Surgical Infections

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

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).

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

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.

Besides the vast success and reliability of lower extremity joint replacement, deep and periprosthetic infection remains a serious complication of such operations. Many publications addressing periprosthetic infection have remarked about this “devastating” complication, with a risk around 1% after total hip arthroplasty and between 1% and 2% after total knee arthroplasty. The purpose of this study is to assess current trends in prevention of contamination with improved up-to-date pre-operative skin preparation methods and intra-operative draping.

A literature review was conducted in MEDLINE, Web of Science, and the Cochrane database, looking for high-quality papers summarizing the most widely held and up-to-date concepts of perioperative measures for reducing infection, focusing on the best available evidence concerning skin preparation for joint arthroplasty (THR and THR) and surgical draping.

Current evidence suggests the use of alcohol solutions for pre-operative painting with emphasis on the use of chlorhexidine gluconate solutions beginning the night before surgery. Hair removal should be performed in the operating room with electric clippers, not razor blades. In order to enhance drape adhesion to the skin, the use of iodophor-in-alcohol solutions is recommended over the traditional scrub-and-paint technique. Disposable non-woven drapes are superior to reusable woven cotton/linen drapes in resisting bacterial penetration. Finally, the use of adherent plastic adhesive incision drapes for the prophylaxis of post-operative surgical site infections is considered not necessary in orthopedic surgery.

The importance of skin preparation and adequate and reliable draping cannot be overemphasized for infection prevention, especially in clean operations such as THR and TKR. Thorough and strict protocols are mandatory for every department, as well as education curricula for operating room personnel. Further randomized studies are mandatory to specify the effect of the above measures, their pitfalls, and their improvement, along with further crucial details such as cost–benefit analysis of different pre-operative preparations in preventing infections.

Surgical site infection (SSI) remains the most frequent complication after colorectal resection. The role of sutures coated with antimicrobial agents such as triclosan in reducing SSI is controversial.

This was a multi-center randomized controlled trial with patients and outcome assessors blinded to treatment. The study was performed in four university referral hospitals. Patient candidates for elective colorectal resection were assigned randomly to abdominal incision closure with polyglactin 910 triclosan-coated sutures (triclosan group) or with polyglactin 910 without triclosan (control group). The primary outcome was the rate of SSI within 30 d after hospital discharge. The secondary outcomes were the overall rate of incision complications and length of hospital stay (LOS).

Two hundred eighty-one patients (triclosan group: 140; control group: 141) were analyzed after randomization. The rate of SSI was 12.9% (18/140) in the triclosan group versus 10.6% (15/141) in the control group (odds ratio: 1.24; 95% confidence interval: 0.60–2.57; p=0.564). Secondary outcome analysis showed an overall incision complication rate of 38.3% in the control group versus 45.7% in the triclosan group (odds ratio: 1.36; 95% confidence interval: 0.84–2.18; p=0.208). Median LOS was 11 d in both groups (p=0.55).

Surgical sutures coated with triclosan do not appear to be effective in reducing the rate of SSI.

Bacteria colonizing an enterocutaneous fistula tract have not been clarified. The aims of this study were to investigate the pathogen spectra of fistulous tracts and their resistance to antibiotics in patients with chronic fistulas.

We conducted a one-year prospective single-center study. In the absence of significant sepsis, consecutively stabilized patients with chronic enterocutaneous fistula were included. Microbiology and antimicrobial susceptibility of isolates from the tracts were analyzed. The correlations between the existence of bacteria and various clinical values were investigated further.

Forty-one patients were enrolled, of whom eight had a negative culture. A total of 48 bacterial strains were harvested, including 42 strains of gram-negative bacteria and six strains of gram-positive bacteria, most of which were multiple-drug-resistant. The three bacteria cultured most often were Escherichia coli (11 strains; 22.9%), Pseudomonas aeruginosa (eight strains; 16.7%), and Klebsiella pneumoniae (eight strains). Binary logistic regression analysis with forward (conditional) stepwise selection found that fistula length correlated with positive bacterial results (p=0.018). Other variables, namely entire length of hospitalization and fistula duration and location, were unrelated to the presence of micro-organisms in fistula tracts.

Multiple-drug-resistant gram-negative bacteria were the main pathogens colonizing chronic fistula tracts. Fistula length was significantly associated with the presence of pathogens in a multivariable logistic regression model.

To determine if there is a difference in periocular post-operative infection rates when utilizing new versus re-processed monopolar electrocautery tips.

Retrospective cohort study of 4,976 consecutive surgical cases involving 17,149 procedures. Post-operative infections were identified using chart review, facility infection surveillance records, and surgeon reporting. The main outcome measure was the presence or absence of infection within 30 post-operative days. The Fischer exact test was used to compare infection rates between cautery modalities. All statistical analysis was conducted at the 0.05 α level.

There was no statistically significant difference between new and re-processed monopolar cautery infection rates (p=0.3879).

Post-operative infection rates are similar for periocular surgery using both new and re-processed monopolar cautery. These findings suggest that re-processed cautery is a viable option for periocular surgery to decrease cost and reduce material waste without affecting the quality of care.

Pelvic lymphocyst infection is a rare complication after lymphadenectomy for malignant gynecologic tumors. Although medical therapy is a useful addition to surgical drainage, the appropriate antibiotic regimen is unknown because few studies have examined the causative organisms. The purpose of this case series was to identify the micro-organisms infecting pelvic lymphocysts.

This was a single-center, retrospective, case-series review conducted at a tertiary-care cancer center between October 2002 and March 2013. The participants included all patients who experienced their first pelvic lymphocyst infection after undergoing pelvic lymphadenectomy for cervical, endometrial, or ovarian cancer and exhibited positive lymphocyst fluid culture. Computed tomography- or sonography-guided percutaneous aspiration procedures were performed to obtain lymphocyst fluid for culture.

During the study period, 878 patients underwent lymphadenectomy for gynecologic malignant tumors, and 13 developed a pelvic lymphocyst infection documented microbiologically. Cultures identified Staphylococcus aureus (three patients), S. epidermidis (one patient), Streptococcus agalactiae (three patients), Enterococcus (two patients), Escherichia coli (one patient), and anaerobic bacteria (three patients). They were all monomicrobial infections.

Our study and other smaller ones suggest that lymphocyst infections following pelvic lymphadenectomy for malignant gynecologic tumors usually are monomicrobial and caused by gram-positive cocci, including Staphylococcus, Streptococcus, and Enterococcus, and anaerobes such as Bacteroides fragilis. These bacteria should be considered when selecting empiric antibiotic therapy.

Intestinal fatty acid binding protein (iFABP) is elevated in plasma by intestinal injury. We investigated the influence of surgical trauma and severe sepsis caused by abdominal and pulmonary infection on plasma iFABP concentrations.

Seventy-nine patients were included in this prospective observational study: 31 patients before elective major abdominal surgery (EMS), 33 patients with severe sepsis on admission to the intensive care unit (ICU), and 15 healthy volunteers who served as controls. Blood samples were taken before and after surgery for a period up to 5 d.

Prior to surgery, EMS patients had increased iFABP concentrations in those patients with intestinal cancer compared with patients without intestinal cancer (217 pg/mL, interquartile range [IQR] I–III 100–369 pg/mL versus 79 pg/mL, IQR I–III: 0–182 pg/mL; p<0.01) and with controls (114 pg/mL, IQR I–III: 103–124 pg/mL; p<0.01). Surgical trauma increased iFABP levels in patients without intestinal cancer (240 pg/mL, IQR I–III 111–305 pg/mL; p<0.01). Within 24 h after surgery, iFABP levels decreased to normal values. Patients with severe sepsis of abdominal origin had elevated concentrations compared with controls (324 pg/mL [IQR I–III 0–649 pg/mL]; p=0.05); in patients with pneumonia, iFABP levels were not significantly increased. Discrimination between intestinal- and pulmonary-induced sepsis was low (area under the curve [AUC] 0.693; 95% confidence interval 0.512–0.874).

Surgical trauma and severe sepsis lead to elevated iFABP concentrations. However, intestinal malignant disease and in some patients severe sepsis caused by pneumonia also resulted in elevated iFABP concentrations. The results support the idea that epithelial injury of many causes leads to elevated concentrations of iFABP. The value of iFABP for differentiating pulmonary from intestinal sepsis is limited.

Reported surgical site infection rates range from 2.1% to 40% after colorectal surgery and are believed to be underestimated depending on the method of surveillance. The study aims were to identify an accurate incidence and associated risk factors for abdominal incision surgical site infection after elective open colorectal surgery in a Saudi population.

This was a prospective observational longitudinal study of 300 consecutive adult patients, recruited upon admission to an 800-bed tertiary referral center. All consenting adults admitted for elective open colorectal surgery were included. Patients were followed for 36 d post-surgery by two certified and experienced wound care experts who diagnosed abdominal incision surgical site infections. The definition provided by the U.S. Centers for Disease Control and Prevention was used. Statistical analysis was performed using both univariate and multivariable logistic regression.

Data were analyzed for 296 patients; the incidence of abdominal surgical site infection was 30%. Factors associated with surgical site infection by univariate analysis were pre-operative pre-albumin (p=0.04, odds ratio [OR] 0.81, 95% confidence interval [CI] 0.66–0.99); operative difficulty because of truncal obesity (p=0.006, OR 2.19, 95% CI 1.25–3.84) and obesity measured by body mass index (p=0.002, OR 4.00, 95% CI 1.95–8.20). Multivariable analysis identified only two significant risk factors: Pre-operative pre-albumin (p=0.02, OR 0.76, 95% CI 0.60–0.96), and obesity measured by body mass index (BMI; p=0.001, OR 4.71, 95% CI 2.20–10.10).

Obesity and nutritional status correlated with post-operative abdominal surgical site infection. The method of surveillance and length of follow-up impact the rate reported.

Antiseptic agents are widely used in hospitals and are essential when prevention and control of nosocomial infections is required. It is necessary to consider several aspects that affect the biocide activity because they have direct impact on the nosocomial infection rate. Organisms belonging to the Staphylococcus genus are involved in such infections and chlorhexidine digluconate (CHXD) is one of the most used antiseptic agents for human and animal health. In the context of such infections, anti-bacterial peptides have been isolated from platelets and have been termed platelet microbicidal proteins (PMP). Platelet microbicidal proteins have been shown to enhance the bacterial inhibitory activities of sub-therapeutic concentrations of antibiotics. The main objective of this study was to investigate the effect of brief exposure to different sub-therapeutic concentrations of CHXD on the susceptibility of staphylococci to PMP.

The influence of brief exposure to three different sub-therapeutic concentrations of CHXD (0.005%, 0.0025%, and 0.00125%) on the subsequent staphylocidal effect of PMP was evaluated.

Among all clinical staphylococcal strains studied, all isolates were considered to be resistant to the bactericidal action of PMP. Exposure of staphylococci to CHXD prior to PMP resulted in significantly increased staphylococcal killing compared with the killing achieved with PMP alone. This enhanced effect was most marked for concentrations of CHXD of 0.005%.

The combined data indicate that PMP exerts cooperative bactericidal effect with CHXD. The anti-staphylococcal PMP and CHXD synergistic activity in vitro demonstrated in the present study make these molecules potentially useful for preventing endovascular catheter-associated infections. Future research based on animal and human models is needed to elucidate the in vivo efficacies and toxicities and utility in clinical practice.

Infection of megaprostheses after bone tumor resection is a major concern; management is challenging. This study evaluated the survivability from such infections, the microbial isolates, treatment tactics, and outcome of megaprosthesis reconstructions.

We studied 1,161 patients retrospectively who underwent megaprosthesis reconstruction for limb salvage after a sarcoma from 1983 to 2010. The mean followup was 9 y (range 3–20 y). We evaluated the overall survival of the megaprosthesis reconstructions in patients with infection and the survival with respect to the type of megaprosthesis, site of reconstruction, cemented or cementless fixation, type of tumor, adjuvant treatments, microbial isolate(s), treatment tactics, and outcome.

The incidence of infection was 8.6%. The most common microbial isolate was Staphylococcus epidermidis (47%). Overall survival with definitive management of infection was 88% at 10 y and 84% at 20 y. Survival was higher for cementless reconstructions and not different with respect to the type of megaprosthesis, site of reconstruction, or adjuvant therapy. Infections resolved completely with one- or two-stage surgery in 75% of patients. The rate of amputation because of infection was 21%.

Megaprosthesis reconstructions may be infected in 8.6% of cases. Infections more commonly occur late, caused usually by S. epidermidis. The survival rate is higher with cementless megaprosthesis reconstructions and no different with respect to the type of tumor or megaprosthesis or the adjuvant treatments. One-stage revision is effective for acute post-operative infections; however, two-stage revision surgery is necessary for early and late infections. The rate of amputation because of occurrence or persistence of megaprosthesis infection is 21%.

Catheter-associated urinary tract infection (CAUTI) and ventilator-associated pneumonia (VAP) are considered performance measures. We analyzed the incidence, prevalence, and risk of CAUTI and VAP in trauma patients, as well as the demographic and injury factors related to these infections and their relative risks of negative outcomes (prolonged length of stay [LOS], sepsis, and death).

Trauma registry data were analyzed (age >18 y; LOS >24 h) from January 1, 2007, to December 31, 2011. Demographics and injury location, severity, and type were analyzed relative to outcomes along with device-associated infection, as defined by the U.S. Centers for Disease Control and Prevention. The outcomes analyzed were intensive care unit (ICU) and hospital LOS, sepsis, and in-hospital death. Multivariable logistic regression was then used to identify the factors contributing to sepsis, including device-associated infections.

The included population (n=10,755) was 66.6% male and had a mean age of 45.1 y, with blunt trauma in 91.8% and a median Injury Severity Score (ISS) of 10 points. Patients developing CAUTI (n=324; 3.0%; p<0.005) were more likely to be female (59.4%), had a higher median ISS (20.5), and were older (56.7 years). Patients with VAP (n=161; 1.5%; p<0.005) had a higher median ISS (27). Patients with sepsis (n=149; 1.4%; p<0.005) had a higher median ISS (24.0) and were older (52.3 y). Sepsis was associated with prolonged LOS and death, as expected (p<0.005). In multivariable analysis, independent predictors of sepsis were CAUTI (odds ratio [OR] 16.15; p<0.001), VAP (OR 6.95; p<0.001), ISS (OR 1.05 per unit; p<0.001), age (OR 1.02 per year; p<0.001), and penetrating, abdominal, pelvic, or chest injury.

Development of CAUTI and VAP are significantly associated with a higher risk of sepsis in trauma patients after adjustment for age and injury type, location, and severity. This study suggests the importance of device-associated infections as vectors for sepsis in trauma and highlights the importance of prevention initiatives.

There are several studies regarding risk factors affecting surgical site infections (SSIs); nevertheless, there are an insufficient number of studies focusing on risk factors for SSI in hepatobiliary (HPB) surgery. In this study, we aimed to determine risk factors related to HPB surgery.

A total of 1,418 patients were included in this study, all of whom underwent hepatobiliary system surgery in a five-year period between January 2005 and December 2009. Demographic data, patient- and surgery-related risk factors, and laboratory parameters were analyzed retrospectively from a database maintained prospectively.

The overall incidence of SSI was 3.94% for HPB surgery. In multivariable analysis, blood transfusion (OR: 20.9), the presence of surgical drains (OR: 10.7), a pre-operative hospital stay of more than eight days (OR: 8.1), diabetes mellitus (OR: 6.2), chronic obstructive pulmonary disease (OR: 6.127), inappropriate antimicrobial prophylaxis (OR: 6), obesity (OR: 3.2), the presence of an external-internal biliary drainage catheter (OR: 2), and a direct bilirubin concentrations more than 15 mg/dL (OR: 1.4) were determined as independent risk factors related to SSI. E.coli and Enterococcus spp. were the pathogens isolated most commonly in SSIs.

Most of the independent risk factors for hepatobiliary system surgery are similar to those for other general abdominal surgical procedures. The presence of an external-internal biliary drainage catheter and direct bilirubin concentrations higher than 15 mg/dL were found to be specific risk factors for HPB surgery.

The role of bactibilia as a risk factor for an unfavorable outcome during biliary disease or surgical procedures remains obscure. Our aim was to identify possible risk factors for bactibilia and their possible relations to complications after elective cholecystectomy. As secondary aims, composition and antibiotic resistance patterns were studied.

Bile and gallbladder mucosa samples from 358 elective cholecystectomies were collected prospectively between June 2009 and June 2012. Ordinary microbiologic cultures and antibiograms were performed. All pre-operative factors associated with bactibilia were studied by stepwise logistic regression multivariable analysis.

The bacteria isolated most frequently from 103 positive cultures were Escherichia coli (21.3%), Enterococcus spp. (14.7%), and Enterobacter spp. (14.7%) with a global amoxicillin-clavulanic acid resistance rate of 53.7%. Age >65 y, male gender, previous instrumentation or disease of the biliary tract, and high American Society of Anesthesiologists score were independent risk factors. No correlation was found between bactibilia and surgical complications.

Although the influence of bactibilia in developing surgical complications is limited, its composition and the high rate of resistance can be influential enough to modify antibiotic treatment in biliary tract infections, especially in high-risk patients.

Haemophilus species bacteria (HSB) are known pathogens responsible for early pneumonia in intubated trauma patients. The primary goal of this study was to examine the incidence and extent of hypoxemia in intubated trauma patients who develop early ventilator-associated pneumonia (VAP) secondary to HSB. On the basis of our clinical experiences, we hypothesized that patients with Haemophilus species bacteria pneumonia (HSBP) would have a high rate of hypoxemia but that the effect would be transient.

Retrospective review of intubated trauma patients from an urban level I trauma center with HSBP diagnosed by deep tracheal aspirate or bronchoalveolar lavage from April 2007 to November 2012. Collected variables included day of HSBP diagnosis; PaO₂ to F_IO₂ ratio (P:F) at HSBP diagnosis as well as HSBP day three and HSBP day seven; injury severity score (ISS) and its component parts; admission Glasgow Coma Scale (GCS) score; and mortality. Hypoxemia was defined as P:F <200. χ² Tests were utilized to assess factors that differed between hypoxemic and non-hypoxemic patients; data are presented as median (interquartile range, IQR). Results: Sixty-nine patients were identified (80% male; age, 35 y [range, 24–49]; ISS 27 [9–59]). Diagnosis of HSBP occurred early (hospital day 4 [range, 3–5]). Forty-three percent of patients had acute respiratory distress syndrome (ARDS) on HSBP day 1; this decreased to 26% on day three and to 30% on day seven. Forty patients (77%) had a tracheostomy performed. Patients with hypoxemia were significantly less likely to have a severe head injury (GCS<9), p<0.05. Patients with hypoxemia had similar hospital length of stay and mortality to patients who did not develop hypoxemia.

Haemophilus species bacteria pneumonia in trauma patients is associated with high rates of transient hypoxemia and a high tracheostomy rate, although subsequent outcomes are not affected. Patients with head injuries had a lower incidence of hypoxemia from pneumonia.

Enterobacteriaceae (3,235 isolates), Pseudomonas aeruginosa (476 isolates), and Acinetobacter baumannii (106 isolates) from inpatient intra-abdominal infections (IAIs) were collected for the 2010–2012 Study for Monitoring Antimicrobial Resistance Trends (SMART) program in the United States. This report evaluates the in vitro activity of several antimicrobial agents recommended for treatment of IAIs and compares profiles of isolates from intensive care units (ICUs) and non-intensive care units (non-ICUs).

Gram-negative bacilli from hospitalized patients with IAIs were obtained each year from 2010–2012 from hospitals in the United States and tested for susceptibility to 12 antibiotics according to 2012 Clinical and Laboratory Standards Institute (CLSI) guidelines.

The most active agents against members of the Enterobacteriaceae family from both ICUs and non-ICUs were amikacin, ertapenem, and imipenem-cilastatin, whereas the least active agent was ampicillin-sulbactam. Amikacin was the only agent with good activity against P. aeruginosa, whereas none of the agents tested exhibited substantial activity against A. baumannii. Amikacin, ceftazidime, ceftriaxone, ciprofloxacin, levofloxacin, and imipenem-cilastatin were significantly less active against Enterobacteriaceae from ICU patients, whereas cefepime and ceftazidime were significantly less active against P. aeruginosa from ICU patients. Intensive care unit isolates were more likely to be multi-drug–resistant than non-ICU isolates, although there was no difference in extended-spectrum β-lactamase (ESBL) production rates between the two patient groups.

Despite increasing resistance trends, in this study amikacin, ertapenem, and imipenem-cilastatin were shown to have good in vitro activity against the most frequently isolated gram-negative bacilli from IAIs in ICU and non-ICU settings.

To analyze treatment modalities and results in patients with severe odontogenic maxillofacial infections during a 10-y period.

Medical records of 1,077 patients hospitalized because of severe odontogenic maxillofacial infections during 2003–2012 were reviewed. The sample consisted of the records that matched inclusion criteria. For each patient the following data were collected: Age, gender, presence of systemic diseases, length of hospital stay, causal tooth, location of inflammation, treatment, results of bacteriologic sampling, and anti-bacterial susceptibility.

Male to female ratio was 1.4:1. Two or more anatomic spaces were involved in 42.9% of cases, 37.3% of which involved the floor of the mouth. Penicillin in combination with gentamicin or metronidazole was prescribed in 69% of cases. Sixty-two different micro-organism species were identified with predominance of Streptococcus haemolyticus (42.9%). The microbial analysis showed the highest susceptibility of predominant micro-organisms to penicillin was 76.9% and the highest resistance was to metronidazole (27.9%).

The frequency of odontogenic maxillofacial infection remained almost unchanged during a 10-y period. Single-space infections were more common (57.1%) than infections involving two or more spaces. Susceptibility to penicillin remains relatively high; therefore, penicillin can remain part of the armamentarium for treatment of odontogenic maxillofacial infections.

Infections and inflammation of the lower limb skin, soft tissues, and vessels are more common than in other body regions. The aim was to determine whether cryptic bacteria dwelling in deep tissues are the cause.

We performed bacteriologic studies of specimens harvested from arteries of amputated ischemic legs, leg varices, and tissue fluid/lymph and lymphatics in lymphedema.

Calf arteries contained isolates in 61% and femoral arteries in 36%, whereas normal cadaveric organ donors' arteries in 11%. Bacterial deoxyribonucleic acid (DNA) was detected in 70%. The majority of isolates belonged to the coagulase-negative staphylococci and Staphylococcus aureus; however, highly pathogenic bacteria were also detected. All were sensitive to all antibiotics except penicillin. Saphenous vein varices contained bacterial cells in 40% and controls 4%; bacterial DNA was found in 69%. The majority of bacteria were S. epidermidis and S. aureus susceptible to all antibiotics except penicillin, Lymph and epifascial lymphatics limb contained bacteria in 60% and 33% samples, respectively and controls in 7%. Most were S. epidermidis susceptible to all antibiotics except penicillin.

Cryptic bacteria are present in lower limb tissues and may play a pathologic role in surgical site infections. Proper antibacterial prophylaxis should be considered when planning surgical interventions.

Numerous studies have described various complications after endoprosthetic reconstructive operations. However, there are limited reports that focus specifically on deep infections (e.g., deep incisional surgical site infections), which remain one of the most dreaded complications of these operations, with rates ranging from 10% to 17%. Thus, this study was undertaken to determine the deep infection rates and to analyze possible risk factors, clinico-pathologic characteristics, and treatment modalities of endoprosthetic infections.

We reviewed retrospectively the records of 105 consecutive patients who underwent endoprosthesis replacements from January 2007 to September 2011, with a minimal follow-up period of 32 mo. Comparison was made between patients with and without endoprosthetic infections.

Thirteen of the 150 patients (12.38%) who underwent endoprosthetic operations developed deep infections. Ninety-seven (92.4%) patients presented with a primary bone/soft tissue tumor, 5 (4.8%) with bone metastasis, and 3 (2.9%) with non-tumor conditions. Distal femoral was the most common implant location (42%). The majority of the infections (6/13) occurred within 3 mo post-operation. An elevated C-reactive protein concentration or erythrocyte sedimentation rate were present consistently in all patients at time of diagnosis, whereas clinical presentations and leukocytosis were inconsistent in determining infection. Staphylococcus aureus and coagulase-negative staphylococci (CoNS) were the most common organisms isolated, with high numbers demonstrating methicillin-resistance. Overall, multi-drug resistance was noted in 52.6% of the isolated strains. Four risk factors were associated independently with deep infection by multivariable analysis (p<0.05) and these were proximal tibia endoprosthesis, pelvic endoprosthesis, pre-operative duration of hospitalization of more than 48 h, and additional surgical procedures performed after the initial endoprosthetic insertion. Overall, infection was eradicated successfully in 53.8% (7/13) of the patients. Two-stage revision successfully treated the infection in 80% (4/5) of the patients, whereas surgical debridement without a change of implant was successful in only 42.8% (3/7) of patients. Amputation was performed in three patients.

Patients undergoing endoprosthetic replacement for various orthopedic oncologic conditions have high infection rates. The present study allows early identification of such patients in view of the high morbidity associated with this condition. This report also highlights the high rate of multi-drug–resistant infections, especially methicillin-resistant strains of S. aureus and CoNS encountered, which complicates further the management of these patients.

Surgical site infections (SSIs) increase morbidity and mortality rates and generate additional cost for the healthcare system. Pre-operative blood transfusion and the subcutaneous fat thickness (SFT) have been described as risk factors for SSI in other surgical areas. The purpose of this study was to assess the impact of pre-operative blood transfusion and the SFT on the occurrence of SSI in posterior thoracic spine surgery.

In total, 244 patients (median age 55 y; 97 female) who underwent posterior thoracic spine fusions from 2008 to 2012 were reviewed retrospectively. Patient-specific characteristics, pre-operative hemoglobin concentration/hematocrit values, the amount of blood transfused, and the occurrence of a post-operative SSI were documented. The SFT was measured on pre-operative computed tomography scans.

Surgical site infection was observed in 26 patients (11%). The SFT was 13 mm in patients without SSI and 14 mm in those with infection (p=0.195). The odds ratio for patients with pre-operative blood transfusion to present with SSI was 3.1 (confidence interval [CI] 1.4–7.2) and 2.7 (CI 1.1–6.4) when adjusted for age. There was no difference between the groups with regard to pre-operative hemoglobin concentration (p=0.519) or hematocrit (p=0.908). The SFT did not differ in the two groups.

Allogeneic red blood cell transfusion within 48 h prior to surgery was an independent risk factor for SSI after posterior fusion for the fixation of thoracic spine instabilities. Pre-operative blood transfusion tripled the risk, whereas SFT had no influence on the occurrence of SSI.

The majority of infections treated by surgeons are nosocomial infections (NI). The frequency of these infections in relation to the organ operated on as well as the organisms involved are not well defined. Detailed knowledge of these issues is essential for optimal care of surgical patients. This study aimed to determine infection rates and the responsible pathogens after major elective surgery of the pancreas, liver, stomach, and esophagus.

Between January 1, 2005 and August 31, 2007, the records of all patients of the Department of General, Abdominal and Vascular Surgery, University Hospital Magdeburg (Germany) with elective resection of the pancreas, liver, stomach, and esophagus were evaluated retrospectively. Study parameters were: Patient number, age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, indication for resection, operation duration, length of stay (LOS) in the intensive care unit (ICU) and in hospital, mortality, organ-related rate and kind of NI, and microbiologic spectrum. Nosocomial infections were defined as: Surgical site infection (U.S. Centers for Disease Control and Prevention [CDC] 1 or 2) and intra-abdominal infection (CDC 3), urinary tract infection, clinical sepsis, blood stream and catheter-related infection, respiratory tract infection, and pneumonia.

A total of 358 patients were included: 150 (42%) with pancreas resection, 91 (25%) with liver resection, 105 (29%) with gastric resection, and 12 (3%) with esophagus resection. Median LOS in the ICU for all groups was 48.8 h (interquartile range [IQR] 24.9–91.8 h), median LOS in hospital was 16 d (IQR 13–23 d), and in-hospital mortality was 4.5%. Patients with NI had significantly greater in-hospital death and prolonged stay in hospital and ICU (p<0.001). In 120 (33.5%) patients, one or more NI occurred (range, 83% in esophagus patients to 21% in liver patients). Intra-abdominal (16.5%) and surgical site infections (12.3%) were most frequent; 80.8% of the NI were culture-positive. The most frequent clinically relevant isolates were Escherichia coli (12.4%), coagulase-negative staphylococci (CoNS) (12.2%), and Enterococcus faecium (9.7%). The highest resistance rates were found for Staphylococcus aureus (methicillin-resistant S. aureus [MRSA] 29.4%) and Pseudomonas aeruginosa (23.5%).

For patients undergoing elective surgery of the pancreas, liver, stomach, and esophagus, considerable differences in demographic factors, frequency, and kind of NI exist. The consequences of NI force surgeons to analyze pre-operative risk factors carefully, assess indications for operation thoroughly, and optimize all controllable parameters.

An accurate and readily available biomarker for identifying patients with complicated intra-abdominal infection needing special attention in critical care units because of their greater risk of dying would be of value for intensivists.

A multi-center, observational, retrospective study explored blood lactate, C-reactive protein (CRP), and procalcitonin (PCT) concentrations, and also Sequential Organ Failure Assessment (SOFA) and Simplified Acute Physiology Score (SAPS II) as mortality predictors in all adult patients with complicated intra-abdominal infection (cIAI) admitted to Surgical Critical Care Units (SCCUs) for ≥48 h in four Spanish hospitals (June 2012–June 2013). Logistic regression models (step-wise procedure) were constructed using as dependent variables “intra-SCCU mortality” or “overall mortality,” and variables showing differences (p≤0.1) in bivariate analyses as independent variables.

One hundred twenty-one cases were included. Mortality intra-SCCU (R²=0.189, p=0.001) was associated with SAPS II (categorized as high if ≥47) (OR=9.55; 95% CI, 1.09–83.85; p=0.042) and 24 h-lactate (≥5.87 categorized as high) (OR=6.90; 95% CI, 1.28–37.08). Overall mortality (R²=0.275, p=0.001) was associated with peak PCT (≥100 categorized as high) (OR=11.28; 95% CI, 1.80–70.20), peak lactate (≥1.8 categorized as high) (OR=8.86; 95% CI, 1.51–52.10) and SOFA at admission (≥7 categorized as high) (OR=8.14; 95% CI, 1.69–39.20), but was predicted better (R²=0.275, p=0.001) by a single dummy variable (high peak PCT-high peak lactate concentrations) (OR=99.11; 95% CI, 5.21–1885.97; p=0.002).

In the present study, SAPS II and 24 h-lactate concentrations predicted intra-SCCU mortality whereas overall mortality was predicted better by concurrent high PCT and lactate peak concentrations than by clinical scores or by each biomarker separately.

Metal implants are used frequently in orthopedic procedures and the occurrence of subclinical low-virulence infection is difficult to diagnose. The objective of this study was to examine the hypothesis that peri-prosthetic subclinical infections may be diagnosed effectively in a murine model system using scintigraphic imaging with ^99mTc-labeled ceftizoxime.

A sample population of 3-mo old Wistar rats (mean weight 327 g) was divided randomly into a control group (n=6), which received sterile implants, and an experimental group (n=6), which received implants contaminated with Staphylococcus aureus strain ATCC6538-P. Animals were anesthetized and femoral titanium implants were fixed beneath muscle tissue in left hind limbs. Three weeks after surgery, animals were injected with ^99mTc-ceftizoxime solution (62.9 MBq) and scintigraphic images were obtained at 3.5 and 6.5 h after tracer injection.

According to the scintigraphic images, the radiopharmaceutical showed affinity for the operated thigh areas of experimental animals but not for those of the control group. There was no difference between the control and experimental groups regarding the amount of radioactivity in the regions of interest measured at 3.5 h after injection of radiolabeled antibiotic, but the between-group difference determined at 6.5 h after treatment was statistically significant (p=0.026). Moreover, the level of radioactivity recorded in resected thigh tissues derived from experimental animals was greater than that of the control group (p=0.035).

^99mTc-ceftizoxime scintigraphy can localize preferentially periprosthetic-infected areas adjacent to metal implants in a murine model. Furthermore, the radiolabeled antibiotic appears to be capable of detecting alterations in the micro-environment close to the implant and of reaching the bacteria attached to the implant surface.