Nationwide observational study of mortality from complicated intra-abdominal infections and the role of bacterial cultures

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.

Association between Intraoperative Early Warning Score and Mortality and In-Hospital Stay in Lower Gastrointestinal Spontaneous Perforation

Background

Early warning scores (EWSs) can be easily calculated from physiological indices; however, the extent to which intraoperative EWSs and the corresponding changes are associated with patient prognosis is unknown. In this study, we investigated whether EWS and the corresponding time-related changes are associated with patient outcomes during the anesthetic management of lower gastrointestinal perforation.

Methods

This was a single-center, retrospective cohort study conducted at a tertiary emergency care center. Adult patients who underwent surgery for spontaneous lower gastrointestinal perforations between September 1, 2012, and December 31, 2019, were included. The National Early Warning Score (NEWS) and Modified Early Warning Score (MEWS) were calculated based on the intraoperative physiological indices, and the associations with in-hospital death and length of hospital stay were investigated.

Results

A total of 101 patients were analyzed. The median age was 70 years, and there were 11 cases of in-hospital death (mortality rate: 10.9%). There was a significant association between the intraoperative maximum NEWS and in-hospital death (odds ratio (OR): 1.60, 95% confidence interval (CI): 1.10-2.32, p=0.013) and change from initial to maximum NEWS (OR: 1.60, 95% CI: 1.07-2.40, p=0.023) in the crude analysis. However, when adjustments were made for confounding factors, no statistically significant associations were found. Other intraoperative EWS values and changes were not significantly associated with the investigated outcomes. The preoperative sepsis-related organ failure assessment score and the intraoperative base excess value were significantly associated with in-hospital death.

Conclusions

No clear association was observed between EWSs and corresponding changes and in-hospital death in cases of lower gastrointestinal perforation. The preoperative sepsis-related organ failure assessment score and intraoperative base excess value were significantly associated with in-hospital death.

Sepsis Team Organizational Model to Decrease Mortality for Intra-Abdominal Infections: Is Antibiotic Stewardship Enough?

Introduction. Sepsis is an overwhelming reaction to infection with significant morbidity, requiring urgent interventions in order to improve outcomes. The 2016 Sepsis-3 guidelines modified the previous definitions of sepsis and septic shock, and proposed some specific diagnostic and therapeutic measures to define the use of fluid resuscitation and antibiotics. However, some open issues still exist. Methods. A literature research was performed on PubMed and Cochrane using the terms "sepsis" AND "intra-abdominal infections" AND ("antibiotic therapy" OR "antibiotic treatment"). The inclusion criteria were management of intra-abdominal infection (IAI) and effects of antibiotic stewardships programs (ASP) on the outcome of the patients. Discussion. Sepsis-3 definitions represent an added value in the understanding of sepsis mechanisms and in the management of the disease. However, some questions are still open, such as the need for an early identification of sepsis. Sepsis management in the context of IAI is particularly challenging and a prompt diagnosis is essential in order to perform a quick treatment (source control and antibiotic treatment). Antibiotic empirical therapy should be based on the kind of infection (community or hospital acquired), local resistances, and patient's characteristic and comorbidities, and should be adjusted or de-escalated as soon as microbiological information is available. Antibiotic Stewardship Programs (ASP) have demonstrated to improve antimicrobial utilization with reduction of infections, emergence of multi-drug resistant bacteria, and costs. Surgeons should not be alone in the management of IAI but ideally inserted in a sepsis team together with anaesthesiologists, medical physicians, pharmacists, and infectious diseases specialists, meeting periodically to reassess the response to the treatment. Conclusion. The cornerstones of sepsis management are accurate diagnosis, early resuscitation, effective source control, and timely initiation of appropriate antimicrobial therapy. Current evidence shows that optimizing antibiotic use across surgical specialities is imperative to improve outcomes. Ideally every hospital and every emergency surgery department should aim to provide a sepsis team in order to manage IAI.

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.

Systematic Review and Meta-Analysis of Wound Bundles in Emergency Midline Laparotomy Identifies That It Is Time for Improvement

BACKGROUND

Emergency midline laparotomy is the cornerstone of survival in patients with peritonitis. While bundling of care elements has been shown to optimize outcomes, this has focused on elective rather than emergency abdominal surgery. The aim of this study was to undertake a systematic review and meta-analysis of factors affecting the development of surgical site infection (SSI) in patients undergoing midline emergency laparotomy.

METHODS

An ethically approved, PROSPERO registered (ID: CRD42020193246) meta-analysis and systematic review, searching PubMed, Scopus, Web of Science and Cochrane Library electronic databases from January 2015 to June 2020 and adhering to PRISMA guidelines was undertaken. Search headings included "emergency surgery", "laparotomy", "surgical site infection", "midline incision" and "wound bundle". Suitable publications were graded using Methodological Index for Non-Randomised Studies (MINORS); papers scoring ≥16/24 were included for data analysis. The primary outcome in this study was SSI rates following the use of wound bundles. Secondary outcomes consisted of the effect of the individual interventions included in the bundles and the SSI rates for superficial and deep infections. Five studies focusing on closure techniques were grouped to assess their effect on SSI.

RESULTS

This study identified 1875 articles. A total of 58 were potentially suitable, and 11 were included after applying MINORS score. The final cohort included 2,856 patients from eight countries. Three papers came from the USA, two papers from Japan and the remainder from Denmark, England, Iran, Netherlands, Spain and Turkey. There was a 32% non-significant SSI reduction after the implementation of wound bundles (RR = 0.68; CI, 0.39-1.17; p = 0.16). In bundles used for technical closure the reduction in SSI of 15% was non-significant (RR = 0.85; CI, 0.57-1.26; p = 0.41). Analysis of an effective wound bundle was limited due to insufficient data.

CONCLUSIONS

This study identified a significant deficit in the world literature relating to emergency laparotomy and wound outcome optimisation. Given the global burden of emergency general surgery urgent action is needed to assess bundle's ability to potentially improve outcome after emergency laparotomy.

Novel Beta-Lactam/Beta-Lactamase Plus Metronidazole vs Carbapenem for Complicated Intra-abdominal Infections: A Meta-analysis of Randomized Controlled Trials

Background

Complicated intra-abdominal infections (cIAIs) remain a leading cause of death in surgical wards, in which antibiotic treatment is crucial. We aimed to compare the efficacy and safety of novel β-lactam/β-lactamase inhibitors (BL/BLIs) in combination with metronidazole and carbapenems in the treatment of cIAIs.

Methods

A comprehensive search of randomized controlled trials (RCTs) was performed using Medline, Embase, and Cochrane Library, which compared the efficacy and safety of novel BL/BLIs and carbapenems for the treatment of cIAIs.

Results

Six RCTs consisting of 2254 patients were included. The meta-analysis showed that novel BL/BLIs in combination with metronidazole had a lower clinical success rate (risk difference [RD], -0.05; 95% CI, -0.07 to -0.02; I ² = 0%) and a lower microbiological success rate (RD, -0.04; 95% CI, -0.08 to -0.00; I ² = 0%). No difference was found between the 2 groups in incidence of adverse events (RD, 0.02; 95% CI, -0.01 to 0.06; I ² = 0%), serious adverse events (SAEs; RD, 0.01; 95% CI, -0.02 to 0.03; I ² = 0%), or mortality (RD, 0.01; 95% CI, -0.00 to 0.02). However, ceftazidime/avibactam had a higher risk of vomiting (RD, 0.03; 95% CI, 0.01 to 0.05; I ² = 47%), and the ceftolozane/tazobactam subgroup showed a higher incidence of SAEs (RD, 0.12; 95% CI, 0.01 to 0.03).

Conclusions

The efficacy of novel BL/BLIs in combination with metronidazole was not as high as that of carbapenems. Although no significant differences were found with respect to overall adverse events, SAEs, or mortality, the novel BL/BLIs has a higher risk of vomiting. We still need to be cautious about the clinical application of a new anti-infective combination.

Trial registration

PROSPERO ID: 42020166061.