Longitudinal outcomes of intra-abdominal infection complicated by critical illness

Managing the Open Abdomen: Selecting an Appropriate Treatment Strategy

Significance: The laparotomy is a common surgical procedure with a wide range of indications. Ideally, once the goals of surgery were achieved, the incision edges could then be approximated and the abdomen primarily closed. However, in some circumstances, it may be impossible to achieve primary closure, and instead the abdomen is intentionally left open. This review discusses the indications and objectives for the open abdomen (OA), summarizes the most common techniques for temporary abdominal closure, and illustrates treatment algorithms grounded in the current recommendations from specialty experts. Recent Advances: Still a relatively young technique, multiple strategies, and technologies have emerged to manage the OA. So too have the recommendations evolved, based on updated classifications that take wound characteristics into account. Recent studies have also brought greater clarity on recommendations for managing infection and malnutrition to support improved clinical outcomes. Critical Issues: The status of the OA can change rapidly depending on the patient's condition, the wound quality, and many other factors. Thus, there is a significant need for comprehensive treatment strategies that can be adapted to these developing circumstances. Future Directions: Treatment recommendations should be continuously updated as new technologies are introduced and old techniques fall out of use.

Risk factors of acute respiratory distress syndrome in sepsis caused by intra-abdominal infections: A retrospective study

BACKGROUND

Intra-abdominal infections are frequently associated with acute respiratory distress syndrome, which significantly affects patient prognosis. However, little is known about the specific risk factors of acute respiratory distress syndrome in sepsis caused by intra-abdominal infections.

METHODS

This retrospective study included adult patients with intra-abdominal sepsis admitted to the intensive care unit of a tertiary teaching hospital in China between June 2017 and June 2022. Patients were categorized based on the presence or absence of acute respiratory distress syndrome. Data, including vital signs, laboratory values, and severity scores collected within 24 hours of sepsis diagnosis, as well as outcomes within 90 days, were analyzed. Multivariable logistic regression was used to identify independent risk factors associated with acute respiratory distress syndrome.

RESULTS

A total of 738 patients were included, of whom 218 (29.5%) developed acute respiratory distress syndrome. Patients with acute respiratory distress syndrome were younger, had a higher body mass index and disease severity scores, and exhibited higher proportions of septic shock and hospital-acquired intra-abdominal infections. The mortalities in the intensive care unit and at 28 and 90 days were higher in the acute respiratory distress syndrome group. In the multivariate logistic regression model, age under 65 years (odds ratio [95% confidence interval]: 1.571 [1.093-2.259]), elevated body mass index (2.070 [1.382-3.101] for overweight, 6.994 [3.207-15.255]) for obesity, septic shock (2.043 [1.400-2.980]), procalcitonin (1.009 [1.004-1.015]), hospital-acquired intra-abdominal infections (2.528[1.373-4.657]), and source of intra-abdominal infections (2.170 [1.140-4.128] for biliary tract infection, 0.443 [0.217-0.904] for gastroduodenal perforation) were independently associated with acute respiratory distress syndrome.

CONCLUSION

In patients with intra-abdominal sepsis, age under 65 years, higher body mass index and procalcitonin, septic shock, hospital-acquired intra-abdominal infections, and biliary tract infection were risk factors for acute respiratory distress syndrome.

Timing of surgical operation for patients with intra-abdominal infection: A systematic review and meta-analysis

BACKGROUND

Intra-abdominal infections (IAIs) is the most common type of surgical infection, with high associated morbidity and mortality rates. In recent years, due to the use of antibiotics, various drug-resistant bacteria have emerged, making the treatment of abdominal infections more challenging. Early surgical exploration can reduce the mortality of patients with abdominal infection and the occurrence of complications. However, available evidence regarding the optimal timing of IAI surgery is still weak. In study, we compared the effects of operation time on patients with abdominal cavity infection and tried to confirm the best timing of surgery.

AIM

To assess the efficacy of early vs delayed surgical exploration in the treatment of IAI, in terms of overall mortality.

METHODS

A systematic literature search was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Ovid, and ScienceDirect. The systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses method. Based on the timing of the surgical operation, we divided the literature into two groups: Early surgery and delayed surgery. For the early and delayed surgery groups, the intervention was performed with and after 12 h of the initial surgical intervention, respectively. The main outcome measure was the mortality rate. The literature search was performed from May 5 to 20, 2021. We also searched the World Health Organization International Clinical Trials Registry Platform search portal and ClinicalTrials.gov on May 20, 2021, for ongoing trials. This study was registered with the International Prospective Register of Systematic Reviews.

RESULTS

We identified nine eligible trial comparisons. Early surgical exploration of patients with IAIs (performed within 12 h) has significantly reduced the mortality and complications of patients, improved the survival rate, and shortened the hospital stay.

CONCLUSION

Early surgical exploration within 12 h may be more effective for the treatment of IAIs relative to a delayed operation.

Prognostic performance of neutrophil CD64 expression in patients with complicated intra-abdominal infections - a prospective study

No study yet analyzed the prognostic abilities of neutrophil CD64 expression (nCD64) in complicated intra-abdominal infections (cIAIs), therefore our aim was to evaluate the possible association between this biomarker and outcome in such patients. This single-center prospective study was conducted in the Department of Surgical Diseases at a University Hospital 'Prof. Dr. Stoyan Kirkovich' Stara Zagora for the period November 2018 - August 2021. We used flow cytometry to measure the percentage of nCD64 preoperatively and on the 3rd postoperative day (POD) in 62 patients with cIAIs and 31 healthy controls. Of the 62 enrolled patients, nine (14.5%) died during hospitalization. The perioperative expression of nCD64 was significantly higher in non-survivors compared to survivors (p = 0.02 before surgery and p = 0.024 after surgery). ROC Curve analysis revealed the good prognostic value of pre- and postoperative nCD64 levels as mortality predictors (AUROC = 0.744 and 0.765, respectively). Preoperatively, the identified sensitivity and specificity for nCD64 cut-off = 94.8% were 66.7% and 84.6%, respectively and on the 3rd POD for nCD64 cut-off = 84.85% we observed a sensitivity of 71.4% and a specificity of 78.8%. Neutrophil CD64 shows good prognostic value in patients with cIAIs both preoperatively and on the 3rd POD.

Intra-abdominal Infections

Intra-abdominal infections (IAIs) are a common cause of sepsis, and frequently occur in intensive care unit (ICU) patients. IAIs include many diagnoses, including peritonitis, cholangitis, diverticulitis, pancreatitis, abdominal abscess, intestinal perforation, abdominal trauma, and pelvic inflammatory disease. IAIs are the second most common cause of infectious morbidity and mortality in the ICU after pneumonia. IAIs are also the second most common cause of sepsis in critically ill patients, and affect approximately 5% of ICU patients. Mortality with IAI in ICU patients ranges from 5 to 50%, with the wide variability related to the specific IAI present, associated patient comorbidities, severity of illness, and organ dysfunction and failures. It is important to have a comprehensive understanding of IAIs as potential causes of life-threatening infections in ICU patients to provide the best diagnostic and therapeutic care for optimal patient outcomes in the ICU.

[Eritonitis outcome prediction]

The review is devoted to the most common general clinical and specific grading systems for peritonitis outcome prediction. Particular attention is paid to methodological approaches, prediction reliability, simplicity of use in clinical practice and their importance in decision-making. It is shown that none of the modern grading systems is universal and absolutely reliable. Combining several systems is quite difficult and will take additional time that is impossible for intraoperative environment. Despite various systems for peritonitis outcome prediction, none of them can completely satisfy surgeons, primarily in choice of surgical access, intervention type and option for its completion.

New System For Predicting The Outcome Of Secondary Peritonitis

Despite improvements in the methods of diagnostics, surgical interventions and intensive care, the problem of treating patients with diffuse peritonitis remains relevant. Diffuse peritonitis is a major contributor to mortality in all urgent care settings and the second leading cause of sepsis in critically ill patients. At the same time, even in developed countries, the number of patients with peritonitis does not tend to decrease, and mortality rates remain high, reaching 90-93% with the development of abdominal sepsis and toxic shock syndrome. One of the ways to reduce mortality in peritonitis is the use of objective systems for prognosis of the peritonitis outcome, allowing to compare the results of patient treatment and to choose the optimal treatment tactics for each particular patient. The objective — To develop a new system for predicting the outcome of secondary peritonitis (survival or death) focused on the criteria of abdominal sepsis and multiple organ dysfunction syndrome (associated or not associated with peritonitis), and to analyze its accuracy versus the most common comparable systems. Material and Methods — Our study was based on analyzing the treatment outcomes in 352 patients with secondary diffuse peritonitis. On admission, sepsis was diagnosed in 15 (4.3%), and toxic shock in 4 (1.1%) patients. The main causes of death were purulent intoxication and/or sepsis (51 cases or 87.9%), cancer intoxication (4 cases or 6.9%), and acute cardiac failure (3 cases or 5.2%). We analyzed the effectiveness of several systems of predicting the peritonitis outcomes: the Mannheim’s Peritoneal Index (MPI), World Society for Emergency Surgery Sepsis Severity Score (WSES SSS), Acute Physiology and Chronic Health Evaluation II (APACHE II) system, general Sequential Organ Failure Assessment Score (gSOFA), as well as the Peritonitis Prognosis System (PPS) developed by the authors. The probability of the effect of 40 clinical and laboratory parameters on the outcome of patients with secondary peritonitis was analyzed via using parametric and nonparametric methods of statistical analysis (Fisher’s test, Mann-Whitney U test, Chi-squared test with Yates’s continuity correction). The criteria were selected that had a predictive power for the lethal outcome (p <0.05), and they were included in the PPS system. To compare the predictive value of the PPS, ROC analysis was conducted with construction of receiver operating characteristic curves for each analyzed system of predicting the peritonitis outcome. The STATISTICA 8 software was used for performing the statistical analysis. Results — The following criteria were of greatest importance in predicting the lethal outcome: a patient’s age, a presence of a malignant neoplasm, a nature of the exudate, the development of sepsis (toxic shock), as well as multiple organ dysfunction not associated with the developed peritonitis. PPS exhibited the greatest accuracy in terms of predicting mortality in patients with secondary diffuse peritonitis (AUC=0.942) versus minimal in APACHE II (AUC=0.840). Conclusion — APACHE II, MPI, WSES SSS and PPS can be considered reliable in terms of mortality prognosis in peritonitis patients. PPS has the greatest accuracy of predicting the mortality in patients with secondary diffuse peritonitis (94%).

Clinical Efficacy and Safety of Cefoperazone-Sulbactam in Treatment of Intra-Abdominal Infections: A Systematic Review and Meta-Analysis

Background: In this systematic review and meta-analysis, we aimed to assess the clinical efficacy and safety of cefoperazone-sulbactam against alternative antibiotics in the treatment of intra-abdominal infections. Methods: The PubMed, Cochrane, Web of Science, Ovid Medline, and CKNI databases were searched for relevant articles up to November 25, 2020. The primary outcome was clinical efficacy rate, and the secondary outcomes were microbiologic eradication rate, mortality rate, and adverse event (AE) risk. Results: Twelve studies involving 1,674 patients were included. Overall, the clinical efficacy rate of cefoperazone-sulbactam and comparators was 87.7% and 81.7%, respectively, and cefoperazone-sulbactam was associated with a higher clinical efficacy rate than that the comparator (odds ratio [OR] 1.98; 95% confidence interval [CI] 1.31-3.00; I² = 36%). Additionally, cefoperazone-sulbactam was associated with a lower clinical failure rate (OR 0.40; 95% CI 0.28-0.57; I² = 0) and a higher clinical cure rate (OR 1.54; 95% CI 1.17-2.03; I² = 0) than the comparators. Cefoperazone-sulbactam was associated with a higher microbiologic eradication rate than the comparator (OR 2.54; 95% CI 1.72-3.76; I² = 0). Finally, there was no significant difference between cefoperazone-sulbactam and the comparators in terms of mortality rate (OR 090; 95% CI 0.38-2.16; I² = 0) and AE risk (OR 1.07; 95% CI 0.74-1.55; I² = 0). Conclusions: The clinical efficacy and safety of cefoperazone-sulbactam were similar to those of alternative antibiotics in the treatment of intra-abdominal infections. Therefore, cefoperazone-sulbactam could be recommended as an effective and safe antibiotic for treating intra-abdominal infections.

Performance of nasal methicillin-resistant Staphylococcus aureus screening for intra-abdominal infections in critically ill adult patients

STUDY OBJECTIVE

Intra-abdominal infections (IAIs) are a common reason for intensive care unit (ICU) admissions, and methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon pathogen in IAIs. Although more data are available in the setting of non-abdominal sources, there are limited data on the performance of nasal MRSA screening for MRSA IAIs. The primary objective of this study was to evaluate the performance of nasal MRSA screening for MRSA IAIs in critically ill adult patients.

DESIGN

This was a multicenter, retrospective, cohort study.

SETTING

A 14-hospital healthcare system between January 1, 2014, and August 31, 2019.

PATIENTS

Adult patients admitted to an ICU for at least 24 h with a diagnosis code for an IAI, a nasal MRSA surveillance screen within 30 days, and an intra-abdominal culture were eligible for inclusion.

INTERVENTION

The primary outcome was to evaluate the performance of nasal MRSA screening for MRSA IAIs by calculating the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

MEASUREMENTS AND MAIN RESULTS

Out of 863 patients randomly screened, a total of 192 patients were included. The study population had a mean age of 60 (SD ±15) years, and 101 (53%) patients were male. Six (3.1%) patients were positive for an MRSA IAI, of which four (66.7%) demonstrated a positive nasal MRSA screen. A total of 186 (96.8%) patients were negative for a MRSA IAI, of which 19 (10.2%) were nasal MRSA-positive and 167 (89.8%) were nasal MRSA-negative. Nasal MRSA screening demonstrated the following performance: accuracy 89.1% (95% CI: 83.8%-93.1%), sensitivity 66.7% (95% CI: 22.3%-95.7%), specificity 89.8% (95% CI: 84.5%-93.7%), PPV 17.4% (95% CI: 9.4%-30.0%), and NPV 98.8% (95% CI: 96.4%-99.6%). There were no significant differences in clinical outcomes, including renal replacement-free days, ICU and hospital length of stay, and in-hospital mortality.

CONCLUSIONS

Among critically ill adult patients with IAIs, a negative nasal MRSA screen within 30 days may help to empirically exclude MRSA as a causative pathogen.

Current progress of source control in the management of intra-abdominal infections

Intra-abdominal infection (IAI) is a deadly condition in which the outcome is associated with urgent diagnosis, assessment and management, including fluid resuscitation, antibiotic administration while obtaining further laboratory results, attaining precise measurements of hemodynamic status, and pursuing source control. This last item makes abdominal sepsis a unique treatment challenge. Delayed or inadequate source control is an independent predictor of poor outcomes and recognizing source control failure is often difficult or impossible. Further complicating issue in the debate is surrounding the timing, adequacy, and procedures of source control. This review evaluated and summarized the current approach and challenges in IAI management, which are the future research directions.

Epidemiology and outcomes of source control procedures in critically ill patients with intra-abdominal infection

PURPOSE

To describe the characteristics and procedural outcomes of source control interventions among Intensive Care Unit (ICU) patients with severe intra-abdominal-infection (IAI).

MATERIAL AND METHODS

We identified consecutive patients with suspected IAI in whom a source control intervention had been performed in two tertiary ICUs in the Netherlands, and performed retrospective in-depth case reviews to evaluate procedure type, diagnostic yield, and adequacy of source control after 14 days.

RESULTS

A total of 785 procedures were observed among 353 patients, with initial interventions involving 266 (75%) surgical versus 87 (25%) percutaneous approaches. Surgical index procedures typically involved IAI of (presumed) gastrointestinal origin (72%), whereas percutaneous index procedures were mostly performed for infections of the biliary tract/pancreas (50%) or peritoneal cavity (33%). Overall, 178 (50%) patients required multiple interventions (median 3 (IQR 2-4)). In a subgroup of 236 patients having their first procedure upon ICU admission, effective source control was ultimately achieved for 159 (67%) subjects. Persistence of organ failure was associated with inadequacy of source control at day 14, whereas trends in inflammatory markers were non-predictive.

CONCLUSIONS

Approximately half of ICU patients with IAI require more than one intervention, yet successful source control is eventually achieved in a majority of cases.

Management of Severe Sepsis of Abdominal Origin

Severe sepsis is a life-threatening condition that may occur as a sequela of intra-abdominal infections (IAIs) of all types. Diagnosis of IAIs is predicated upon the combination of physical examination and imaging techniques. Diffuse peritonitis usually requires urgent surgical intervention. In the absence of diffuse peritonitis, abdominal computed tomography remains the most useful test for the diagnosis of IAIs, and is essential to both guide therapeutic interventions and evaluate suspected treatment failure in the critically ill patient. Parameters most consistently associated with poor outcomes in patients with IAIs include increased illness severity, failed source control, inadequate empiric antimicrobial therapy, and healthcare-acquired, as opposed to community-acquired infection. Whereas community-acquired IAI is characterized predominantly by enteric gram-negative bacilli and anaerobes that are susceptible to narrow-spectrum agents, healthcare-acquired IAI (e.g., anastomotic dehiscence, postoperative organ-space surgical site infection) frequently involves at least one multi-drug resistant pathogen, necessitating broad-spectrum therapy guided by both culture results and local antibiograms. The cornerstone of effective treatment for abdominal sepsis is early and adequate source control, which is supplemented by antibiotic therapy, restoration of a functional gastrointestinal tract (if possible), and support of organ dysfunction. Furthermore, mitigation of deranged immune and coagulation responses via therapy with recombinant human activated protein C may improve survival significantly in severe cases complicated by septic shock and multiple organ dysfunction syndrome.

Intraabdominal Infections in Older Adults

Intraabdominal infections represent a diagnostic and therapeutic challenge in the elderly population. Atypical presentations, diagnostic delays, additional comorbidities, and decreased physiologic reserve contribute to high morbidity and mortality, particularly among frail patients undergoing emergency abdominal surgery. While many infections are the result of age-related inflammatory, mechanical, or obstructive processes, infectious complications of feeding tubes are also common. The pillars of treatment are source control of the infection and judicious use of antibiotics. A patient-centered approach considering the invasiveness, risk, and efficacy of a procedure for achieving the desired outcomes is recommended. Structured communication and time-limited trials help ensure goal-concordant treatment.

Therapeutic management of peritonitis: a comprehensive guide for intensivists

PURPOSE

The management of peritonitis in critically ill patients is becoming increasingly complex due to their changing characteristics and the growing prevalence of multidrug-resistant (MDR) bacteria.

METHODS

A multidisciplinary panel summarizes the latest advances in the therapeutic management of these critically ill patients.

RESULTS

Appendicitis, cholecystitis and bowel perforation represent the majority of all community-acquired infections, while most cases of healthcare-associated infections occur following suture leaks and/or bowel perforation. The micro-organisms involved include a spectrum of Gram-positive and Gram-negative bacteria, as well as anaerobes and fungi. Healthcare-associated infections are associated with an increased likelihood of MDR pathogens. The key elements for success are early and optimal source control and adequate surgery and appropriate antibiotic therapy. Drainage, debridement, abdominal cleansing, irrigation, and control of the source of contamination are the major steps to ensure source control. In life-threatening situations, a "damage control" approach is the safest way to gain time and achieve stability. The initial empirical antiinfective therapy should be prescribed rapidly and must target all of the micro-organisms likely to be involved, including MDR bacteria and fungi, on the basis of the suspected risk factors. Dosage adjustment needs to be based on pharmacokinetic parameters. Supportive care includes pain management, optimization of ventilation, haemodynamic and fluid monitoring, improvement of renal function, nutrition and anticoagulation.

CONCLUSIONS

The majority of patients with peritonitis develop complications, including worsening of pre-existing organ dysfunction, surgical complications and healthcare-associated infections. The probability of postoperative complications must be taken into account in the decision-making process prior to surgery.

Fungal Culture Positivity in Patients with Perforation Peritonitis

BACKGROUND

Perforation peritonitis is the most common surgical emergency. A large number of microorganisms have been cultured from the abdominal fluid obtained from patients with gastrointestinal perforation peritonitis. The present study was undertaken to determine the frequency of positive fungal culture in perforation peritonitis as Candida co-infection is reported to be a bad prognostic factor in these patients.

MATERIALS AND METHODS

The intraoperative specimens of abdominal fluid collected during laparotomy from 140 consecutive patients of gastro-intestinal perforation were analysed by microbial culture for bacteria and fungi. Their antimicrobial susceptibility was also studied.

RESULTS

The mean presenting age of the patients was 35 years and 120 (85.7%) of them were males. Aerobic Gram Negative Bacilli (AGNB) were observed in 82 (79.6%) of the culture positive abdominal fluid specimens, of which 58 (70.7%) were Escherichia coli. Gram negative bacteria were most frequently isolated from colorectal perforation (100%) while Gram positive bacteria were from upper gastrointestinal perforation (47.2%). Candida was cultured in as many as 68 of 140 (48.6%) specimens. Its prevalence was highest in patients with gastroduodenal perforation (70.5%) and was altogether absent in patients having appendicular perforation.

CONCLUSION

High prevalence of fungal culture positivity of peritoneal fluid of patients of perforation peritonitis shows that along with the bacterial culture, fungal cultures should always be asked for in such patients. Adequate and timely antimicrobial treatment including treatment of fungal infection could help reduce mortality in this group of patients.

Clinical and economic consequences of failure of initial antibiotic therapy for patients with community-onset complicated intra-abdominal infections

Objectives

Complicated intra-abdominal infection (cIAI) is infection that extends beyond the hollow viscus of origin into the peritoneal space, and is associated with either abscess formation or peritonitis. There are few studies that have assessed the actual costs and outcomes associated with failure of initial antibiotic therapy for cIAI. The aims of this study were to evaluate risk factors and impact on costs and outcomes of failure of initial antibiotic therapy for community-onset cIAI.

Methods

A retrospective study was performed at eleven tertiary-care hospitals. Hospitalized adults with community-onset cIAI who underwent an appropriate source control procedure between August 2008 and September 2011 were included. Failure of initial antibiotic therapy was defined as a change of antibiotics due to a lack of improvement of the clinical symptoms and signs associated with cIAI in the first week.

Results

A total of 514 patients hospitalized for community-onset cIAI were included in the analysis. The mean age of the patients was 53.3 ± 17.6 years, 72 patients (14%) had health care-associated infection, and 48 (9%) experienced failure of initial antibiotic therapy. Failure of initial antibiotic therapy was associated with increased costs and morbidity. After adjustment for covariates, patients with unsuccessful initial therapy received an additional 2.9 days of parenteral antibiotic therapy, were hospitalized for an additional 5.3 days, and incurred $3,287 in additional inpatient charges. Independent risk factors for failure of initial antibiotic therapy were health care-associated infection, solid cancer, and APACHE II ≥13.

Conclusions

To improve outcomes and costs in patients with community-onset cIAI, rapid assessment of health care-associated risk factors and severity of disease, selection of an appropriate antibiotic regimen accordingly, and early infection source control should be performed.

The Challenge of Antimicrobial Resistance in Managing Intra-Abdominal Infections

BACKGROUND

In recent years, there has been a worldwide increase in infections caused by microorganisms resistant to multiple antimicrobial agents.

METHODS

In the past few decades, an increased prevalence of infections caused by antibiotic-resistant pathogens, including Enterococcus spp., carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter baumannii, extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp., carbapenemase-producing Klebsiella pneumoniae, and resistant Candida spp., also has been observed among intra-abdominal infections (IAIs).

RESULTS

The increasing prevalence of multi-drug resistance is responsible for a substantial increase in morbidity and mortality rates associated with IAIs.

CONCLUSIONS

It is necessary for every surgeon treating IAIs to understand the underlying epidemiology and clinical consequences of antimicrobial resistance. Emergence of drug resistance, combined with the lack of new agents in the drug development pipeline, indicates that judicious antimicrobial management will be necessary to preserve the utility of the drugs available currently.

Ceftolozane/Tazobactam Plus Metronidazole for Complicated Intra-abdominal Infections in an Era of Multidrug Resistance: Results From a Randomized, Double-Blind, Phase 3 Trial (ASPECT-cIAI)

This phase 3 trial compared ceftolozane/tazobactam plus metronidazole vs meropenem for the treatment of complicated intra-abdominal infections. Ceftolozane/tazobactam plus metronidazole was noninferior to meropenem. High rates of presumed microbiological eradication of Enterobacteriaceae and Pseudomonas aeruginosa were found with both regimens.

Background. Increasing antimicrobial resistance among pathogens causing complicated intra-abdominal infections (cIAIs) supports the development of new antimicrobials. Ceftolozane/tazobactam, a novel antimicrobial therapy, is active against multidrug-resistant Pseudomonas aeruginosa and most extended-spectrum β-lactamase (ESBL)–producing Enterobacteriaceae.

Methods. ASPECT-cIAI (Assessment of the Safety Profile and Efficacy of Ceftolozane/Tazobactam in Complicated Intra-abdominal Infections) was a prospective, randomized, double-blind trial. Hospitalized patients with cIAI received either ceftolozane/tazobactam (1.5 g) plus metronidazole (500 mg) every 8 hours or meropenem (1 g) every 8 hours intravenously for 4–14 days. The prospectively defined objectives were to demonstrate statistical noninferiority in clinical cure rates at the test-of-cure visit (24–32 days from start of therapy) in the microbiological intent-to-treat (primary) and microbiologically evaluable (secondary) populations using a noninferiority margin of 10%. Microbiological outcomes and safety were also evaluated.

Results. Ceftolozane/tazobactam plus metronidazole was noninferior to meropenem in the primary (83.0% [323/389] vs 87.3% [364/417]; weighted difference, −4.2%; 95% confidence interval [CI], −8.91 to .54) and secondary (94.2% [259/275] vs 94.7% [304/321]; weighted difference, −1.0%; 95% CI, −4.52 to 2.59) endpoints, meeting the prespecified noninferiority margin. In patients with ESBL-producing Enterobacteriaceae, clinical cure rates were 95.8% (23/24) and 88.5% (23/26) in the ceftolozane/tazobactam plus metronidazole and meropenem groups, respectively, and 100% (13/13) and 72.7% (8/11) in patients with CTX-M-14/15 ESBLs. The frequency of adverse events (AEs) was similar in both treatment groups (44.0% vs 42.7%); the most common AEs in either group were nausea and diarrhea.

Conclusions. Treatment with ceftolozane/tazobactam plus metronidazole was noninferior to meropenem in adult patients with cIAI, including infections caused by multidrug-resistant pathogens.

Clinical Trials Registration. NCT01445665 and NCT01445678.

Abdominal infections in the intensive care unit: characteristics, treatment and determinants of outcome

BACKGROUND

Abdominal infections are frequent causes of sepsis and septic shock in the intensive care unit (ICU) and are associated with adverse outcomes. We analyzed the characteristics, treatments and outcome of ICU patients with abdominal infections using data extracted from a one-day point prevalence study, the Extended Prevalence of Infection in the ICU (EPIC) II.

METHODS

EPIC II included 13,796 adult patients from 1,265 ICUs in 75 countries. Infection was defined using the International Sepsis Forum criteria. Microbiological analyses were performed locally. Participating ICUs provided patient follow-up until hospital discharge or for 60 days.

RESULTS

Of the 7,087 infected patients, 1,392 (19.6%) had an abdominal infection on the study day (60% male, mean age 62 ± 16 years, SAPS II score 39 ± 16, SOFA score 7.6 ± 4.6). Microbiological cultures were positive in 931 (67%) patients, most commonly Gram-negative bacteria (48.0%). Antibiotics were administered to 1366 (98.1%) patients. Patients who had been in the ICU for ≤ 2 days prior to the study day had more Escherichia coli, methicillin-sensitive Staphylococcus aureus and anaerobic isolates, and fewer enterococci than patients who had been in the ICU longer. ICU and hospital mortality rates were 29.4% and 36.3%, respectively. ICU mortality was higher in patients with abdominal infections than in those with other infections (29.4% vs. 24.4%, p < 0.001). In multivariable analysis, hematological malignancy, mechanical ventilation, cirrhosis, need for renal replacement therapy and SAPS II score were independently associated with increased mortality.

CONCLUSIONS

The characteristics, microbiology and antibiotic treatment of abdominal infections in critically ill patients are diverse. Mortality in patients with isolated abdominal infections was higher than in those who had other infections.

The value of critical care

The primary focus of this review is on the cost-effectiveness of critical care. The rapid growth in health care expenditures has engendered careful scrutiny of the practice of medicine with regard not only to effectiveness but also to efficiency. This shift necessitates that physicians understand the effectiveness of their interventions and the cost at which this effectiveness is obtained. Cost-effectiveness and cost-utility analyses have become crucial evaluative tools in medicine. Explicit articulation of comparative cost-effectiveness facilitates the allocation of limited resources. Physicians and policy-makers must evaluate such studies with caution, skepticism, and attention to the methods used.

[Analysis of organ failure and mortality in sepsis due to secondary peritonitis]

OBJECTIVES

To identify the organs most susceptible to develop multiorgan dysfunction syndrome (MODS) in patients with sepsis due to secondary peritonitis, and to determine the outcome and mortality predicting utility of the SOFA (Sequential Organ Failure Assessment) system.

DESIGN

A prospective, observational cohort study was made.

SETTING

The resuscitation unit of a third-level university hospital.

PATIENTS

A prospective, observational cohort study was made of 102 patients with sepsis of abdominal origin and failure of at least one organ related to the infection. The demographic characteristics were documented, along with the abdominal origin of sepsis, mortality after 28 days, and the daily SOFA score.

RESULTS

The mortality rate after 28 days was 55%. A total of 53% of the patients presented failure of two or more organs on the first day of admission. The mean daily SOFA score was significantly higher among the patients that died after day 4 of admission. The variables showing a statistically significant correlation to increased mortality were: MODS (P=.000), central nervous system failure (P=.000) and SOFA score on day 4 of admission (P=.012). The area under the ROC curve showed the mortality predicting capacity of the SOFA score on day 4 of admission to be 0.703 (95%CI 0.538-0.853; P=.026). The maximum discriminating capacity was recorded for MODS, with an area under the ROC curve of 0.776 (95%CI 0.678-0.874; P=.000).

CONCLUSIONS

Organ failure outcome as predicted by the SOFA score showed high precision - the mean SOFA score on day 4 of admission being a good mortality predictor. MODS was the main cause of death, while central nervous system, renal and respiratory failure were identified as the mortality risk factors.

Depletion of neutrophil extracellular traps in vivo results in hypersusceptibility to polymicrobial sepsis in mice

Introduction

Although the formation of neutrophil (PMN) extracellular traps (NETs) has been detected during infection and sepsis, their role in vivo is still unclear. This study was performed in order to evaluate the influence of NETs depletion by administration of recombinant human (rh)DNase on bacterial spreading, PMN tissue infiltration and inflammatory response in a mouse model of polymicrobial sepsis.

Methods

In a prospective controlled double-armed animal trial, polymicrobial sepsis was induced by cecal ligation and puncture (CLP). After CLP, mice were treated with rhDNase or phosphate buffered saline, respectively. Survival, colony forming unit (CFU) counts in the peritoneal cavity, lung, liver and blood were determined. PMN and platelet counts, IL-6 and circulating free (cf)-DNA/NETs levels were monitored. PMN infiltration, as well as organ damage, was analyzed histologically in the lungs and liver. Capability and capacity of PMN to form NETs were determined over time.

Results

cf-DNA/NETs were found to be significantly increased 6, 24, and 48 hours after CLP when compared to the levels determined in sham and naïve mice. Peak levels after 24 hours were correlated to enhanced capacity of bone marrow-derived PMN to form NETs after ex vivo stimulation with phorbol-12-myristate-13-acetate at the same time. rhDNase treatment of mice resulted in a significant reduction of cf-DNA/NETs levels 24 hours after CLP (P < 0.001). Although overall survival was not affected by rhDNase treatment, median survival after 24 hours was significantly lower when compared with the CLP group (P < 0.01). In mice receiving rhDNase treatment, CFU counts in the lung (P < 0.001) and peritoneal cavity (P < 0.05), as well as serum IL-6 levels (P < 0.001), were found to be already increased six hours after CLP. Additionally, enhanced PMN infiltration and tissue damage in the lungs and liver were found after 24 hours. In contrast, CFU counts in mice without rhDNase treatment increased later but more strongly 24 hours after CLP (P < 0.001). Similarly, serum IL-6 levels peaked after 24 hours (P < 0.01).

Conclusions

This study shows, for the first time, that depletion of NETs by rhDNase administration impedes the early immune response and aggravates the pathology that follows polymicrobial sepsis in vivo.

Efficacy of therapy with recombinant human activated protein C of critically ill surgical patients with infection complicated by septic shock and multiple organ dysfunction syndrome

BACKGROUND

Septic shock causing or complicating critical surgical illness results in high mortality. Drotrecogin alfa (activated), known also as recombinant human activated protein C (rhAPC) has become controversial as therapy, owing to persisting questions of efficacy and safety. We hypothesized rhAPC to be effective therapy for critically ill surgical patients with septic shock.

METHODS

Open-label therapy with rhAPC (by predefined criteria) of 108 critically ill surgical patients. Treated patients were matched individually in prospect for age, gender, Acute Physiology and Chronic Health Evaluation (APACHE)-II and -III scores, site of infection, and organism (0-2 points each, maximum 12 points) with 108 patients from our 15,000-patient surgical intensive care unit database who did not receive rhAPC. No match was accepted if <6 points. Multiple organ dysfunction (MOD) scores and data regarding cortisol concentrations, bleeding complications, and transfusion requirements were collected. The primary endpoint was 28-day mortality, with mortality for hospitalization and resolution of organ dysfunction as secondary endpoints. Statistical analyses included ANOVA, c statistic, binary logistic regression, and Kaplan-Meier time-to-event and Cox proportional hazards analyses; α=0.05.

RESULTS

The mean match score was 9.2±0.1 points (range, 6-12 points). Patients were well matched by all criteria, including baseline MOD score (9.5±0.7 vs. 9.8±0.3 points, p=0.66). Mean age was 68.1±1.1 years (p=0.49), Mean APACHE-III score was 99.6±1.5 points (p=0.87). Mean time to rhAPC administration was 25±3 h. Survival at 28 days after rhAPC was 71.3% vs. 49.1% (p=0.001); hospital survival was 57.4% vs. 40.7% (p=0.02). By logistic regression, rhAPC therapy resulted in improved 28-day survival (OR 2.57, 95% CI 1.46-4.52, p=0.001) (model χ2 11.244, p=0.001); and hospital survival (OR 1.96, 95% CI 1.14-3.36, p=0.015) (model χ2 6.03, p=0.014). The MOD score decreased significantly (p=0.012) during rhAPC therapy.

CONCLUSION

Therapy with rhAPC appeared to improve survival in surgical ICU patients with life-threatening infection characterized by septic shock and organ dysfunction.

[What should and should not be covered in intraabdominal infection]

Despite improvements in our knowledge of the physiopathology of severe infection, diagnostic methods, antibiotic therapy, postoperative care and surgical techniques, a substantial number of patients with intraabdominal infection (IAI) will develop advanced stages of septic insult requiring admission to the intensive care unit. The success of treatment of IAI is multifactorial and the best antibiotic protocol may be insufficient unless adequate control of the focus of infection has been achieved. The present article discusses the appropriacy of empirical antibiotic therapy and the main pathogens associated with treatment failure. We also analyze the patients at risk of infection with microorganisms requiring broad-spectrum antimicrobial coverage. However, excessive antibiotic treatment, in terms of either spectrum or duration, could jeopardize future patients in an environment already threatened by the scarcity of research and development into new molecules required for the emergence of pathogens resistant to current antibiotics.

Treatment of complicated intra-abdominal infections in the era of multi-drug resistant bacteria

The management of severe intra-abdominal infections remains a major challenge facing surgeons and intensive care physicians, because of its association with high morbidity and mortality. Surgical management and intensive care medicine have constantly improved, but in the recent years a rapidly continuing emergence of resistant pathogens led to treatment failure secondary to infections with multi-drug resistant bacteria. In secondary peritonitis the rate of resistant germs at the initial operation is already 30%. The lack of effective antibiotics against these pathogens resulted in the development of new broad-spectrum compounds and antibiotics directed against resistant germs. But so far no "super-drug" with efficacy against all resistant bacteria exists. Even more, soon after their approval, reports on resistance against these novel drugs have been reported, or the drugs were withdrawn from the market due to severe side effects. Since pharmaceutical companies reduced their investigations on antibiotic research, only few new antimicrobial derivates are available.

In abdominal surgery you may be in fear that in the future more and more patients with tertiary peritonitis secondary to multi-drug resistant species are seen with an increase of mortality after secondary peritonitis.

This article reviews the current treatment modalities for complicated intra-abdominal infections with special reference to the antibiotic treatment of complicated intra-abdominal infections with multi-drug resistant species.

Percentages of CD4+ T regulatory cells and HLA-DR expressing monocytes in severe intra-abdominal infections

To study the immune status of patients with severe abdominal infections, we assayed percentages of CD4+ T regulatory cells (CD4+CD25+FOXP3+ Treg) and human leukocyte antigen DR (HLA-DR) expressing CD14+ cells in peripheral blood. A total of 46 subjects with varying acute physiology and chronic health evaluation II (APACHE II) scores were included in the study. There was a significant (p < 0.01) increase in the percentage of CD4+CD25+FOXP3+ Treg and a significant (p < 0.01) decrease in HLA-DR expressing CD14+ cells with increasing APACHE II score. Such modifications may contribute to the aggravation of severe intra-abdominal infections.

The pathogen of ventilator-associated pneumonia does not influence the mortality rate of surgical intensive care unit patients treated with a rotational antibiotic system

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the leading causes of morbidity in critically ill surgical patients. Certain pathogens (e.g., methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa) have been associated with an excess mortality rate from sepsis in several studies, but not in the surgical setting specifically or when protocol-driven antibiotic therapy is administered.

PURPOSE

We sought to determine which factors and, in particular, whether the individual pathogen affected the mortality rate in our surgical intensive care unit (ICU), where a rotational antibiotic system has been employed continuously since 1997. We hypothesized that the type of pathogen and illness severity were the primary influences on the mortality rate of patients with VAP.

METHODS

A total of 198 consecutive patients from a university surgical ICU, with clinical signs of VAP confirmed by quantified isolation of significant numbers of a pathogen (> or =10(4) colony-forming units [cfu]/mL) from bronchoalveolar (BAL) fluid obtained by fiberoptic bronchoscopy, were identified prospectively from January 2001 to November 2004. The data collected were age, sex, Acute Physiology and Chronic Health Evaluation (APACHE) III score, multiple organ dysfunction score, unit day of diagnosis, time (h) to antibiotic administration (TTA), appropriateness of initial therapy (AIT), unit and hospital length of stay, and mortality rate. Pathogens were classified as non-lactose-fermenting gram-negative bacilli (NGNB), lactose-fermenting gram-negative bacilli (LGNB), methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus, yeast, community-acquired pneumonia (e.g., Streptococcus pneumoniae), or other pathogens. Patients with a polymicrobial isolate were placed in the "other" category.

RESULTS

The overall mortality rate was 32.3% vs. 55% as predicted by APACHE III normative data. The overall AIT was 92%. The mortality rate for NGNB infections was 35.6% vs. 29.4% for LGNB infections (p = NS). By logistic regression, neither TTA, AIT, nor pathogen influenced the mortality rate.

CONCLUSIONS

The type of pathogen does not influence death in surgical ICU patients with VAP diagnosed rigorously and treated by a rotational antibiotic system. The high proportion of AIT as a result of the rotational antibiotic administration system optimizes bacterial killing and negates the impact of bacterial resistance, contributing to better outcomes.

Infections of respiratory or abdominal origin in ICU patients: what are the differences?

INTRODUCTION

There are few data related to the effects of different sources of infection on outcome. We used the Sepsis Occurrence in Acutely ill Patients (SOAP) database to investigate differences in the impact of respiratory tract and abdominal sites of infection on organ failure and survival.

METHODS

The SOAP study was a cohort, multicenter, observational study which included data from all adult patients admitted to one of 198 participating intensive care units (ICUs) from 24 European countries during the study period. In this substudy, patients were divided into two groups depending on whether, on admission, they had abdominal infection but no respiratory infection or respiratory infection but no abdominal infection. The two groups were compared with respect to patient and infection-related characteristics, organ failure patterns, and outcomes.

RESULTS

Of the 3,147 patients in the SOAP database, 777 (25%) patients had sepsis on ICU admission; 162 (21%) had abdominal infection without concurrent respiratory infection and 380 (49%) had respiratory infection without concurrent abdominal infection. Age, sex, and severity scores were similar in the two groups. On admission, septic shock was more common in patients with abdominal infection (40.1% vs. 29.5%, P = 0.016) who were also more likely to have early coagulation failure (17.3% vs. 9.5%, P = 0.01) and acute renal failure (38.3% vs. 29.5%, P = 0.045). In contrast, patients with respiratory infection were more likely to have early neurological failure (30.5% vs. 9.9%, P < 0.001). The median length of ICU stay was the same in the two groups, but the median length of hospital stay was longer in patients with abdominal than in those with respiratory infection (27 vs. 20 days, P = 0.02). ICU (29%) and hospital (38%) mortality rates were identical in the two groups.

CONCLUSIONS

There are important differences in patient profiles related to the site of infection; however, mortality rates in these two groups of patients are identical.

Prognostic factors in critically ill patients suffering from secondary peritonitis: a retrospective, observational, survival time analysis

BACKGROUND

Acute mortality of unselected critically ill patients has improved during the last 15 years. Whether these benefits also affect survival of critically ill patients with secondary peritonitis is unclear as is the relevance of specific prognostic factors, such as source control.

METHODS

We performed a retrospective analysis of data collected prospectively from March 1993 to February 2005. A cohort of 319 consecutive postoperative patients with secondary peritonitis requiring intensive care was evaluated. End points for outcome analysis were derived from daily changes of hazard rate.

RESULTS

Four-month survival rate after intensive care unit (ICU) admission was 31.7%. For patients who have survived for more than 4 months, the 1-year survival was 82.7%. After adjustment for relevant covariates, a high disease severity at ICU admission and during ICU stay, specific comorbidities (extended malignancies, liver cirrhosis) and sources of infection (distal esophagus, stomach), and an inadequate initial antibiotic therapy were associated with worse 4-month prognosis. Inability to obtain source control was the most important determinant of mortality, and treatment after 2002 was combined with improved prognosis.

CONCLUSIONS

Four-month prognosis of critically ill, surgical patients with secondary peritonitis is poor and mostly determined by the ability to obtain source control. Outcome has improved since 2002, and after successful surgical and intensive care therapy long-term survival seems to be good.

Pharmacokinetics of meropenem determined by microdialysis in the peritoneal fluid of patients with severe peritonitis associated with septic shock

Our objective was to describe the pharmacokinetics of meropenem in the peritoneal fluid (PF) of six patients with severe peritonitis and septic shock and to relate measured concentrations to the minimum inhibitory concentration of bacteria. Microdialysis catheters were placed into the peritoneal space during surgery. Meropenem concentrations in plasma and in PF were analyzed using compartmental modeling. Meropenem areas under the concentration-time curve were lower in PF than in plasma (average ratio, 73.8+/-15%) because of degradation confirmed ex vivo. Compartment modeling with elimination from a peripheral compartment described the data adequately, and was used to simulate steady-state concentration profiles in plasma and PF during various dosing regimens. At the currently recommended dosing regimen of 1 g infused over 20 min every 8 h, PF concentrations of meropenem in patients with severe peritonitis associated with septic shock reach values sufficient for antibacterial effects against susceptible, but not always against intermediately susceptible, bacteria.

Intra-abdominal infections

PURPOSE OF REVIEW

The aim of this article is to outline developments in the three cornerstones of treatment of intra-abdominal infections during critical illness: source control; antimicrobial therapy; and mitigation of deranged immune and coagulation responses.

RECENT FINDINGS

Although adequate source control remains the goal of mechanical management of intra-abdominal infections, neither planned re-laparotomy nor open-abdomen management appears to offer a survival benefit as compared with on-demand re-laparotomy. Novel approaches to restoration of a functional gastrointestinal tract have emerged as alternatives to more invasive surgery. A persistent increase in the prevalence of intra-abdominal infections caused by multidrug resistant pathogens has led researchers to investigate shorter-course antimicrobial therapy and other antibiotic administration strategies with encouraging initial results. Therapy with recombinant human activated protein C should now be considered for patients with severe abdominal sepsis associated with a high risk of death.

SUMMARY

Because randomized controlled trials of intra-abdominal infections involve critically ill patients infrequently, only limited evidence-based recommendations regarding the management of these patients may be drawn. Therapy should focus above all else on timely obtainment of adequate source control, in conjunction with judicious use of antimicrobial therapy dictated by individual patient risk factors for infection with multidrug resistant pathogens.

Decreased Neutrophil Response in a Model of Chronic IntraperitonealKlebsiellaInfection

BACKGROUND

Previously, we developed an infection model by intraperitoneal (IP) injection of Klebsiella pneumoniae. The high early mortality rate prompted a study of the effect of gentamicin on the disease course.

METHODS

Infection was induced in Balb/c mice by IP inoculation of 10(3) colony-forming units (cfu) of K. pneumoniae serotype 2. Mice then received either saline or gentamicin twice daily at 5 mg/kg/day. Survival and weight loss were determined daily over 14 days. Leukocyte counts (WBC) were performed on peritoneal lavage fluid (PL) and peripheral blood. Bacterial counts in blood, lung homogenate, and PL were determined by culture.

RESULTS

A significant survival benefit was seen in the gentamicin group by 48 h (p < 0.05), which persisted at 14 days. Weight loss of 2 g (p < 0.05) occurred in all mice by day three, with recovery seen only in the gentamicin-treated mice. Mice that did not regain their weight by day seven or lost more than 4 g (20%) died. All animals had peritoneal bacteria recovered at all time points. The gentamicin group showed fewer bacteria at one day in lung, blood, and PL, the difference being significant for the PL. Gentamicin did not clear peritoneal bacteria, and counts remained at inoculum concentration (10(3) cfu), but elicited no significant neutrophil influx. Whereas there was a progressive increase in total lavage WBC over time, the gentamicin group showed no significant neutrophil influx in PL or lung until bacterial counts exceeded 10(5) cfu.

CONCLUSIONS

Despite persistent intra-abdominal infection, gentamicin treatment significantly prolonged survival in this uniformly lethal model. Although antibiotic treatment did not suppress bacteremia, it did diminish bacterial spread from the blood to the lung. This procedure produced a clinically relevant, novel model of antibiotic-treated chronic intraperitoneal infection, which will allow future study of specific host defense mechanisms.

Organ dysfunction and long term outcome in secondary peritonitis

BACKGROUND AND AIMS

Secondary peritonitis is still associated with high mortality, especially when multiorgan dysfunction complicates the disease. Good prognostic tools to predict long term outcome in individual patients are lacking and therefore require further study.

PATIENTS AND METHODS

163 consecutive patients with secondary peritonitis were included, except those with postoperative or traumatic peritonitis. In 58 patients treated in the intensive care unit (ICU), organ dysfunction was quantified using Sequential Organ Failure Assessment (SOFA) score in the first 4 days. Predictive factors for poor outcome were evaluated in all patients. Hospital and 1-year mortality was assessed.

RESULTS

Hospital mortality was 19% and 1-year mortality 23%. Acute physiology and chronic health evaluation II (APACHE II), previous functional status, and sepsis category were predictive of fatal outcome in the total cohort (p = 0.034, p < 0.001, and p < 0.001). In patients treated in the ICU, advanced age and admission SOFA score were independent predictors of death (p = 0.014, p < 0.0001). The SOFA score showed the best discriminative ability for poor outcome (AuROC 0.78).

CONCLUSION

Degree of organ dysfunction measured using SOFA score was the best predictor of hospital mortality in patients suffering from secondary peritonitis.

Intra-abdominal infections: considerations for the use of the carbapenems

Intra-abdominal infection remains a common and frequently severe medical condition, carrying with it significant morbidity and mortality. These infections are almost always polymicrobial in nature as they are caused by mixed aerobic/anaerobic intestinal flora. Despite substantial improvements in both the medical and surgical management of these infections over the last several decades, there remains an opportunity to further enhance the utilization of adjunctive antibiotic therapy. As a result of the epidemiology and the current resistance profile of the infecting pathogens, the carbapenems represent a class of antibiotics that are considered appropriate for the treatment of severe intra-abdominal infections. This review will discuss the classification and microbiology of these infections and emerging resistance in the pathogens of interest. The review also and focuses on the role of the carbapenems in the management of the constellation of diseases known as intra-abdominal infection.