Cefazolin Might Be Adequate for Perioperative Antibiotic Prophylaxis in Intra-Abdominal Infections without Sepsis: A Quality Improvement Study

Prediction of complications associated with general surgery using a Bayesian network

BACKGROUND

Numerous attempts have been made to identify risk factors for surgery complications, but few studies have identified accurate methods of predicting complex outcomes involving multiple complications.

METHODS

We performed a prospective cohort study of general surgical inpatients who attended 4 regionally representative hospitals in China from January to June 2015 and January to June 2016. The risk factors were identified using logistic regression. A Bayesian network model, consisting of directed arcs and nodes, was used to analyze the relationships between risk factors and complications. Probability ratios for complications for a given node state relative to the baseline probability were calculated to quantify the potential effects of risk factors on complications or of complications on other complications.

RESULTS

We recruited 19,223 participants and identified 21 nodes, representing 9 risk factors and 12 complications, and 55 direct relationships between these. Respiratory failure was at the center of the network, directly affected by 5 risk factors, and directly affected 7 complications. Cardiopulmonary resuscitation and sepsis or septic shock also directly affected death. The area under the receiver operating characteristic curve for the ability of the network to predict complications was >0.7. Notably, the probability of other severe complications or death significantly increased when a severe complication occurred. Most importantly, there was a 141-fold higher risk of death when cardiopulmonary resuscitation was required.

CONCLUSION

We have created a Bayesian network that displays how risk factors affect complications and their interrelationships and permits the accurate prediction of complications and the creation of appropriate preventive guidelines.

Incidence of Bacteriobilia and the Correlation with Antibioticoprophylaxis in Low-Risk Patients Submitted to Elective Videolaparoscopic Cholecystectomy: A Randomized Clinical Trial

Cholelithiasis has a major impact on global health and affects an average of 20% of the Western population. The main risk factors are females, age over 40 years, obesity and pregnancy. Most of the time it is asymptomatic, but when there are symptoms, they are generally nonspecific. Bile was considered sterile, but today it is known that it contains a complex bacterial flora, which causes biofilm in the gallbladder and gallstones. Among the main bacteria associated with cholelithiasis are Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, species of Enterococcus spp. and Acinetobacter spp. Antibiotic prophylaxis is used in an attempt to reduce postoperative infections, especially at the surgical site. However, some authors found no relationship between the use of antibiotic prophylaxis and a lower risk of surgical site infection. Thus, the aim of this double-blind randomized clinical trial was to compare the existence or not of bacteriobilia in patients at low anesthetic risk who underwent videolaparoscopic cholecystectomy, and its correlation with the use of prophylactic antibiotics. This study included 40 patients between 18 and 65 years old, diagnosed with cholelithiasis, symptomatic or not, with low anesthetic risk classified by the American Society of Anesthesiology in ASA I or ASA II, without complications or previous manipulation of the bile duct, who underwent elective video cholecystectomy, divided into two groups: Experimental Group A (n = 20), which received 2 g of Cephalotin (first-generation Cephalosporin, Keflin®, ABL antibiotics, Cosmópolis, Brazil) during anesthetic induction, and Control Group B (n = 20), where no antibiotics were administered until bile collection. After the procedure, a bile sample was collected and culture and antibiogram were performed. In the sample, 22 (55%) were classified as ASA I and 18 (45%) as ASA II. It was observed that 81.8% of the patients who had a positive culture did not use antibiotics, against 18.2% of those who used prophylaxis. When comparing patients regarding anesthetic risk, ASA I patients had a positive culture in 9.1% of cases, against 90.9% in patients classified as ASA II. It was concluded that patients with higher anesthetic risk (ASA II) have a higher chance of bacteriobilia and benefit from antibiotic prophylaxis when compared to patients with lower anesthetic risk (ASA I).

In vitro and Ex vivo Assessments of the Compatibility of Fibrin Sealant with Antimicrobial Compounds

Background: Fibrin sealants are used as antimicrobial-releasing carriers for preventing surgical site infections; however, it is important to determine the release kinetics and antimicrobial effects of drugs added to fibrin sealants and the effects of drugs on clot/clotting properties. Materials and Methods: The antimicrobial and antibiofilm activity of cefazolin, colistin, gentamicin, oxacillin, tobramycin, and silver nitrate released from fibrin sealant were characterized using in vitro and ex vivo assays against bacteria commonly found on the skin. The effects of antimicrobial agents on the physical structure of the fibrin sealant were assessed with scanning electron microscopy (SEM) and on the clotting rate and strength of fibrin clots using run-off tests and rheology. Results: Generally, antibiotic agents were released gradually from fibrin sealant and were stable after release, with antimicrobial effects evident up to three days. Cefazolin, gentamicin, and oxacillin prevented biofilm formation of Staphylococcus aureus in porcine skin explants; gentamicin and colistin prevented biofilm formation of Pseudomonas aeruginosa. Gentamicin, cefazolin, colistin, and tobramycin did not affect the structural integrity or viscoelastic properties of fibrin sealant; changes were observed with oxacillin (SEM) and particularly silver nitrate (SEM and rheology). No antimicrobial agents caused deterioration of clotting time (run-off tests). Conclusions: From the antimicrobial agents tested, gentamicin and cefazolin showed prolonged release from fibrin sealant, sustained antimicrobial activity, and biofilm prevention properties against Staphylococcus aureus; similar results were observed for gentamicin and colistin against Pseudomonas aeruginosa. For each of these findings, the physical structure of the fibrin sealant, clotting rate, and strength of fibrin clots were unaffected.

Meta-Analysis of Clinical Trials Comparing Cefazolin to Cefuroxime, Ceftriaxone, and Cefamandole for Surgical Site Infection Prevention

Surgical site infections are among the most prevalent and costly healthcare-associated infections, resulting in poor patient outcomes and even death. Cefazolin is a first-generation cephalosporin antibiotic that is widely used for surgical prophylaxis in a variety of surgical disciplines. Although previous studies showed that cefazolin is effective in preventing surgical site infections, other agents, such as cefuroxime and ceftriaxone, were used excessively for surgical patients. The present analysis included only clinical trials comparing the efficacy of cefazolin to cefuroxime, ceftriaxone, and cefamandole in lowering SSIs using PubMed, Google Scholar, and ClinicalTrials.gov. Review Manager software (RevMan version 5.4) was used to conduct the meta-analyses. A total of 12,446 patients were included in the study. Among these patients, 6327 patients received cefazolin and 6119 patients received cefamandole, cefuroxime, or ceftriaxone. Our analysis showed that cefazolin is as effective as cefuroxime, cefamandole, and ceftriaxone in preventing surgical site infections. Hence, our findings have provided evidence for the use of cefazolin before surgeries because of its efficacy, as previous studies showed that it is inexpensive and safer than other agents.

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.

Disease- and Medication-Specific Differences of the Microbial Spectrum in Perianal Fistulizing Crohn's Disease-Relevant Aspects for Antibiotic Therapy

Perianal fistulizing Crohn's Disease (CD) with abscess formation represents an aggressive phenotype in Inflammatory Bowel Disease (IBD) with increased morbidity. Treatment is multidisciplinary and includes antibiotics, but knowledge about the microbial spectrum is rare often resulting in inadequate antimicrobial therapy. In this single center retrospective study, all patients who were operated due to perianal abscess formation were retrospectively analyzed and the microbial spectrum evaluated. Patients were divided into a CD and non-CD group with further subgroup analysis. 138 patients were finally included in the analysis with 62 patients suffering from CD. Relevant differences were detected for the microbial spectrum with anaerobic bacteria being significantly more often isolated from non-CD patients. In a subgroup-analysis of CD patients only, medical therapy had a relevant effect on the microbial spectrum since Streptococcus groups and Enterobacterales were significantly more often isolated in patients treated with steroids compared to those being treated by antibodies. In conclusion, the microbial spectrum of patients suffering from CD varies significantly from non-CD patients and immunosuppressive medication has a relevant effect on isolated pathogens. Based on that, adaption of antibiotic treatment might be discussed in the future.

Microbial Spectrum and Antibiotic Resistance in Patients Suffering from Penetrating Crohn's Disease

Intraabdominal abscess formation occurs in up to 30% of patients suffering from Crohn´s disease (CD). While international guidelines recommend a step-up approach with a combination of empiric antibiotic therapy and percutaneous drainage to delay or even avoid surgery, evidence about microbial spectrum in penetrating ileitis is sparse. We retrospectively assessed outcomes of 46 patients with terminal penetrating Ileitis where microbial diagnostics have been performed and compared microbial spectrum and antibiotic resistance profile of CD patients with patients suffering from diverticulitis with intraabdominal abscess formation. In both groups, the most frequently isolated pathogen was the gram-negative bacterium E. coli belonging to the family of Enterobacterales. However, overall Enterobacterales were significantly more often verifiable in the control group than in CD patients. Furthermore, microbial analysis showed significant differences regarding isolation of anaerobic pathogens with decreased frequency in patients with CD. Subgroup analysis of CD patients to evaluate a potential influence of immunosuppressive therapy on microbial spectrum only revealed that Enterobacterales was less frequently detected in patients treated with steroids. Immunosuppressive therapy did not show any impact on all other groups of pathogens and did not change antibiotic resistance profile of CD patients. In conclusion, we were able to demonstrate that the microbial spectrum of CD patients does differ only for some pathogen species without increased rate of antibiotic resistance. However, the empiric antibiotic therapy for CD-associated intra-abdominal abscess remains challenging since different points such as local epidemiological and microbiological data, individual patient risk factors, severity of infection, and therapy algorithm including non-surgical and surgical therapy options should be considered before therapeutical decisions are made.