Is asymptomatic bacteriuria a risk factor for prosthetic joint infection?

Should a Urinary Tract Infection Be Treated before a Total Joint Arthroplasty?

Periprosthetic joint infection (PJI) is one of the most serious complications after total joint arthroplasty (TJA). The prevalence of urinary tract infection (UTI) is common, particularly among elderly women, a group for whom TJA may be required. The association between preoperative UTI and increased risk of PJI after TJA is unclear. We reviewed key articles concerning the relationship between UTIs and PJI, and summarized recommendations of international consensus on PJI, which was established in Philadelphia in July of 2018. In addition, we distinguish between symptomatic UTI and asymptomatic bacteriuria, because their causative effects on PJI are quite different.

Pre-operative screening for asymptomatic bacteriuria and associations with post-operative outcomes in patients with spinal cord injury

CONTEXT

Screening for asymptomatic bacteriuria (ASB) before non-urologic surgery is common but of unclear benefit. Our aim was to describe pre-operative ASB screening and post-operative outcomes in patients with neurogenic bladder due to spinal cord injury (SCI).

METHODS

This was a descriptive retrospective cohort study of adults with SCI undergoing neurosurgical spine or orthopedic lower limb surgery from 10/1/2012-9/30/2014 at Veterans Affairs (VA) medical centers. National VA datasets and medical record review was used to describe frequency of pre-operative ASB screening, presence of ASB, and association with post-operative surgical site infection, urinary tract infection, and hospital readmission.

RESULTS

175 patients were included. Although over half of patients had pre-operative ASB screening, only 30.8% actually had pre-operative ASB. 15.2% of patients screened were treated for ASB with antibiotics before surgery. Post-operative urinary tract infection (UTI) or surgical site infection (SSI) occurred in 10 (5.7%) patients, and 20 patients (11.4%) were readmitted within 30 days. Neither ASB screening nor the presence of pre-operative ASB were associated with these post-op outcomes (p > 0.2 for all).

CONCLUSION

Pre-operative ASB screening is common in patients with SCI undergoing elective spine and lower limb surgery, although ASB occurs in less than 1/3rd of cases. There were no associations between pre-operative ASB and outcomes. Further studies evaluating the clinical benefit of this practice in patients with SCI should be performed.

Association of Screening and Treatment for Preoperative Asymptomatic Bacteriuria With Postoperative Outcomes Among US Veterans

Importance

Limited data suggest that screening for asymptomatic bacteriuria (ASB) prior to nonurologic procedures is not useful. However, high-quality evidence to support consensus recommendations and influence clinical practice is lacking.

Objective

To characterize the association between detection and treatment of preoperative ASB and postoperative outcomes.

Design, Setting, and Participants

This retrospective cohort study involved patients, predominantly male veterans, who underwent surgical procedures in 109 US facilities within the US Department of Veterans Affairs health care system from October 1, 2008, to September 30, 2013. Participants included patients (n = 68 265) who had cardiac, orthopedic, or vascular surgical procedures. Each received a planned clinician review of complete medical records for antimicrobial prophylaxis as well as 30-day surgical-site infection (SSI) and urinary tract infection (UTI) outcomes, and each had a preoperative urine culture result available within the 30 days prior to the procedure. Data analysis was performed from December 2016 to August 2018.

Main Outcome and Measures

The primary outcome was the association between preoperative ASB and postoperative SSI. The secondary outcomes included postoperative UTI and the association between antimicrobial therapy for ASB and postoperative infectious outcomes.

Results

In total, 68 265 patients (65 664 [96.2%] were men and 2601 [3.8%] were women, with a mean [SD] age of 64.6 [9.2] years) were identified, and 17 611 (25.8%) were eligible for inclusion in the primary analysis. Preoperative urine cultures were performed in 17 749 (26.0%) patients, and the results were positive in 755 (4.3%), of which 617 (81.7%) were classified as ASB. With adjustments for age, American Society of Anesthesiologists class, smoking status, race/ethnicity, sex, and diabetes status, patients with or without ASB had similar odds of SSI (2.4% vs 1.6%; adjusted odds ratio [aOR], 1.58; 95% CI, 0.93-2.70; P = .08). Receipt of antimicrobial therapy with activity against the ASB organism was not associated with a reduced SSI risk (aOR, 1.01; 95% CI, 0.28-3.65; P = .99). Urinary tract infection occurred in 14 (3.3%) of 423 patients with ASB and 196 (1.5%) of 12 913 patients without ASB (aOR, 1.42; 95% CI, 0.80-2.49; P = .22). Treatment or prophylaxis for the ASB organism similarly was not associated with reduced odds of postoperative UTI (aOR 0.68; 95% CI, 0.20-2.30; P = .54). The ASB organisms matched a postoperative wound culture in 2 cases, both Staphylococcus aureus.

Conclusions and Relevance

The findings of this study suggest that receipt of antimicrobial therapy with activity against ASB organisms identified in preoperative urine cultures was not associated with reductions in the risk for postoperative infections, including UTI and SSI; such findings suggest there is evidence for discontinuing the practice of screening and treatment for preoperative ASB.

Curative treatment of prosthetic joint infection in patients younger than 80 vs. 80 or older

OBJECTIVE

Prosthetic joint infection (PJI) is a serious complication of joint replacement surgery. The major pharmacological and surgical treatments required by PJI increase the risk of peri-operative complications in elderly patients. The increase in life expectancy combined with procedural advances make these treatments possible even in the oldest patients. Here, our objective was to compare the characteristics and outcomes of curative PJI treatment in patients < 80 years vs. ≥ 80 years.

METHODS

A prospective single-center design was used to compare the characteristics and outcomes of curative treatment for hip or knee PJI in patients < 80 years and ≥ 80 years admitted in 2004-2014.

RESULTS

Of 765 patients admitted for PJI, 590 were < 80 years and 124 were ≥ 80 years. Medical history and comorbidities were similar in the two groups. The older group had a significantly higher proportion of patients with American Society of Anesthesiologists Scores ≥ 3 and with streptococcal infection (20% vs. 13%, P < 0.05). After complete surgical excision and prolonged antibiotic therapy, the only event whose frequency differed significantly between the two groups was PJI-related death, which was more common in the older patients (6.5% vs. 0.8%, P < 0.05). The 2-year survival rate after one-stage exchange arthroplasty was > 90% in the  ≥80 year group.

CONCLUSION

Patients aged 80 years or older are eligible for the same curative pharmacological and surgical PJI treatments used in their younger counterparts. Before surgery, the risk/benefit ratio of the major surgical procedure required to treat PJI must be assessed on a case-by-case basis.

Potential nutraceutical and food additive properties and risks of coffee: a comprehensive overview

Coffee is a composite mixture of more than a thousand diverse phytochemicals like alkaloids, phenolic compounds, vitamins, carbohydrates, lipids, minerals and nitrogenous compounds. Coffee has multifunctional properties as a food additive and nutraceutical. As a nutraceutical, coffee has anti-inflammatory, anti-oxidant, antidyslipidemic, anti-obesity, type-2 diabetes mellitus (DM), and cardiovascular diseases (CVD), which can serve for the treatment and prevention of metabolic syndrome and associated disorders. On the other hand, as a food additive, coffee has antimicrobial activity against a wide range of microorganisms, inhibits lipid peroxidation (LPO), and can function as a prebiotic. The outcomes of different studies also revealed that coffee intake may reduce the incidence of numerous chronic diseases, like liver disease, mental health, and it also overcomes the all-cause mortality, and suicidal risks. In some studies, high intake of coffee is linked to increase CVD risk factors, like cholesterol, plasma homocysteine and blood pressure (BP). There is also a little evidence that associated the coffee consumption with increased risk of lung tumors in smokers. Among adults who consume the moderate amount of coffee, there is slight indication of health hazards with strong indicators of health benefits. Moreover, existing literature suggests that it may be cautious for pregnant women to eliminate the chances of miscarriages and impaired fetal growth. The primary purpose of this narrative review is to provide an overview of the findings of the positive impacts and risks of coffee consumption on human health. In conclusion, to date, the best available evidence from research indicates that drinking coffee up to 3-4 cups/day provides health benefits for most people.

The Impact of Common Urologic Complications on the Risk of a Periprosthetic Joint Infection

BACKGROUND

Periprosthetic infections after total hip arthroplasty (THA) or total knee arthroplasty (TKA) are substantial complications, and there are conflicting reports of their association with urologic complications. Our objective was to determine whether urinary tract infection (UTI) and acute urinary retention (AUR) are significant risk factors for joint infections after THA or TKA.

METHODS

We performed a population-based, retrospective cohort study of patients who were ≥66 years old when they underwent an initial THA or TKA between April 2003 and March 2013. Investigated exposures included a UTI presenting for treatment within 2 years after joint replacement, as well as AUR within 30 days after THA or TKA. The primary outcome was joint infection requiring hospital admission following THA or TKA (which had to occur within 2.25 years after THA or TKA for the UTI exposure or 120 days for the AUR exposure).

RESULTS

A total of 113,061 patients met the inclusion criteria and had arthroplasties (44,495 THAs and 68,566 TKAs) during the study period. The median age was 74 years (interquartile range [IQR], 70 to 79 years). Of those patients, 28,256 (25.0%) had at least 1 UTI and they were more likely to be older and female; to have had previous antibiotic exposure, cystoscopy, or urinary retention; and to have atrial fibrillation. Most of those UTIs were coded as nonspecific UTI, and the patient was seen for outpatient treatment in a non-emergency department setting. A total of 2,516 patients (2.2%) had AUR within 30 days of the procedure. Those patients were more likely to be older and male, to have medical comorbidities, to have had previous transurethral procedures or cystoscopy and previous urology visits, and to have received a general anesthetic during their procedure. A total of 1,262 patients (1.1%) had joint infection requiring hospital admission. In multivariate Cox regression analysis, UTI was associated with an increased risk of joint infection (hazard ratio [HR], 1.21 [95% confidence interval (CI), 1.14 to 1.28]; p < 0.01). However multivariate analysis did not demonstrate an association between AUR and joint infection (HR, 0.99 [95% CI, 0.60 to 1.64]; p = 0.98).

CONCLUSIONS

UTI was associated with increased risk of hip or knee periprosthetic joint infection, whereas AUR was not a significant risk factor. Timely and appropriate treatment of symptomatic UTIs in this patient population may be important to prevent periprosthetic joint infection.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Perioperative and Modifiable Risk Factors for Periprosthetic Joint Infections (PJI) and Recommended Guidelines

PURPOSE OF REVIEW

Periprosthetic joint infection (PJI) remains a complication that is associated with high morbidity as well as high healthcare expenses. The purpose of this review is to examine patient and perioperative modifiable risk factors that can be altered to help improve rates of PJI.

RECENT FINDINGS

Evidence-based review of literature shows that improved control of post-operative glycemia, appropriate management of obesity, malnutrition, metabolic syndrome, preoperative anemia, and smoking cessation can help minimize risk of PJI. Additionally, use of Staphylococcus aureus screening, preoperative evaluation of vitamin D levels, screening for urinary tract infection, and examination of dental hygiene can help with improving rates of PJI; similarly, appropriate management of perioperative variables such as limiting operating room traffic, appropriate timing, and selection of prophylactic antibiotics and surgical site preparation can help to decrease rates of PJI. In summary, PJI is a morbid complication of total joint arthroplasty. Surgeons should be vigilant of modifiable risk factors that can be improved upon to help minimize the risk of PJI.

Economic Evaluation of Antibacterial Coatings on Healthcare Costs in First Year Following Total Joint Arthroplasty

BACKGROUND

Antibacterial coatings (ABCs) of implants have proven safe and effective to reduce postsurgical infection, but little is known about their possible economic impact on large-scale use. This study evaluated the point of economic balance, during the first year after surgery, and the potential overall annual healthcare cost savings of 3 different antibacterial technologies applied to joint arthroplasty: a dual-antibiotic-loaded bone cement (COPAL G + C), an antibacterial hydrogel coating (DAC), and a silver coating (Agluna).

METHODS

The variables included in the algorithm were average cost and number of primary joint arthroplasties; average cost per patient of the ABC; incidence of periprosthetic joint infections and expected reduction using the ABCs; average cost of infection treatment and expected number of cases.

RESULTS

The point of economic balance for COPAL G + C, DAC, and Agluna in the first year after surgery was reached in patient populations with an expected postsurgical infection rate of 1.5%, 2.6%, and 19.2%, respectively. If applied on a national scale, in a moderately high-risk population of patients with a 5% expected postsurgical infection rate, COPAL G + C and DAC hydrogel would provide annual direct cost savings of approximately €48,800,000 and €43,200,000 (€1220 and €1080 per patient), respectively, while the silver coating would be associated with an economic loss of approximately €136,000,000.

CONCLUSION

This economic evaluation shows that ABC technologies have the potential to decrease healthcare costs primarily by decreasing the incidence of surgical site infections, provided that the technology is used in the appropriate risk class of patients.

Prosthetic Joint Infections: an Update

PURPOSE OF REVIEW

Prosthetic joint infection (PJI) is a rare but serious complication that is frequently misdiagnosed. We aimed to highlight the nuances of PJI diagnosis and antimicrobial therapies and provide clarity in key areas of management.

RECENT FINDINGS

Current research in PJI centers on a potential role for diagnostic biomarkers, molecular techniques, and implant sonication to reduce culture-negativity rates. The optimal duration of antimicrobial therapy remains controversial. A high clinical index of suspicion for PJI combined with data from multiple preoperative and intraoperative tests enables timely diagnosis and treatment. Biomarkers, molecular methods, and implant sonication are currently adjunctive to traditional diagnostic techniques. Shorter courses of antimicrobial therapies as well as the role of chronic suppressive therapy need confirmation by randomized controlled trials. Existing practices for preoperative dental prophylaxis and treatment of asymptomatic bacteriuria warrant revision based on evidence arguing against risk for PJI.

Urine Culture on Admission Impacts Antibiotic Use and Length of Stay: A Retrospective Cohort Study

OBJECTIVE

To examine the impact of urine culture testing on day 1 of admission on inpatient antibiotic use and hospital length of stay (LOS).

DESIGN

We performed a retrospective cohort study using a national dataset from 2009 to 2014.

SETTING

The study used data from 230 hospitals in the United States.

PARTICIPANTS

Admissions for adults 18 years and older were included in this study. Hospitalizations were matched with coarsened exact matching by facility, patient age, gender, Medicare severity-diagnosis related group (MS-DRG), and 3 measures of disease severity.

METHODS

A multilevel Poisson model and a multilevel linear regression model were used to determine the impact of an admission urine culture on inpatient antibiotic use and LOS.

RESULTS

Matching produced a cohort of 88,481 patients (n=41,070 with a culture on day 1, n=47,411 without a culture). A urine culture on admission led to an increase in days of inpatient antibiotic use (incidence rate ratio, 1.26; P<.001) and resulted in an additional 36,607 days of inpatient antibiotic treatment. Urine culture on admission resulted in a 2.1% increase in LOS (P=.004). The predicted difference in bed days of care between admissions with and without a urine culture resulted in 6,071 additional bed days of care. The impact of urine culture testing varied by admitting diagnosis.

CONCLUSIONS

Patients with a urine culture sent on day 1 of hospital admission receive more days of antibiotics and have a longer hospital stay than patients who do not have a urine culture. Targeted interventions may reduce the potential harms associated with low-yield urine cultures on day 1.

Infect Control Hosp Epidemiol 2018;39:547–554

Analysis of postoperative and hematogenous prosthetic joint-infection microbiological patterns in a large cohort

OBJECTIVES

This study was undertaken to analyze prosthetic joint infection (PJI)-causing microorganisms and compare their distribution patterns according to PJI classification.

METHODS

Cohort study from a single referral center for bone-and-joint infections from January 2004 to December 2015.

RESULTS

Nine hundred and twenty-six patients, who developed 997 PJIs, involving the hip (62%), knee (35%) and/or shoulder (1%), were included. PJIs were classified as early postoperative (19%), late chronic (30%), hematogenous (35%) and undetermined (16%). Pathogens most frequently isolated from early-postoperative PJIs were staphylococci (57%), with 25% each Staphylococcus aureus or Staphylococcus epidermidis; 21% were polymicrobial and 10% Gram-negative rods. For late-chronic PJIs, the most frequent microbes were staphylococci (61%), predominantly S. epidermidis (35%); anaerobic bacteria were isolated from 15%; 11% were polymicrobial. Hematogenous PJIs were 99% monomicrobial. Although S. aureus was the most frequently isolated species (28%), streptococci were isolated slightly more often than staphylococci (39% vs. 36%). Among streptococci, group B streptococci were the most frequent (15%). The portal of entry was identified for 52% of hematogenous PJIs: 15% cutaneous, 11% dental, 9% gastrointestinal, 6% urinary, and 11% miscellaneous.

CONCLUSION

Although a wide variety of microorganisms was isolated from PJIs, specific microbiological patterns were observed according to infection classification.

Research progress of asymptomatic bacteriuria before arthroplasty: A systematic review

BACKGROUND

A high prevalence of asymptomatic bacteriuria exists in patients prior to arthroplasty, and urinary tract infection is considered to be a source of postoperative superficial wound and prosthetic joint infections. There is no consensus whether to screen for and treat asymptomatic bacteriuria before arthroplasty.

OBJECTIVE

To summarize the association between asymptomatic bacteriuria and complications after arthroplasty and to evaluate the clinical benefits of treating asymptomatic bacteriuria prior to arthroplasty.

METHOD

We systematically searched PubMed, Embase, and the Cochrane Library to retrieve potentially eligible articles. By screening the titles and abstracts of retrieved records and then reading the full texts of the remaining papers, we finally included 8 English-language articles in this systematic review.

RESULTS

Asymptomatic bacteriuria prior to arthroplasty is significantly associated with an increased occurrence of postoperative prosthetic joint and superficial wound infections. However, there is little evidence for direct or hematogenous seeding of urinary infections, and treating asymptomatic bacteriuria before arthroplasty did not decrease the incidence of postoperative infectious complications.

CONCLUSION

Asymptomatic bacteriuria is not a contraindication for arthroplasty, and the practice of routine preoperative screening for and treatment of asymptomatic bacteriuria should not be continued.

Peri-operative antibiotic treatment of bacteriuria reduces early deep surgical site infections in geriatric patients with proximal femur fracture

PURPOSE

The aim of this study was to conduct a re-evaluation of current strategies for peri-operative prophylaxis of infections in orthopaedic surgery of geriatric patients (≥65 years) with proximal femoral fractures (PFF).

METHODS

Between 01/2010 and 08/2014 all post-operative infections after stabilization of PFF of 1,089 geriatric patients were recorded retrospectively. All patients pre-operatively received a single dose of 1.5 g cefuroxime (group 1). These were compared to prospectively determined post-operative rates of surgical site infection (SSI) of 441 geriatric patients, which were operated on between 09/2014 and 03/2017 due to PFF. In this second group we investigated the urinary tract on admission. Bacteriuria was treated with the pre-operative single dose of 1.5 g cefuroxime along with ciprofloxacin for five days, beginning on admission. Level of significance was set to p < 0.05.

RESULTS

A total of 141 patients of group 2 had a bacteriuria. Seventy-seven of these patients revealed biochemical signs of manifest urinary tract infection. Multi-resistant pathogens were found in 15 patients and pathogens were cefuroxime-resistant in 37. The differences of SSI after at least three months were 2.1% in group 1 and 0.45% in group 2 for all patients with surgery of PFF (p < 0.02) and for those with arthroplasty (p < 0.037) significant.

CONCLUSIONS

The immediate antibiotic therapy of a prevalent bacteriuria for five days decreases the risk of SSI after surgery of PFF. Our single-centre study can only point out the problem of prevalent reservoirs of pathogens and the need for treatment. Evidence-based therapy concepts (indications of antibiotics, classes, duration) have to be developed in multi-centric and prospective studies.

Chlorogenic acid (CGA): A pharmacological review and call for further research

Phenolic acids have recently gained substantial attention due to their various practical, biological and pharmacological effects. Chlorogenic Acid (CGA, 3-CQA) is a most abundant isomer among caffeoylquinic acid isomers (3-, 4-, and 5-CQA), that currently known as 5-CQA as per guidelines of IUPAC. It is one of the most available acids among phenolic acid compounds which can be naturally found in green coffee extracts and tea. CGA is an important and biologically active dietary polyphenol, playing several important and therapeutic roles such as antioxidant activity, antibacterial, hepatoprotective, cardioprotective, anti-inflammatory, antipyretic, neuroprotective, anti-obesity, antiviral, anti-microbial, anti-hypertension, free radicals scavenger and a central nervous system (CNS) stimulator. In addition, it has been found that CGA could modulate lipid metabolism and glucose in both genetically and healthy metabolic related disorders. It is speculated that CGA can perform crucial roles in lipid and glucose metabolism regulation and thus help to treat many disorders such as hepatic steatosis, cardiovascular disease, diabetes, and obesity as well. Furthermore, this phenolic acid (CGA) causes hepatoprotective effects by protecting animals from chemical or lipopolysaccharide-induced injuries. The hypocholesterolemic influence of CGA can result from the altered metabolism of nutrients, including amino acids, glucose and fatty acids (FA). The purpose of this review was to broaden the scope of knowledge of researchers to conduct more studies on this subject to both unveil and optimize its biological and pharmacological effects. As a result, CGA may be practically used as a natural safeguard food additive to replace the synthetic antibiotics and thereby reduce the medicinal cost.

Management of Asymptomatic Bacteriuria, Urinary Catheters and Symptomatic Urinary Tract Infections in Patients Undergoing Surgery for Joint Replacement: A Position Paper of the Expert Group 'Infection' of swissorthopaedics

In this position paper, we review definitions related to this subject and the corresponding literature. Our recommendations include the following statements. Asymptomatic bacteriuria, asymptomatic leukocyturia, urine discolouration, odd smell or positive nitrite sediments are not an indication for antimicrobial treatment. Antimicrobial treatment of asymptomatic bacteriuria does not prevent periprosthetic joint infection, but is associated with adverse events, costs and antibiotic resistance development. Urine analyses or urine cultures in asymptomatic patients undergoing orthopaedic implants should be avoided. Indwelling urinary catheters are the most frequent reason for healthcare-associated urinary tract infections and should be avoided or removed as soon as possible.

"Urinary Tract Infection"-Requiem for a Heavyweight

"Urinary tract infection" ("UTI") is an ambiguous, expansive, overused diagnosis that can lead to marked, harmful antibiotic overtreatment. "Significant bacteriuria," central to most definitions of "UTI," has little significance in identifying individuals who will benefit from treatment. "Urinary symptoms" are similarly uninformative. Neither criterion is well defined. Bacteriuria and symptoms remit and recur spontaneously. Treatment is standard for acute uncomplicated cystitis and common for asymptomatic bacteriuria, but definite benefits are few. Treatment for "UTI" in older adults with delirium and bacteriuria is widespread but no evidence supports the practice, and expert opinion opposes it. Sensitive diagnostic tests now demonstrate that healthy urinary tracts host a ubiquitous, complex microbial community. Recognition of this microbiome, largely undetectable using standard agar-based cultures, offers a new perspective on "UTI." Everyone is bacteriuric. From this perspective, most people who are treated for a "UTI" would probably be better off without treatment. Elderly adults, little studied in this regard, face particular risk. Invasive bacterial diseases such as pyelonephritis and bacteremic bacteriuria are also "UTIs." Mindful decisions about antibiotic use will require a far better understanding of how pathogenicity arises within microbial communities. It is likely that public education and meaningful informed-consent discussions about antibiotic treatment of bacteriuria, emphasizing potential harms and uncertain benefits, would reduce overtreatment. Emphasizing the microbiome's significance and using the term "urinary tract dysbiosis" instead of "UTI" might also help and might encourage mindful study of the relationships among host, aging, microbiome, disease, and antibiotic treatment.

Predicting lower limb periprosthetic joint infections: A review of risk factors and their classification

AIM

To undertook a systematic review to determine factors that increase a patient's risk of developing lower limb periprosthetic joint infections (PJI).

METHODS

This systematic review included full-text studies that reviewed risk factors of developing either a hip or knee PJI following a primary arthroplasty published from January 1998 to November 2016. A variety of keywords were used to identify studies through international databases referencing hip arthroplasty, knee arthroplasty, infection, and risk factors. Studies were only included if they included greater than 20 patients in their study cohort, and there was clear documentation of the statistical parameter used; specifically P-value, hazard ratio, relative risk, or/and odds ratio (OR). Furthermore a quality assessment criteria for the individual studies was undertaken to evaluate the presence of record and reporting bias.

RESULTS

Twenty-seven original studies reviewing risk factors relating to primary total hip and knee arthroplasty infections were included. Four studies (14.8%) reviewed PJI of the hip, 3 (11.21%) of the knee, and 20 (74.1%) reviewed both joints. Nineteen studies (70.4%) were retrospective and 8 (29.6%) prospective. Record bias was identified in the majority of studies (66.7%). The definition of PJI varied amongst the studies but there was a general consensus to define infection by previously validated methods. The most significant risks were the use of preoperative high dose steroids (OR = 21.0, 95%CI: 3.5-127.2, P < 0.001), a BMI above 50 (OR = 18.3, P < 0.001), tobacco use (OR = 12.76, 95%CI: 2.47-66.16, P = 0.017), body mass index below 20 (OR = 6.00, 95%CI: 1.2-30.9, P = 0.033), diabetes (OR = 5.47, 95%CI: 1.77-16.97, P = 0.003), and coronary artery disease (OR = 5.10, 95%CI: 1.3-19.8, P = 0.017).

CONCLUSION

We have highlighted the need for the provider to optimise modifiable risk factors, and develop strategies to limit the impact of non-modifiable factors.

Do Routine Preoperative and Intraoperative Urine Cultures Benefit Pediatric Vesicoureteral Reflux Surgery?

Objective. To determine if routine preoperative and intraoperative urine cultures (UCx) are necessary in pediatric vesicoureteral (VUR) reflux surgery by identifying their association with each other, preoperative symptoms, and surgical outcomes. Materials and Methods. A retrospective review of patients undergoing ureteral reimplant(s) for primary VUR at a tertiary academic medical center between years 2000 and 2014 was done. Preoperative UCx were defined as those within 30 days before surgery. A positive culture was defined as >50,000 colony forming units of a single organism. Results. A total of 185 patients were identified and 87/185 (47.0%) met inclusion criteria. Of those, 39/87 (45%) completed a preoperative UCx. Only 3/39 (8%) preoperative cultures returned positive, and all of those patients were preoperatively symptomatic. No preoperatively asymptomatic patients had positive preoperative cultures. Intraoperative cultures were obtained in 21/87 (24.1%) patients; all were negative. No associations were found between preoperative culture results and intraoperative cultures or between culture result and postoperative complications. Conclusions. In asymptomatic patients, no associations were found between the completion of a preoperative or intraoperative UCx and surgical outcomes, suggesting that not all patients may require preoperative screening. Children presenting with symptoms of urinary tract infection (UTI) prior to ureteral reimplantation may benefit from preoperative UCx.

Methicillin-resistant Staphylococcus aureus as a uropathogen in an Irish setting

Urinary tract infections are one of the most common infectious diseases diagnosed in the community and in the hospital setting. Their treatment is complicated by drug-resistant pathogens and the colonization by microbes of indwelling urinary catheters. This study assessed the occurrence and antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) uropathogens isolated for 5 consecutive years at University Hospital Waterford between 2010 and 2014. We created 4 clinically relevant subdivisions, based on urine source: hospital inpatients, patients from the Emergency Department, patients referred from their General Practitioner, and Nursing Home patients. We performed a retrospective review from the hospital's electronic microbiological system and calculated resistance rates for each of the standard antimicrobial agents. During the 5-year study period, we studied 151 urine isolates obtained from 128 patients who had an MRSA cultured in their urine sample. There was 100% resistance of all MRSA isolates to Flucloxacillin and Coamoxiclav. Ninety-eight percent of isolates were resistant to Ciprofloxacin. The resistance rate for Trimethoprim was 7.4% and there was only 2.7% resistance for Nitrofurantoin. For a clinical subset of patients, we also demonstrated 100% sensitivity for samples tested against Teicoplanin and Vancomycin. Urinary MRSA is an infrequently studied phenomenon, but with the rising trend of hospital superbugs nationally, its management is of critical importance. Suitable agents to address this within our population include Nitrofurantoin in the well patient requiring urinary MRSA eradication or Vancomycin/Teicoplanin in the unwell patient requiring intravenous therapy. In all groups, fluoroquinolones should be avoided due to significant resistance rates.

Prevention of Infection in Orthopedic Prosthetic Surgery

Total joint arthroplasty is a generally safe orthopedic procedure; however, infection is a potentially devastating complication. Multiple risk factors have been identified for development of prosthetic joint infections. Identification of patients at risk and preoperative correction of known risk factors, such as smoking, diabetes mellitus, anemia, malnutrition, and decolonization of Staphylococcus carriers, represent well-established actions to decrease the infection risk. Careful operative technique, proper draping and skin preparation, and appropriate selection and dosing of antimicrobials for perioperative prophylaxis are also very important in prevention of infection.

Prosthetic joint infection development of an evidence-based diagnostic algorithm

BACKGROUND

Increasing rates of prosthetic joint infection (PJI) have presented challenges for general practitioners, orthopedic surgeons and the health care system in the recent years. The diagnosis of PJI is complex; multiple diagnostic tools are used in the attempt to correctly diagnose PJI. Evidence-based algorithms can help to identify PJI using standardized diagnostic steps.

METHODS

We reviewed relevant publications between 1990 and 2015 using a systematic literature search in MEDLINE and PUBMED. The selected search results were then classified into levels of evidence. The keywords were prosthetic joint infection, biofilm, diagnosis, sonication, antibiotic treatment, implant-associated infection, Staph. aureus, rifampicin, implant retention, pcr, maldi-tof, serology, synovial fluid, c-reactive protein level, total hip arthroplasty (THA), total knee arthroplasty (TKA) and combinations of these terms.

RESULTS

From an initial 768 publications, 156 publications were stringently reviewed. Publications with class I-III recommendations (EAST) were considered. We developed an algorithm for the diagnostic approach to display the complex diagnosis of PJI in a clear and logically structured process according to ISO 5807.

CONCLUSIONS

The evidence-based standardized algorithm combines modern clinical requirements and evidence-based treatment principles. The algorithm provides a detailed transparent standard operating procedure (SOP) for diagnosing PJI. Thus, consistently high, examiner-independent process quality is assured to meet the demands of modern quality management in PJI diagnosis.

Antibiotic prophylaxis in orthopaedic surgery: difficult decisions in an era of evolving antibiotic resistance

Prophylactic antibiotics can decrease the risk of wound infection and have been routinely employed in orthopaedic surgery for decades. Despite their widespread use, questions still surround the selection of antibiotics for prophylaxis, timing and duration of administration. The health economic costs associated with wound infections are significant, and the judicious but appropriate use of antibiotics can reduce this risk. This review examines the evidence behind commonly debated topics in antibiotic prophylaxis and highlights the uses and advantages of some commonly used antibiotics. Cite this article: Bone Joint J 2016;98-B:1014-19.

Usefulness of Urinoculture to Patients With Dementia and Femoral Neck Fracture at Admission to Hospital: Preliminary Results

INTRODUCTION

While preoperative urinary tract infection (UTI) has the potential to cause bacteremia and postsurgical acute prosthetic joint infections (APJIs), the influence of asymptomatic bacteriuria (AB) in these infections remains unclear. So the majority of guidelines not recommend the treatment of AB prior to the surgery. However, as patients with dementia usually cannot explain the symptoms of dysuria, the differential diagnosis between AB and UTI may be very difficult in this group of patients. The principal aim of the study was to compare the rate of positive urine culture at admission in patients with femoral neck fracture with and without dementia and secondarily try to assess the connection of positive urinoculture and postoperative acute gram-negative PJI.

METHODS

All patients with a femoral neck fracture underwent a urine culture on hospital admission and were prospectively recorded. Variables such as sex, age, institutionalization, dementia and other comorbidities, PJI rate, and in-hospital death were collected. The results of cultures were retrospectively revised. Patients who received postoperative antibiotics or had been diagnosed with UTI during hospital stay were excluded. Statistical comparisons between patients with and without dementia were performed using SPSS software version 17.

RESULTS

A total of 148 patients were included (52 with dementia). The rate of positive urine culture was 32% (n = 16) in patients with dementia and 11.5% in patients without dementia (P = .003). Of these 16 patients with dementia and positive urine culture, 2 (12.5%) developed an acute gram-negative PJI, whereas there were no cases in the group without dementia (P = .011).

DISCUSSION

The only difference between UTI and AB is the expression of symptoms by the patient. However, as patients with dementia have difficulties to explain UTI symptoms, some UTI may be underdiagnosed.

CONCLUSION

Patients with dementia have a statistically higher rate of presurgical positive urine culture compared with patients without dementia.

Screening Patients Undergoing Total Hip or Knee Arthroplasty with Perioperative Urinalysis and the Effect of a Practice Change on Antimicrobial Use

OBJECTIVE

To identify predictors of treatment for urinary tract infections (UTI) among patients undergoing total hip (THA) or knee (TKA) arthroplasties and to assess an intervention based on these predictors.

DESIGN

We conducted a retrospective cohort study of 200 consecutive patients undergoing THA/TKA between February 21, 2011, and June 30, 2011, to identify predictors of treatment for UTI and a prospective cohort study of 50 patients undergoing these procedures between May 21, 2012, and July 17, 2012, to assess the association of signs or symptoms and UTI treatment. We then conducted a before-and-after study to assess whether implementing an intervention affected the frequency of treatment for UTI before or after THA/TKA.

SETTING

The orthopedics department of a university health center.

PATIENTS

Patients undergoing THA or TKA.

INTERVENTION

Surgeons revised their UTI screening and treatment practices.

RESULTS

Positive leukocyte esterase (P<.0001; P<.0001) and urine white blood cell count>5 (P=.01; P=.01) were associated with preoperative or postoperative UTI treatment. In the prospective study, 12 patients (24%) had signs and symptoms consistent with UTI. The number of patients treated for presumed UTI decreased 80.2% after the surgeons changed their practices, and surgical site infection (SSI) rates, including prosthetic joint infections (PJIs), did not increase.

CONCLUSIONS

Urine leukocyte esterase and white blood cell count were the strongest predictors of treatment for UTI before or after THA/TKA. The intervention was associated with a significant decrease in treatment for UTI, and SSI/PJI rates did not increase.

Infect Control Hosp Epidemiol 2017;38:281–286

Risk factors for deep sternal wound infection after cardiac surgery: Influence of red blood cell transfusions and chronic infection

BACKGROUND

Deep sternal wound infection (DSWI) following cardiac surgery is a serious complication, but risk factors associated with DSWI have not been fully elucidated.

METHODS

We analyzed all DSWI cases at our institution from 2010-2013 in adult cardiac median sternotomy cases, based on Society of Thoracic Surgeons or National Healthcare Safety Network definitions, but with 1-year surveillance postsurgery. Controls were matched 3:1 per case for procedure, age, and year of surgery. Demographic and operative data were pulled from Society of Thoracic Surgeons database and chart review. Potential variables were evaluated using univariate and multivariate conditional logistic regression.

RESULTS

Out of 1,894 surgeries performed, 39 DSWI cases (2%) and 117 controls were identified. In univariate analyses, patients with red blood cell (RBC) transfusion ≥ 4 units, any platelet transfusion, previous infections, and chronic infections were associated with higher DSWI. RBC transfusion ≥ 4 units (P = .037) and chronic infections (P = .029) remained significant risk factors for DSWI in multivariate analysis. Preoperative anemia alone was not associated with more DSWI, but its interaction with RBC transfusion ≥ 4 units was significant.

CONCLUSIONS

High-volume RBC transfusions and chronic infections were strongly associated with DSWI in our population and represent potentially modifiable areas for improvement.

Is Preoperative Assessment and Treatment of Asymptomatic Bacteriuria Necessary for Reducing the Risk of Postoperative Symptomatic Urinary Tract Infections After Urologic Surgical Procedures?

OBJECTIVE

To evaluate whether it is always necessary to test for the presence of asymptomatic bacteriuria (AB) in patients undergoing urologic surgical procedures, and if present, whether to treat AB with antimicrobial prophylaxis.

MATERIALS AND METHODS

All patients who underwent urologic surgical procedures from December 2008 to October 2013 in a tertiary referral urologic center were considered for this study. All patients received antimicrobial prophylaxis in line with European Association of Urology guidelines on urologic infections. AB was diagnosed if ≥10⁵ colony-forming units/mL were cultured. The population was subdivided into 2 groups: group A, patients with preoperative AB, and group B, patients without AB. Data on postoperative symptomatic urinary tract infections (UTIs) were compared for the 2 groups.

RESULTS

A total of 2201 patients were considered eligible for this study and were analyzed; 668 (30.4%) patients were found to harbor AB (group A), and 1533 (69.6%) patients did not have AB (group B). Microbiologically verified symptomatic postoperative UTIs occurred in 198 patients (8.9%). No difference in terms of overall rate of postoperative symptomatic UTI was found between the 2 groups (group A: 70 [10.4%] and group B: 128 [8.3%]; OR: 1.28 95%CI 0.94-1.74; P = .12), as well as in terms of urosepsis (group A: 2 [0.30%] and group B: 4 [0.26%]; P = 1.0).

CONCLUSION

In patients undergoing urologic surgical procedures who are receiving antimicrobial prophylaxis in accordance with European Association of Urology guidelines, the preoperative presence of AB in this study was not associated with a higher incidence of postoperative symptomatic UTI.

Avoiding Unnecessary Preoperative Testing

Given the low-risk nature of cataract surgery, no preoperative testing is indicated unless the patient needs it for another reason. Although electrocardiograms may have a role in preoperative testing in patients at high risk of cardiovascular disease, or if the procedure carries with it significant operative risks, they are often unnecessary. Urinalysis and coagulation studies not should be routine because they have not shown any value in predicting complications. Although these tests are not individually expensive, the aggregate cost is substantial. As good stewards of the medical system, physicians need to use these tests more judiciously.

Risk factors for periprosthetic joint infection following primary total hip or knee arthroplasty: a meta-analysis

To identify risk factors for periprosthetic joint infection following primary total joint arthroplasty, a systematic search was performed in Pubmed, Embase and Cochrane library databases. Pooled odds ratios (ORs) or standardised mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. Patient characteristics, surgical-related factors and comorbidities, as potential risk factors, were investigated. The main factors associated with infection after total joint arthroplasty (TJA) were male gender (OR, 1·48; 95% CI, 1.19-1.85), age (SMD, -0·10; 95% CI, -0.17--0.03), obesity (OR, 1·54; 95% CI, 1·25-1·90), alcohol abuse (OR, 1·88; 95% CI, 1·32-2·68), American Society of Anesthesiologists (ASA) scale > 2 (OR, 2·06; 95% CI, 1·77-2·39), operative time (SMD, 0·49; 95% CI, 0·19-0·78), drain usage (OR, 0·36; 95% CI, 0·18-0·74), diabetes mellitus (OR, 1·58; 95% CI, 1·37-1·81), urinary tract infection (OR, 1·53; 95% CI, 1.09-2.16) and rheumatoid arthritis (OR, 1·57; 95% CI, 1·30-1·88). Among these risk factors, ASA score > 2 was a high risk factor, and drain usage was a protective factor. There was positive evidence for some factors that could be used to prevent the onset of infection after TJA.

Discontinuation of peri-operative gentamicin use for indwelling urinary catheter manipulation in orthopaedic surgery

BACKGROUND

Gentamicin has historically been used prior to insertion and removal of indwelling urinary catheters (IDCs) around elective joint replacement surgery to prevent infection; however, this indication is not recognized in the Australian Therapeutic Guidelines: Antibiotic and the paradigm for safe use of gentamicin has shifted.

METHODS

The antimicrobial stewardship team of a 500 bed tertiary regional hospital performed a retrospective clinical study of gentamicin IDC prophylaxis around total hip and knee arthroplasties. Results were presented to the orthopaedic surgeons. A literature review identified no guidelines to support gentamicin prophylaxis and only a very low risk of bacteraemia associated with IDC insertion/removal in patients with established bacteriuria. Consensus was reached with the surgeons to discontinue this practice. Subsequent prospective data collection was commenced to determine effectiveness, with weekly feedback to the Department Head of Orthopaedics.

RESULTS

Data from 137 operations pre-intervention (6 months) were compared with 205 operations post-intervention (12 months). The median patient age was 72 years in both groups. Following the intervention, reductions in gentamicin use were demonstrated for IDC insertion (59/137 (42%) to 4/205 (2%), P < 0.01) and removal (39/137 (28%) to 6/205 (3%), P < 0.01). No gentamicin use was observed during the final 40 weeks of the post-intervention period. There were no significant differences between the groups for pre-operative bacteriuria, surgical site infections or acute kidney injury.

CONCLUSION

A collaborative approach using quality improvement methodology can lead to an evidence-based reappraisal of established practice. Regular rolling audits and timely feedback were useful in sustaining change.

What is the role of catheter antibiotic prophylaxis for patients undergoing joint arthroplasty?

BACKGROUND

Antimicrobial prophylaxis at the time of urinary catheter insertion and removal is commonly administered in patients undergoing joint arthroplasty, despite the lack of evidence to support this practice. The rationale is the theoretical risk of prosthetic joint infection arising from bacterial seeding from the urinary tract at the time of catheterization. In an era of antimicrobial stewardship, further assessment is warranted.

METHODS

This study aimed to investigate the incidence of catheter-associated (CA) bacteriuria and bacteraemia in patients undergoing total joint arthroplasty and to assess the antimicrobial susceptibility of any isolated microorganisms. This prospective observational study undertaken over a 6-month period (May to October 2014) included 99 patients undergoing elective primary hip and knee arthroplasty at St Vincent's Hospital, Melbourne. Urine specimens were collected at insertion and removal of urinary catheters along with blood cultures upon urinary catheter removal.

RESULTS

Overall 98% of the cohort received catheter antimicrobial prophylaxis for urinary catheter insertion and removal; the majority of patients received gentamicin (94%). Bacteriuria on catheter insertion had an incidence of 4.4%. The incidence of CA bacteriuria was 1.3%. All cultured organisms were sensitive to commonly used antibiotics including cephazolin. There were no cases of bacteraemia with urinary catheter removal. Increasing age, American Society of Anesthesiologists status and female gender were associated with the development of bacteriuria.

CONCLUSION

The incidence of CA bacteriuria and bacteraemia with antimicrobial prophylaxis is low. This study provokes discussion about the requirement of catheter prophylaxis in this surgical context and the utility of preoperative urine screening.

The Paradigm Shift to Non-Treatment of Asymptomatic Bacteriuria

Asymptomatic bacteriuria, also called asymptomatic urinary infection, is a common finding in healthy women, and in women and men with abnormalities of the genitourinary tract. The characterization and introduction of the quantitative urine culture in the 1950s first allowed the reliable recognition of asymptomatic bacteriuria. The observations that a substantial proportion of patients with chronic pyelonephritis at autopsy had no history of symptomatic urinary infection, and the high frequency of pyelonephritis observed in pregnant women with untreated asymptomatic bacteriuria, supported a conclusion that asymptomatic bacteriuria was harmful. Subsequent screening and long term follow-up programs for asymptomatic bacteriuria in schoolgirls and women reported an increased frequency of symptomatic urinary tract infection for subjects with asymptomatic bacteriuria, but no increased morbidity from renal failure or hypertension, or increased mortality. Treatment of asymptomatic bacteriuria did not decrease the frequency of symptomatic infection. Prospective, randomized, comparative trials enrolling premenopausal women, children, elderly populations, patients with long term catheters, and diabetic patients consistently report no benefits with antimicrobial treatment of asymptomatic bacteriuria, and some evidence of harm. Several studies have also reported that antimicrobial treatment of asymptomatic bacteriuria increases the short term risk of pyelonephritis. Current investigations are exploring the potential therapeutic intervention of establishing asymptomatic bacteriuria with an avirulent Escherichia coli strain to prevent symptomatic urinary tract infection for selected patients.

Innate immune evasion of Escherichia coli clinical strains from orthopedic implant infections

Escherichia coli is one of the first causes of Gram-negative orthopedic implant infections (OII). Those infections, usually hematogenous, mostly originate from the urinary tract. We investigated the strategies developed by E. coli in this context to evade host innate immune responses, i.e. complement and polymorphonuclear neutrophils (PMN). Twenty strains from OII were compared with 20 strains from bacteremia in patients with non-infected orthopedic implant. In both groups, 6/20 (30 %) strains lysed PMNs, due to the production of the pore-forming toxin α-hemolysin (HlyA). For the others, resistance to phagocytic killing by PMN was not significantly different between both groups. In contrast, resistance to complement-mediated serum killing was significantly higher in OII strains than in the others (65 % vs 10 %; P <0.001). In E. coli, different mechanisms have been involved in complement resistance. Here, serum resistance was not linked to a group 2 capsule, or a loss of outer membrane permeability, or the recruitment of the complement inhibitor C4bp, but was significantly associated with the synthesis of long-chain LPS, regardless of the O-antigen. Thus, serum resistance could promote seeding of peri-implant tissues by helping E. coli to either persist in blood and reach the site of infection or overcome localized complement activation.

Increased infection risk after hip hemiarthroplasty in institutionalized patients with proximal femur fracture

In patients undergoing hip hemiarthroplasty (HHA) secondary to proximal femur fracture, acute periprosthetic joint infection (PJI) is one of the most important complications. We have detected an increased risk of PJI in chronic institutionalized patients (CIPs), and a higher number of early postoperative infections are caused by Gram-negative bacteria (GNB), not covered by the current prophylaxis (cefazolin in noninstitutionalized patients (NIPs) and cotrimoxazole in CIPs). We sought to compare infection characteristics between NIPs and CIPs, analyzing predisposing factors, causative pathogens, and antibiotic prophylaxis-related microbiological characteristics. We performed a retrospective review of our prospective institutional database to identify all patients consecutively admitted for HHA to treat proximal femur fracture at our centre between 2011 and 2013. PJI was diagnosed in 21 of 381 (5.51%) patients, with 10 of 105 (9.52%) in the CIP group and 11 of 276 (3.99%) in the NIP group, and statistical significance was achieved. GNB accounted for PJI in 14 (66.67%) patients. We detected a single case of methicillin-resistant Staphylococcus aureus (MRSA) infection in the NIP group. We confirm a higher risk of acute PJI among institutionalized patients, commonly caused by Gram-negative microorganisms, which are not covered by the current prophylaxis. New prophylactic strategies should be investigated in order to reduce this problem.

Patient-specific risk factors for infection in arthroplasty procedure

All patients are not equally at risk when it comes to postoperative infections, whether the risks are related to the environment or the patient. Patient-specific infection risk factors for arthroplasty should be a focal point during the preoperative consultation as they impact the treatment decision. Eighty percent of patients have at least one modifiable infection risk factor. These risk factors must be corrected preoperatively whenever possible so that the patient is operated under the best possible conditions, with the lowest possible infection risk. The screenings and preoperative preparations are multidisciplinary but must also involve the patient. The information provided to the patient must match the patient's infectious risk profile. This lecture will review every infection risk factor, whether it is modifiable or not, and then suggest how the treatment decision should be adapted to each patient's infection risk.

Asymptomatic Bacteriuria in Clinical Urological Practice: Preoperative Control of Bacteriuria and Management of Recurrent UTI

Asymptomatic bacteriuria (ABU) is a common clinical condition that often leads to unnecessary antimicrobial use. The reduction of antibiotic overuse for ABU is consequently an important issue for antimicrobial stewardship and to reduce the emergence of multidrug resistant strains. There are two issues in everyday urological practice that require special attention: the role of ABU in pre-operative prophylaxis and in women affected by recurrent urinary tract infections (rUTIs). Nowadays, this is the time to think over our practice and change our way of thinking. Here, we aimed to summarize the current literature knowledge in terms of ABU management in patients undergoing urological surgery and in patients with rUTIs. In the last years, the approach to patient with ABU has changed totally. Prior to all surgical procedures that do not enter the urinary tract, ABU is generally not considered as a risk factor, and screening and treatment are not considered necessary. On the other hand, in the case of all procedures entering the urinary tract, ABU should be treated in line with the results of a urine culture obtained before the procedure. In patients affected by rUTIs, ABU can even have a protective role in preventing symptomatic recurrence, particularly when Enterococcus faecalis (E. faecalis) has been isolated.