Antimicrobial susceptibility changes of Escherichia coli and Klebsiella pneumoniae intra-abdominal infection isolate-derived pathogens from Chinese intra-abdominal infections from 2011 to 2015

Background

To explore the susceptibility trends of antimicrobials and resistance increase to antibiotics of Enterobacteriaceae isolated from patients in China with intra-abdominal infections (IAI) from 2011 to 2015.

Methods

MIC₉₀ and MIC₅₀ values of 12 commonly used antibiotics from Escherichia coli and Klebsiella pneumoniae isolated from IAI samples were determined.

Results

A total of 8,477 Gram-negative bacterial pathogens were collected from 21 medical centers in China. The majority of IAI isolate-derived pathogens were E. coli (3,854, 45.5%) and K. pneumoniae (1,670, 19.7%) of which 1,990 (23.5%) were consecutively collected from community acquired (CA) and 6,186 (73.0%) from hospital acquired (HA) IAIs. The drugs with the highest efficacy against E. coli and K. pneumoniae isolates derived from IAI samples were imipenem, ertapenem, amikacin and piperacillin-tazobactam. MIC₉₀ values for piperacillin-tazobactam were 64 µg/mL in 2015 with fluctuations from 16–64 µg/mL through the years for E. coli, but were stable at ≥64 µg/mL from 2011 to 2015 for K. pneumoniae isolates. Susceptibilities to ertapenem, imipenem and amikacin were high for E. coli isolates throughout the study, but K. pneumoniae isolated from abscesses, colon and peritoneal fluid collected from medical and surgical ICUs showed an increasing trend of carbapenem resistance in 2015.

Conclusion

In 2015 there was a trend of enhanced carbapenem resistance, particularly for K. pneumoniae isolated from IAI samples obtained from patients in ICUs.

Spectrum of Trained Innate Immunity Induced by Low-Virulence Candida Species against Lethal Polymicrobial Intra-abdominal Infection

Polymicrobial intra-abdominal infections (IAI) are clinically prevalent and cause significant morbidity and mortality, especially those involving fungi. Our laboratory developed a mouse model of polymicrobial IAI and demonstrated that coinfection with Candida albicans and Staphylococcus aureus (C. albicans/S. aureus) results in 80 to 90% mortality in 48 to 72 h due to robust local and systemic inflammation.

Polymicrobial intra-abdominal infections (IAI) are clinically prevalent and cause significant morbidity and mortality, especially those involving fungi. Our laboratory developed a mouse model of polymicrobial IAI and demonstrated that coinfection with Candida albicans and Staphylococcus aureus (C. albicans/S. aureus) results in 80 to 90% mortality in 48 to 72 h due to robust local and systemic inflammation. Surprisingly, inoculation with Candida dubliniensis and S. aureus resulted in minimal mortality, and rechallenge of mice with lethal C. albicans/S. aureus conferred >90% protection up to 60 days postinoculation. Protection was mediated by Gr-1⁺ polymorphonuclear leukocytes, indicating a novel form of trained innate immunity (TII). The purpose of this study was to determine the microbial requirements and spectrum of innate-mediated protection. In addition to Candida dubliniensis, several other low-virulence Candida species (C. glabrata, C. auris, and C. albicansefg1Δ/Δ cph1Δ/Δ) and Saccharomyces cerevisiae conferred significant protection with or without S. aureus. For C. dubliniensis-mediated protection, hyphal formation was not required, with protection conferred as early as 7 days after primary challenge but not at 120 days, and also following multiple lethal C. albicans/S. aureus rechallenges. This protection also extended to a lethal intravenous (i.v.) C. albicans challenge but had no effect in the C. albicans vaginitis model. Finally, studies revealed the ability of the low-virulence Candida species that conferred protection to invade the bone marrow by 24 h post-primary challenge, with a positive correlation between femoral bone marrow fungal infiltration at 48 h and protection upon rechallenge. These results support and further extend the characterization of this novel TII in protection against lethal fungal-bacterial IAI and sepsis.

The Efficacy and Safety of Doripenem in the Treatment of Acute Bacterial Infections-A Systemic Review and Meta-Analysis of Randomized Controlled Trials

This study aims to assess the efficacy and safety of doripenem on treating patients with acute bacterial infections. The Pubmed, Embase, and Cochrane databases were searched up to April 2019. Only randomized clinical trials comparing doripenem and other comparators for the treatment of acute bacterial infection were included. The primary outcome was the clinical success rate and the secondary outcomes were microbiological eradication rate and risk of adverse events. Eight randomized controlled trials (RCTs) were included. Overall, doripenem had a similar clinical success rate with comparators (odds ratio [OR], 1.15; 95% CI, 0.79-1.66, I2 = 58%). Similar clinical success rates were noted between doripenem and comparators for pneumonia (OR, 0.84; 95% CI, 0.46-1.53, I² = 72%) and for intra-abdominal infections (OR, 1.00; 95% CI, 0.57-1.72). For complicated urinary tract infection, doripenem was associated with higher success rate than comparators (OR, 1.89, 95% CI, 1.13-3.17, I² = 0%). The pool analysis comparing doripenem and other carbapenems showed no significant differences between each other (OR, 0.96, 95% CI, 0.59-1.58, I² = 63%). Doripenem also had a similar microbiological eradication rate with comparators (OR, 1.08; 95% CI, 0.86-1.36, I² = 0%). Finally, doripenem had a similar risk of treatment-emergent adverse events as comparators (OR, 0.98; 95% CI, 0.83-1.17, I² = 33%). In conclusion, the clinical efficacy of doripenem is as high as that of the comparator drugs in the treatment of acute bacterial infection; furthermore, this antibiotic is as well tolerated as the comparators.

Empirical metronidazole for patients with severe bacterial infection: A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Metronidazole is the preferred empirical anti-anaerobic agent for patients with suspected anaerobic infection. The balance between benefits and harms of empirical metronidazole is unclear. We aimed to assess patient-important benefits and harms of empirical metronidazole vs placebo/no treatment in adult patients with severe bacterial infection of any origin.

METHODS

We conducted a systematic review with meta-analysis and trial sequential analysis of randomized clinical trials assessing empirical metronidazole vs placebo/no treatment in adult hospitalized patients with severe bacterial infection. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, the Cochrane Handbook and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. A protocol and statistical analysis plan was published prior to conducting the review.

RESULTS

We included a total of nine trials (n = 1753 patients), all of which were adjudicated as having high risk of bias. We found no difference in the primary outcome mortality within 90 days (relative risk 1.56, 95% confidence interval 0.39-6.25). Fewer patients receiving metronidazole had secondary infections (relative risk 0.43, 95% CI: 0.27-0.68). Trial sequential analysis indicated high risk of random errors due to lack of data, and the quality of evidence was very low for all outcomes.

CONCLUSIONS

There is low quantity and quality of evidence supporting the use of empirical metronidazole in adult patients with severe bacterial infections of any origin, and no firm evidence for benefit or harm.

Comparison of Short-Course and Prolonged Antimicrobial Therapy in the Management of Intra-Abdominal Infections

Background: Guidelines recommend an antimicrobial therapy duration of four to seven days for intra-abdominal infections (IAIs). Despite evidence that shorter treatments are appropriate for this disease state, longer durations frequently are utilized in clinical practice. This study compared the clinical outcomes of short course (SC) and prolonged course (PC) antimicrobial therapy for IAI. Methods: This was a noninterventional, retrospective, single-center study. Adults admitted with documented IAI who received antimicrobial treatment for ≥48 hours were included. Results: A total of 175 patients were enrolled, 73 patients receiving SC (≤7 days) and 102 patients receiving PC (>7 days) therapy. No significant differences were observed in the primary outcome of clinical cure (74% versus 67.6%; p = 0.367). Secondary outcomes including hospital length of stay (LOS) (5.5 versus 5.8 days; p = 0.372), intensive care unit (ICU) LOS (3 versus 5 days; p = 0.117), 28-day all-cause mortality rate (4.1% versus 2%; p = 0.651), and 30-day re-admission rate (19.2% versus 20.6%; p = 0.818) also were not significantly different. Conclusions: There was no significant difference in the rate of clinical cure between SC and PC antimicrobial therapy. These results further support guideline recommendations for a shorter duration of antimicrobial therapy in IAI.

Monitoring the antimicrobial susceptibility of Gram-negative organisms involved in intraabdominal and urinary tract infections recovered during the SMART study (Spain, 2016 and 2017)

OBJECTIVE

Continuous antimicrobial resistance surveillance is recommended by Public Health authorities. We up-dated data from the SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study in Spain.

METHODS

The antimicrobial susceptibility data and extended-spectrum beta-lactamase (ESBL) production in isolates recovered from intra-abdominal (IAI) (n=1,429) and urinary tract (UTI) (n=937) infections during the 2016- 2017 SMART study in 10 Spanish hospitals were analysed.

RESULTS

Escherichia coli was the most frequently microorganism isolated (48.3% and 53.7%) followed by Klebsiella spp. (11.5% and 21.9%) in IAIs and UTIs, respectively. Figures for Pseudomonas aeruginosa were 9.0% and 6.1%, being more frequently recovered from patients with nosocomial infections. Overall, 9.9% (IAI) and 14.0% (UTI) of E. coli, Klebsiella spp. and Proteus mirabilis isolates were ESBL-producers, being Klebsiella pneumoniae (34.5%) from UTI of nosocomial origin the most frequent. ESBL-producers were higher in patients >60 years in both IAIs and UTIs. As in previous years, amikacin (96.3%-100% susceptibility), ertapenem (84.2%-100%) and imipenem (70.3%- 100%) were the most active antimicrobials tested among Enterobacterales species. The activity of amoxicillin-clavulanic, piperacillin-tazobactam, and ciprofloxacin susceptibility was lower, particularly among ESBL-producers. Ertapenem susceptibility (88.9%-100%) was retained in ESBL-E. coli isolates that were resistant to these antimicrobials but decreased (28.6%-100%) in similar isolates of K. pneumoniae.

CONCLUSIONS

Continuous antimicrobial resistance surveillance from the SMART study reveals overall maintenance of ESBL-producers in Spain, although with higher presence in isolates from UTIs than from IAIs. Moreover, ertapenem activity was high in E. coli irrespective of ESBL production but decreased in K. pneumoniae, particularly among ESBL-producers.

Retrospective Analysis of Post-Operative Antibiotics in Complicated Appendicitis

Background: There is no consensus regarding the ideal post-operative antibiotic strategy for surgically managed complicated appendicitis. The goal of this study was to investigate different antibiotic regimens used for this purpose at our institution and their association with post-operative outcomes. Methods: The 1,102 patients underwent appendectomy from 2012 to 2016. A detailed chart review was performed on the 188 with complicated appendicitis based on standardized definitions. Descriptive and inferential statistics were used to analyze post-operative antibiotic use and complications. Results: Of the 188 cases of complicated appendicitis, 143 (76%) were classified as perforated by the operative surgeon. These patients were significantly more likely to be started on antibiotics after appendectomy (83.9% versus 33.3%; p < 0.001) and have a greater length of stay (LOS) (p = 0.006). The development of a surgical site infection (SSI) was significantly associated with a clinical diagnosis of diabetes (p = 0.04); the presence of free fluid, abscess, or perforation on pre-operative imaging (p = 0.002, 0.039, and 0.012, respectively); and a decision by the surgeon to leave a drain (p = 0.001). On multiple logistic regression analysis adjusted for free fluid on pre-operative imaging and an intra-operative decision to leave a drain, patients receiving one day or three or more days of antibiotics had higher odds of developing an SSI than patients who did not receive any post-operative antibiotics. Conclusions: In this cohort, operative surgeons accurately identified patients with complicated appendicitis who did not require post-operative antibiotics. For patients deemed to require them, two days of treatment was associated with reduced odds of SSI compared with shorter or longer antibiotic courses. The optimal course of antibiotics remains to be identified, but these findings suggest that longer post-operative courses do not avert SSI compared with two days of antibiotics. A prospective trial could clarify the optimal duration and route of antibiotic therapy in the setting of surgical complicated appendicitis.

Recurrence of Citrobacter koseri-associated Intra-abdominal Infection 2 Years after Spilled Gallstones during Laparoscopic Cholecystectomy

Spilled gallstones during laparoscopic cholecystectomy (LC) are common. Lost gallstones can lead to complications such as intra-abdominal abscesses, which can occur days, months, or even years after the procedure. Citrobacter koseri belongs to the family of Enterobacteriaceae. It is a low-virulence pathogen; however, it is linked to infections of the urinary tract and abdomen. We report the case of a 70-year-old diabetic male who presented with C. koseri- associated subhepatic abscess. Two years prior, he had emphysematous cholecystitis and liver abscess caused by C. koseri. During his LC, gallstones were spilled in the abdominal cavity and every effort was made to retrieve them. However, 2 years later, an aspiration of the subhepatic abscess revealed cholesterol fragments. We hypothesize that dislodged cholesterol gallstones and bile, contaminated with C. koseri, were the culprits for the appearance of the subhepatic abscess with the same organism 2 years after the LC.

Tactics to Prevent Intra-Abdominal Infections in General Surgery

BACKGROUND

Abdominal infections following surgery have many severe consequences. Several effective, well-evaluated infection prevention and control processes exist to avoid these infections.

METHODS

This manuscript reviews and provides supporting evidence for common management strategies useful to avoid postoperative abdominal infection.

RESULTS

Prevention of abdominal infection begins with preparation of the environment using standard infection control practices. Peri-operative use of systemic antibiotics, an antibiotic bowel preparation in colorectal surgery, and effective antiseptic preparation of the surgical site all reduce infection rates. Peri-operative supplemental oxygenation, maintenance of core body temperature, and physiologic euglycemia will reduce both incisional and organ-space infections in the abdominal surgery patient. Strategic use of irrigation and drain placement may be useful in some circumstances.

CONCLUSION

Specific methods of prevention are documented to reduce intra-abdominal infections. Prevention requires a multi-disciplinary team including the surgeon, anesthesiologist, and all operating room personnel.

Vancomycin in the treatment of adult intra-abdominal infections: do we have strong evidences?

The management of intra-abdominal infections (IAIs) primarily includes adequate antimicrobial therapy and appropriate source control. Vancomycin is a fundamental and most effective antimicrobial agent. The aim of this study is to search and evaluate the quality of clinical evidences regarding the exclusive use of vancomycin for the management of adult IAIs. For this purpose, we first summarized the recommendations on exclusive use of vancomycin in adult IAIs from six leading guidelines and excavated the relevant supporting references. We subsequently conducted a literature search to screen eligible clinical studies in this field for possible systematic review. Our investigation demonstrates that the exclusive use of vancomycin is recommended in restricted indications, that is, IAIs caused by Enterococcus spp. or methicillin-resistant Staphylococcus aureus. However, the supporting references in the guidelines are more subjective instead of objective, which mainly originate from experts’ personal experiences or from the therapeutic efficacy of vancomycin in other types of infections rather than in IAIs. Furthermore, our literature search fails to find high-level evidence. In conclusion, current low-level evidences are inadequate to elicit strong recommendations on the exclusive use of vancomycin in the treatment of adult IAIs. Our study would be helpful for the rational use of vancomycin and deceleration of the emerging vancomycin resistance rates.

The Role of Ertapenem for the Treatment of Complicated Intra-abdominal Infections With a Positive Culture for Enterococcus faecalis

Controversy remains as to whether Enterococcus faecalis recovered from intra-abdominal infections (IAIs) requires targeted therapy. In a multicenter study comparing patients with IAIs from which E. faecalis was identified in intra-abdominal cultures, no difference in clinical outcomes was observed between patients receiving ertapenem vs those receiving piperacillin/tazobactam.

Ertapenem non-susceptibility and independent predictors of the carbapenemase production among the Enterobacteriaceae isolates causing intra-abdominal infections in the Asia-Pacific region: results from the Study for Monitoring Antimicrobial Resistance Trends (SMART)

Objectives

This study investigated the prevalence rates of carbapenemase positivity, antibiotic susceptibility, and independent predictors of carbapenemase producers among the Enterobacteriaceae isolates recovered from patients with intra-abdominal infections (IAI) in the Asia-Pacific region between 2008 and 2014.

Materials and methods

Multiplex PCR was used for the detection of specific β-lactamases, while the broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of antibiotics among the IAI-related Enterobacteriaceae isolates. We studied the abovementioned parameters in 484 ertapenem-non-susceptible (Erta-NS) isolates and explored the independent predictors of carbapenemase-producing Enterobacteriaceae (CPE) isolates.

Results

Eighty (16.5%) Erta-NS-IAI Enterobacteriaceae isolates were found to be CPE. Vietnam and the Philippines had the highest CPE prevalence rates. The IAI isolates of Enterobacter species and Klebsiella pneumoniae followed by Escherichia coli were the three major pathogens with 77.4%, 40.9%, and 11.7% Erta-NS prevalence rates, respectively. Furthermore, the highest CPE prevalence (35%) was noted among the Erta-NS-K. pneumoniae isolates. The CPE isolates harboring the bla_NDM, bla_KPC, or blaOXA-48-like alleles had higher imipenem MIC levels than those harboring the bla_IMP alleles. Using multivariate logistic regression analysis, we concluded that Erta-NS-IAI isolates with an imipenem non-susceptible phenotype (OR, 56.4), with cefepime MIC >8 µg/mL (OR, 4.4), cultured from the peritoneal space samples (tissue or abscess; OR, 3.3), and harboring the extended-spectrum β-lactamase encoding allele (OR, 11.5) are independent predictors of CPE.

Conclusion

Imipenem non-susceptibility, cefepime MIC >8 µg/mL, and the peritoneal space as a culture site are independent clinical predictors of CPE among the Erta-NS-IAI Enterobacteriaceae isolates in the Asia-Pacific region.

Complicated intra-abdominal infections: a prospective validation study of the WSES Sepsis Severity Score

INTRODUCTION

The World Society of Emergency Surgery (WSES) recently developed and validated a sepsis severity score for complicated intra-abdominal infections (cIAIs). We aimed to prospectively study the validity of this score in our local setting and compare it with global findings.

METHODS

In a prospective study of 100 consecutive adult patients with cIAIs treated at Al-Ain Hospital, United Arab Emirates, from October 2014 to January 2016, we studied patients' demographics, disease, risk factors, WSES Sepsis Severity Score, management, hospital stay and mortality. Our findings were compared with those from a recent global multicentre prospective study from 53 countries (n = 4,496).

RESULTS

Compared with global data, our patients were more likely to be male (p < 0.0001) and younger (p < 0.0001), with more appendicitis and perforated peptic ulcers (p < 0.0001), significantly lower sepsis severity score (p < 0.0001) and more delays in surgical intervention (p = 0.001). Nevertheless, they had similar adequate source control (p = 0.54) and surgical reinterventions (p = 0.63). Overall, our patients had a significantly lower mortality rate (1.0% vs. 9.3% in global data; p = 0.001). A direct logistic regression model showed that the WSES Sepsis Severity Score significantly predicted mortality (p < 0.0001), but our hospital's setting was not predictive of mortality compared with other hospitals (p = 0.18).

CONCLUSION

Although our patient demographics and hospital's setting significantly differed from those of other international hospitals, the WSES Sepsis Severity Score was very accurate in predicting mortality among our patients, which supports its generalisability for all patient populations worldwide.

A New Scoring System to Predict Blood Stream Infections in Patients with Complicated Intra-Abdominal Infections: Experience from a Tertiary Referral Hospital in China

BACKGROUND

This purpose of this study was to investigate the effects of blood stream infections (BSIs) on the prognosis of patients with complicated intra-abdominal infections (IAIs) and to make predictions based on patients' characteristics on admission.

PATIENTS AND METHODS

One hundred eighty-seven patients with complicated IAI in 2014 and 2015 were included in our retrospective analysis, except for those diagnosed with central line-associated blood stream infections (CLABSIs). Patients with BSIs were compared with patients without BSIs. Multivariable logistic regression was applied to identify factors associated with BSIs and also the subtypes of BSIs. The predictive score systems were established further.

RESULTS

Seventy-four patients (39.6%) with complicated IAIs developed BSIs after admission. Four factors evaluated on admission were associated independently with BSIs including alanine aminotransferase (ALT) ≥66 U/L (two scores), insensitivity to initial empirical antibiotic agents (IIEA; three scores), Sepsis-Related Organ Failure Assessment (SOFA) score of two or more (three scores), and generalized peritonitis (four scores). A total score of five or more was regarded as the critical value in the combined test to predict BSIs, with a sensitivity of 0.78 and a specificity of 0.73. Blood stream infections were further divided as secondary BSIs and non-secondary BSIs. The risk factors of secondary BSIs included IIEA (three scores), SOFA score of two or more (five scores), and generalized peritonitis (eight scores), where a total score of nine or more was regarded as the critical value in the combined test, with a sensitivity of 0.68 and a specificity of 0.87, whereas the risk factors of non-secondary BSIs included IIEA (three scores), SOFA score of two or more (three scores) and procalcitonin (PCT) ≥0.43 mcg/L (three scores), where a total score of six or more was regarded as the critical value in the combined test, with a sensitivity of 0.75 and a specificity of 0.70. Moreover, BSIs were linked with the worse clinical outcomes in organ functions, hospitalization costs, and mortality.

CONCLUSIONS

Our new scoring methods may have potential advantages on the early prediction and recognition of BSIs in patients with complicated IAIs.

Surgical site infections after pancreatic surgery in the era of enhanced recovery protocols

Few data exist on risk factors (RF) for surgical site infections (SSI) among patients treated in an enhanced recovery after surgery (ERAS) pathway. This study aimed to assess RF for SSI after pancreas surgery in a non-ERAS group and an ERAS cohort.An exploratory retrospective analysis of all pancreas surgeries prospectively collected (01/2000-12/2015) was performed. RF for SSI were calculated using uni- and multivariable binary logistic regressions in non-ERAS and ERAS patients.Pancreas surgery was performed in 549 patients. Among them, 144 presented a SSI (26%). In the non-ERAS group (n = 377), SSI incidence was 27% (99/377), and RF for SSI were male gender and preoperative biliary stenting. Since 2012, 172 consecutive patients were managed within an ERAS pathway. Forty-five patients (26%) had SSI. On multivariable analysis no RF for SSI in the ERAS cohort was found. In the ERAS group, patients with a pathway compliance ≤70% had higher occurrence of SSI (30/45 = 67% vs. 7/127 = 6%, p < 0.001) and patients with and without SSI had similar median overall compliances (77%, IQR 71-80 vs. 80%, IQR 73-83, p = 0.097).In the non-ERAS cohort, male gender and preoperative biliary stenting were RF for SSI, whereas in the ERAS group no RF for SSI was found. In an ERAS pathway, having an overall compliance >70% might diminish the SSI rate.

Identification of Specific Components of the Eicosanoid Biosynthetic and Signaling Pathway Involved in Pathological Inflammation during Intra-abdominal Infection with Candida albicans and Staphylococcus aureus

Polymicrobial intra-abdominal infections (IAIs) are a significant cause of morbidity and mortality, particularly when fungal pathogens are involved. Our experimental murine model of IAI involving intraperitoneal inoculation of Candida albicans and Staphylococcus aureus results in synergistic lethality (∼80%) due to exacerbated inflammation. Monomicrobial infection results in no mortality, despite a microbial burden and dissemination similar to those in a coinfection. In the coinfection model, the immunomodulatory eicosanoid prostaglandin E₂ (PGE₂) was determined to be necessary and sufficient to induce mortality, implicating PGE₂ as the central mediator of the amplified inflammatory response. The aim of this study was to identify key components of the PGE₂ biosynthetic and signaling pathway involved in the inflammatory response and explore whether these can be targeted to prevent or reduce mortality. Using selective pharmacological inhibitors of cyclooxygenases (COX) or PGE₂ receptor antagonists in the C. albicans-S. aureus IAI mouse model, we found that inhibition of COX and/or blocking of PGE₂ receptor 1 (EP1) or PGE₂ receptor 3 (EP3) signaling reduced proinflammatory cytokine production, promoted interleukin-10 production, reduced cellular damage in the peritoneal cavity, and, most importantly, significantly improved survival. The greatest effect on survival was obtained by the simultaneous inhibition of COX-1 activity and EP1 and EP3 receptor signaling. Importantly, early inhibition of PGE₂ pathways dramatically improved the survival of fluconazole-treated mice compared with that achieved with fluconazole treatment alone. These findings indicate that COX-1 and the EP1 and EP3 receptors mediate the downstream pathological effects of PGE₂ during polymicrobial IAI and may serve as effective therapeutic targets.

Novel Method Suggests Global Superiority of Short-Duration Antibiotics for Intra-abdominal Infections

Desirability of outcome ranking and response adjusted for duration of antibiotic risk (DOOR/RADAR) are novel and innovative methods of evaluating data in antibiotic trials. We analyzed data from a noninferiority trial of short-course antimicrobial therapy for intra-abdominal infection (STOP-IT), and results suggest global superiority of short-duration therapy for intra-abdominal infections.

Antibiotic Use and Antimicrobial Resistance of Surgical Patients with Peritonitis at a Tertiary Referral Hospital in Rwanda

BACKGROUND

There is growing recognition of the worsening problem of antibiotic resistance and the need for antibiotic stewardship in low-resource settings. The aim of this study was to describe antibiotic use and antimicrobial resistance in patients undergoing surgery for peritonitis at a Rwandan referral hospital.

PATIENTS AND METHODS

All surgical patients with peritonitis at a Rwandan referral hospital were enrolled. Prospective data were collected on epidemiology, clinical features, interventions, and outcomes. Antibiotic agents were prescribed and cultures were collected according to surgeon discretion. High risk for antibiotic treatment failure or death was defined as patients with severe sepsis, older than 70 years of age, tumor, or operating room delay more than 24 hours from hospital admission. Logistic regression was used to determine factors associated with high risk of antibiotic treatment failure or death.

RESULTS

Over a six-month period, 280 patients underwent operation for peritonitis; 79 patients were excluded because no infectious etiology was identified at operation. Data on antibiotic usage were available for 165 patients. The most common diagnoses were intestinal obstruction (n = 43) and appendicitis (n = 36). Most patients received antibiotic agents, the most of of which being third-generation cephalosporins (n = 149; 90%) and metronidazole (n = 140; 85%). The mean duration of antibiotics was 5.1 days (range: 0-14). Overall, 80 (54%) patients were high-risk for antibiotic treatment failure or death. Risk for antibiotic treatment failure or death was associated with localized peritonitis (p = 0.001) and high American Society of Anesthesiologist score (p = 0.003). Cultures were collected from 33 patients and seven patients had an organism isolated. Escherichia coli was identified in in five surgical specimens and two 2 urine cultures. All Escherichia coli specimens showed resistance to cephalosporins.

CONCLUSIONS

Broad antibiotic coverage with third-generation cephalosporins and metronidazole is common in Rwandan surgical patients with peritonitis. Areas for improvement should focus on choice and duration of antibiotic agents, tailored to underlying diagnosis and risk factors for antibiotic treatment failure or death. More data are needed on antibiotic resistance patterns to guide antimicrobial therapy.

Addressing social influences reduces antibiotic duration in complicated abdominal infection: a mixed methods study

BACKGROUND

Antimicrobial therapy for intra-abdominal infections is often inappropriately prolonged. An intervention addressing factors influencing the duration of intravenous antibiotic use was undertaken. This study reports the antibiotic prescribing patterns before and after the intervention and a qualitative analysis of the experience of the intervention.

METHODS

Quantitative: A retrospective audit of patients with complicated intra-abdominal infection before and after a multifaceted persuasive intervention was performed. Qualitative: Semi-structured interviews were performed to evaluate which elements of the intervention were perceived to be effective.

RESULTS

An intervention including collaborative inter-specialty and inter-professional educational meetings, and education of all professional streams was undertaken. Quantitative: Twenty-three patients before and 22 patients after the intervention were included. The total duration of antibiotics decreased significantly following the intervention (9.2 versus 6.6 days P = 0.02). The duration of intravenous antibiotics did not change significantly (5.4 versus 4.5 days, P = 0.06). Qualitative: Eighteen health-care professionals participated. Thematic analysis indicated that a collaborative approach between senior surgical and infectious disease specialists in the pre-intervention stage led to perceived ownership and leadership of the intervention by the surgical team, which was thought critical to the success of the intervention. Conversely, the ability of nurses and pharmacists to influence antibiotic practice was considered limited and a poster promoting the intervention was perceived as ineffective.

CONCLUSION

Consultant leadership and specialty ownership of the process were perceived to be critical in the success of the intervention. Antibiotic stewardship programs which address social factors may have greater efficacy to optimize antimicrobial prescribing.

An innovative method for placing a double-lumen irrigation-suction tube in the management of abdominal infection: A case report

RATIONALE

Currently, the use of double-lumen irrigation-suction tube for drainage has become increasingly more common. However, the insertion process is complex, and the position of the double cannula placed in this manner is not accurate. We developed a method for placing the drainage tube and use it in the treatment of an abdominal infection.

PATIENT CONCERNS

A 51-year-old man with an abdominal infection due to colonic anastomotic fistula was admitted. Routine laboratory tests revealed an elevated white blood cell count (17 × 10/L) and C-reactive protein level (78 mg/L). Computed tomography (CT) revealed that the peritoneal cavity was filled with fluid.

DIAGNOSES

The patient was diagnosed with colonic anastomosis fistula by gastrointestinal radiography. Abdominal infection was diagnosed based on CT scan, inflammatory markers, and patient signs and symptoms.

INTERVENTIONS

Two punctures were performed. After skin expansion, the source of infection was drained with a suction catheter (diameter = 1.0 cm) under continuous negative pressure of 150 to 200 millibars, along with continuous saline irrigation at 300 mL/h.

OUTCOMES

Pus in the abdomen drained completely. The abdominal infection was controlled. There were no adverse events.

LESSONS

Abdominal infection in fistulas is a fatal disease. The main therapeutic target is full drainage at an early stage. Precise positioning of the tube, continuous negative pressure irrigation and drainage are key points in the treatment.

Drain Failure in Intra-Abdominal Abscesses Associated with Appendicitis

BACKGROUND

Previous studies have suggested that percutaneous drainage and interval appendectomy is an effective treatment for appendicitis with associated abscess. Few studies to date have analyzed risk factors for failed drain management. We hypothesized that older patients with more co-morbidities would be at higher risk for failing conservative treatment.

METHODS

The 2010-2014 editions of the National Inpatient Sample (NIS) were queried for patients with diagnoses of peri-appendiceal abscesses. Minors and elective admissions were excluded. We identified patients who underwent percutaneous drainage and defined drain failure as undergoing a surgical operation after drainage but during the same inpatient visit to assess for factors associated with failure of drainage alone as a treatment. After univariable analysis, binomial logistic regression was used to assess for independent risk factors. Frequencies were analyzed by χ² and continuous variables by Student's t-test.

RESULTS

A total of 2,209 patients with appendiceal abscesses received drains; 561 patients (25.4%) failed conservative management and underwent operative intervention. On univariable analysis, patients who failed conservative management were younger, more likely to be Hispanic, have more inpatient diagnoses, and to have undergone drainage earlier in the hospital course. Multivariable regression demonstrated that the number of diagnoses, female sex, and Hispanic race were predictive of failure of drainage alone. Older age, West and Midwest census regions, and later drain placement were predictive of successful treatment with drainage alone. Failure was associated with more charges and longer hospital stay but not with a higher mortality rate.

CONCLUSION

Approximately a quarter of patients will fail management of appendiceal abscess with percutaneous drain placement alone. Risk factors for failure are patient complexity, female sex, earlier drainage, and Hispanic race. Failure of drainage is associated with higher total charges and longer hospital stay; however, no change in the mortality rate was noted.

Immune Protection against Lethal Fungal-Bacterial Intra-Abdominal Infections

Polymicrobial intra-abdominal infections (IAIs) are clinically prevalent and cause significant morbidity and mortality, especially those involving fungi. Our laboratory developed a mouse model of IAI and demonstrated that intraperitoneal inoculation with Candida albicans or other virulent non-albicans Candida (NAC) species plus Staphylococcus aureus resulted in 70 to 80% mortality in 48 to 72 h due to robust local and systemic inflammation (sepsis). Surprisingly, inoculation with Candida dubliniensis or Candida glabrata with S. aureus resulted in minimal mortality, and rechallenge of these mice with lethal C. albicans/S. aureus (i.e., coninfection) resulted in >90% protection. The purpose of this study was to define requirements for C. dubliniensis/S. aureus-mediated protection and interrogate the mechanism of the protective response. Protection was conferred by C. dubliniensis alone or by killed C. dubliniensis plus live S. aureus. S. aureus alone was not protective, and killed S. aureus compromised C. dubliniensis-induced protection. C. dubliniensis/S. aureus also protected against lethal challenge by NAC plus S. aureus and could protect for a long-term duration (60 days between primary challenge and C. albicans/S. aureus rechallenge). Unexpectedly, mice deficient in T and B cells (Rag-1 knockouts [KO]) survived both the initial C. dubliniensis/S. aureus challenge and the C. albicans/S. aureus rechallenge, indicating that adaptive immunity did not play a role. Similarly, mice depleted of macrophages prior to rechallenge were also protected. In contrast, protection was associated with high numbers of Gr-1^hi polymorphonuclear leukocytes (PMNLs) in peritoneal lavage fluid within 4 h of rechallenge, and in vivo depletion of Gr-1⁺ cells prior to rechallenge abrogated protection. These results suggest that Candida species can induce protection against a lethal C. albicans/S. aureus IAI that is mediated by PMNLs and postulated to be a unique form of trained innate immunity.

Polymicrobial intra-abdominal infections are clinically devastating infections with high mortality rates, particularly those involving fungal pathogens, including Candida species. Even in patients receiving aggressive antimicrobial therapy, mortality rates remain unacceptably high. There are no available vaccines against IAI, which is complicated by the polymicrobial nature of the infection. IAI leads to lethal systemic inflammation (sepsis), which is difficult to target pharmacologically, as components of the inflammatory response are also needed to control the infection. Our studies demonstrate that prior inoculation with low-virulence Candida species provides strong protection against subsequent lethal infection with C. albicans and S. aureus. Surprisingly, protection is long-lived but not mediated by adaptive (specific) immunity. Instead, protection is dependent on cells of the innate immune system (nonspecific immunity) and provides protection against other virulent Candida species. This discovery implies that a form of trained innate immunity may be clinically effective against polymicrobial IAI.

Evaluation of a Short Course of Antimicrobial Therapy for Complicated Intra-Abdominal Infections in Critically Ill Surgical Patients

BACKGROUND

The optimal duration of antimicrobial therapy for treatment of complicated intra-abdominal infections (cIAI) in critically ill surgical patients is unknown. Recent evidence suggests that a short (four-day) course of therapy may be effective, however data in severely critically ill patients are limited.

PATIENTS AND METHODS

A single-center, retrospective, cohort study was conducted at a tertiary academic medical center. Adult patients admitted to the surgical intensive care unit (SICU) with cIAI between December 2011 and July 2015 were enrolled. Patients undergoing transplantation and those with less than 24 h in the SICU were excluded. Patients were divided into two groups, short (≤ 7 d) and long (> 7 d) antimicrobial therapy. The primary outcome was treatment failure, which was defined as a composite of recurrent cIAI, secondary extra-abdominal infection, and/or in-hospital mortality from any cause. Categorical and continuous data were analyzed with χ² and Mann-Whitney U tests, respectively. Binary logistic regression was performed to determine factors associated with treatment failure and mortality.

RESULTS

Of 1,679 patients screened, 240 were included, 103 in the short and 137 in the long group. Patients in the short and long groups received a median of 5 and 14 d of therapy, respectively (p < 0.001). Treatment failure occurred less frequently with a short duration of therapy (39% versus 63%, p < 0.001) and it occurred two days sooner after source control in patients receiving the shorter courses of antimicrobial therapy (short, median 6 d, interquartile range [IQR] 3-9; long, 8 d, IQR 6-14; p < 0.001). Logistic regression demonstrated that a long duration of therapy was associated with treatment failure (odds ratio [OR] 2.186, 95% confidence interval [CI] 1.251-3.820, p = 0.006), but not with mortality (OR 0.738, 95% CI 0.329-1.655, p = 0.461).

CONCLUSIONS

In critically ill surgical patients with cIAI, a short duration of antimicrobial therapy after source control resulted in similar outcomes to previously published studies, providing support for the safety of this approach in critically ill patients.

Rapid Source-Control Laparotomy: Is There a Mortality Benefit?

BACKGROUND

The purpose of this study was to determine the influence rapid source-control laparotomy (RSCL) has on the mortality rate in non-trauma patients with intra-abdominal infection. The hypothesis was that RSCL reduces deaths and hospital lengths of stay (LOS) in patients compared with definitive repair and primary fascial closure (PFC).

METHODS

The International Classification of Diseases-10 codes for sepsis, gastric and duodenal ulcer perforation or hemorrhage, incisional or ventral hernia with obstruction, intestinal volvulus, ileus with obstruction, diverticulitis with perforation or abscess, vascular disorder of intestine, non-traumatic intestinal perforation, peritoneal abscess, and unspecified peritonitis were used to query the 2015 National Surgical Quality Improvement Project (NSQIP) database for all patients treated with either RSCL or PFC. The two groups of patients were compared on the basis of LOS and deaths. Collected data included age, gender, body mass index (BMI), site classification, American Society of Anesthesiologists (ASA) class, operative time, number of risk factors, and pre-operative septic state.

RESULTS

After adjusting for the aforementioned variables, propensity score-matched cohorts (n = 210 in each cohort) were used to evaluate the influence of incision closure type on LOS and mortality rate. The odds of death (31.4% vs. 21.4%) with RSCL was 1.78 (95% confidence interval 1.08-2.95; p = 0.02) times that of PFC. Closure type was not significantly associated with an increased LOS (median 14 vs. 11 days; p = 0.35).

CONCLUSIONS

This retrospective cohort analysis demonstrated that RSCL is associated with higher odds of death in general surgical patients with intra-abdominal infection. There is a need for further studies to delineate what, if any, physiologic parameters indicate a need for RSCL.

Peripheral blood leucocytes show differential expression of tumour progression-related genes in colorectal cancer patients who have a postoperative intra-abdominal infection: a prospective matched cohort study

AIM

Anastomotic leak is associated with higher rates of recurrence after surgery for colorectal cancer. However, the mechanisms responsible are unknown. We hypothesized that the infection-induced inflammatory response may induce overexpression of tumour progression-related genes in immune cells. The aim was to investigate the effect of postoperative intra-abdominal infection on the gene expression patterns of peripheral blood leucocytes (PBL) after surgery for colorectal cancer.

METHOD

Prospective matched cohort study. Patients undergoing surgery for colorectal cancer were included. Patients who had anastomotic leak or intra-abdominal abscess were included in the infection group (n = 23) and matched with patients without complications for the control group (n = 23). PBL were isolated from postoperative blood samples. Total RNA was extracted and hybridized to the Affymetrix Human Gene 1.0 ST microarray.

RESULTS

Patients in the infection group displayed 162 upregulated genes and 146 downregulated genes with respect to the control group. Upregulated genes included examples coding for secreted cytokines involved in tumour growth and invasion (S100P, HGF, MMP8, MMP9, PDGFC, IL1R2). Infection also upregulated some proangiogenic genes (CEP55, TRPS1) and downregulated some inhibitors of angiogenesis (MME, ALOX15, CXCL10). Finally, some inhibitors (HP, ORM1, OLFM4, IRAK3) and activators (GNLY, PRF1, FGFBP2) of antitumour immunity were upregulated and downregulated, respectively, suggesting that the inflammatory environment caused by a postoperative infection favours immune evasion mechanisms of the tumour.

CONCLUSION

Analysis of PBL shows differential expression of certain tumour progression-related genes in colorectal cancer patients who have a postoperative intra-abdominal infection, which in turn may promote the growth of residual cancer cells to become recurrent tumours.

Elevated Levels of Plasma Mitochondrial DNA Are Associated with Clinical Outcome in Intra-Abdominal Infections Caused by Severe Trauma

BACKGROUND

The purpose of our study was to determine prospectively relationships between plasma mitochondrial deoxyribonucleic acid (mtDNA) concentration and clinical outcome in patients with intra-abdominal infections (IAIs) induced by severe abdominal trauma.

PATIENTS AND METHODS

The DNA was isolated from serum samples taken from patients with IAIs at hospital days zero, one, and two. Plasma mtDNA concentration was assessed by real-time polymerase chain reaction (PCR). The study population's clinical and laboratory data were analyzed.

RESULTS

The mtDNA damage-associated molecular patterns were expressed as a PCR threshold cycle number using four selected sequences. The patients with IAIs had significant higher plasma mtDNA than healthy control subjects. Patients with IAIs with sepsis apparently had elevated mtDNA levels compared with non-septic patients with IAIs (30.9 ± 2.0 vs. 28.7 ± 2.4; 33.3 ± 2.6 vs. 28.9 ± 2.4; 32.9 ± 1.6 vs. 31.2 ± 2.2; 33.1 ± 3.6 vs. 28.1 ± 2.2, respectively). Patients with IAIs in whom multiple organ dysfunction syndrome (MODS) developed also had increased mtDNA concentration compared with those who did not (31.0 ± 1.8 vs. 27.9 ± 1.8; 32.9 ± 2.4 vs. 27.8 ± 1.7; 32.9 ± 1.5 vs. 29.8 ± 1.7; 32.0 ± 3.8 vs. 27.1 ± 2.1, respectively). Baseline mtDNA concentration had high effectiveness in predicting death for patients with IAIs who had severe trauma using receiver operating characteristic analysis. Furthermore, serum mtDNA levels on admission correlated with the lactate concentration, but no significant correlations were found between mtDNA levels and levels of white blood cells, C-reactive protein, and procalcitonin.

CONCLUSIONS

Plasma mtDNA was associated with the occurrence of sepsis, MODS, and death in patients with IAIs caused by severe abdominal trauma.

Microbiomic Analysis of Intra-Abdominal Infections by Using Denaturing High-Performance Liquid Chromatography: A Prospective Observational Study

BACKGROUND

Intra-abdominal infections represent a subgroup of septic syndromes with high death rates and the need for prompt and appropriate antimicrobial therapy. Conventional culture-based microbial identification has notable shortcomings in the diagnostics of polymicrobial infections. Modern culture-independent molecular methods may represent a new diagnostic approach. The current study aimed to compare the results obtained from the denaturing high-performance liquid chromatography WAVE^® system as a culture-independent diagnostic tool with those obtained from standard culture-based microbiologic testing in the clinical setting of severe intra-abdominal sepsis.

PATIENTS AND METHODS

The study included 42 samples of pathologic intra-abdominal fluids, collected from 37 patients with intra-abdominal sepsis. Micro-organisms grown in culture and detected by the WAVE system were compared. Further, we recorded clinical data including baseline characteristics and the use of antibiotic agents.

RESULTS

In 38.1% of the analyzed samples, the classic, culture-based methods showed no bacterial growth on agar plates, in comparison with the microbiomic analysis in which the proportion of samples with negative signal was 31%. In about 40% of the patients, both methods detected one microbiologic agent, whereas in approximately one quarter of the samples, two or more agents were identified. The detection rate of certain bacteria such as Enterobacteriacae or Enterococcus faecium was significantly higher using the microbiomic analysis. Bacteria such as Haemophilus, Lactobacillus, Clostridium, Methylobacterium, Collinsella aerofaciens, and Solobacterium moorei were detected exclusively using microbiomic analysis.

CONCLUSION

The culture independent molecular WAVE system provided additional information, especially concerning unusual, fastidious bacteria in patients with intra-abdominal infections. Further, it has a higher detection rate for polymicrobial infection and delivers results much sooner than conventional microbiologic methods.

Recommendations for intra-abdominal infections consensus report

Guidelines include the recommendations of experts from various specialties within a topic in consideration of data specific to each country. However, to date there has not been a guideline standardizing the nomenclature and offering recommendations for intra-abdominal infections (IAIs) in Turkey. This is mainly due to the paucity of laboratory studies regarding the clinical diagnosis and treatment of IAIs or the sensitivity of microorganisms isolated from patients with IAIs. However, due to the diversification of host characteristics and advancements in technological treatment methods, it has become imperative to 'speak a common language'. For this purpose May 2015, a group of 15 experts in intra-abdominal infections, under the leadership of the Infectious Diseases and Clinical Microbiology Specialty Society of Turkey (EKMUD) and with representatives from the Turkish Surgical Association, Turkish Society of Colon and Rectal Surgery, Hernia Society, Turkish Society of Hepato-pancreato-biliary Surgery, and the Turkish Society of Hospital Infections and Control, was formed to analyze relevant studies in the literature. Ultimately, the suggestions for adults found in this consensus report were developed using available data from Turkey, referring predominantly to the 2010 guidelines for diagnosing and managing complicated IAIs in adults and children by the Infectious Diseases Society of America (IDSA) and the Surgical Infection Society. The recommendations are presented in two sections, from the initial diagnostic evaluation of patients to the treatment approach for IAI. This Consensus Report was presented at the EKMUD 2016 Congress in Antalya and was subsequently opened for suggestions on the official websites of the Infectious Diseases and Clinical Microbiology Specialty Society of Turkey and Turkish Surgical Association for one month. The manuscript was revised according to the feedback received.

Antimicrobial Stewardship: A Call to Action for Surgeons

Despite current antimicrobial stewardship programs (ASPs) being advocated by infectious disease specialists and discussed by national and international policy makers, ASPs coverage remains limited to only certain hospitals as well as specific service lines within hospitals. The ASPs incorporate a variety of strategies to optimize antimicrobial agent use in the hospital, yet the exact set of interventions essential to ASP success remains unknown. Promotion of ASPs across clinical practice is crucial to their success to ensure standardization of antimicrobial agent use within an institution. To effectively accomplish this standardization, providers who actively engage in antimicrobial agent prescribing should participate in the establishment and support of these programs. Hence, surgeons need to play a major role in these collaborations. Surgeons must be aware that judicious antibiotic utilization is an integral part of any stewardship program and necessary to maximize clinical cure and minimize emergence of antimicrobial resistance. The battle against antibiotic resistance should be fought by all healthcare professionals. If surgeons around the world participate in this global fight and demonstrate awareness of the major problem of antimicrobial resistance, they will be pivotal leaders. If surgeons fail to actively engage and use antibiotics judiciously, they will find themselves deprived of the autonomy to treat their patients.

Pathogen Prevalence and Antimicrobial Susceptibility Among Enterobacteriaceae Causing Hospital-associated Intra-abdominal Infections in Adults in the United States (2012-2013)

PURPOSE

Selection and prompt initiation of the appropriate empiric antimicrobial therapy are critical to decrease morbidity and mortality and shorten the length of hospitalization among patients with hospital-associated intra-abdominal infections (HA-IAIs). Therapeutic choices for the treatment of patients with HA-IAI require careful consideration. This study was conducted to evaluate the antimicrobial susceptibility of common pathogens collected from adult patients with HA-IAI in the United States.

METHODS

Gram-negative bacilli (N = 1285) were collected during 2012-2013 from SMART (Study for Monitoring Antimicrobial Resistance Trends). Isolates were tested at a central laboratory by using Clinical and Laboratory Standards Institute methods and interpretation of susceptibility to 12 antimicrobial agents.

FINDINGS

Most of the isolates (80.8%) were Enterobacteriaceae, and Escherichia coli was the most common species. Susceptibility to frequently used antimicrobial agents for treating IAI showed that ertapenem, imipenem, and amikacin were more active than other agents against Enterobacteriaceae, including multidrug-resistant isolates. More than 92% of E coli, including extended-spectrum β-lactamase (ESBL) producers, and Klebsiella pneumoniae isolates were susceptible to ertapenem, imipenem, and amikacin. Cefepime was the most active (>90% susceptibility) cephalosporin against all species except K pneumoniae (86.6%) but with much reduced activity against isolates with ESBLs. Piperacillin/tazobactam had reduced activity against Enterobacter species (70.4%-76.4% susceptible) and ESBL-producing K pneumoniae (22.5% susceptible). Fluoroquinolones exhibited poor activity against E coli (overall susceptibility <70%).

IMPLICATIONS

Proper empiric antimicrobial treatment, including combining appropriate agents, of HA-IAI requires detailed understanding of the epidemiology of common pathogens and antimicrobial resistance patterns. In light of rising rates of antimicrobial resistance, ongoing surveillance is critical for clinical decision-making.

Treatment Modalities and Antimicrobial Stewardship Initiatives in the Management of Intra-Abdominal Infections

Antimicrobial stewardship programs (ASPs) focus on improving the utilization of broad spectrum antibiotics to decrease the incidence of multidrug-resistant Gram positive and Gram negative pathogens. Hospital admission for both medical and surgical intra-abdominal infections (IAIs) commonly results in the empiric use of broad spectrum antibiotics such as fluoroquinolones, beta-lactam beta-lactamase inhibitors, and carbapenems that can select for resistant organisms. This review will discuss the management of uncomplicated and complicated IAIs as well as highlight stewardship initiatives focusing on the proper use of broad spectrum antibiotics.

Prospective evaluation of the Sunshine Appendicitis Grading System score

BACKGROUND

Although there is a wealth of information predicting risk of post-operative intra-abdominal collection and guiding antibiotic therapy following appendicectomy, confusion remains because of lack of consensus on the clinical severity and definition of 'complicated' appendicitis. This study aimed to develop a standardized intra-operative grading system: Sunshine Appendicitis Grading System (SAGS) for acute appendicitis that correlates independently with the risk of intra-abdominal collections.

METHODS

Two-hundred and forty-six patients undergoing emergency laparoscopy for suspected appendicitis were prospectively scored according to the severity of appendicitis and followed up for complications including intra-abdominal collection. After termination of the study, the SAGS score was repeated by an independent surgeon based on operation notes and intra-operative photography to determine inter-rater agreement. The primary outcome measure was incidence of intra-abdominal collection, secondary outcome measures were all complications and length of stay.

RESULTS

SAGS score demonstrated good inter-rater agreement (kappa K_w 0.869; 95% CI 0.796-0.941; P < 0.001). A risk ratio of 2.594 (95% CI 0.655-4.065; P < 0.001) for intra-abdominal collection was found using SAGS score as a predictor. The discriminative ability of SAGS score was supported by an area under the curve value of 0.850 (95% CI 0.799-0.892; P < 0.001).

CONCLUSIONS

SAGS score can be used to simply and accurately classify the severity of appendicitis and to independently predict the risk of intra-abdominal collection. It can therefore be used to stratify risk, guide antibiotic therapy, follow-up and standardize the definitions of appendicitis severity for future research.

Examinations of ascites from prophylactic drains can predict intra-abdominal infections after living donor liver transplantation

Studies suggest that prophylactic intra-abdominal drains are unnecessary for cadaveric liver transplantation using whole liver grafts because there is no benefit from drainage. However, no studies have investigated on the necessity of prophylactic drains after LDLT using split-liver grafts or reduced-liver grafts, which may present a high risk of post-transplant intra-abdominal infections. This retrospective study investigated whether the ascitic data on POD 5 after LDLT can predict intra-abdominal infections and on the post-transplant management of prophylactic drains. Between March 2008 and March 2013, 90 LDLTs were performed. We assessed the number of ascitic cells, biochemical examinations, and cultivation tests at POD1 and POD5. The incidence rates of post-transplant intra-abdominal infections were 24.4%. The multivariate analysis showed that left lobe and S2 monosegment grafts were a significant risk factor for intra-abdominal infections (p = 0.006). The patients with intra-abdominal infections had significantly higher acsitic LDH levels and the positive rate of ascitic culture at POD5 in comparison with patients without infections (p < 0.001 and p = 0.014, respectively). LDLT using left lobe and S2 monosegment grafts yields a high risk for post-transplant intra-abdominal infections, and ascitic LDH and cultivation tests at POD5 via prophylactic drains can predict intra-abdominal infections.

Management of abdominal sepsis--a paradigm shift?

The abdomen is the second most common source of sepsis and secondary peritonitis. The most common causes of abdominal sepsis are perforation, ischemic necrosis or penetrating injury to the abdominal viscera. Management consists of control of the infection source, restoration of gastrointestinal tract (GI) function, systemic antimicrobial therapy and support of organ function. Mortality after secondary peritonitis is still high. Excluding patient-related factors such as age or co-morbidities that can not be influenced at the time of intervention, delay to surgical intervention and inability to obtain source control are the main determinants of outcome. In patients with severe physiological derangement or difficult intraperitoneal conditions, where a prolonged operation and complete anatomical repair may not be possible or appropriate, it is becoming increasingly popular to utilize a damage control strategy with abbreviated laparotomy and planned reoperations. The main components of damage control laparotomy for secondary peritonitis are postponing the reconstruction of intestinal anastomoses to a second operation (deferred anastomosis) and leaving the abdomen open with some form of temporary abdominal closure (TAC). Advances in the management techniques of the open abdomen and new negative pressure-based TAC-devices have significantly reduced the previously observed prohibitive morbidity associated with open abdomens. These advancements have led to current fascial closure rates after TAC approaching 90%. The cornerstones of appropriate antimicrobial therapy are the timing, spectrum and dosing of antibiotics. Enteral nutrition should be started as soon as possible in hemodynamically stable patients but withheld when the patient is on a significant dose of vasopressors or whenever GI hypoperfusion is suspected. Timely source control with appropriate use of antimicrobial agents and early intensive care offers the best chance of survival for patients with abdominal sepsis. The introduction of the concept of damage control to the management of secondary peritonitis represents a paradigm shift in the same way as in management of major trauma. Although limited and repeated surgical interventions have been shown to be safe, the actual benefits need to be demonstrated in controlled studies.

Pancreas-Kidney transplantation: Impact of dialysis modality on the outcome

It remains controversial whether dialysis modality prior to SPKT (simultaneous pancreas-kidney transplantation) affects the outcome. We analyzed outcomes in type 1 diabetic patients undergoing SPKT, comparing peritoneal dialysis (PD) and hemodialysis (HD) groups: 119 had been on HD; 39 on PD. They were comparable except regarding dialysis time, higher in HD patients (30 ± 23 vs. 21 ± 15 months, P = 0.003). Thrombosis-driven relaparotomy was more frequent in PD patients (12.8% vs. 1.7%, P = 0.014). Pancreas loss due to infection was higher in PD patients (12.8% vs. 3.4%, P = 0.042). Thrombosis-related kidney loss was more frequent in PD patients (5.1%, vs. 0% in HD patients, P = 0.058). Thirteen deaths occurred, more within the PD group (17.9% vs. 5%; P = 0.011), being infection the leading cause (13.5%, vs. 1.7% in HD patients, P = 0.010). Patient survival was inferior in PD patients. Besides PD, cardiovascular disease and graft failure were independent predictors of patient death. In conclusion, PD patients more frequently complicated with intra-abominal infection leading to pancreatic loss and with renal thrombosis, with adverse impact on survival. As a PD first strategy in end-stage renal disease patients is generally associated with good outcomes, these gloomier results after SPKT urge for careful adjustment of infection and thrombosis prophylactic protocols in PD patients.

Infection, antibiotic therapy and risk of colorectal cancer: a nationwide nested case-control study in patients with Type 2 diabetes mellitus

Patients with Type 2 diabetes mellitus are at a higher risk of colorectal cancer (CRC). The objective of our study was to examine the inter-relationship among infection sites, systemic antibiotic use and risk of CRC among patients with Type 2 diabetes mellitus. From a diabetic cohort from the Taiwan's National Health Insurance claims database, we identified 3,593 incident colon cancer cases, 1,979 rectal cancer cases and 22,288 controls and conducted a nested case-control study to examine the association between antibiotic use and CRC incidence. Logistic regression models were applied to estimate the odds ratio (OR) and the 95% confidence interval (95% CI) between infection sites, antibiotic use and CRC incidence. Patients with intra-abdominal infection were significantly associated with increased risk for colon cancer (OR = 2.01, 95% CI = 1.73-2.35) and rectal cancer (OR = 1.59, 95% CI = 1.26-2.00). Any antianaerobic antibiotic use was associated with a higher risk of colon cancer (OR = 2.31, 95% CI = 2.12-2.52) and rectal cancer (OR = 1.69, 95% CI = 1.50-1.90) but without an obvious dose-response relationship for cumulative use. Antianaerobic antibiotics also increased the risks for those with nonintra-abdominal infection. No association was found between antiaerobic agent use and the CRC risk. The results suggest intra-abdominal infections and antianaerobic antibiotic use may be a marker for precancerous lesions or early CRC, although the possibility of antianaerobic antibiotics playing an additional role cannot be excluded. Further research examining the relationship between intra-abdominal infection, antianaerobic antibiotics use and possible change of microbiota leading to colorectal carcinogenesis is warranted.

C-reactive protein is an early predictor of septic complications after elective colorectal surgery

BACKGROUND

Nowadays, most patients who undergo colorectal surgery are discharged early. An early predictor of septic complications could avoid readmissions and decrease morbidity. CRP could be a good predictor allowing a safe discharge.

METHODS

A prospective, observational study was conducted from November 2007 to October 2008. All patients who underwent elective colorectal surgery were included. Clinical (temperature, pulse, abdominal tenderness, bowel movements) and laboratory data (C-reactive protein, leukocyte count) were recorded and evaluated as early predictors of septic complications (namely, anastomotic leaks). All detected leaks were considered fistulas, independently of their clinical significance. Clinical and inflammatory parameters were analyzed with univariate and multivariate techniques; logistic regression was performed and areas under the receiver operating characteristic curve were compared.

RESULTS

A total of 133 patients were included. The overall incidence of anastomotic leaks was 15.5% and mortality was 4.5%. C-reactive protein at postoperative days 2 and 4 was a good predictor of anastomotic leak (areas under the curve were 0.715 and 0.845, respectively) and other postoperative septic complications (areas under the curve were 0.804 and 0.787), showing the highest accuracy among clinical and laboratory data. A cutoff of 125 mg/l in the level of C-reactive protein at postoperative day 4 yielded a sensitivity of 81.8% and a negative predictive value of 95.8% for the detection of anastomotic leakage.

CONCLUSIONS

C-reactive protein is a simple way to ensure a safe discharge from hospital after elective colorectal surgery. Patients with CRP values >125 mg/l on the fourth postoperative day should not be discharged.