Spontaneous peritonitis in critically ill cirrhotic patients: a diagnostic algorithm for clinicians and future perspectives

Burden of severe infections due to carbapenem-resistant pathogens in intensive care unit

Intensive care units (ICU) for various reasons, including the increasing age of admitted patients, comorbidities, and increasingly complex surgical procedures (e.g., transplants), have become "the epicenter" of nosocomial infections, these are characterized by the presence of multidrug-resistant organisms (MDROs) as the cause of infection. Therefore, the perfect match of fragile patients and MDROs, as the cause of infection, makes ICU mortality very high. Furthermore, carbapenems were considered for years as last-resort antibiotics for the treatment of infections caused by MDROs; unfortunately, nowadays carbapenem resistance, mainly among Gram-negative pathogens, is a matter of the highest concern for worldwide public health. This comprehensive review aims to outline the problem from the intensivist's perspective, focusing on the new definition and epidemiology of the most common carbapenem-resistant MDROs (Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacterales) to emphasize the importance of the problem that must be permeating clinicians dealing with these diseases.

Clinical Characteristics and Early Diagnosis of Spontaneous Fungal Peritonitis/Fungiascites in Hospitalized Cirrhotic Patients with Ascites: A Case-Control Study

BACKGROUND

Spontaneous fungal peritonitis (SFP) and fungiascites is less well-recognized and described in patients with liver cirrhosis. The aims of this study were to determine the clinical characteristics, prognosis, and risk factors of cirrhotic patients with SFP/fungiascites and to improve early differential diagnosis with spontaneous bacterial peritonitis (SBP).

METHODS

This was a retrospective case-control study of 54 cases of spontaneous peritonitis in cirrhotic patients (52 SFP and 2 fungiascites) with fungus-positive ascitic culture. Fifty-four SBP cirrhotic patients with bacteria-positive ascitic culture were randomly enrolled as a control group. A nomogram was developed for the early differential diagnosis of SFP and fungiascites.

RESULTS

Hospital-acquired infection was the main cause of SFP/fungiascites. Of the 54 SFP/fungiascites patients, 31 (57.41%) patients carried on with the antifungal treatment, which seemed to improve short-term (30-days) mortality but not long-term mortality. Septic shock and HCC were independent predictors of high 30-day mortality in SFP/fungiascites patients. We constructed a predictive nomogram model that included AKI/HRS, fever, (1,3)-β-D-glucan, and hospital-acquired infection markers for early differential diagnosis of SFP/fungiascites in cirrhotic patients with ascites from SBP, and the diagnostic performance was favorable, with an AUC of 0.930 (95% CI: 0.874-0.985).

CONCLUSIONS

SFP/fungiascites was associated with high mortality. The nomogram established in this article is a useful tool for identifying SFP/fungiascites in SBP patients early. For patients with strongly suspected or confirmed SFP/fungiascites, timely antifungal therapy should be administered.

Performance of Leukocyte Esterase Reagent Strips in the Detection of Spontaneous Bacterial Peritonitis in Cirrhotic Patients: A Systematic Review and Meta-analysis

Background

Spontaneous bacterial peritonitis (SBP) is a bacterial infection associated with a high mortality rate in cirrhotic patients. The gold standard for the detection of SBP is a manual cell count from ascitic fluid; however, alternative screening methods are under investigation. In particular, leukocyte esterase reagent strips (LERS) has been studied as an alternative method to detect SBP with a low cost and instant turnaround time. Therefore, this study aims to evaluate the performance of LERS in the detection of SBP.

Methods

A literature search was performed for studies evaluating LERS for the detection of SBP on PubMed, Embase, Scopus, Cochrane, and clinical trial registries. Summary sensitivity, specificity, log diagnostic odds ratio (LDOR), and the area under the summary receiver operating curve (AUC) were calculated according to the respective manufacturer.

Results

In total, 31 studies were evaluated. The summary sensitivity of Aution Sticks, Combur, Multistix, Periscreen reagent strips was 0.962 (95% confidence interval [CI] 0.926, 0.998), 0.892 (95% CI 0.846, 0.938), 0.806 (95% CI 0.738, 0.874), and 0.939 (95% CI 0.900, 0.979), respectively. The summary specificity of Aution Sticks, Combur, Multistix, and Periscreen reagent strips was 0.940 (95% CI 0.904, 0.976), 0.922 (95% CI 0.874, 0.970), 0.974 (95% CI 0.962, 0.985), and 0.672 (95% CI 0.381, 0.963), respectively.

Conclusion

LERS appears to have a notable overall performance for the detection of SBP. LERS appeared to be an acceptable alternative to diagnose SBP in facilities without ability to perform cell count. However, there were significant differences in performance between each manufacturer.

Immune Resolution Dilemma: Host Antimicrobial Factor S100A8/A9 Modulates Inflammatory Collateral Tissue Damage During Disseminated Fungal Peritonitis

Intra-abdominal infection (peritonitis) is a leading cause of severe disease in surgical intensive care units, as over 70% of patients diagnosed with peritonitis develop septic shock. A critical role of the immune system is to return to homeostasis after combating infection. S100A8/A9 (calprotectin) is an antimicrobial and pro-inflammatory protein complex used as a biomarker for diagnosis of numerous inflammatory disorders. Here we describe the role of S100A8/A9 in inflammatory collateral tissue damage (ICTD). Using a mouse model of disseminated intra-abdominal candidiasis (IAC) in wild-type and S100A8/A9-deficient mice in the presence or absence of S100A9 inhibitor paquinimod, the role of S100A8/A9 during ICTD and fungal clearance were investigated. S100A8/A9-deficient mice developed less ICTD than wild-type mice. Restoration of S100A8/A9 in knockout mice by injection of recombinant protein resulted in increased ICTD and fungal clearance comparable to wild-type levels. Treatment with paquinimod abolished ICTD and S100A9-deficient mice showed increased survival compared to wild-type littermates. The data indicates that S100A8/A9 controls ICTD levels and antimicrobial activity during IAC and that targeting of S100A8/A9 could serve as promising adjunct therapy against this challenging disease.

Spontaneous bacterial peritonitis due to carbapenemase-producing Enterobacteriaceae: Etiology and antibiotic treatment

Carbapenem antibiotics were first introduced in the 1980s and have long been considered the most active agents for the treatment of multidrug-resistant gram-negative bacteria. Over the last decade, carbapenem-resistant Enterobacteriaceae (CRE) have emerged as organisms causing spontaneous bacterial peritonitis. Infections caused by CRE have shown a higher mortality rate than those caused by bacteria sensitive to carbapenem antibiotics. Current antibiotic guidelines for the treatment of spontaneous bacterial peritonitis are insufficient, and rapid de-escalation of empiric antibiotic treatment is not widely recognized. This review summarizes the molecular characteristics, epidemiology and possible treatment of spontaneous bacterial peritonitis caused by CRE.

Multivariate predictive model for asymptomatic spontaneous bacterial peritonitis in patients with liver cirrhosis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a detrimental infection of the ascitic fluid in liver cirrhosis patients, with high mortality and morbidity. Early diagnosis and timely antibiotic administration have successfully decreased the mortality rate to 20%-25%. However, many patients cannot be diagnosed in the early stages due to the absence of classical SBP symptoms. Early diagnosis of asymptomatic SBP remains a great challenge in the clinic.

AIM

To establish a multivariate predictive model for early diagnosis of asymptomatic SBP using positive microbial cultures from liver cirrhosis patients with ascites.

METHODS

A total of 98 asymptomatic SBP patients and 98 ascites liver cirrhosis patients with negative microbial cultures were included in the case and control groups, respectively. Multiple linear stepwise regression analysis was performed to identify potential indicators for asymptomatic SBP diagnosis. The diagnostic performance of the model was estimated using the receiver operating characteristic curve.

RESULTS

Patients in the case group were more likely to have advanced disease stages, cirrhosis related-complications, worsened hematology and ascites, and higher mortality. Based on multivariate analysis, the predictive model was as follows: y (P) = 0.018 + 0.312 × MELD (model of end-stage liver disease) + 0.263 × PMN (ascites polymorphonuclear) + 0.184 × N (blood neutrophil percentage) + 0.233 × HCC (hepatocellular carcinoma) + 0.189 × renal dysfunction. The area under the curve value of the established model was 0.872, revealing its high diagnostic potential. The diagnostic sensitivity was 73.5% (72/98), the specificity was 86.7% (85/98), and the diagnostic efficacy was 80.1%.

CONCLUSION

Our predictive model is based on the MELD score, polymorphonuclear cells, blood N, hepatocellular carcinoma, and renal dysfunction. This model may improve the early diagnosis of asymptomatic SBP.

Novel strategies for the management of bacterial and fungal infections in patients with liver cirrhosis: focus on new antimicrobials

Introduction: Liver cirrhosis is a frequent condition caused by different etiologies. Bacterial and fungal infections are common complications, representing an independent prognostic stage in patients with cirrhosis, dramatically worsening their clinical outcomes.Areas covered: The present review article addresses manifold points and to this purpose an inductive literature search of MEDLINE database through PubMed was performed. First, it provides an overview on the mechanisms underlying immune disfunctions in patients with cirrhosis, who are prone to develop infections being at higher risk than the general population. Second, commonest types of bacterial and fungal infections in patients with advanced liver disease are described, focusing on their deleterious impact as decompensating events. Third, the rise of multidrug-resistant (MDR) bacteria and fungi as causative agents of infection in cirrhotic subjects is illustrated. Eventually, the most promising novel therapeutic options against MDR pathogens and fungi are reviewed.Expert opinion: The management of bacterial and fungal infections in patients with cirrhosis is difficult, due to the frequent co-existence of renal impairment, low platelet count and other conditions that limit the antimicrobial choice. New antibacterial and antifungal compounds may overcome this issue by providing a better tolerability profile, along with equal or superior efficacy compared with older drugs.

Epidemiological investigation of non-fermentative bacterial infection in cirrhotic patients

Background: This study aimed to describe the clinical characteristics of NFGNB in patients with cirrhosis as well as the risk factors for short-term mortality. Methods: A retrospective analysis was performed in patients with cirrhosis and NFGNB infections from 2011 to 2016 . Results: 144 episodes in 134 patients with liver cirrhosis and NFGNB infections were found in total. Of these, 81.2% were hospital-acquired or healthcare- associated infections, while only 18.8% of NFGNB infections originated from the community. A. baumannii were the most frequently isolated bacteria (39 episodes), followed by S. maltophilia (38 episodes) and P. aeruginosa (31 episodes). MDR- and non-MDR-NFGNB comprised 62.5% and 37.5% of infections respectively. The Kaplan-Meier survival curve showed no significant difference between MDR and non-MDR NFGNB patients (74.1% vs 75.5%, P = 0.811). Neither MDR or the subgroup of common NFGNB (P. aeruginosa, A. baumannii, S. maltophilia) was associated with the 28-day mortality (all P >0.05). Low albumin levels and high Tbil levels were both independent risk factors for 28-day mortality (HR = 0.930, 95%CI (0.869, 0.995), P = 0.035; HR = 1.003, 95%CI (1.002, 1.005), P < 0.001, respectively). Conclusions: Diabetes increased 28-day mortality significantly, however, MDR status, site of infection and bacteria type did not.

Spontaneous bacterial peritonitis caused by Gram-negative bacteria: an update of epidemiology and antimicrobial treatments

Introduction: Spontaneous bacterial peritonitis (SBP) is a main infectious complication in end-stage liver disease (ESLD) patients. The increasing trend of bacterial resistance in ESLD patients with SBP has been associated with low treatment efficacy of traditional therapy. Cephalosporin use has been restricted to community-acquired infections and in areas/health care settings with low rates of multidrug-resistant (MDR) bacteria. To date, several changes are necessary with regard to empiric therapy recommendations in areas/health care settings with high rates of MDR bacteria. Areas covered: An overview of the epidemiology and antimicrobial treatments of SBP caused by Gram-negative bacteria. Expert opinion: Broad-spectrum antibiotics have been recommended as empiric therapy for suspected SBP in areas/health care settings with high rates of MDR bacteria and secondary treatment, with newer antibiotics, for SBP caused by MDR-Gram-negative bacteria (i.e. new beta-lactam/beta-lactamase inhibitor combinations, cefiderocol, plazomicin, and eravacycline) either alone or in combination.

New antimicrobial options for the management of complicated intra-abdominal infections

Complicated intra-abdominal infections (cIAIs) are a common cause of morbidity and mortality in surgical patients. Optimal management of cIAI requires early source control in combination with adequate antimicrobial treatment and aggressive fluid resuscitation. cIAIs are mainly caused by Gram-negative bacilli and anaerobes. Broad-spectrum single-agent or combination drug regimens against these microorganisms are the mainstay of therapy. However, development of antimicrobial resistance has become an increasingly large concern: multidrug-resistant organisms are associated with a higher rate of inadequate antimicrobial therapy, which in turn is associated with higher mortality rate, longer hospital stay, and increased cost compared to adequate antimicrobial therapy. In this mini-review, we discuss the effectiveness of several new antimicrobial agents, recently approved or in advanced phases of clinical development, for the treatment of cIAIs, including the new beta-lactam and beta-lactamase inhibitor combinations (ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/cilastatin/relebactam, aztreonam/avibactam), siderophore cephalosporins (cefiderocol), aminoglycosides (plazomicin), and tetracyclines (eravacycline).

Unsolved Issues in the Treatment of Spontaneous Peritonitis in Patients with Cirrhosis: Nosocomial Versus Community-acquired Infections and the Role of Fungi

INTRODUCTION

Historically, spontaneous bacterial peritonitis (SBP) has represented one of the most frequent and relevant infectious complications of advanced liver disease, and this is still valid today. Nevertheless, in recent years the role of fungi as causative pathogens of primary peritonitis in patients with cirrhosis has become not negligible. Another issue is linked with the traditional distinction, instrumental in therapeutic choice, between community-acquired and nosocomial forms, according to the onset. Between these two categories, another one has been introduced: the so-called "healthcare-associated infections".

OBJECTIVE

To discuss the most controversial aspects in the management of SBP nowadays in the light of best available evidence.

METHODS

A review of recent literature through MEDLINE was performed.

RESULTS

The difference between community-acquired and nosocomial infections is crucial to guide empiric antibiotic therapy, since the site of acquisition impact on the likelihood of multidrug-resistant bacteria as causative agents. Therefore, third-generation cephalosporins cannot be considered the mainstay of treatment in each episode. Furthermore, the distinction between healthcare-associated and nosocomial form seems very subtle, especially in areas wherein antimicrobial resistance is widespread, warranting broad-spectrum antibiotic regimens for both. Finally, spontaneous fungal peritonitis is a not common but actually underestimated entity, linked to high mortality. Especially in patients with septic shock and/or failure of an aggressive antibiotic regimen, the empiric addition of an antifungal agent might be considered.

CONCLUSION

Spontaneous bacterial peritonitis is one of the most important complications in patients with cirrhosis. A proper empiric therapy is crucial to have a positive outcome. In this respect, a careful assessment of risk factors for multidrug-resistant pathogens is crucial. Likewise important, mostly in nosocomial cases, is not to overlook the probability of a fungal ascitic infection, namely a spontaneous fungal peritonitis.

Management of bacterial and fungal infections in end stage liver disease and liver transplantation: Current options and future directions

Patients with liver cirrhosis are susceptible to infections due to various mechanisms, including abnormalities of humoral and cell-mediated immunity and occurrence of bacterial translocation from the intestine. Bacterial infections are common and represent a reason for progression to liver failure and increased mortality. Fungal infections, mainly caused by Candida spp., are often associated to delayed diagnosis and high mortality rates. High level of suspicion along with prompt diagnosis and treatment of infections are warranted. Bacterial and fungal infections negatively affect the outcomes of liver transplant candidates and recipients, causing disease progression among patients on the waiting list and increasing mortality, especially in the early post-transplant period. Abdominal, biliary tract, and bloodstream infections caused by Gram-negative bacteria [e.g., Enterobacteriaceae and Pseudomonas aeruginosa (P. aeruginosa)] and Staphylococcus spp. are commonly encountered in liver transplant recipients. Due to frequent exposure to broad-spectrum antibiotics, invasive procedures, and prolonged hospitalizations, these patients are especially at risk of developing infections caused by multidrug resistant bacteria. The increase in antimicrobial resistance hampers the choice of an adequate empiric therapy and warrants the knowledge of the local microbial epidemiology and the implementation of infection control measures. The main characteristics and the management of bacterial and fungal infections in patients with liver cirrhosis and liver transplant recipients are presented.

Secondary bacterial peritonitis and pelvic abscess due to Clostridium difficile

A 70-year-old man with a history of hepatic cirrhosis presented with abdominal discomfort and distention. Physical examination revealed abdominal distention, positive fluid wave and abdominal tenderness. Due to concerns for spontaneous bacterial peritonitis (SBP), paracentesis was performed. Fluid analysis revealed 5371 total nucleated cells with 48% neutrophils. Ceftriaxone was then initiated for the treatment of SBP. Bacterial cultures of the fluid, however, grew Clostridium difficile Therefore, metronidazole was added. An abdominal ultrasound revealed a pelvic fluid collection that was suspicious for an abscess on an abdominal CT scan. The patient underwent CT-guided drain placement into the pelvic fluid collection. The fluid aspirate was consistent with an abscess. However, cultures were negative in the setting of ongoing antibiotic therapy. The patient was treated with a 10-day course of ceftriaxone and metronidazole and was discharged home with outpatient follow-up.

Current and emerging pharmacotherapy for the treatment of bacterial peritonitis

INTRODUCTION

Spontaneous bacterial peritonitis (SBP) is the quintessential model of bacterial infection in cirrhotic patients. In these particularly frail subjects, infections clearly worsen prognosis increasing substantially mortality. Furthermore, treatment of SBP has become more challenging because of the growing impact of multidrug-resistant (MDR) bacteria.

AREAS COVERED

This review addresses the reasons behind the change in therapeutic recommendations for SBP that have occurred in the past few years, by focusing on the following aspects: the importance of an early appropriate empirical treatment, the difference between nosocomial and non-nosocomial forms and the overall microbiological shift (rise of Gram-positive bacteria and MDR strains) that have affected SBP.

EXPERT OPINION

Until recently, third-generation cephalosporins have represented the cornerstone of SBP treatment, a safe choice covering the most important causative agents, namely Enterobacteriaceae. Unfortunately, massive exposure to health systems makes cirrhotic patients prone to MDR infections, which poses significant challenges, all the while not forgetting to strike a balance between effective antimicrobial activity and the risk of toxicity in these fragile subjects. Moreover, there is sparse information about new antibiotics in cirrhotic patients and about drugs levels in ascitic fluid. Therefore, further research is needed to optimize the treatment of SBP.

Are third-generation cephalosporins still the empirical antibiotic treatment of community-acquired spontaneous bacterial peritonitis? A systematic review and meta-analysis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a common complication among cirrhotic patients. Guidelines recommend third-generation cephalosporins (3GCs) as empiric antibiotic therapy (EAT) of SBP. Recently, a broad-spectrum EAT was shown to be more effective than cephalosporins in the treatment of nosocomial spontaneous bacterial peritonitis (N-SBP); however, the prevalence of 3GCs-resistant bacteria is high in the nosocomial setting and broad-spectrum EAT cannot be used in all cases of SBP.

AIM

The aim of this study was to evaluate the 3GCs resistance distribution between N-SBP and community-acquired spontaneous bacterial peritonitis (CA-SBP) to clarify whether 3GCs are still an effective therapeutic intervention for CA-SBP.

METHODS

We searched for studies that reported the aetiology of SBP and the resistance profile of both gram-positive and gram-negative bacteria in MEDLINE and Google Scholar databases (since 1 January 2000 to 30 April 2017). A meta-analysis was carried out to estimate the risk difference [relative risk (RR) and 95% confidence intervals (CIs)] for 3GCs resistance in N-SBP and CA-SBP. Heterogeneity was assessed using the I-test.

RESULTS

A total of eight studies were included, including 1074 positive cultures of ascitic fluid in cirrhotic patients; 462 positive cultures were from N-SBP and, among these, 251 (54.3%) were 3GCs resistant. Six hundred and twelve positive cultures were from CA-SBP and, among these, 207 (33.8%) were 3GCs-resistant SBP. A pooled RR of 3GCs resistance in N-SBP compared with CA-SBP showed a significant difference (RR=1.67, 95% CI: 1.14-2.44; P=0.008). We carried out two subgroup analyses: the first according to the median year of study observation (before vs. since 2008) and the second according to the country of the study (China vs. others). The studies carried out before 2008 (327 SBP-positive culture) showed a significantly higher risk for 3GCs-resistant strains in N-SBP compared with CA-SBP (RR=2.36, 95% CI: 1.39-3.99; P=0.001), whereas this was not found in SBP acquired after 2008 (RR=1.24, 95% CI: 0.83-1.84; P=0.29). N-SBP occurring in China had no significantly higher risk for 3GCs-resistant strains compared with CA-SBP (RR=1.44, 95% CI: 0.87-2.37; P=0.16).

CONCLUSION

Our findings suggest that although the pooled RR of 3GCs resistance in N-SBP compared with CA-SBP show that 3GCs are still an effective option for the treatment of CA-SBP, the subanalysis of studies that enroled patients in the last decade did not show a significant higher RR of 3GCs resistance in N-SBP compared with CA-SBP. Therefore, in centres where local patterns of antimicrobial susceptibility (with low rates of 3GCs resistance) are not available, 3GCs should not be used initially for CA-SBP treatment. Future studies are needed to confirm this trend of 3GCs resistance.

Spontaneous bacterial and fungal peritonitis in patients with liver cirrhosis: A literature review

Spontaneous bacterial (SBP) and spontaneous fungal peritonitis (SFP) can be a life-threatening infection in patients with liver cirrhosis (LC) and ascites. One of the possible mechanisms of developing SBP is bacterial translocation. Although the number of polymorphonuclear cells in the culture of ascitic fluid is diagnostic for SBP, secondary bacterial peritonitis is necessary to exclude. The severity of underlying liver dysfunction is predictive of developing SBP; moreover, renal impairment and infections caused by multidrug-resistant (MDR) organism are associated with a fatal prognosis of SBP. SBP is treated by antimicrobials, but initial empirical treatment may not succeed because of the presence of MDR organisms, particularly in nosocomial infections. Antibiotic prophylaxis is recommended for patients with LC at a high risk of developing SBP, gastrointestinal bleeding, or a previous episode of SBP, but the increase in the risk of developing an infection caused by MDR organisms is a serious concern globally. Less is known about SFP in patients with LC, but the severity of underlying liver dysfunction may increase the hospital mortality. SFP mortality has been reported to be higher than that of SBP partially because the difficulty of early differentiation between SFP and SBP induces delayed antifungal therapy for SFP.

Liver fungal infections: an overview of the etiology and epidemiology in patients affected or not affected by oncohematologic malignancies

Fungal infections of the liver, most commonly caused by Candida spp., often occur in patients with hematologic malignancies treated with chemotherapy. Colonization of the gastrointestinal tract is thought to be the main origin of dissemination of Candida; mucositis and neutropenia facilitate the spread of Candida from the gastrointestinal tract to the liver. Hepatic involvement due to other fungi is a less common infectious complication in this setting. Fungal infections represent a less common cause of hepatic abscesses in non-oncohematologic population and the trend appears to be decreasing in recent years. Understanding of the etiology and epidemiology of fungal infections of the liver is indicated for an appropriate antimicrobial therapy and an overall optimal management of fungal liver infections.