDG was measured in the peritoneal fluid and serum between day 1 (D1) and D10. Patients with a positive peritoneal fluid yeast culture (YP) were compared to those with a negative yeast culture (YN). The evolution of serum BDG was compared in the two groups. Seventy patients were included (sixty-five analyzed): YP group (n = 19) and YN group (n = 46). Median peritoneal BDG concentration during surgery was 2890 pg.mL⁻¹ [IQR: 942–12,326] in the YP group vs. 1202 pg.mL⁻¹ [IQR: 317–4223] in the YN group (p = 0.13). Initial serum BDG concentration was 130 pg.mL⁻¹ [IQR: 55–259] in the YP group vs. 88 pg.mL⁻¹ [IQR: 44–296] in the YN group (p = 0.78). No difference in evolution of serum BDG concentrations was observed between the groups (p = 0.18). In conclusion, neither peritoneal BDG nor serum BDG appear to be good discriminating markers for the diagnosis of yeast IAI. In addition, monitoring the evolution of serum BDG in yeast IAI did not appear to be of any diagnostic value.

Ceftolozane/tazobactam versus colistin in the treatment of ventilator-associated pneumonia due to extensively drug-resistant Pseudomonas aeruginosa

Resistant strains of Pseudomonas aeruginosa are common pathogens in the intensive care unit (ICU), limiting available therapeutic options. We aimed to compare ceftolozane/tazobactam (C/T) with colistimethate sodium (CMS) in the treatment of ventilator-associated pneumonia (VAP) due to extensively drug-resistant (XDR) Pseudomonas aeruginosa. A retrospective, observational study was performed at a tertiary care ICU. Clinical and microbiological success rate, 28-day all-cause mortality, and adverse events were compared in patients who received C/T with those treated with systemic CMS. A total of 51 patients were included (18 in the C/T and 33 in the CMS group). Clinical success rates in the C/T and CMS groups were 13 (72.2%) and 10 (30.3%), respectively. On multivariate regression analysis, treatment with C/T was independently associated with clinical success (odds ratio 4.47, 95% CI 1.17–17.08). There was no difference in 28-day all-cause mortality (27.8% and 33.3% in the C/T and CMS group, p = 0.76). Acute kidney injury was more common in patients who received CMS (48.5% vs 11.1%, p = 0.01). In our study, ceftolozane/tazobactam was more efficacious in the treatment of XDR Pseudomonas aeruginosa VAP and showed a better safety profile compared to CMS.

Risk Factors for Mortality in Abdominal Infection Patients in ICU: A Retrospective Study From 2011 to 2018

To identify the risk factors related to the patient's 28-day mortality, we retrospectively reviewed the records of patients with intra-abdominal infections admitted to the ICU of Nanfang Hospital, Southern Medical University from 2011 to 2018. Multivariate Cox proportional hazard regression analysis was used to identify independent risk factors for mortality. Four hundred and thirty-one patients with intra-abdominal infections were analyzed in the study. The 28-day mortality stepwise increased with greater severity of disease expression: 3.5% in infected patients without sepsis, 7.6% in septic patients, and 30.9% in patients with septic shock (p &lt; 0.001). In multivariate analysis, independent risk factors for 28-day mortality were underlying chronic diseases (adjusted HR 3.137, 95% CI 1.425–6.906), high Sequential Organ Failure Assessment (SOFA) score (adjusted HR 1.285, 95% CI 1.160–1.424), low hematocrit (adjusted HR 1.099, 95% CI 1.042–1.161), and receiving more fluid within 72 h (adjusted HR 1.028, 95% CI 1.015–1.041). Compared to the first and last 4 years, the early use of antibiotics, the optimization of IAT strategies, and the restriction of positive fluid balance were related to the decline in mortality of IAIs in the later period. Therefore, underlying chronic diseases, high SOFA score, low hematocrit, and receiving more fluid within 72 h after ICU admission were independent risk factors for patients' poor prognosis.

Metagenomic Next-Generation Sequencing for the Microbiological Diagnosis of Abdominal Sepsis Patients

Objectives

For patients with intra-abdominal infection (IAI), the rapid and accurate identification of pathogens remains a challenge. Metagenomic next-generation sequencing (mNGS) is a novel technique for infectious diseases, but its application in IAI is limited. In this study, we compared the microbiological diagnostic ability of plasma mNGS with that of conventional peritoneal drainage (PD) culture in critical care settings.

Methods

From January 2018 to December 2020, a prospective observational study was performed at a tertiary teaching hospital in China and data on 109 abdominal sepsis patients were collected. The pathogen detection performance of plasma mNGS and PD culture method were compared.

Measurements and Results

Ninety-two positive cases detected on PD culture, while plasma mNGS detected 61 positive cases. Forty-five patients (44.0%) had at least one matched pair of plasma mNGS and PD culture results. Compared with PD culture, the plasma mNGS was more rapid (27.1 ± 4.0 vs. 68.9 ± 22.3 h, p < 0.05). The patients received initial antibiotic treatment matched with mNGS detection showed better clinical outcomes.

Conclusion

For abdominal sepsis patients, plasma mNGS can provide early, noninvasive, and rapid microbiological diagnosis. Compared with conventional PD smear, culture, and blood culture methods, plasma mNGS promote the rapid detection of pathogenic bacteria.

Risk Factors for Intra-Abdominal Candidiasis in Intensive Care Units: Results from EUCANDICU Study

INTRODUCTION

Intra-abdominal infections represent the second most frequently acquired infection in the intensive care unit (ICU), with mortality rates ranging from 20% to 50%. Candida spp. may be responsible for up to 10-30% of cases. This study assesses risk factors for development of intra-abdominal candidiasis (IAC) among patients admitted to ICU.

METHODS

We performed a case-control study in 26 European ICUs during the period January 2015-December 2016. Patients at least 18 years old who developed an episode of microbiologically documented IAC during their stay in the ICU (at least 48 h after admission) served as the case cohort. The control group consisted of adult patients who did not develop episodes of IAC during ICU admission. Matching was performed at a ratio of 1:1 according to time at risk (i.e. controls had to have at least the same length of ICU stay as their matched cases prior to IAC onset), ICU ward and period of study.

RESULTS

During the study period, 101 case patients with a diagnosis of IAC were included in the study. On univariate analysis, severe hepatic failure, prior receipt of antibiotics, prior receipt of parenteral nutrition, abdominal drain, prior bacterial infection, anastomotic leakage, recurrent gastrointestinal perforation, prior receipt of antifungal drugs and higher median number of abdominal surgical interventions were associated with IAC development. On multivariate analysis, recurrent gastrointestinal perforation (OR 13.90; 95% CI 2.65-72.82, p = 0.002), anastomotic leakage (OR 6.61; 95% CI 1.98-21.99, p = 0.002), abdominal drain (OR 6.58; 95% CI 1.73-25.06, p = 0.006), prior receipt of antifungal drugs (OR 4.26; 95% CI 1.04-17.46, p = 0.04) or antibiotics (OR 3.78; 95% CI 1.32-10.52, p = 0.01) were independently associated with IAC.

CONCLUSIONS

Gastrointestinal perforation, anastomotic leakage, abdominal drain and prior receipt of antifungals or antibiotics may help to identify critically ill patients with higher probability of developing IAC. Prospective studies are needed to identify which patients will benefit from early antifungal treatment.

Intra-abdominal Infections

Intra-abdominal infections (IAIs) are a common cause of sepsis, and frequently occur in intensive care unit (ICU) patients. IAIs include many diagnoses, including peritonitis, cholangitis, diverticulitis, pancreatitis, abdominal abscess, intestinal perforation, abdominal trauma, and pelvic inflammatory disease. IAIs are the second most common cause of infectious morbidity and mortality in the ICU after pneumonia. IAIs are also the second most common cause of sepsis in critically ill patients, and affect approximately 5% of ICU patients. Mortality with IAI in ICU patients ranges from 5 to 50%, with the wide variability related to the specific IAI present, associated patient comorbidities, severity of illness, and organ dysfunction and failures. It is important to have a comprehensive understanding of IAIs as potential causes of life-threatening infections in ICU patients to provide the best diagnostic and therapeutic care for optimal patient outcomes in the ICU.

Characteristics of Sepsis-2 septic shock patients failing to satisfy the Sepsis-3 septic shock definition: an analysis of real-time collected data

BACKGROUND

Baseline characteristics and disease severity of patients with septic shock according to the new Sepsis-3 definition may differ from patients that only comply with the Sepsis-2 definition. We conducted a retrospective cohort study on the ICU of a Belgian tertiary care facility to seek out differences between these two patient groups and to identify variables associated with no longer satisfying the latest definition of septic shock.

RESULTS

Of 1198 patients with septic shock according to the Sepsis-2 consensus definition, 233 (19.4%) did not have septic shock according to the Sepsis-3 shock definition. These patients more often had medical admission reasons and a respiratory infection as cause for the septic shock. They less often had surgery on admission and were less likely to have chronic liver disease (5.6% vs 16.2%, absolute difference 10.6% (95% CI 6.4-14.1%). Patients with septic shock only according to the old definition had significant lower APACHE II and SOFA scores and lower hospital mortality (31.6% vs 55.3%, p < 0.001). In a multivariate analysis, following variables were associated with Sepsis-2 shock patients no longer being defined as such by the Sepsis-3 definition: respiratory infection (OR 1.485 (95% CI 1.56-2.089), p = 0.023), a medical admission reason (OR 1.977 (95% CI 1.396-2.800) and chronic liver disease (OR 0.345 (95% CI 0.181-0.660), p < 0.001).

CONCLUSIONS

One in five patients with septic shock according to the Sepsis-2 consensus definition is no longer considered as such when the Sepsis-3 shock criteria are applied. A medical admission reason, a respiratory infection and absence of chronic liver disease are independently associated with no longer being identified as having septic shock by the Sepsis-3 criteria.

Tertiary peritonitis: considerations for complex team-based care

Peritonitis, as a major consequence of hollow visceral perforation, anastomotic disruption, ischemic necrosis, or other injuries of the gastrointestinal tract, often drives acute care in the emergency department, operating room, and the ICU. Chronic critical illness (CCI) represents a devastating challenge in modern surgical critical care where successful interventions have fostered a growing cohort of patients with prolonged dependence on mechanical ventilation and other organ supportive therapies who would previously have succumbed much earlier in the acute phase of critical illness. An important subset of CCI patients are those who have survived an emergency abdominal operation, but who subsequently require prolonged open abdomen management complicated by persistent peritoneal space infection or colonization, fistula formation, and gastrointestinal (GI) tract dysfunction; these patients are described as having tertiary peritonitis (TP).The organ dysfunction cascade in TP terminates in death in between 30 and 64% of patients. This narrative review describes key—but not all—elements in a framework for the coordinate multiprofessional team-based management of a patient with tertiary peritonitis to mitigate this risk of death and promote recovery. Given the prolonged critical illness course of this unique patient population, early and recurrent Palliative Care Medicine consultation helps establish goals of care, support adjustment to changes in life circumstance, and enable patient and family centered care.

How to Handle CT-Guided Abscess Drainages in Microbiological Analyses? Sterile Vials vs. Blood Culture Bottles for Transport and Processing

The aim of this investigation was to compare microbiological analyses of 100 computed tomography-guided drainages from infectious foci (thoracic, abdominal, musculoskeletal), transported and analyzed by two widely established techniques, that are (i) sterile vials or (ii) inoculated blood culture bottles. The mean number of detected microorganisms from blood culture (aerobic/anaerobic) or conventional method (sterile vial, solid and broth media) per specimen were comparable with 1.29 and 1.41, respectively (p = 1.0). The conventional method showed a trend towards shorter time-to-result (median 28.62 h) in comparison to blood culture incubation (median 43.55 h) (p = 0.0722). Of note, detection of anaerobes (13% vs. 36%) and the number of detected microorganisms in polymicrobial infections (2.76 vs. 3.26) differed significantly with an advantage towards conventional techniques (p = 0.0015; p = 0.035), especially in abdominal aspirations. Despite substantially overlapping results from both techniques, the conventional approach includes some benefits which justify its role as standard approach.

Postoperative abdominal sepsis induces selective and persistent changes in CTCF binding within the MHC-II region of human monocytes

Background

Postoperative abdominal infections belong to the most common triggers of sepsis and septic shock in intensive care units worldwide. While monocytes play a central role in mediating the initial host response to infections, sepsis-induced immune dysregulation is characterized by a defective antigen presentation to T-cells via loss of Major Histocompatibility Complex Class II DR (HLA-DR) surface expression. Here, we hypothesized a sepsis-induced differential occupancy of the CCCTC-Binding Factor (CTCF), an architectural protein and superordinate regulator of transcription, inside the Major Histocompatibility Complex Class II (MHC-II) region in patients with postoperative sepsis, contributing to an altered monocytic transcriptional response during critical illness.

Results

Compared to a matched surgical control cohort, postoperative sepsis was associated with selective and enduring increase in CTCF binding within the MHC-II. In detail, increased CTCF binding was detected at four sites adjacent to classical HLA class II genes coding for proteins expressed on monocyte surface. Gene expression analysis revealed a sepsis-associated decreased transcription of (i) the classical HLA genes HLA-DRA, HLA-DRB1, HLA-DPA1 and HLA-DPB1 and (ii) the gene of the MHC-II master regulator, CIITA (Class II Major Histocompatibility Complex Transactivator). Increased CTCF binding persisted in all sepsis patients, while transcriptional recovery CIITA was exclusively found in long-term survivors.

Conclusion

Our experiments demonstrate differential and persisting alterations of CTCF occupancy within the MHC-II, accompanied by selective changes in the expression of spatially related HLA class II genes, indicating an important role of CTCF in modulating the transcriptional response of immunocompromised human monocytes during critical illness.

Sepsis after elective surgery - Incidence, aetiology and outcome

BACKGROUND

Sepsis requiring admission to intensive care (ICU) is a rare complication of elective surgery, but is associated with high morbidity and mortality. The aim of this study was to describe the incidence and outcome of sepsis following elective surgery.

METHODS

This was a retrospective, observational study where all admissions to Icelandic ICUs during calendar years 2006, 2008, 2010, 2012, 2014 and 2016 were screened, identifing patients with sepsis following elective surgery (ACCP/SCCM criteria). The number of elective operations performed at the largest center (Landspitali) during the study years were collected. Descriptive statistics were used to assess the incidence and outcome of patients with sepsis after elective surgery.

RESULTS

During the study years, 88 patients were admitted to Icelandic ICUs with sepsis following elective surgery. Of those, 80 were operated at Landspitali, where the incidence of sepsis was 0.19% per elective procedure, highest following pancreaticoduodenectomies (14%, CI 6-25) and esophagectomies (13%, CI 4-27), but the greatest number of patients (30% (26/88)) developed sepsis after a colorectal procedure. The most common infection sources were the abdomen (65% (57/88)) and lungs/mediastinum (22% (19/88)), frequently polymicrobial (58% (36/62) of patients with cultures). The incidence of insufficient empirical antibiotics was high (50% (30/60)). The median ICU and hospital length-of-stay were 5.5 and 26 days and the 28-day and 1-year mortality rates were 16% (14/88) and 41% (36/87), respectively.

CONCLUSIONS

Incidence of sepsis following elective surgery is low in Iceland but mortality is high. Initial antimicrobial therapy needs careful consideration in these hospital-acquired, often polymicrobial infections.

Clinical Efficacy and Safety of Cefoperazone-Sulbactam in Treatment of Intra-Abdominal Infections: A Systematic Review and Meta-Analysis

Background: In this systematic review and meta-analysis, we aimed to assess the clinical efficacy and safety of cefoperazone-sulbactam against alternative antibiotics in the treatment of intra-abdominal infections. Methods: The PubMed, Cochrane, Web of Science, Ovid Medline, and CKNI databases were searched for relevant articles up to November 25, 2020. The primary outcome was clinical efficacy rate, and the secondary outcomes were microbiologic eradication rate, mortality rate, and adverse event (AE) risk. Results: Twelve studies involving 1,674 patients were included. Overall, the clinical efficacy rate of cefoperazone-sulbactam and comparators was 87.7% and 81.7%, respectively, and cefoperazone-sulbactam was associated with a higher clinical efficacy rate than that the comparator (odds ratio [OR] 1.98; 95% confidence interval [CI] 1.31-3.00; I² = 36%). Additionally, cefoperazone-sulbactam was associated with a lower clinical failure rate (OR 0.40; 95% CI 0.28-0.57; I² = 0) and a higher clinical cure rate (OR 1.54; 95% CI 1.17-2.03; I² = 0) than the comparators. Cefoperazone-sulbactam was associated with a higher microbiologic eradication rate than the comparator (OR 2.54; 95% CI 1.72-3.76; I² = 0). Finally, there was no significant difference between cefoperazone-sulbactam and the comparators in terms of mortality rate (OR 090; 95% CI 0.38-2.16; I² = 0) and AE risk (OR 1.07; 95% CI 0.74-1.55; I² = 0). Conclusions: The clinical efficacy and safety of cefoperazone-sulbactam were similar to those of alternative antibiotics in the treatment of intra-abdominal infections. Therefore, cefoperazone-sulbactam could be recommended as an effective and safe antibiotic for treating intra-abdominal infections.

Novel Multiparametric Nomogram for Overall Survival Prediction in Complicated Intra-Abdominal Infection: A Multicenter Study in China

Background: Complicated intra-abdominal infections (cIAIs) in the abdominal cavity or within an abdominal organ are numerous and frequent dangerous entities in the treatment of critically ill patients. Early clinical evaluation is necessary.

Methods: This retrospective multicenter study included patients from 10 intensive care units (ICUs). Risk factors for the overall survival (OS) of patients with cIAI were selected using least absolute shrinkage and selection operator regression, and a nomogram was constructed subsequently. Calibration curve and receiver operating characteristic (ROC) curve were used to evaluate the calibration and discriminative ability.

Results: In total, 544 patients diagnosed with cIAI were enrolled and divided into the study (n = 276) and validation (n = 268) sets. Sex, acute gastrointestinal injury, acute kidney injury, rare bacterium infection, Charlson score, and APACHE II score were identified as independent risk factors and were constructed for the nomogram. The nomogram showed marked calibration capability with a concordance index (C-index) of 0.909 and 0.831 in the study and validation set, respectively. Compared with the common clinical prognostic scoring system, the nomogram achieved the highest discrimination ability with an area under the curve (AUC) value of 0.91 and 0.83 in the study set and validation set, respectively.

Conclusions: Our newly constructed nomogram provides a useful tool for risk stratification and prognosis evaluation of cIAI.

Risk Factors and Molecular Epidemiology of Complicated Intra-Abdominal Infections With Carbapenem-Resistant Enterobacteriaceae: A Multicenter Study in China

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) infections are associated with poor patient outcomes. Data on risk factors and molecular epidemiology of CRE in complicated intra-abdominal infections (cIAI) in China are limited. This study examined the risk factors of cIAI with CRE and the associated mortality based on carbapenem resistance mechanisms.

METHODS

In this retrospective analysis, we identified 1024 cIAI patients hospitalized from January 1, 2013 to October 31, 2018 in 14 intensive care units in China. Thirty CRE isolates were genotyped to identify β-lactamase-encoding genes.

RESULTS

Escherichia coli (34.5%) and Klebsiella pneumoniae (21.2%) were the leading pathogens. Patients with hospital-acquired cIAI had a lower rate of E coli (26.0% vs 49.1%; P < .001) and higher rate of carbapenem-resistant Gram-negative bacteria (31.7% vs 18.8%; P = .002) than those with community-acquired cIAI. Of the isolates, 16.0% and 23.4% of Enterobacteriaceae and K pneumoniae, respectively, were resistant to carbapenem. Most carbapenemase-producing (CP)-CRE isolates carried blaKPC (80.9%), followed by blaNMD (19.1%). The 28-day mortality was 31.1% and 9.0% in patients with CRE vs non-CRE (P < .001). In-hospital mortality was 4.7-fold higher for CP-CRE vs non-CP-CRE infection (P = .049). Carbapenem-containing combinations did not significantly influence in-hospital mortality of CP and non-CP-CRE. The risk factors for 28-day mortality in CRE-cIAI included septic shock, antibiotic exposure during the preceding 30 days, and comorbidities.

CONCLUSIONS

Klebsiella pneumoniae had the highest prevalence in CRE. Infection with CRE, especially CP-CRE, was associated with increased mortality in cIAI.

Performance of nasal methicillin-resistant Staphylococcus aureus screening for intra-abdominal infections in critically ill adult patients

STUDY OBJECTIVE

Intra-abdominal infections (IAIs) are a common reason for intensive care unit (ICU) admissions, and methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon pathogen in IAIs. Although more data are available in the setting of non-abdominal sources, there are limited data on the performance of nasal MRSA screening for MRSA IAIs. The primary objective of this study was to evaluate the performance of nasal MRSA screening for MRSA IAIs in critically ill adult patients.

DESIGN

This was a multicenter, retrospective, cohort study.

SETTING

A 14-hospital healthcare system between January 1, 2014, and August 31, 2019.

PATIENTS

Adult patients admitted to an ICU for at least 24 h with a diagnosis code for an IAI, a nasal MRSA surveillance screen within 30 days, and an intra-abdominal culture were eligible for inclusion.

INTERVENTION

The primary outcome was to evaluate the performance of nasal MRSA screening for MRSA IAIs by calculating the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

MEASUREMENTS AND MAIN RESULTS

Out of 863 patients randomly screened, a total of 192 patients were included. The study population had a mean age of 60 (SD ±15) years, and 101 (53%) patients were male. Six (3.1%) patients were positive for an MRSA IAI, of which four (66.7%) demonstrated a positive nasal MRSA screen. A total of 186 (96.8%) patients were negative for a MRSA IAI, of which 19 (10.2%) were nasal MRSA-positive and 167 (89.8%) were nasal MRSA-negative. Nasal MRSA screening demonstrated the following performance: accuracy 89.1% (95% CI: 83.8%-93.1%), sensitivity 66.7% (95% CI: 22.3%-95.7%), specificity 89.8% (95% CI: 84.5%-93.7%), PPV 17.4% (95% CI: 9.4%-30.0%), and NPV 98.8% (95% CI: 96.4%-99.6%). There were no significant differences in clinical outcomes, including renal replacement-free days, ICU and hospital length of stay, and in-hospital mortality.

CONCLUSIONS

Among critically ill adult patients with IAIs, a negative nasal MRSA screen within 30 days may help to empirically exclude MRSA as a causative pathogen.

Current progress of source control in the management of intra-abdominal infections

Intra-abdominal infection (IAI) is a deadly condition in which the outcome is associated with urgent diagnosis, assessment and management, including fluid resuscitation, antibiotic administration while obtaining further laboratory results, attaining precise measurements of hemodynamic status, and pursuing source control. This last item makes abdominal sepsis a unique treatment challenge. Delayed or inadequate source control is an independent predictor of poor outcomes and recognizing source control failure is often difficult or impossible. Further complicating issue in the debate is surrounding the timing, adequacy, and procedures of source control. This review evaluated and summarized the current approach and challenges in IAI management, which are the future research directions.

High mobilization of CD133+/CD34+ cells expressing HIF-1α and SDF-1α in septic abdominal surgical patients

Background

The control of endothelial progenitor cells (CD133+/CD34+ EPCs) migrating from bone marrow to peripheral blood is not completely understood. Emerging evidence suggests that stromal cell-derived factor-1α (SDF-1α) mediates egression of EPCs from bone marrow, while the hypoxia inducible factor (HIF) transcriptional system regulates SDF-1α expression. Our study aimed to investigate the time course of circulating CD133+/CD34+ EPCs and its correlation with the expression of HIF-1α protein and SDF-1α in postoperative laparoscopic abdominal septic patients.

Methods

Postoperative patients were divided in control (C group) and septic group (S group) operated immediately after the diagnosis of sepsis/septic shock. Blood samples were collected at baseline (0), 1, 3 and 7 postoperative days for CD133+/CD34+ EPCs count expressing or not the HIF-1α and SDF-1α analysis.

Results

Thirty-two patients in S group and 39 in C group were analyzed. In C group CD133+/CD34+ EPCs count remained stable throughout the study period, increasing on day 7 (173 [0–421] /μl vs baseline: P = 0.04; vs day 1: P = 0.002). In S group CD133+/CD34+ EPCs count levels were higher on day 3 (vs day 1: P = 0.006 and day 7: P = 0.026). HIF-1α expressing CD133+/CD34+ EPCs count decreased on day 1 as compared with the other days in C group (day 0 vs 1: P = 0.003, days 3 and 7 vs 1: P = 0.008), while it was 321 [0–1418] /μl on day 3 (vs day 1; P = 0.004), and 400 [0–587] /μl on day 7 in S group. SDF-1α levels were higher not only on baseline but also on postoperative day 1 in S vs C group (219 [124–337] pg/ml vs 35 [27–325] pg/ml, respectively; P = 0.01).

Conclusion

Our results indicate that sepsis in abdominal laparoscopic patients might constitute an additional trigger of the EPCs mobilization as compared with non-septic surgical patients. A larger mobilization of CD133+/CD34+ EPCs, preceded by enhanced plasmatic SDF-1α, occurs in septic surgical patients regardless of HIF-1α expression therein.

Trial registration

ClinicalTrials.gov no. NCT02589535. Registered 28 October 2015.

The Bucharest ESTES consensus statement on peritonitis

INTRODUCTION

Peritonitis is still an important health problem associated with high morbidity and mortality. A multidisciplinary approach to the management of patients with peritonitis may be an important factor to reduce the risks for patients and improve efficiency, outcome, and the cost of care.

METHODS

Expert panel discussion on Peritonitis was held in Bucharest on May 2017, during the 17th ECTES Congress, involving surgeons, infectious disease specialists, radiologists and intensivists with the goal of defining recommendations for the optimal management of peritonitis.

CONCLUSION

This document is an updated presentation of management of peritonitis and represents the summary of the final recommendations approved by a panel of experts.

Clinical and Microbiological Characteristics of Patients with Complicated Intra-abdominal Infections in Intensive Care Unit

In order to investigate the clinical and microbiological characteristics of patients with complicated intra-abdominal infections (cIAIs) in intensive care unit (ICU), the clinical data of 612 cIAIs patients from January 2016 to December 2018 were retrospectively collected. Clinical characteristics, distribution of pathogens and drug resistance were statistically analyzed. It was found that patients with community-acquired intra-abdominal infections (CA-IAIs) made up a majority of cIAIs patients. The positive rate of abdominal drainage fluid culture was 55.56%. Gramnegative bacteria accounted for the majority, the most commonly isolated bacteria of which were Escherichia coli (20.96%), Klebsiella pneumoniae (10.20%) and Pseudomonas aeruginosa (5.57%). The most commonly isolated gram-positive bacteria were Enterococcus (16.88%) and Methicillin-resistant staphylococcus aureus (MRSA, 3.90%). Enterobacter isolates showed high resistance rate to most cephalosporins and low resistance rate to piperacillin/tazobactam and carbapenems. Extended spectrum beta-lactamase (ESBL) screen positive isolates from CA-IAIs patients showed an increasing trend in past three years. Enterococcus and MRSA showed high resistance rate to clindamycin, quinolone, erythromycin and tetracycline, while they showed high sensitivity rate to linezolid, tegacycline, teicoplanin and vancomycin. Our results indicate that isolated bacteria from abdominal drainage fluid show high resistance rates to commonly used antibiotics in ICU patients with cIAIs. The curative effects on diseases should be monitored continuously when antibiotics are used. Meanwhile, we should always keep eyes on drug-resistant bacteria, especially when the treatment efficacy is not good.

Antimicrobial Susceptibility of Microorganisms Isolated from Patients with Intraabdominal Infection in Korea: a Multicenter Study

BACKGROUND

This study evaluated the antimicrobial susceptibility of pathogens isolated from Korean patients with intraabdominal infections (IAIs).

METHODS

This multicenter study was conducted at 6 university-affiliated hospitals in Korea between 2016 and 2018. All patients with microbiologically proven IAIs were retrospectively included, while patients with spontaneous bacterial peritonitis or continuous ambulatory peritoneal dialysis peritonitis were excluded. Identification and antimicrobial susceptibility testing were performed using automated microbiology systems.

RESULTS

A total of 2,114 non-duplicated clinical isolates were collected from 1,571 patients. Among these pathogens, 510 (24.1%) were isolated from nosocomial infections, and 848 isolates (40.1%) were associated with complicated IAIs. The distribution of the microorganisms included aerobic gram-negative (62.6% of isolates), aerobic gram-positive (33.7%), anaerobic (0.9%), and fungal (2.8%) pathogens. The most common pathogens were Escherichia coli (23.8%), followed by Enterococcus spp. (23.1%) and Klebsiella spp. (19.8%). The susceptibility rates of E. coli and Klebsiella spp. to major antibiotics were as follows: amoxicillin/clavulanate (62.5%, 83.0%), cefotaxime (61.4%, 80.7%), ceftazidime (63.7%, 83.1%), cefepime (65.3%, 84.3%), ciprofloxacin (56.4%, 86.3%), piperacillin/tazobactam (99.0%, 84.8%), amikacin (97.4%, 98.3%), and imipenem (99.8%, 98.8%). The susceptibility rates of Enterococcus spp. to ampicillin were 61.0%, amoxicillin/clavulanate, 63.6%; ciprofloxacin, 49.7%; imipenem, 65.2%; and vancomycin, 78.2%. The susceptibility rates of Pseudomonas aeruginosa and Acinetobacter spp. to imipenem were 77.4% and 36.7%, respectively.

CONCLUSION

Enterococcus spp. with susceptibility to limited antibiotics was one of the main pathogens in Korean IAIs, along with E. coli and Klebsiella spp., which were highly susceptible to imipenem, amikacin, and piperacillin/tazobactam. Meanwhile, the low susceptibilities of E. coli or Klebsiella spp. to amoxicillin/clavulanate, advanced-generation cephalosporins, and ciprofloxacin should be considered when determining empirical antibiotic therapy in clinical practice.

Clinical implications of multidrug-resistant microorganisms and fungi isolated from patients with intra-abdominal infections in the Republic of Korea: a multicenter study

The purpose of this study was to evaluate the clinical significance of fungi and multidrug-resistant organisms (MDROs) isolated from patients with intra-abdominal infections (IAIs). This multicenter study included consecutive patients admitted for microbiologically proven IAIs at 6 university-affiliated hospitals in South Korea between 2016 and 2018. A total of 1571 patients were enrolled. Multivariable logistic regression analysis revealed that the isolation of MDROs, isolation of Candida spp., underlying renal diseases, Charlson comorbidity score ≥ 3, septic shock, failure to receive a required surgery or invasive intervention, secondary bacteremia due to IAIs, and lower body mass index were found to be independent predictors for 28-day mortality. However, the isolation of Enterococcus spp. was not identified as a significant risk factor. MDROs and Candida spp. were found in 42 (2.7%) and 395 (25.1%), patients respectively. The isolation of MDROs or Candida spp. was a surrogate marker of 28-day mortality.

Post-operative abdominal infections: epidemiology, operational definitions, and outcomes

Postoperative abdominal infections are an important and heterogeneous health challenge in intensive care units (ICU) and encompass postoperative infectious processes developing within the abdominal cavity that may be caused by either bacterial or fungal pathogens. In this narrative review, we discuss postoperative bacterial and fungal abdominal infections, covering also multidrug-resistant (MDR) pathogens. We also cover clinically preeminent aspects such as the definition of postoperative abdominal infections, which still remains difficult owing to their heterogeneity in patient characteristics, clinical presentation, ecology and antimicrobial treatment. With regard to treatment, modifiable factors such as source control and antimicrobial therapy play a key role in influencing the prognosis of postoperative abdominal infections, but several conditions may hamper their correct application; thus efforts should necessarily be devoted towards improving their appropriateness and timing. Hot topics regarding the characteristics and management of postoperative abdominal infections are discussed in this narrative review.

Therapeutic drug monitoring of β-lactam antibiotics in the critically ill: direct measurement of unbound drug concentrations to achieve appropriate drug exposures

Objectives

To describe the achievement of unbound β-lactam antibiotic concentration targets in a therapeutic drug monitoring (TDM) programme in critically ill patients, and the factors associated with failure to achieve a target concentration.

Patients and methods

Plasma samples and clinical data were obtained for analysis from a single centre prospectively. Unbound concentrations of ceftriaxone, cefazolin, meropenem, ampicillin, benzylpenicillin, flucloxacillin and piperacillin were directly measured using ultracentrifugation. Factors associated with the achievement of pharmacokinetic/pharmacodynamic (PK/PD) targets or negative clinical outcomes were evaluated with binomial logistic regression.

Results

TDM data from 330 patients, and 369 infection episodes, were included. The range of doses administered was 99.4% ± 45.1% relative to a standard daily dose. Dose increases were indicated in 33.1% and 63.4% of cases to achieve PK/PD targets of 100% fT>MIC and 100% fT>4×MIC, respectively. Dose reduction was indicated in 17.3% of cases for an upper PK/PD threshold of 100% fT>10×MIC. Higher protein bound β-lactams (ceftriaxone and benzylpenicillin) had better therapeutic target attainment (P < 0.01), but were prone to excessive dosing. Augmented renal clearance (calculated CLCR >130 mL/min) increased the odds of failure to achieve 100% fT>MIC and 100% fT>4×MIC (OR 2.47 and 3.05, respectively; P < 0.01).

Conclusions

Measuring unbound concentrations of β-lactams as part of a routine TDM programme is feasible and demonstrates that a large number of critically ill patients do not achieve predefined PK/PD targets. The clinical significance of this finding is unknown due to the lack of correlation between PK/PD findings and clinical outcomes.