Epidemiology and Risk Factors for Isolation of Multi-Drug-Resistant Organisms in Patients with Complicated Intra-Abdominal Infections

Influence of β-lactam pharmacodynamics on the systems microbiology of gram-positive and gram-negative polymicrobial communities

Objectives

We sought to evaluate the pharmacodynamics of β-lactam antibacterials against polymicrobial communities of clinically relevant gram-positive and gram-negative pathogens.

Methods

Two Enterococcus faecalis isolates, two Staphylococcus aureus isolates, and three Escherichia coli isolates with varying β-lactamase production were evaluated in static time-killing experiments. Each gram-positive isolate was exposed to a concentration array of ampicillin (E. faecalis) or cefazolin (S. aureus) alone and during co-culture with an E. coli isolate that was β-lactamase-deficient, produced TEM-1, or produced KPC-3/TEM-1B. The results of the time-killing experiments were summarized using an integrated pharmacokinetic/pharmacodynamics analysis as well as mathematical modelling to fully characterize the antibacterial pharmacodynamics.

Results

In the integrated analysis, the maximum killing of ampicillin (Emax) against both E. faecalis isolates was ≥ 4.11 during monoculture experiments or co-culture with β-lactamase-deficient E. coli, whereas the Emax was reduced to ≤ 1.54 during co-culture with β-lactamase-producing E. coli. In comparison to monoculture experiments, culturing S. aureus with KPC-producing E. coli resulted in reductions of the cefazolin Emax from 3.25 and 3.71 down to 2.02 and 2.98, respectively. Two mathematical models were created to describe the interactions between E. coli and either E. faecalis or S. aureus. When in co-culture with E. coli, S. aureus experienced a reduction in its cefazolin Kmax by 24.8% (23.1%RSE). Similarly, β-lactamase-producing E. coli preferentially protected the ampicillin-resistant E. faecalis subpopulation, reducing Kmax,r by 90.1% (14%RSE).

Discussion

β-lactamase-producing E. coli were capable of protecting S. aureus and E. faecalis from exposure to β-lactam antibacterials.

Cost-effectiveness of ceftazidime/avibactam plus metronidazole versus meropenem as first-line empiric therapy for the treatment of complicated intra-abdominal infections: A study based on the in-vitro surveillance data in China

BACKGROUND

With the increase in drug resistance rates of pathogens isolated from complicated intra-abdominal infections (cIAIs), ceftazidime/avibactam (CAZ-AVI) is increasingly used clinically. However, given the high drug cost and the fact that not yet covered by the health insurance payment, this study evaluated the cost-effectiveness of CAZ-AVI plus metronidazole versus meropenem as a first-line empiric treatment for cIAIs from the perspective of the Chinese healthcare system.

METHODS

A decision analytic model with a one-year time horizon was constructed to assess the cost-effectiveness based on the entire disease course. Model inputs were mainly obtained from clinical studies, published literature, and publicly available databases. Primary outcomes were cost, quality-adjusted life years (QALYs), life years (Lys), and incremental cost-effectiveness ratio (ICER). One-way sensitivity analysis and probabilistic sensitivity analysis were also performed.

RESULTS

In the base cases, compared to meropenem, CAZ-AVI plus metronidazole had a shorter mean hospital length of stay (-0.77 days per patient) and longer life expectancy (+0.05 LYs and +0.06 QALYs). CAZ-AVI plus metronidazole had an ICER of $25517/QALY, which is well below the threshold of $31509 per QALY in China. The one-way sensitivity analysis showed that the change of the treatment duration of CAZ-AVI plus metronidazole was the parameter that most influenced the results of the ICER. In probabilistic sensitivity analysis, CAZ-AVI plus metronidazole was the optimal strategy in 75% of simulations at $31510/QALY threshold.

CONCLUSIONS

CAZ-AVI plus metronidazole could be considered as a cost-effective option for the empiric treatment of patients with cIAIs in China, and this benefit will be more evident when the price of CAZ-AVI decreases by 23.8%.

Retrospective analysis of drug resistance characteristics and infection related risk factors of multidrug-resistant organisms (MDROs) isolated from the orthopedics department of a tertiary hospital

Patients infected with multidrug-resistant organisms (MDROs) are known to exhibit longer hospital stays and a significantly poorer prognosis. We performed a 6-year retrospective analysis of nosocomial infections reported in the orthopedics department of our institution, to gain valuable insights into antibiotic sensitivity and infectious characteristics of MDROs, in order to deduce effective measures to control the occurrence of multidrug-resistant infections in clinical practice. A retrospective, single center surveillance study (January 2012-December 2017) was performed on the nosocomial infections recorded in the department of orthopedics. A nosocomial infection is defined as one that develops when a patient is residing in a hospital but was not present at the time of admission. All relevant data, including basic patient information, cultivated bacterial strains, and antimicrobial resistance, was obtained from the hospital information system. A total of 1392 strains of pathogenic bacteria were isolated; 358 belonged to MDROs (detection rate = 25.7%). All the isolated strains of MDROs were mostly from secretions (52.2%). The number of cases infected with MDROs were 144 (40.2%) and 129 (36.0%) in the trauma and spinal wards, respectively. MRSA showed high resistance to β lactam antibiotics, but was sensitive to quinolone antibiotics, linezolid and cotrimoxazole. ESBL-positive strains showed more sensitivity to carbapenem antibiotics (resistance rate < 10%). MDR nonfermenters showed high resistance to most antibiotics. Logistic multivariate analysis revealed age, open injury, and central nervous system injury as independent risk factors for multidrug resistant infections. A high antibiotic resistance rate and an increasing prevalence of infections with MDROs was identified in the orthopedics department. Patients with open injury, central nervous system injury and those aged ≥ 60 years, were more prone to multidrug-resistant infections. Clinicians should pay more attention to such patients in order to actively prevent and control the occurrence of infections caused by MDROs.

Acute diffuse peritonitis secondary to a seminal vesicle abscess: A case report

BACKGROUND

Seminal vesicle abscess (SVA) is the manifestation of a relatively rare urinary system infection. In response to urinary system inflammation, an abscess forms in special locations. However, acute diffuse peritonitis (ADP) induced by SVA is unusual.

CASE SUMMARY

We report a case of a left SVA in a male patient complicated with pelvic abscess, ADP, multiple organ dysfunction syndrome, infectious shock, bacteremia, and acute appendiceal extraserous suppurative inflammation as a result of a long-term indwelling urinary catheter. The patient received a course of morinidazole + cefminol antibiotics but showed no obvious relief, so the perineal SVA underwent puncture drainage and abdominal abscess drainage + appendectomy was performed. The operations were successful. After the operation, anti-infection, anti-shock, and nutritional support treatments were continued and various laboratory indicators were regularly reviewed. The patient was discharged from the hospital after recovery. This disease is a challenge for the clinician because of the unusual spreading path of the abscess. Moreover, appropriate intervention and adequate drainage of abdominal and pelvic lesions are necessary, especially when the primary focus cannot be determined.

CONCLUSION

The etiology of ADP varies, but acute peritonitis secondary to SVA is very rare. In this patient, the left SVA not only affected the adjacent prostate and bladder but also spread retrogradely through the vas deferens, forming a pelvic abscess in the loose tissues of the extraperitoneal fascia layer. Inflammation involving the peritoneal layer led to ascites and pus accumulation in the abdominal cavity, and appendix involvement led to extraserous suppurative inflammation. In clinical practice, surgeons need to consider the results of various laboratory tests and imaging examinations to make comprehensive judgments involving the diagnosis and treatment plan.

Korean Guidelines for Use of Antibiotics for Intra-abdominal Infections in Adults

The guidelines are intended to provide practical information for the correct use of antibiotics for intra-abdominal infections in Korea. With the aim of realizing evidence-based treatment, these guidelines for the use of antibiotics were written to help clinicians find answers to key clinical questions that arise in the course of patient care, using the latest research results based on systematic literature review. The guidelines were prepared in consideration of the data on the causative pathogens of intra-abdominal infections in Korea, the antibiotic susceptibility of the causative pathogens, and the antibiotics available in Korea.

Antimicrobial Challenge in Acute Care Surgery

The burden of infections in acute care surgery (ACS) is huge. Surgical emergencies alone account for three million admissions per year in the United States (US) with estimated financial costs of USD 28 billion per year. Acute care facilities and ACS patients represent boost sanctuaries for the emergence, development and transmission of infections and multi-resistant organisms. According to the World Health Organization, healthcare-associated infections affected around 4 million cases in Europe and 1.7 million in the US alone in 2011 with 39,000 and 99,000 directly attributable deaths, respectively. In this scenario, antimicrobial resistance arose as a public-health emergency that worsens patients’ morbidity and mortality and increases healthcare costs. The optimal patient care requires the application of comprehensive evidence-based policies and strategies aiming at minimizing the impact of healthcare associated infections and antimicrobial resistance, while optimizing the treatment of intra-abdominal infections. The present review provides a snapshot of two hot topics, such as antimicrobial resistance and systemic inflammatory response, and three milestones of infection management, such as source control, infection prevention, and control and antimicrobial stewardship.

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.

Risk Factors for Mortality Among Critical Acute Pancreatitis Patients with Carbapenem-Resistant Organism Infections and Drug Resistance of Causative Pathogens

Introduction

Carbapenem-resistant organisms (CRO) have emerged as a major global public health threat, but their role in critical acute pancreatitis (CAP) is still not defined. Our study aims to investigate risk factors associated with mortality and drug resistance among CAP patients with CRO infection.

Methods

The clinical characteristics of CAP patients with CRO infection and drug resistance of causative pathogens from January 1, 2016, to October 1, 2021, were reviewed retrospectively. Independent risk factors for mortality were determined via univariate and multivariate analyses.

Result

Eighty-two CAP patients suffered from CRO infection, with mortality of 60.0%. The independent risk factors for mortality were procalcitonin > 5 ng/L (hazard ratio = 2.300, 95% confidence interval = 1.180–4.484, P = 0.014) and lactic acid > 2 mmol/L (hazard ratio = 2.101, 95% confidence interval = 1.151–3.836, P = 0.016). The pancreas was the main site of infection, followed by lung, bloodstream and urinary tract. Klebsiella pneumoniae and Acinetobacter baumannii were the main pathogenic bacteria of CRO strains with extensive antibiotic resistance (> 60%) to 6 of 8 common antibiotics, except sulfamethoxazole (56.3%) and tigecycline (33.2%).

Conclusion

CRO infection has become a serious threat for CAP patients, with high rates of mortality. Procalcitonin and lactic acid represent two independent risk factors for mortality in CAP patients with CRO infection. Klebsiella pneumoniae and Acinetobacter baumannii are the primary categories of CRO pathogens. Greater efforts are needed for early prevention and prompt treatment of CRO infections in CAP patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00624-w.

Development and Validation of a Predictive Scoring System for In-hospital Death in Patients With Intra-Abdominal Infection: A Single-Center 10-Year Retrospective Study

Objective: To develop and validate a scoring system to predict the risk of in-hospital death in patients with intra-abdominal infection (IAI).

Materials and Methods: Patients with IAI (n = 417) treated at our hospital between June 2010 and May 2020 were retrospectively reviewed. Risk factors for in-hospital death were identified by logistic regression analysis. The regression coefficients of each risk factor were re-assigned using the mathematical transformation principle to establish a convenient predictive scoring system. The scoring system was internally validated by bootstrapping sample method.

Results: Fifty-three (53/417, 12.7%) patients died during hospitalization. On logistic regression analysis, high APACHE II score (P = 0.012), pneumonia (P = 0.002), abdominal surgery (P = 0.001), hypoproteinemia (P = 0.025), and chronic renal insufficiency (P = 0.001) were independent risk factors for in-hospital death. On receiver operating characteristic curve analysis, the composite index combining these five risk factors showed a 62.3% sensitivity and 80.2% specificity for predicting in-hospital death (area under the curve: 0.778; 95% confidence interval: 0.711–0.845, P < 0.001). The predictive ability of the composite index was better than that of each independent risk factor. A scoring system (0–14 points) was established by re-assigning each risk factor based on the logistic regression coefficient: APACHE II score (10–15 score, 1 point; >15 score, 4 points); pneumonia (2 points), abdominal surgery (2 points), hypoproteinemia (2 points), and chronic renal insufficiency (4 points). Internal validation by 1,000 bootstrapping sample showed relatively high discriminative ability of the scoring system (C-index = 0.756, 95% confidence interval: 0.753–0.758).

Conclusions: The predictive scoring system based on APACHE II score, pneumonia, abdominal surgery, hypoproteinemia, and chronic renal insufficiency can help predict the risk of in-hospital death in patients with IAI.

Antibiotic-resistant microorganisms in patients with bloodstream infection of intraabdominal origin: risk factors and impact on mortality

BACKGROUND

Knowledge of resistance patterns is essential to choose empirical treatment. We aimed to determine the risk factors for antibiotic-resistant microorganisms (ARM) in intraabdominal infections (IAI) and their impact on mortality.

METHODS

Retrospective cohort study of patients with bacteremia from IAI origin in a single hospital between January 2006 and July 2017.

RESULTS

A total of 1485 episodes were recorded, including 381 (25.6%) due to ARM. Independent predictors of ARM were cirrhosis (OR 2; [95% CI 1.15-3.48]), immunosuppression (OR 1.49; 1.12-1.97), prior ceftazidime exposure (OR 3.7; 1.14-11.9), number of prior antibiotics (OR 2.33; 1.61-3.35 for 1 antibiotic), biliary manipulation (OR 1.53; 1.02-2.96), hospital-acquisition (OR 2.77; 1.89-4) and shock (OR 1.48; 1.07-2). Mortality rate of the whole cohort was 11.1%. Age (OR 1.03; 1.01-1.04), cirrhosis (OR 2.32; 1.07-4.38), urinary catheter (OR 1.99; 1.17-3.38), ultimately (OR 2.28; 1.47-3.51) or rapidly (OR 13.3; 7.12-24.9) fatal underlying disease, nosocomial infection (OR 2.76; 1.6-4.75), peritonitis (OR 1.95, 1.1-3.45), absence of fever (OR 2.17; 1.25-3.77), shock (OR 5.96; 3.89-9.13), and an ARM in non-biliary infections (OR 2.14; 1.19-3.83) were independent predictors of 30-day mortality. Source control (OR 0.24; 0.13-0.44) and 2015-2017 period (OR 0.29; 0.14-0.6) were protective.

CONCLUSION

Biliary manipulation and septic shock are predictors of ARM. The presence of an ARM from a non-biliary focus is a poor-prognosis indicator. Source control continues to be of paramount importance.

Novel Multiparametric Nomogram for Overall Survival Prediction in Complicated Intra-Abdominal Infection: A Multicenter Study in China

Background: Complicated intra-abdominal infections (cIAIs) in the abdominal cavity or within an abdominal organ are numerous and frequent dangerous entities in the treatment of critically ill patients. Early clinical evaluation is necessary.

Methods: This retrospective multicenter study included patients from 10 intensive care units (ICUs). Risk factors for the overall survival (OS) of patients with cIAI were selected using least absolute shrinkage and selection operator regression, and a nomogram was constructed subsequently. Calibration curve and receiver operating characteristic (ROC) curve were used to evaluate the calibration and discriminative ability.

Results: In total, 544 patients diagnosed with cIAI were enrolled and divided into the study (n = 276) and validation (n = 268) sets. Sex, acute gastrointestinal injury, acute kidney injury, rare bacterium infection, Charlson score, and APACHE II score were identified as independent risk factors and were constructed for the nomogram. The nomogram showed marked calibration capability with a concordance index (C-index) of 0.909 and 0.831 in the study and validation set, respectively. Compared with the common clinical prognostic scoring system, the nomogram achieved the highest discrimination ability with an area under the curve (AUC) value of 0.91 and 0.83 in the study set and validation set, respectively.

Conclusions: Our newly constructed nomogram provides a useful tool for risk stratification and prognosis evaluation of cIAI.

Risk Factors and Molecular Epidemiology of Complicated Intra-Abdominal Infections With Carbapenem-Resistant Enterobacteriaceae: A Multicenter Study in China

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) infections are associated with poor patient outcomes. Data on risk factors and molecular epidemiology of CRE in complicated intra-abdominal infections (cIAI) in China are limited. This study examined the risk factors of cIAI with CRE and the associated mortality based on carbapenem resistance mechanisms.

METHODS

In this retrospective analysis, we identified 1024 cIAI patients hospitalized from January 1, 2013 to October 31, 2018 in 14 intensive care units in China. Thirty CRE isolates were genotyped to identify β-lactamase-encoding genes.

RESULTS

Escherichia coli (34.5%) and Klebsiella pneumoniae (21.2%) were the leading pathogens. Patients with hospital-acquired cIAI had a lower rate of E coli (26.0% vs 49.1%; P < .001) and higher rate of carbapenem-resistant Gram-negative bacteria (31.7% vs 18.8%; P = .002) than those with community-acquired cIAI. Of the isolates, 16.0% and 23.4% of Enterobacteriaceae and K pneumoniae, respectively, were resistant to carbapenem. Most carbapenemase-producing (CP)-CRE isolates carried blaKPC (80.9%), followed by blaNMD (19.1%). The 28-day mortality was 31.1% and 9.0% in patients with CRE vs non-CRE (P < .001). In-hospital mortality was 4.7-fold higher for CP-CRE vs non-CP-CRE infection (P = .049). Carbapenem-containing combinations did not significantly influence in-hospital mortality of CP and non-CP-CRE. The risk factors for 28-day mortality in CRE-cIAI included septic shock, antibiotic exposure during the preceding 30 days, and comorbidities.

CONCLUSIONS

Klebsiella pneumoniae had the highest prevalence in CRE. Infection with CRE, especially CP-CRE, was associated with increased mortality in cIAI.

Outcomes after Surgery among Patients Diagnosed with One or More Multi-Drug-Resistant Organisms

Background: Infections with multi-drug-resistant organisms (MDROs) may be difficult to treat and prolong patient hospitalization and recovery. Multiple MDRO coinfections may increase the complexity of clinical management. However, association between multiple MDROs and outcomes of patients who undergo surgery is unknown. Patients and Methods: We performed a retrospective, cross-sectional analysis of the 2016 National Inpatient Sample for identified by International Classification of Disease, 10th Revision Clinical Modification (ICD-10-CM) diagnosis codes associated with multi-drug-resistant organisms: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), multi-drug-resistant gram-negative bacilli, and Clostridioides difficile infection (CDI). Admitted patients with diagnosis codes for MDROs were cross-matched with codes for common general surgery procedures. Outcomes of interest included length of stay and mortality. Weighted univariable and multivariable analyses accounting for the survey methodology were performed. Results: Of 1,550,224 patients undergoing surgery in 2016, 39,065 (3%) admissions were diagnosed with an MDRO and 1,176 (0.1%) were associated with dual MDROs diagnoses. Patients diagnosed with one MDRO were hospitalized three times longer (17.3 days; 95% confidence interval [CI], 16.8-17.7) and patients diagnosed with two MDROs five times longer (31.6 days; 95% CI, 27.0-36.2; p < 0.0001) than undiagnosed patients (6.1 days; 95% CI, 6.1-6.1; all p < 0.0001). On multivariable analysis, the strongest predictor of mortality was a diagnosis of two MDRO infections (odds ratio [OR], 4.8; 95% CI, 3.16-7.21; p < 0.0001). The second strongest predictor was diagnosis of single MDRO infection (OR, 2.9; 95% CI, 2.64-3.20; p < 0.0001). Conclusion: Presence of an MDRO was associated with increased odds of mortality and length of stay in admitted surgical patients. Interventions to reduce MDRO infection among surgical patients may reduce hospital length of stay and mortality.

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

Background

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

Methods

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

Results

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

Conclusions

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

Trial registration

PROSPERO ID: 42020166061.

Management of infections caused by WHO critical priority Gram-negative pathogens in Arab countries of the Middle East: a consensus paper

Antimicrobial resistance is an important global issue that impacts the efficacy of established antimicrobial therapy. This is true globally and within the Arab countries of the Middle East, where a range of key Gram-negative pathogens pose challenges to effective therapy. There is a need to establish effective treatment recommendations for this region given specific challenges to antimicrobial therapy, including variations in the availability of antimicrobials, infrastructure and specialist expertise. This consensus provides regional recommendations for the first-line treatment of hospitalized patients with serious infections caused by World Health Organization critical priority Gram-negative pathogens Acinetobacter baumannii and Pseudomonas aeruginosa resistant to carbapenems, and Enterobacteriaceae resistant to carbapenems and third-generation cephalosporins. A working group comprising experts in infectious disease across the region was assembled to review contemporary literature and provide additional consensus on the treatment of key pathogens. Detailed therapeutic recommendations are formulated for these pathogens with a focus on bacteraemia, nosocomial pneumonia, urinary tract infections, skin and soft tissue infections, and intra-abdominal infections. First-line treatment options are provided, along with alternative agents that may be used where variations in antimicrobial availability exist or where local preferences and resistance patterns should be considered. These recommendations take into consideration the diverse social and healthcare structures of the Arab countries of the Middle East, meeting a need that is not filled by international guidelines. There is a need for these recommendations to be updated continually to reflect changes in antimicrobial resistance in the region, as well as drug availability and emerging data from clinical trials.

Epidemiology and Risk Factors for Superficial Surgical Site Infections after Appendectomy for Acute Appendicitis: A Secondary Data Analysis

Background: The identification of risk factors for superficial surgical site infections (SSSIs) associated with appendectomy is paramount in the management of patients with acute appendicitis (AA). Methods: This study was a secondary data analysis from a prospective multi-center observational study. It included all consecutive hospitalized patients with AA who underwent appendectomy and were monitored for complications at 30 days after the intervention. A case-control approach was used to evaluate risk factors associated with the occurrence of SSSI. Results: Among 2,667 patients, 156 (5.8%) developed an SSSI. The series included 1,449 males (54.3%) and 1,218 females with a median age of 29 years (interquartile range [IQR] 20-45 years). Antimicrobial therapy within the previous 30 days was reported by 170 patients (6.4%), and a C-reactive protein concentration (CRP) >50 mg/L was observed in 609 (22.8%). A total of 960 patients (36.0%) underwent open surgery, 1,699 (63.7%) laparoscopic surgery, and 8 (0.3%) another surgical intervention. In 2,575 patients (95.6%), a pathological appendix was detected during the operation. In 776 patients (29.1%), an intra-operative abdominal drain (IAD) was placed; 125 patients (4.7%) were admitted to the intensive care unit. The median hospital length of stay was 3 days (IQR 2-5 days). The overall mortality rate was 0.11%. Multinomial logistic regression analysis of risk factors demonstrated that statistically significant risk factors independently associated with the occurrence of SSSIs were antimicrobial therapy within the previous 30 days, CRP >50 mg/L, open surgical procedures, presence of IAD, and intra-operative findings of complex appendicitis. Conclusions: Knowledge of five easily recognizable variables, assessable at hospital admission or as soon as the surgical intervention is concluded, might identify patients with a greater risk of developing an SSSI.

CE: Infection in Acute Care: Evidence for Practice

Infection may be either a cause for admission to an acute care hospital or health care associated, a complication of receiving care for another illness in the acute care environment. In recent years, there has been significant research investigating risk factors for infection in the hospital setting, best practices for diagnosis and treatment, and ways to prevent many health care-associated infections. Multidrug-resistant organisms are a consequence of antibiotic overuse, poor environmental hygiene, and our increasing ability to keep chronically ill patients alive longer through invasive intensive care support. This article reviews the evidence on infection in acute care settings, with a focus on community- and hospital-acquired pneumonia, surgical site infections, and Clostridioides difficile infection. Recommendations for integrating this evidence into nursing practice are offered.

Impact of Multi-Drug-Resistant Pneumonia on Outcomes of Critically Ill Trauma Patients

Background: Rates of infections with multi-drug-resistant organisms (MDROs) are increasing among critically ill patients. Among non-surgical patients, MDROs increase directly the risk of adverse secondary events including death. However, similar effects do not appear to occur among surgical patients. Specifically, among critically injured trauma patients, it is unknown whether degree of injury versus the presence of an MDRO increases the risk of death. Methods: This is a retrospective chart review of admitted adult trauma patients. Data included demographics, medical comorbidities, injury severity score, infections, occurrence of pneumonia including microbiology sensitivity profile, hospital course, and outcomes. Results: Patients requiring adminission to the intensive care unit (ICU) were more severely injured with greater degree of thoracic and head trauma and had a greater burden of pre-trauma medical comorbidities. Among those admitted to the ICU, 93 patients developed pneumonia. Patients who developed pneumonia were younger and more severely injured, with higher rates of thoracic and head injuries and higher rates of smoking. Development of pneumonia was associated with worse outcomes. However, among patients with pneumonia, comparing MDRO to pan-sensitive (PanSens) infections, PanSens infection occurred earlier and were more likely associated with pre-trauma smoking status. There was no difference in injury patterns, medical comorbidities, or outcomes. Conclusion: The development of pneumonia among trauma patients reflects degree of injury and underlying medical status. However, development of MDRO versus PanSens pneumonia did not affect trauma-related outcomes further. This information will guide family discussions and critical care decisions better among vulnerable trauma patients.

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.

Critically ill patients with community-onset intraabdominal infections: Influence of healthcare exposure on resistance rates and mortality

The concept of healthcare-associated infections (as opposed to hospital-acquired infections) in intraabdominal infections (IAIs) is scarcely supported by data in the literature. The aim of the present study was to analyse community-onset IAIs (non-postoperative/non-nosocomial) in patients admitted to intensive care units (ICUs), to investigate differences in resistance patterns linked to healthcare exposure and mortality-associated factors. A one-year prospective observational study (17 Spanish ICUs) was performed distributing cases as healthcare-associated infections (HCAI), community-acquired infections (CAI) and immunocompromised patients (ICP). Bacteria producing extended-spectrum β-lactamases (ESBL) and/or carbapenemase (CPE), high-level aminoglycoside- and/or methicillin- and/or vancomycin- resistance were considered antimicrobial resistant (AMR). Mortality-associated factors were identified by regression multivariate analysis. Of 345 patients included (18.8% HCAI, 6.1% ICP, 75.1% CAI), 51.6% presented generalized peritonitis; 32.5% were >75 years (55.4% among HCAI). Overall, 11.0% cases presented AMR (7.0% ESBL- and/or CPE), being significantly higher in HCAI (35.4%) vs. CAI (5.8%) (p<0.001) vs. ICP (0%) (p = 0.003). Overall 30-day mortality was 14.5%: 23.1% for HCAI and 11.6% for CAI (p = 0.016). Mortality (R2 = 0.262, p = 0.021) was positively associated with age >75 years (OR = 6.67, 95%CI = 2.56-17.36,p<0.001), Candida isolation (OR = 3.05, 95%CI = 1.18-7.87,p = 0.022), and SAPS II (per-point, OR = 1.08, 95%CI = 1.05-1.11, p<0.001) and negatively with biliary infections (OR = 0.06, 95%CI = 0.01-0.48,p = 0.008). In this study, the antimicrobial susceptibility pattern of bacteria isolated from patients with healthcare contact was shifted to resistance, suggesting the need for consideration of the healthcare category (not including hospital-acquired infections) for severe IAIs. 30-day mortality was positively related with age >75 years, severity and Candida isolation but not with AMR.

Adjunctive therapy of intravenous colistin to intravenous tigecycline for adult patients with non-bacteremic post-surgical intra-abdominal infection due to carbapenem-resistant Acinetobacter baumannii

Post-surgical intra-abdominal infections (IAIs) due to carbapenem-resistant Acinetobacter baumannii (CRAB) are difficult to treat due to suboptimal peritoneal penetrations of several antimicrobial agents. Tigecycline has favorable outcomes of treating IAIs due to multidrug-resistant organisms but occurrence of breakthrough bacteremia has been observed because this agent has low serum level. Colistin has in vitro activity against CRAB but data on treatment of IAIs is limited due to poor peritoneal penetration. The purpose of this retrospective study is to explore the outcomes of adjunctive intravenous (IV) colistin to IV tigecycline in the treatment of IAIs caused by CRAB. Of 28 patients with non-bacteremic post-surgical IAIs due to CRAB, 14 patients received IV tigecycline alone and 14 patients received IV tigecycline with IV colistin. The 14-day, 30-day, in-hospital mortality rates, the rate of breakthrough bacteremia and the rate of bacterial eradication were not significantly different. The adjunctive therapy of IV colistin was associated with significantly higher rates of renal complications (10/14) than those receiving IV tigecycline alone (3/14) (P value = 0.023). In addition, the patients receiving adjunctive IV colistin had significantly more unfavorable non-clinical outcomes including longer length of hospital stay (P value = 0.049) and higher antimicrobial cost (P value = 0.008) and non-antimicrobial costs (P value = 0.037). In this study, adjunctive IV colistin to conventional IV tigecycline in the treatment of non-bacteremic post-surgical IAIs caused by CRAB did not yield clinical benefit but caused higher renal complication and unfavorable non-clinical outcomes.

Multicenter performance evaluation of the Unyvero IAI cartridge for detection of intra-abdominal infections

Intra-abdominal infections (IAIs) are one of the most common type of infections in patients with sepsis and an important cause of death in intensive care units. Early detection and treatment are necessary to reduce patient complications and improve outcomes. The Unyvero IAI Application (Curetis GmbH) is the first automated assay to rapidly and simultaneously identify a large panel of bacteria, fungi, toxins, and antibiotic resistance markers directly from IAI-related samples. The assay was evaluated in four European clinical laboratories in comparison to routine microbiological practices. A total of 300 clinical samples were tested with an overall sensitivity of 89.3% and specificity of 99.5%, while time to results was reduced by an average of about 17 h compared to identification (ID) results and 41 h compared to full antibiotic susceptibility testing (AST) results. The Unyvero IAI was able to detect additional microorganisms compared with culture, in particular anaerobes, with most detections confirmed by sequencing. The most frequent resistance markers detected were mecA/mecC (n = 25), aacA4 (n = 20), and bla_CTX-M (n = 17) and carbapenemase genes were identified in nine specimens. Further studies are now required to determine the clinical impact of this new rapid test which could play a role in the successful treatment of IAI.