The Surgical Infection Society Guidelines on the Management of Intra-Abdominal Infection: 2024 Update

Background: The Surgical Infection Society (SIS) published evidence-based guidelines for the management of intra-abdominal infection (IAI) in 1992, 2002, 2010, and 2017. Here, we present the most recent guideline update based on a systematic review of current literature. Methods: The writing group, including current and former members of the SIS Therapeutics and Guidelines Committee and other individuals with content or guideline expertise within the SIS, working with a professional librarian, performed a systematic review using PubMed/Medline, the Cochrane Library, Embase, and Web of Science from 2016 until February 2024. Keyword descriptors combined "surgical site infections" or "intra-abdominal infections" in adults limited to randomized controlled trials, systematic reviews, and meta-analyses. Additional relevant publications not in the initial search but identified during literature review were included. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) system was utilized to evaluate the evidence. The strength of each recommendation was rated strong (1) or weak (2). The quality of the evidence was rated high (A), moderate (B), or weak (C). The guideline contains new recommendations and updates to recommendations from previous IAI guideline versions. Final recommendations were developed by an iterative process. All writing group members voted to accept or reject each recommendation. Results: This updated evidence-based guideline contains recommendations from the SIS for the treatment of adult patients with IAI. Evidence-based recommendations were developed for antimicrobial agent selection, timing, route of administration, duration, and de-escalation; timing of source control; treatment of specific pathogens; treatment of specific intra-abdominal disease processes; and implementation of hospital-based antimicrobial agent stewardship programs. Summary: This document contains the most up-to-date recommendations from the SIS on the prevention and management of IAI in adult patients.

Reducing the duration of antibiotic therapy in surgical patients through a specific nationwide antimicrobial stewardship program. A prospective, interventional cohort study

BACKGROUND

Guidelines recommend 5-7 days of antibiotic treatment in patients with surgical infection and adequate source control. This nationwide stewardship intervention aimed to reduce the duration of treatments in surgical patients to <7 days.

METHODS

Prospective cohort study evaluating surgical patients receiving antibiotics ≥7 days in 32 hospitals. Indication for treatment, quality of source control, type of recommendations issued, and adherence to the recommendations were analysed. Temporal trends in the percentages of patients with treatment >7 days were evaluated using a linear regression model and Pearson's correlation coefficients.

RESULTS

A total of 32 499 patients were included. Of these, 13.7% had treatments ≥7 days. In all, 3912 stewardship interventions were performed, primarily in general surgery (90.7%) and urology (8.1%). The main types of infection were intra-abdominal (73.4%), skin/soft tissues (9.8%) and urinary (9.2%). The septic focus was considered controlled in 59.9% of cases. Out of 5458 antibiotic prescriptions, the most frequently analysed drugs were piperacillin/tazobactam (21.7%), metronidazole (11.2%), amoxicillin/clavulanate (10.3%), meropenem (10.7%), ceftriaxone (9.3%) and ciprofloxacin (6.7%). The main recommendations issued were: treatment discontinuation (35.0%), maintenance (40.0%) or de-escalation (15.5%), and the overall adherence rate was 91.5%. With adequate source control, the most frequent recommendation was to terminate treatment (51.2%). Throughout the study period, a significant decrease in the percentage of prolonged treatments was observed (Pc=-0.69;P < 0.001).

CONCLUSIONS

This stewardship programme reduced the duration of treatments in surgical departments. Preference was given to general surgery services, intra-abdominal infection, and beta-lactam antibiotics, including carbapenems. Adherence to the issued recommendations was high.

Surgeon-led 7-VINCut Antibiotic Stewardship Intervention Decreases Duration of Treatment and Carbapenem Use in a General Surgery Service

Antibiotic stewardship programs optimize the use of antimicrobials to prevent the development of resistance and improve patient outcomes. In this prospective interventional study, a multidisciplinary team led by surgeons implemented a program aimed at shortening the duration of antibiotic treatment <7 days. The impact of the intervention on antibiotic consumption adjusted to bed-days and discharges, and the isolation of multiresistant bacteria (MRB) was also studied. Furthermore, the surgeons were surveyed regarding their beliefs and feelings about the program. Out of 1409 patients, 40.7% received antibiotic therapy. Treatment continued for over 7 days in 21.5% of cases, and, as can be expected, source control was achieved in only 48.8% of these cases. The recommendations were followed in 90.2% of cases, the most frequent being to withdraw the treatment (55.6%). During the first 16 months of the intervention, a sharp decrease in the percentage of extended treatments, with R2 = 0.111 was observed. The program was very well accepted by surgeons, and achieved a decrease in both the consumption of carbapenems and in the number of MRB isolations. Multidisciplinary stewardship teams led by surgeons seem to be well received and able to better manage antibiotic prescription in surgery.

Sepsis 2019: What Surgeons Need to Know

The definition of sepsis continues to be as dynamic as the management strategies used to treat this. Sepsis-3 has replaced the earlier systemic inflammatory response syndrome (SIRS)-based diagnoses with the rapid Sequential Organ Failure Assessment (SOFA) score assisting in predicting overall prognosis with regards to mortality. Surgeons have an important role in ensuring adequate source control while recognizing the threat of carbapenem-resistance in gram-negative organisms. Rapid diagnostic tests are being used increasingly for the early identification of multi-drug-resistant organisms (MDROs), with a key emphasis on the multidisciplinary alert of results. Novel, higher generation antibiotic agents have been developed for resistance in ESKCAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) organisms while surgeons have an important role in the prevention of spread. The Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial has challenged the previous paradigm of length of antibiotic treatment whereas biomarkers such as procalcitonin are playing a prominent role in individualizing therapy. Several novel therapies for refractory septic shock, while still investigational, are gaining prominence rapidly (such as vitamin C) whereas others await further clinical trials. Management strategies presented as care bundles continue to be updated by the Surviving Sepsis Campaign, yet still remain controversial in its global adoption. We have broadened our temporal and epidemiologic perspective of sepsis by understanding it both as an acute, time-sensitive, life-threatening illness to a chronic condition that increases the risk of mortality up to five years post-discharge. Artificial intelligence, machine learning, and bedside scoring systems can assist the clinician in predicting post-operative sepsis. The public health role of the surgeon is key. This includes collaboration and multi-disciplinary antibiotic stewardship at a hospital level. It also requires controlling pharmaceutical sales and the unregulated dispensing of antibiotic agents globally through policy initiatives to control emerging resistance through prevention.

Is fixed short-course antimicrobial therapy justified for patients who are critically ill with intra-abdominal infections?

A long-course antibiotic therapy increases the risk of antibiotic resistance. A 7- to 14-day duration of therapy has been traditionally adopted in patients with intra-abdominal infections (IAIs). Prophylactic antibiotic use is warranted in uncomplicated IAIs, in which the infection involves a single organ, and the source of the infection is completely eradicated by a surgical procedure. A large, randomized clinical trial of the treatment of complicated IAIs recently demonstrated that a fixed 4-day course of antibiotic therapy was as effective as a long-course therapy in patients who underwent adequate source control. Considering the poor prognosis and lack of clear evidence available for shortening the duration of antibiotic therapy in patients who are critically ill or those with ongoing signs of sepsis, the duration of therapy for complicated IAIs should be individually determined according to the clinical course. Limiting therapy to no more than 7 days seems to be warranted in patients who are critically ill with a good clinical response.

Fluoroquinolone-based versus β-lactam-based regimens for complicated intra-abdominal infections: a meta-analysis of randomised controlled trials

Complicated intra-abdominal infections (cIAIs) are common and confer significant morbidity, mortality and costs. In this era of evolving antimicrobial resistance, selection of appropriate empirical antimicrobials is paramount. This systematic review and meta-analysis of randomised controlled trials compared the effectiveness and safety of fluoroquinolone (FQ)-based versus β-lactam (BL)-based regimens for the treatment of patients with cIAIs. Primary outcomes were treatment success in the clinically evaluable (CE) population and all-cause mortality in the intention-to-treat (ITT) population. Subgroup analyses were performed based on specific antimicrobials, infection source and isolated pathogens. Seven trials (4125 patients) were included. FQ-based regimens included moxifloxacin (four studies) or ciprofloxacin/metronidazole (three studies); BL-based regimens were ceftriaxone/metronidazole (three studies), carbapenems (two studies) or piperacillin/tazobactam (two studies). There was no difference in effectiveness in the CE (2883 patients; RR = 1.00, 95% CI 0.95-1.04) or ITT populations (3055 patients; RR = 0.97, 95% CI 0.94-1.01). Mortality (3614 patients; RR = 1.04, 95% CI 0.75-1.43) and treatment-related adverse events (2801 patients; RR = 0.97, 95% CI 0.70-1.33) were also similar. On subset analysis, moxifloxacin was slightly less effective than BLs in the CE (1934 patients; RR = 0.96, 95% CI 0.93-0.99) and ITT populations (1743 patients; RR = 0.94, 95% CI 0.91-0.98). Although FQ- and BL-based regimens appear equally effective and safe for the treatment of cIAIs, limited data suggest slightly inferior results with moxifloxacin. Selection of empirical coverage should be based on local bacterial epidemiology and patterns of resistance as well as antimicrobial stewardship protocols.

Choosing wisely: what is the actual role of antimicrobial stewardship in Intensive Care Units?

More than two-thirds of critically ill patients receive an antimicrobial therapy with a percentage between 30% and 50% of all prescribed antibiotics reported to be unnecessary, inappropriate or misused. Since inappropriate prescription of antibiotic drugs concurs to dissemination of the multidrug resistant organisms, a reasoned antibiotics use is crucial especially in Intensive Care Unit (ICU), where up to 60% of the admitted patients develops an infection during their ICU stay. Even if the concept of antimicrobial stewardship (AS) has been clearly described as a series of coordinated interventions designed to improve antimicrobial agents use, few studies are reporting about its effectiveness to improve outcomes, reduce adverse events and costs and decrease resistance rate spread. Moreover, although it is recognized that AS programs are particularly indicated in the critical setting due to the huge number of antimicrobial drugs used, the optimal characteristics of these interventions and the best system to evaluate their effectiveness are still unclear. Specific interventions, designed tacking into account the peculiarities of the ICU setting, are hence necessary to set-up an "in-ICU-stewardship," including prompt identification of infected patients, selection of appropriate empiric treatments, optimization of dosing and route of administration, improvement of diagnostic techniques, early de-escalation to achieve shorter duration and avoid unnecessary therapies. The present narrative review summarizes the "state of art" about AS programmes and discusses the effects of the interventions possibly applied in ICU setting to optimize the patient's treatment, reduce the micro-organisms resistance and contain the hospital resources utilization.

Abdominal sepsis

PURPOSE OF REVIEW

To summarize the recent evidence on the treatment of abdominal sepsis with a specific emphasis on the surgical treatment.

RECENT FINDINGS

A multitude of surgical approaches towards abdominal sepsis are practised. Recent evidence shows that immediate closure of the abdomen has a better outcome. A short course of antibiotics has a similar effect as a long course of antibiotics in patients with intra-abdominal infection without severe sepsis.

SUMMARY

Management of abdominal sepsis requires a multidisciplinary approach. Closing the abdomen permanently after source control and only reopening it in case of deterioration of the patient without other (percutaneous) options is the preferred strategy. There is no convincing evidence that damage control surgery is beneficial in patients with abdominal sepsis. If primary closure of the abdomen is impossible because of excessive visceral edema, delayed closure using negative pressure therapy with continuous mesh-mediated fascial traction shows the best results.

Empiric Antibiotics for Sepsis

BACKGROUND

Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. Early recognition and treatment are the cornerstones of management.

METHODS

Review of the English-language literature.

RESULTS

For both sepsis and septic shock "antimicrobials [should be] be initiated as soon as possible and within one hour" (Surviving Sepsis Campaign). The risk of progression from severe sepsis to septic shock increases 8% for each hour before antibiotics are started. Selection of antimicrobial agents is based on a combination of patient factors, predicted infecting organism(s), and local microbial resistance patterns. The initial drugs should have activity against typical gram-positive and gram-negative causative micro-organisms. Anaerobic coverage should be provided for intra-abdominal infections or others where anaerobes are significant pathogens. Empiric antifungal or antiviral therapy may be warranted. For patients with healthcare-associated infections, resistant micro-organisms will further complicate the choice of empiric antimicrobials. Recommendations are given for specific infections.

CONCLUSION

Early administration of broad-spectrum antimicrobial drugs is one of the most important, if not the most important, treatment for patients with sepsis or septic shock. Drugs should be initiated as soon as possible, and the choice of should take into account patient factors, common local pathogens, hospital antibiograms and resistance patterns, and the suspected source of infection. Antimicrobial agent therapy should be de-escalated as soon as possible.