Bacteremia in hemodialysis patients

Bloodstream infections: trends and evolution of incidence and etiology in a 12-year period (2010-2021)

INTRODUCTION

The epidemiological evolution of bloodstream infections (BSIs) in the last decade is not clearly defined. Our aim was to analyze the changes in the workload in our institution and to describe the evolution of the incidence and etiology of BSIs in a 12-year period, including the COVID-19 pandemic.

METHODS

All blood cultures received in the laboratory of a tertiary general hospital between 2010 and 2021 were analyzed. Bloodstream infection episodes refer to each episode of bacteremia or fungemia in each patient. Incidence rates per 1000 admissions and per 100,000 population were calculated.

RESULTS

No significant changes in the incidence of BSI episodes/1000 admissions were observed (mean, 31.1), while estimated population-based incidences showed declining trends (mean, 182.8/100,000 inhabitants). There was a slight increase in BSI episodes per 1000 admissions caused by Gram-negatives (mean, 16.6/1000 admissions) and E. coli was the most frequent pathogen (mean, 8.5/1000 admissions). There was no significant rise in episodes caused by ESBL- and carbapenemase-producing E. coli or K. pneumoniae, with a decline in those caused by methicillin-resistant S. aureus. A spike in BSI episodes, fungal BSIs and catheter-related infections was detected in 2020, during the COVID-19 outbreak.

CONCLUSIONS

No clear increase in the incidence of BSI episodes was detected in our center over this period. Gram-negatives are the most frequent etiology, with no clear rise in antimicrobial resistance phenotypes. The COVID-19 pandemic accounted for a small increase in BSI episodes in 2020, probably related to the increase of catheter-related infections.

Hereditary Hemorrhagic Telangiectasia in a Patient Undergoing Hemodialysis with Anticoagulants and Antiplatelets

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder that causes abnormal blood vessel formation and bleeding. We herein report a 61-year-old woman with aggravated HHT symptoms after hemodialysis initiation. She was diagnosed with HHT based on her recurrent bleeding, abnormal blood vessel formation, and family history. Despite bleeding complications, the patient required anticoagulants and antiplatelet agents to treat cardiovascular complications. Eventually, the patient died of extensive cerebral hemorrhaging. Our experience suggests that special attention should be paid to bleeding complications in high-risk patients.

The Assessment of Infection Risk in Patients with Vitiligo Undergoing Dialysis for End-Stage Renal Disease: A Retrospective Cohort Study

Vitiligo is an autoimmune condition that causes patchy skin depigmentation. Although the mechanism by which vitiligo induces immunocompromise is unclear, other related autoimmune diseases are known to predispose those affected to infection. Individuals with vitiligo exhibit epidermal barrier disruption, which could potentially increase their susceptibility to systemic infections; patients with renal disease also show a predisposition to infection. Nevertheless, there is little research addressing the risk of infection in dialysis patients with vitiligo in comparison to those without it. A retrospective analysis was performed on patients with end-stage renal disease (ESRD) in the United States Renal Data System who started dialysis between 2004 and 2019 to determine if ESRD patients with vitiligo are at an increased risk of bacteremia, cellulitis, conjunctivitis, herpes zoster, or septicemia. Multivariable logistic regression modeling indicated that female sex, black compared to white race, Hispanic ethnicity, hepatitis C infection, and tobacco use were associated with an enhanced risk of vitiligo, whereas increasing age and catheter, versus arteriovenous fistula, and access type were associated with a decreased risk. After controlling for demographics and clinical covariates, vitiligo was found to be significantly associated with an increased risk of bacteremia, cellulitis, and herpes zoster but not with conjunctivitis and septicemia.

Catheter-Related Bloodstream Infections among patients on maintenance haemodialysis: a cross-sectional study at a tertiary hospital in Ghana

BACKGROUND

Catheter-Related Bloodstream Infections (CRBSIs) are notable complications among patients receiving maintenance haemodialysis. However, data on the prevalence of CRBSIs is lacking. This study was conducted to determine the prevalence and factors associated with CRBSIs among patients receiving haemodialysis in the renal unit of the largest tertiary hospital in Ghana.

METHODS

A hospital-based cross-sectional study was conducted on patients receiving maintenance haemodialysis via central venous catheters (CVC) between September 2021 and April 2022. Multivariate analysis using logistic regression was used to determine the risk factors that were predictive of CRBSI. Analysis was performed using SPSS version 23 and a p-value<0.05 was statistically significant.

RESULTS

The prevalence of CRBSI was 34.2% (52/152). Of these, more than half of them (53.9%(28/52)) had Possible CRBSI while 11.5% (6/52) had Definite CRBSI. Among the positive cultures, 62% (21/34) were from catheter sites whilst the rest were from peripheral blood. Gram-negative cultures made up 53% (18/34) of positive cultures with the rest being Gram positive cultures. Acinetobacter baumannii (33.3% (6/18)) was the commonest organism isolated among Gram-negative cultures whilst Coagulase negative Staphylococci (43.7% (7/16)) was the commonest organism isolated among Gram-positve cultures. Gram-negative bacilli were more predominant in this study making up 52.9% of the total bacteria cultured. Sex, duration of maintenance dialysis, underlying cause of End-stage kidney disease, mean corpuscular haemoglobin (MCH), neutrophil count and lymphocyte count were significantly predictive of CRBSI status (p<0.05).

CONCLUSION

There was a high prevalence of CRBSI among patients undergoing haemodialysis. The commonest causative agent was Coagulase negative Staphylococci, however there was a predominance of Gram-negative bacilli as compared to Gram positive cocci. There is a need to set up infection surveillance unit in the renal unit to track CRBSI and put in place measures to reduce these CRBSI.

Assessment of Bacterial Infections and Antibiotic Regimens in Intravenous Drug Users

Bacterial infections in people who inject drugs (PWID) are a significant cause of hospitalizations and increased morbidity in this group. In this review, we evaluated bacterial trends in the most common infections and appropriate empiric antibiotic coverage. Articles from PubMed and Google Scholar were curated in a Google document with shared access. Discussion and development of the paper were achieved over Zoom meetings. The common infections in PWID were skin and soft tissue infections (SSTIs), infective endocarditis, septic arthritis, osteomyelitis, and bloodstream infections (BSIs). The presence of comorbidities increased susceptibility to bacterial infections. Staphylococcus aureus was the predominant species in all the infections and included methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). The current standard of antibiotic use for Staphylococcus species was found to be sufficient. The gram-negative bacillus Serratia marcescens was prevalent in PWID as a causative agent of septic arthritis, osteomyelitis, and infective endocarditis. Its treatment required a combination of β-lactam and either a fluoroquinolone or an aminoglycoside for a prolonged duration. Streptococci were commonly implicated in SSTIs and BSIs. The appropriate response was seen with β-lactam antibiotics. In PWID, Enterococcus and Pseudomonas were implicated in infective endocarditis of native and prosthetic valves. The former being difficult to treat, a new strategy of using dual β-lactam antibiotics was found to be supported by clinical data. Anti-pseudomonal antibiotics can be avoided in other infections seen in this group, as their prevalence was low. PWID, especially those with comorbidities, have an increased risk of acquiring infections with difficult-to-treat microbes. Therefore, empiric antibiotic treatment should be relevant to the infection, for which bacterial trends and antibiotic susceptibility must be reassessed periodically.

Knee and hip arthroplasty joint surgical site wound infection in end-stage renal disease subjects who underwent dialysis or a kidney transplant: A meta-analysis

A meta-analysis study to assess the knee and hip arthroplasty joint surgical site wound infection (SSWI) in end-stage renal disease (ESRD) subjects who underwent dialysis or a kidney transplant (KT). A comprehensive literature examination till February 2023 was implemented and 1046 linked studies were appraised. The picked studies contained 5 471 898 subjects with total joint arthroplasty (TJA) at the baseline, 13 049 of them were haemodialysis or renal transplant, and 5 458 849 were control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of knee and hip arthroplasty SSWI in ESRD subjects who underwent dialysis or a KT by the dichotomous and continuous styles and a fixed or random model. Haemodialysis or renal transplant had a significantly higher postoperative SSWI (OR, 2.13; 95% CI, 1.73-2.62, P < .001) compared with control in TJA subjects. However, no significant difference was observed between haemodialysis and renal transplant in postoperative SSWI (OR, 0.93; 95% CI, 0.16-5.54, P = .94) and between haemodialysis or renal transplant and control in prosthetic joint infection (OR, 1.07; 95% CI, 0.25-4.55, P = .93) in TJA subjects. Haemodialysis had a significantly higher prosthetic joint infection (OR, 1.92; 95% CI, 1.21-3.03, P = .005) compared with renal transplant in TJA subjects. Haemodialysis or renal transplant had a significantly higher postoperative SSWI in TJA subjects. Also, haemodialysis had a significantly higher prosthetic joint infection compared with renal transplant in TJA subjects. Although precautions should be taken when commerce with the consequences because a low number of selected studies was picked for certain comparisons in this meta-analysis.

Practices, Knowledge, and Attitudes of Nephrologists Towards Prescribing and Monitoring Vancomycin at Dialysis Centers

BACKGROUND

Vancomycin dosing protocols are varied in the literature for hemodialysis patients. This study sought to determine nephrologists' practices, knowledge, attitudes, and barriers toward prescribing and monitoring vancomycin at dialysis centers.

METHODS

A cross-sectional and multi-center study was conducted in Kuwait using a validated self-administered questionnaire among 168 nephrologists. Descriptive and comparative analyses were performed using SPSS (version 28).

RESULTS

The response rate was 75% (n = 126). Over half of nephrologists frequently prescribed a vancomycin loading dose of 1000 mg (53.2%) and a maintenance dose of 500 mg (51.6%) to all patients. Their overall median (IQR) percentage knowledge about the therapeutic monitoring of vancomycin was 66.7% (33.3) and was found to be higher in nephrologists aged ≤ 40 years and in registrars/senior registrars (p < 0.05). Their overall median (IQR) attitude score was 4.0 (1.0) [positive attitude]. Nephrologists with > 15 years of practice experience expressed higher attitudes (p < 0.05). The top two perceived barriers were a lack of clear local hospital/national guidelines (60.3%) for vancomycin dosing in dialysis and inconsistencies among different dosing references and guidelines (51.6%).

CONCLUSION

Findings showed that nephrologists have varying practices, moderate knowledge, and positive attitudes toward prescribing and monitoring vancomycin and highlight the need for interventions to overcome the perceived barriers.

Access- and non-access-related infections among patients receiving haemodialysis: Experience of an academic centre in Oman

Objective

The aim of this study was to examine the epidemiology of access and non-access-related infections in patients receiving haemodialysis at an academic tertiary hospital in Oman.

Methods

This was a retrospective observational study of 287 hospitalized patients who received haemodialysis during the period January 2018 to December 2019 at Sultan Qaboos University Hospital, Muscat, Oman.

Results

A total of 202 different infections were documented in 142 of the 287 patients (49.5%). Pneumonia was the most common infection in the patients examined, accounting for 24.8% (50/202) of the total infections. This was followed by bloodstream infections, with a prevalence of 19.8% (40/202). Klebsiella pneumoniae was the most prevalent isolate (19.0%; 47/248). The highest number of multidrug-resistant infections were caused by multidrug-resistant K. pneumoniae (29.9%; 23/77).

Conclusions

Infections in patients undergoing haemodialysis are common and are dominated by non-access-related infections. Pneumonia was found to be the most prevalent infection in this population. Gram-negative bacteria, predominantly K. pneumoniae, were the most prevalent isolates. The study reported an alarming number of multidrug-resistant organisms, accounting for 31.0% of the total bacterial isolates from various clinical specimens.

Microbiota analysis in the hemodialysis population - Focusing on Enterobacteriaceae

BACKGROUND

Infection is a recognized risk factor for mortality among hemodialysis (HD) population, including infection caused by Enterobacteriaceae. We aimed to investigate Enterobacteriaceae in gut microbiota among HD patients and to analyze associations between microbiota and clinical parameters.

METHODS

This prospective study of microbiota analysis in HD patients was conducted in April-May 2019. A control group without recent antibiotic use or hospitalization was used for comparison. Stool samples underwent 16S rRNA sequencing, using Greengenes 16S rRNA database for microbiota analysis.

RESULTS

Among 96 hemodialysis (HD) patients, mean age was 61.9 ± 0.8 years and mean duration of HD was 6.5 ± 0.7 years. No significant differences were found in alpha diversity between HD and control groups (HD group 949.5, controls 898; p = 0.16) although significant between-group differences were found in beta diversity (p < 0.001). At phylum level, HD group had a higher abundance of Firmicutes and Proteobacteria, but lower abundance of Bacteriodetes. At genus level, Escherichia-Shigella complex increased among HD patients who had hospitalization with 1 year (median 0.024 vs 0.004, p = 0.054) and Klebsiella was associated with emergency room visit within 1 year among HD patients (p = 0.002).

CONCLUSIONS

Alpha diversity in HD patients is not lower than that in healthy controls but significant between-group differences are found in microbiota composition according to beta diversity, due to decreased Bacteriodetes and increased Firmicutes and Proteobacteria. Deeper microbiota analyses for Enterobacteriaceae are necessary. Whether change in dietary components can help to decrease mortality among dialysis population warrants further research.

Antimicrobial stewardship in solid organ transplant-Opportunities in the National Health Service

BACKGROUND

Antimicrobial stewardship (AMS) is an intervention, which ensures the appropriateness of antimicrobial use to avoid in part the rising problem of antimicrobial resistance and negative effects of inappropriate antimicrobial use. In the solid organ transplant (SOT) population, which is prone to a particularly high risk of infection resulting from immunosuppression and anatomical issues with each type of SOT, the need for good stewardship has never been more important. This article looks at current AMS practice in SOT units in the United Kingdom and how things could be improved in the future.

METHODS

The current practice of AMS alongside national antimicrobial resistance rates were reviewed using national mandatory reporting data. The background to the current practice and policies in place in the National Health Service (NHS) were also reviewed and possibilities for future approaches explored.

RESULTS

AMS is a requirement within all NHS hospitals in the United Kingdom as per government policy. Mandatory reporting of specific bloodstream infections (BSIs) and antimicrobial consumption alongside financial incentives has been the approach nationwide. Gram-negative resistance rates in BSIs have been increasing prior to the COVID-19 pandemic. Little SOT-specific data on antimicrobial resistance exists, and the general approach to AMS in SOT units has generally modeled the national approach.

CONCLUSION

Although there is a good, standardized approach to AMS in the NHS, there is a need for SOT-specific AMS approaches to be developed in the United Kingdom. More data is required on antimicrobial resistance rates, and studies are needed to investigate optimal antimicrobial prophylaxis regimens for each solid organ group. Tools to aid AMS efforts and novel treatment options for complex multiresistant infection must also be explored amongst transplant centers.

Polyarticular Sepsis Secondary to Staphylococcus aureus Bacteremia Post-acute Hemodialysis: A Case Report

Polyarticular septic arthritis (PASA) is less common than monoarticular septic arthritis (MASA). There is a low incidence of PASA in immunocompetent patients. This case report describes the development of PASA after hemodialysis through the permcath after a single session.

Dysnatremia and risk of bloodstream infection in dialysis patients

Background

Emerging data suggest that sodium disarrays including hyponatremia are potential risk factors for infection ensuing from impairments in host immunity, which may be exacerbated by coexisting conditions (i.e. mucosal membrane and cellular edema leading to breakdown of microbial barrier function). While dysnatremia and infection-related mortality are common in dialysis patients, little is known about the association between serum sodium levels and the risk of bloodstream infection in this population.

Methods

Among 823 dialysis patients from the national Biospecimen Registry Grant Program who underwent serum sodium testing over the period January 2008–December 2014, we examined the relationship between baseline serum sodium levels and subsequent rate of bloodstream infection. Bloodstream infection events were directly ascertained using laboratory blood culture data. Associations between serum sodium level and the incidence of bloodstream infection were estimated using expanded case mix–adjusted Poisson regression models.

Results

In the overall cohort, ∼10% of all patients experienced one or more bloodstream infection events during the follow-up period. Patients with both lower sodium levels <134 mEq/l and higher sodium levels ≥140 mEq/l had higher incident rate ratios (IRRs) of bloodstream infection in expanded case mix analyses (reference 136–<138 mEq/l), with adjusted IRRs of 2.30 [95% confidence interval (CI) 1.19–4.44], 0.77 (95% CI 0.32–1.84), 1.39 (95% CI 0.78–2.47), 1.88 (95% CI 1.08–3.28) and 1.96 (95% CI 1.08–3.55) for sodium levels <134, 134–<136, 138–<140, 140–<142 and ≥142 Eq/l, respectively.

Conclusions

Both lower and higher baseline serum sodium levels were associated with a higher rate of subsequent bloodstream infections in dialysis patients. Further studies are needed to determine whether correction of dysnatremia ameliorates infection risk in this population.

Antibiotics Utilization Patterns and Dosage Appropriateness among Patients Receiving Hemodialysis

Chronic kidney disease (CKD) is a global health challenge, with a reported prevalence of around 10%. Prescribing for patients receiving hemodialysis (HD) is challenging and complicated by polypharmacy, comorbidities, and changes in clearance of medications. The aim of this study was to evaluate antibiotics utilization patterns and dosage appropriateness in patients receiving HD at a tertiary hospital. A retrospective study was carried on 287 adult inpatients, who received HD and at least one antibiotic in a tertiary hospital in Oman. Data were extracted using the hospital’s electronic patient information system. Dosage appropriateness was assessed by identifying the dosage and frequency of prescribed antibiotics and comparing them with international guidelines. The main outcome measures were antibiotics utilization patterns and dosing inappropriateness. The most commonly prescribed parenteral antibiotic was piperacillin + tazobactam (20%), while the most common prescribed oral antibiotic was azithromycin (41.7%). For prophylaxis, cefazolin (54.6%) was the main antibiotic prescribed. The most commonly used antibiotic for external use was mupirocin ointment (38.5%). The overall dosing inappropriateness was 29.5%. Vancomycin was the most common parenteral antibiotic subjected to dosing inappropriateness (19.8%). However, trimethoprim + sulfamethoxazole was more inappropriately prescribed among the oral route (28.6%).

In conclusion, the most utilized antibiotic was piperacillin + tazobactam followed by vancomycin. The study reported some inappropriate dosing of antibiotics. Such a study opens the door for the establishment of local guidelines for the improved practice of antibiotics use in HD patients.

Clinical Characteristics and In-Hospital Outcomes in Dialysis Patients with Septic Arthritis

Background and Objectives: Septic arthritis is a medical emergency associated with high morbidity and mortality. The incidence rate of septic arthritis among dialysis patients is higher than the general population, and dialysis patients with bacteremia frequently experience adverse outcomes. The aim of this study was to identify the clinical features and risk factors for longer hospital length of stay (LOS), positive blood culture, and in-hospital mortality in dialysis patients with septic arthritis. Materials and Methods: The medical records of 52 septic arthritis dialysis patients admitted to our hospital from 1 January 2009 to 31 December 2020 were analyzed. The primary outcomes were bacteremia and in-hospital mortality. Variables were compared, and risk factors were evaluated using linear and logistic regression models. Results: Twelve (23.1%) patients had positive blood cultures. A tunneled cuffed catheter for dialysis access was used in eight (15.4%) patients, and its usage rate was significantly higher in patients with positive blood culture than in those with negative blood culture (41.7 vs. 7.5%, p = 0.011). Fever was present in 15 (28.8%) patients, and was significantly more frequent in patients with positive blood culture (58.3 vs. 20%, p = 0.025). The most frequently involved site was the hip (n = 21, 40.4%). The most common causative pathogen was Gram-positive cocci, with MRSA (n = 7, 58.3%) being dominant. The mean LOS was 29.9 ± 25.1 days. The tunneled cuffed catheter was a significant predictor of longer LOS (Coef = 0.49; Cl 0.25−0.74; p < 0.001). The predictors of positive blood culture were fever (OR = 4.91; Cl 1.10−21.83; p = 0.037) and tunneled cuffed catheter (OR = 7.60; Cl 1.31−44.02; p = 0.024). The predictor of mortality was tunneled cuffed catheter (OR = 14.33; Cl 1.12−183.18; p = 0.041). Conclusions: In the dialysis population, patients with tunneled cuffed catheter for dialysis access had a significantly longer hospital LOS. Tunneled cuffed catheter and fever were independent predictors of positive blood culture, and tunneled cuffed catheter was the predictor of in-hospital mortality. The recognition of the associated factors allows for risk stratification and determination of the optimal treatment plan in dialysis patients with septic arthritis.

Diagnostic Value of Systemic Inflammatory Response Index for Catheter-Related Bloodstream Infection in Patients Undergoing Haemodialysis

Objective

This study was aimed at investigating the diagnostic value of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), C-reactive protein-to-albumin ratio (CAR), and systemic inflammatory response index (SIRI) for catheter-related bloodstream infection (CRBSI) in patients undergoing haemodialysis.

Methods

A total of 296 patients undergoing haemodialysis with vascular access were selected and divided into the infected (58 patients) and uninfected (238 patients) groups. Their aetiological and general characteristics were retrospectively collected. The NLR, PLR, CAR, and SIRI were calculated.

Results

The NLR, PLR, CAR, and SIRI values in the infected group were significantly higher than those in the uninfected group (P < 0.05). After the anti-infective treatment, the NLR, PLR, CAR, and SIRI values in patients with CRBSI were significantly decreased (P < 0.05). The NLR, CAR, and SIRI showed diagnostic efficacy in patients with CRBSI with cut-off values of 4.485 (area under the curve (AUC) = 0.827, 95%confidence interval (CI) = 0.768–0.887), 0.975 (AUC = 0.836, 95%CI = 0.779–0.892), and 3.390 (AUC = 0.947, 95%CI = 0.919–0.976). The CAR and SIRI values in patients with gram-negative bacterial infection were significantly higher than those with gram-positive bacterial infection (P < 0.05). The AUCs of CAR and SIRI were 0.693 (0.537–0.848) and 0.821 (0.700–0.942) in differentiating gram-negative and gram-positive bacterial infections, respectively.

Conclusion

Our results showed SIRI as a novel and efficient indicator for the early diagnosis of CRBSI in patients undergoing haemodialysis.

The Dilemma: Whether to Proceed or Postpone a Patient With Pyrexia at Induction of Anesthesia for Coronary Artery Bypass Graft Surgery

Routine surgery may be postponed if a patient has high white blood cells (WBC) and/or pyrexia. However, postponement carries the risk of myocardial ischaemia or infarction in a patient having coronary artery bypass graft (CABG) surgery. Our case raises this dilemma in a high-risk patient that was further compromised by acute right ventricular (RV) dysfunction. A 51-year-old diabetic with end-stage renal failure, chest pain, and a recent non-ST elevation myocardial infarction (NSTEMI) who had previously refused surgery now presented for urgent CABG. During central line insertion, he started shivering and stated that he felt cold. His temperature was not measured pre-intubation, but he felt warm to the touch with no chest pain. Blood pressure (BP) 190/80 mmHg and HR 110 bpm. Iv glyceryl nitrate (GTN) and fentanyl controlled the BP. Cerebral oximetry was used to measure brain regional saturation (rSO₂) with probes placed on the forehead pre-induction. Post-intubation his temperature was 38.1°C, end-tidal carbon dioxide (EtCO₂) 9.2 kPa, heart rate (HR) 120 bpm. His recent NSTEMI and surgical referral two years previously meant that his ischaemic risk was high, and we decided to proceed with the surgery. During the internal mammary artery (IMA) harvesting and use of a retractor (IMAR), there was a steady fall in the rSO₂ readings along with hypotension and an increase in central venous pressure (CVP) becoming critical after 60 minutes. At this point, the patient went onto cardiopulmonary bypass (CPB). The patient required triple vasoactive support to wean off CPB. In the intensive care unit (ICU), he required immediate support for RV failure, including nitric oxide. The next day, the patient grew Gram-negative blood cultures. In hindsight, we should have checked his temperature before induction and postponed or postponed post-induction. Regarding the IMAR or any retractor, the operating team will pay much closer attention to any haemodynamic changes resulting from their use and act accordingly. 

Antimicrobial activity of hemodialysis catheter lock solutions in relation to other compounds with antiseptic properties

Proper protection of vascular access after haemodialysis is one of the key measures for the prevention of catheter-related infections. Various substances with bactericidal and anticoagulant properties are used to fill catheters, but due to the unsatisfactory clinical effects and occurrence of adverse reactions, the search for new substances is still ongoing. In the present paper, we compared the in vitro antimicrobial activity of solutions used for tunnelled catheter locking (taurolidine, trisodium citrate) and solutions of substances that could potentially be used for this purpose (sodium bicarbonate, polyhexanide-betaine). The studies have been conducted on bacteria that most commonly cause catheter-related infections. The values of both minimum inhibitory concentration and minimum biofilm eradication concentration of the substances were determined. The ability of the tested substances to eradicate biofilm from the dialysis catheter surface was also evaluated. The results showed that polyhexanide-betaine inhibited the growth of all microbes comparably to taurolidine, even after ≥ 32-fold dilution. The activity of trisodium citrate and sodium bicarbonate was significantly lower. Polyhexanide exhibited the highest activity in the eradication of bacterial biofilm on polystyrene plates. The biofilm formed on a polyurethane dialysis catheter was resistant to complete eradication by the test substances. Polyhexanide-betaine and taurolidine showed the highest activity. Inhibition of bacterial growth regardless of species was observed not only at the highest concentration of these compounds but also after dilution 32-128x (taurolidine) and 32-1024x (polyhexanide-betaine). Therefore, it can be assumed that taurolidine application as a locking solution prevents catheter colonization and systemic infection development. Taurolidine displays high antimicrobial efficacy against Gram-positive cocci as well as Gram-negative bacilli. On the contrary, the lowest antibacterial effect displayed product contained sodium bicarbonate. The inhibitions of bacterial growth were not satisfactory to consider it as a substance for colonization prevention. Polyhexanidine-betaine possessed potent inhibitory and biofilm eradication properties comparing to all tested products. PHMB is applied as a wound irrigation solution worldwide. However, based on our results, we assume that the PHMB is a promising substance for catheter locking solutions thanks to its safety and high antimicrobial properties.

Dialysis patients have comparable results to patients who have received kidney transplant after total joint arthroplasty: a systematic review and meta-analysis

Patients with end-stage renal disease (ESRD) have inferior outcomes after hip and knee total joint arthroplasty (TJA), with higher risk for surgical site complications (SSC) and periprosthetic joint infection (PJI).

We conducted a systematic review and meta-analysis regarding outcomes after hip and knee TJA in ESRD patients who have received dialysis or a kidney transplant (KT) using PubMed, MEDLINE, Cochrane Reviews, and Embase in order to: (1) determine the mortality and infection rate of TJA in patients receiving dialysis or KT and (2) to identify risk factors associated with the outcome.

We included 22 studies and 9384 patients (dialysis, n = 8921, KT, n = 463). The overall mortality rate was 14.9% and was slightly higher in KT patients (dialysis vs. KT, 13.8% vs. 15.8%). The overall SSC rate was 3.4%, while dialysis and KT patients each had an incidence of 3.3% and 3.6%, respectively. For PJI, the overall rate was 3.9%, while the incidence for dialysis patients was 4.0% and for KT patients was 3.7%.

Using multi-regression analysis, age, sex, the type of arthroplasty (knee or hip) performed, and the form of renal replacement therapy (dialysis or KT) were not significant risk factors.

In patients on dialysis or who had received a KT, TJA is associated with a slight increase in mortality, SSC and PJI rates.

Cite this article: EFORT Open Rev 2021;6:618-628. DOI: 10.1302/2058-5241.6.200116

Infective Endocarditis: A Focus on Oral Microbiota

Infective endocarditis (IE) is an inflammatory disease usually caused by bacteria entering the bloodstream and settling in the heart lining valves or blood vessels. Despite modern antimicrobial and surgical treatments, IE continues to cause substantial morbidity and mortality. Thus, primary prevention and enhanced diagnosis remain the most important strategies to fight this disease. In this regard, it is worth noting that for over 50 years, oral microbiota has been considered one of the significant risk factors for IE. Indeed, among the disparate recommendations from the American heart association and the European Society of Cardiology, there are good oral hygiene and prophylaxis for high-risk patients undergoing dental procedures. Thus, significant interest has grown in the role of oral microbiota and it continues to be a subject of research interest, especially if we consider that antimicrobial treatments can generate drug-resistant mutant bacteria, becoming a severe social problem. This review will describe the current knowledge about the relationship between oral microbiota, dental procedures, and IE. Further, it will discuss current methods used to prevent IE cases that originate from oral pathogens and how these should be focused on improving oral hygiene, which remains the significant persuasible way to prevent bacteremia and systemic disorders.

Staphylococcus aureus colonization increases the risk of bacteremia in hemodialysis patients: a molecular epidemiology approach with time-dependent analysis

BACKGROUND

Bacteremia is the second cause of death in hemodialysis patients and colonization may be a risk factor. We analyzed the association between Staphylococcus aureus or multidrug-resistant Gram-negative bacteria colonization and bacteremia in hemodialysis patients.

METHODS

A prospective cohort study was conducted. Colonization status was determined at baseline, 2, and 6 months later. The time-to-first-bacteremia was analyzed using the baseline status and time-dependent nature of colonization. The recurrence of bacteremia given colonization status was evaluated using a Poisson regression model. The genetic relatedness between isolates that colonized and caused bacteremia were established by molecular typing methods.

RESULTS

Seventy-one patients developed bacteremia over the course of follow-up, with the majority of cases being caused by S aureus (n = 28; 39.4%) and only three caused by multidrug-resistant Gram-negative bacteria. S aureus colonization was associated with an increased risk of bacteremia in time-dependent analysis (HR:4.64; 95%CI: 1.72-12.53) and with recurrence of infection in Poisson model (IRR:5.90, 95%CI: 2.29-15.16). Molecular methods revealed that 77.8% of patients with S aureus bacteremia were colonized with the same strain that caused the infection.

CONCLUSIONS

S aureus is a cause of endogenous infection in hemodialysis patients. Colonization is associated with both time-to-first-bacteremia and the recurrence of infection. The prompt identification of colonized patients and the evaluation of decolonization protocols are needed.

Epidemiology of bloodstream infections in a Scottish haemodialysis population with focus on vascular access method

BACKGROUND

Infection is the second highest cause of mortality in end-stage renal disease, with a significant proportion relating to haemodialysis (HD) vascular access-related infection (VARI).

AIM

To report the rate and antimicrobial resistance (AMR) of all-source bloodstream infections (BSIs) by vascular access type in a Scottish HD cohort.

METHODS

Retrospective analysis was undertaken of data on adult patients attending seven HD units during 2017. Total HD days for each vascular access type were calculated. BSIs were analysed with rates expressed per 1000 HD days. AMR was verified using health board microbiology databases.

FINDINGS

Excluding contaminant organisms, there was an overall BSI rate of 0.57 per 1000 HD days. The highest all-source and vascular access-related infection (VARI) BSI rates per 1000 HD days were in the non-tunnelled central venous catheter (CVC) group (3.11 and 2.07 respectively), followed by tunnelled CVC (1.10 and 0.67), arteriovenous graft (0.51 and 0.31), and finally arteriovenous fistula (0.29 and 0.02). The non-VARI BSI rates were lowest in the arteriovenous graft group. Staphylococci comprised the majority of events, with Staphylococcus aureus implicated in 29%. Gram-negative BSIs were prevalent, particularly in CVC groups, and associated with higher mortality. Multidrug-resistant (MDR) S. aureus and carbapenem resistance were relatively low. MDR Gram-negatives were high compared with the Scottish population.

CONCLUSION

Arteriovenous fistula access is confirmed as having lowest all-source and VARI BSI rates, and arteriovenous graft access the lowest non-VARI BSI rates. Staphylococci remain the prevailing genus; however, the contributions of Gram-negative BSIs, the higher mortality, and proportion of MDR organisms in this group are notable.

Fatal neck pain in a patient on maintenance hemodialysis

Infectious spondylodiscitis (IS) is defined as the pathogenic invasion of the vertebrae and intervertebral disks. It is a serious condition that can lead to many complications such as chronic pain, permanent neurological deficits, and even death. Vertebral surgical procedures, invasive urinary tract manipulations, and central line-associated bloodstream infection are the primary methods by which microorganisms reach the vertebrae and intervertebral disks. Hemodialysis (HD) patients are regularly exposed to bloodstream infections due to long-term catheter utilization or repeated vascular puncturing in patients with arteriovenous fistula. Due to the high risk of blood stream infections, HD patients have a higher risk of developing IS. Despite advanced diagnostic methods, diagnosis of spondylodiscitis is often delayed due to insidious and nonspecific symptoms, allowing dissemination of the infection, which explains the high level of mortality due to spondylodiscitis in HD patients. The infectious process typically occurs in the thoracic or lumbar region, although cervical IS does occur. We herein report the case of a 67-year-old man on HD who developed infectious cervical spondylodiscitis. The diagnosis was established a few days after symptom onset, but the issue was unfortunately fatal despite a well-conducted antibiotic treatment.

Characterization of the Bacterial Biofilm Communities Present in Reverse-Osmosis Water Systems for Haemodialysis

Biofilm in reverse osmosis (RO) membranes is a common problem in water treatment at haemodialysis facilities. Bacteria adhere and proliferate on RO membranes, forming biofilms, obstructing and damaging the membranes and allowing the transfer of bacteria and/or cellular components potentially harmful to the health of haemodialysis patients. Our aim was to characterize the bacterial community associated to biofilm of RO membranes and to identify potentially pathogenic bacteria present in the haemodialysis systems of two dialysis centres in Chile. The diversity of the bacterial communities present on RO membranes and potable and osmosed water samples was evaluated using Illumina sequencing. Additionally, bacteria from potable water, osmosed water and RO membrane samples were isolated, characterized and identified by Sanger’s sequencing. The molecular analyses of metagenomics showed that the phyla having a greater relative abundance in both dialysis centres were Proteobacteria and Planctomycetes. Pseudomonas, Stenotrophomonas, Agrobacterium, Pigmentiphaga, Ralstonia, Arthrobacter, Bacteroides and Staphylococcus were bacterial genera isolated from the different samples obtained at both haemodialysis centres. Pseudomonas spp. was a bacterial genus with greater frequency in all samples. Pseudomonas and Staphylococcus showed higher levels of resistance to the antibiotics tested. Results demonstrated the presence of potentially pathogenic bacteria, showing resistance to antimicrobials on RO membranes and in osmosed water in both dialysis centres studied.

Clinical Characteristics and Risk Factors for Mortality due to Bloodstream Infection of Unknown Origin in Hemodialysis Patients: A Single-Center, Retrospective Study

INTRODUCTION

Hemodialysis patients are at a high risk of bloodstream infection (BSI). The risk factors for BSI-associated mortality, especially of unknown origin, remain uncertain. BSI of unknown origin is highly prevalent and related to high mortality. The present study aimed to investigate the clinical and microbiological characteristics of BSI and risk factors for BSI-associated mortality, including BSI of unknown origin, in hemodialysis patients.

METHODS

This study was a single-center, retrospective study conducted from August 2012 to July 2019 in hemodialysis patients with BSI at Kawashima Hospital. Data related to demographics, clinical parameters, BSI sources, causative microorganisms, and initial treatments were collected from the medical records. The predictors for mortality associated with BSI were evaluated by logistic regression.

RESULTS

Among 174 patients, 55 (30.9%) had the infection from unknown origin. The most frequent bacterium was Staphylococcus aureus. Low serum albumin level was an independent predictor of mortality due to BSI (odds ratio [OR]: 0.28, 95% confidence interval [CI]: 0.13-0.59). A lower serum albumin level (≤2.5 g/dL) was associated with poorer mortality. Methicillin-resistant Staphylococcus aureus (MRSA) was independently associated with mortality due to BSI of unknown origin (OR: 6.20, 95% CI: 1.04-37.1); 87.5% cases with BSI of unknown origin due to MRSA were not initially administrated anti-MRSA antibiotics, and in such patients, the mortality rate was 85.7%.

CONCLUSIONS

Serum albumin level of 2.5 g/dL is a cutoff value, which could predict the mortality due to BSI in hemodialysis patients. Considering the high mortality rate of MRSA-associated BSI of unknown origin, wherein no focus of infection was identified in the present study, initial empiric treatment should be considered for MRSA-associated BSI of unknown origin.

Surface modification strategies for hemodialysis catheters to prevent catheter-related infections: A review

Insertion of a central venous catheter is one of the most common invasive procedures applied in hemodialysis therapy for end-stage renal disease. The most important complication of a central venous catheter is catheter-related infections that increase hospitalization and duration of intensive care unit stay, cost of treatment, mortality, and morbidity rates. Pathogenic microorganisms, such as, bacteria and fungi, enter the body from the catheter insertion site and the surface of the catheter can become colonized. The exopolysaccharide-based biofilms from bacterial colonies on the surface are the main challenge in the treatment of infections. Catheter lock solutions and systemic antibiotic treatment, which are commonly used in the treatment of hemodialysis catheter-related infections, are insufficient to prevent and terminate the infections and eventually the catheter needs to be replaced. The inadequacy of these approaches in termination and prevention of infection revealed the necessity of coating of hemodialysis catheters with bactericidal and/or antiadhesive agents. Silver compounds and nanoparticles, anticoagulants (e.g., heparin), antibiotics (e.g., gentamicin and chlorhexidine) are some of the agents used for this purpose. The effectiveness of few commercial hemodialysis catheters that were coated with antibacterial agents has been tested in clinical trials against catheter-related infections of pathogenic bacteria, such as Staphylococcus aureus and Staphylococcus epidermidis with promising results. Novel biomedical materials and engineering techniques, such as, surface micro/nano patterning and the conjugation of antimicrobial peptides, enzymes, metallic cations, and hydrophilic polymers (e.g., poly [ethylene glycol]) on the surface, has been suggested recently.

Clinical characteristics, risk factors and microbiology of infections in patients receiving chronic hemodialysis

BACKGROUND

The infectious complications in hemodialysis patients are still among the main reasons for their increased morbidity and mortality. The possible reasons behind this might be due to impairments in the host defense mechanisms, comorbidities, invasive procedures and pathogenicity of the infecting organisms. With the increased incidence of bacteremia in hemodialysis patients and the overt use of antibiotics, we have witnessed a rise in the number of new multidrug resistant (MDR) strains in those patients.

AIM

We aim to determine the epidemiology, risk factors and complications of infections in patients receiving chronic hemodialysis, particularly bloodstream infections.

METHODS

This is a retrospective case-control study involving patients undergoing hemodialysis at a tertiary care center. We studied the prevalence of infectious complications among those patients as well as the responsible agent in each respective infectious episode and the risk factors associated with bacteremia.

FINDINGS

46.6% of the studied population had at least one documented episode of infection. The most common were blood and respiratory infections (33.2% and 32.7% respectively). Among patients with bacteremia, coagulase-negative Staphylococcus was the predominant pathogen (49% of cases), followed by Staphylococcus aureus and Escherichia coli. Mortality was higher in patients who had MDR bacteremia, and in those who had mechanical ventilation or intensive care unit (ICU) admission.

CONCLUSION

Due to the alarming increase in the incidence of infection among hemodialysis patients and its strong association with mortality, further studies are needed to look for risk factors associated with infection and for ways to control those risk factors.

¿Se infectan más los catéteres tunelizados para hemodiálisis cuando los pacientes ingresan en el hospital?

La infección de los catéteres para hemodiálisis constituye una de las causas de mayor morbimortalidad. La hipótesis intuitiva de que los catéteres se infectan más durante la hospitalización no ha sido verificada en la literatura. Objetivo: Conocer si la hospitalización es un factor de riesgo de bacteriemia relacionada con catéter. Material y Método: Análisis retrospectivo de las bacteriemias asociadas a catéter durante un período de 4 años de un centro periférico extrahospitalario de hemodiálisis dependiente de un Servicio de Nefrología de un hospital de tercer nivel durante el período 2014-2017. Se recogieron los tiempos de empleo de catéteres y las bacteriemias relacionadas con catéter divididos en 2 escenarios: Hospital y centro periférico. Se aplicó el Modelo de Regresión de Poisson para comparar las bacteriemias Hospital vs centro periférico. Un mismo paciente pudo padecer bacteriemia más de una vez y en los dos escenarios. Resultados: Se emplearon 361 catéteres en 174 pacientes con tiempo total de uso 91.491 días, con 103 episodios de bacteriemia.Tasas de bacteriemias: hospitalizado 7,81/1000 días/catéter y centro periférico 0,81/1000 días/catéter. El riesgo de sufrir bacteriemia se multiplicó por 9,6 durante la hospitalización vs centro periférico (p

Peritoneal Dialysis Does Not Carry the Same Risk as Hemodialysis in Patients Undergoing Hip or Knee Arthroplasty

BACKGROUND

Dialysis has been associated with increased complication rates following total hip arthroplasty (THA) and total knee arthroplasty (TKA). The current literature on this issue is limited and does not distinguish between hemodialysis and peritoneal dialysis. The purpose of this study was to determine (1) the differences in the infection and other complication rates after THA or TKA between patients on peritoneal dialysis and those on hemodialysis and (2) the differences in complication rates after THA or TKA between patients on peritoneal dialysis and matched controls without dialysis dependence.

METHODS

Patients who had undergone primary THA or TKA from 2005 to 2014 were identified in the 100% Medicare files; 531 patients who underwent TKA and 572 patients who underwent THA were on peritoneal dialysis. These patients were matched 1:1 to patients on hemodialysis and 1:3 with patients who were not receiving either form of dialysis. Multivariate regression analysis was performed to examine several adverse events, including the prevalence of infection at 1 year and hospital readmission at 30 days.

RESULTS

The infection rates at 1 year after THA were significantly lower in the peritoneal dialysis group than in the hemodialysis group: 1.57% (95% confidence interval [CI] = 0.7% to 3.0%) and 4.20% (95% CI = 2.7% to 6.2%), respectively, with an odds ratio (OR) of 0.30 (95% CI = 0.12 to 0.71). This was also the case for the infection rates 1 year after TKA (3.39% [95% CI = 2.0% to 5.3%] and 6.03% [95% CI = 4.2% to 8.4%], respectively; OR = 0.67 [95% CI = 0.49 to 0.93]). Peritoneal dialysis appears to result in a similar infection rate when compared with matched controls. The rates of other assessed complications, such as hospital readmission, emergency room visits, and mortality, were very similar between the peritoneal dialysis and hemodialysis groups but were often significantly higher than the rates in non-dialysis-dependent controls.

CONCLUSIONS

The increased risk of complications in dialysis-dependent patients following THA or TKA depends on the mode of the dialysis. Whereas patients on hemodialysis have a significantly higher risk of infection, patients on peritoneal dialysis do not appear to have this same risk when compared with non-dialysis-dependent patients. These results suggest that the mode of dialysis should be considered when assessing the risk associated with THA or TKA.

LEVEL OF EVIDENCE

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

Three years' experience of dialysis event surveillance

BACKGROUND

The main study aim was to track infections, evaluate performance, and identify opportunities for improved practice since infections, especially those associated with multidrug-resistant organisms, are the second most common cause of death among end-stage renal disease patients.

METHODS

This study describes the establishment of baseline dialysis event surveillance at a large dialysis center. Every month, the dialysis center staff reported the total number of maintenance hemodialysis patients to the department of infection control and hospital epidemiology. The surveillance system for dialysis events included monthly monitoring of hemodialysis patients in outpatient settings for positive blood cultures, intravenous antimicrobial initiation, and local vascular access infections.

RESULTS

We calculated the pooled mean rates of positive blood cultures, intravenous antimicrobial initiation, and local vascular access infections during the period from June 1, 2014 to September 30, 2017. Results indicated more dialysis events were attributed to the CVC than any other dialysis vascular access. Regardless of vascular access type, intravenous antimicrobial initiation was the most commonly reported dialysis-associated event.

CONCLUSIONS

Dialysis events surveillance can be used to produce a decrease in both morbidity and mortality rates in hemodialysis patients.

Dialysis dependence and modality impact complication rates after shoulder arthroplasty

BACKGROUND

The goals of the study were to determine (1) the incidence of dialysis patients undergoing shoulder arthroplasty (SA), (2) the association of dialysis modality with complications after SA, and (3) the association of dialysis dependence with death in patients undergoing SA and nonsurgical dialysis-dependent controls.

METHODS

Using an insurance database, we identified dialysis-dependent patients undergoing SA and compared them with a matched control cohort without dialysis use. We performed an analysis comparing patients using peritoneal dialysis (PD), patients using hemodialysis (HD), matched non-dialysis-dependent controls, and matched PD and HD nonsurgical patients. Complications including in-hospital death, emergency department visits, hospital readmission, infection, and revision surgery were assessed.

RESULTS

The incidence of SA in dialysis patients has significantly increased. Compared with controls, dialysis-dependent patients had increased rates of in-hospital death (odds ratio [OR], 7.60; P < .0001), emergency department visits (OR, 4.16; P < .0001), hospital admission (OR, 1.63; P < .0001), and infection within 1 year (OR, 1.90; P = .009). Compared with patients receiving HD, PD patients had lower rates of death (OR, 0.40; P = .008), hospital readmission (OR, 0.43; P = .047), and revision surgery (OR, 0.23; P = .037). as well as a lower incidence of infection (OR, 0.30; P = .018). Compared with controls, PD patients had similar rates of most complications. Compared with nonsurgical dialysis-dependent patients, the SA procedure itself was not associated with an increased mortality rate.

CONCLUSIONS

Although dialysis represents a significant independent risk factor for complications after SA, this risk is highly influenced by the type of dialysis.

Úlceras de quirodáctilos e dorso de mão esquerda ocasionadas por hipertensão venosa após confecção de fístula arteriovenosa braquiocefálica: relato de caso

Venous ulcers caused by venous hypertension secondary to arteriovenous fistulae are rare. Their etiology can be confirmed by vascular Doppler ultrasonography, which can differentiate between stenosis of central vessels and hemodynamic overload caused by development of tributaries from the vein responsible for the arteriovenous fistula. We present a case caused by hemodynamic overload of a tributary, which diverted the primary flow from the fistula to the distal limb. We chose to ligate the fistula to treat the ulcers and create another arteriovenous fistula in the contralateral limb.

Antibiotic Prophylaxis for Melioidosis in Patients Receiving Hemodialysis in the Tropics? One Size Does Not Fit All

Melioidosis has a high case fatality rate and is more common in patients with chronic kidney disease. Some authors recommended trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis for all hemodialysis (HD) patients during the wet season in melioidosis-endemic regions. Historical data were reviewed to determine if TMP/SMX prophylaxis was warranted in the HD population of Far North Queensland, Australia. Between 1997 and 2017, there were 242 culture-confirmed cases of melioidosis in the region, three (1.2%) occurred in HD patients; all survived without intensive care support. During the study period, there were 843 HD patients in the region with 3,024 cumulative patient years of risk. Even assuming 100% efficacy, it would have been necessary to prescribe TMP/SMX for 1,008 patient years to prevent one case of melioidosis. Given the significant additional cost and potentially life-threatening side effects of TMP/SMX therapy, clinicians should review the local epidemiology of melioidosis before the implementation of universal TMP/SMX prophylaxis in their HD population.

Rate of bacteremia in the hemodialysis patient presenting to the emergency department with fever: a retrospective chart review

BACKGROUND

Infectious disease is the second most common cause of death in patients receiving hemodialysis (HD). When presenting to the emergency department (ED) with fever, it remains a diagnostic challenge to distinguish patients with potentially life-threatening bacterial infections from those with less significant causes of fever. The primary goal of this study was to determine the rate of bacteremia in HD patients presenting to the ED with fever. The secondary goal of this study was to identify any independent risk factors associated with bacteremia in the febrile HD patient.

METHODS

This is a retrospective medical record review of all HD patients who presented to the ED with either subjective fever as primary complaint or with a documented triage temperature of 38 °C or higher during the 3-year period between September 1, 2014, and September 1, 2017. Patient visits were included in the study if blood cultures were ordered in the ED. Data related to demographic information, clinical parameters, diagnostic test results in the ER, final diagnosis, and results of microbiology cultures were collected from each patient encounter. Univariate analysis was performed to identify risk factors associated with bacteremia.

RESULTS

We identified 353 patient visits from 138 unique patients that met inclusion criteria. Fifty-eight percent of these were women, and the average age was 54.6 years. The rate of bacteremia was 31.7%, and the main microorganisms isolated in blood culture were non-MRSA Staphylococcus aureus (40.7%), MRSA (13.3%), Pseudomonas aeruginosa (11.5%), and Enterobacter spp. (11.5%). Independent prognostic factors associated with bacteremia were use of dialysis catheter, prior history of bacteremia, and > 5% neutrophilic band cells (OR 6.55 [95% CI 3.96-10.8; p < 0.0001]; OR 8.87 [95% CI 5.32-14.8; p < 0.0001]; OR 3.32 [95% CI 1.90-5.80; p < 0.0001] respectively).

CONCLUSION

HD patients presenting to the ED with fever have high rates of bacteremia, with a significantly higher rate in patients using dialysis catheters or those with a history of bacteremia. Other clinical data available in the ED is minimally useful in predicting bacteremia.

The optimal ethanol lock therapy regimen for treatment of biofilm-associated catheter infections: an in-vitro study

BACKGROUND

Ethanol-based lock therapy (LT) solutions are used as an alternative to antibiotics for the conservative management of catheter-related bloodstream infection. However, no clear consensus on regimen or dose has been reached.

AIM

To find the ethanol-based lock solution containing a sufficiently low concentration of ethanol for reduction of the metabolic activity of bacterial and fungal biofilms.

METHODS

Using an in-vitro model, three concentrations of ethanol (25%, 40%, 70%) were tested, with and without 60 IU of heparin, at six different time-points and against 24 h preformed biofilms of Staphylococcus aureus ATCC29213, Staphylococcus epidermidis (clinical isolate), Enterococcus faecalis ATCC33186, Candida albicans ATCC14058, and Escherichia coli ATCC25922. The reduction in the metabolic activity of the biofilm was measured using the tetrazolium salt assay and LT was considered to be successful when metabolic activity fell by >90%. Regrowth inhibition was then tested within 24 h and seven days after each LT regimen only at the ethanol concentration of the most successful LT regimen.

FINDINGS

The most successful LT was achieved with 40% ethanol + 60 IU of heparin only at 24, 72, and 24 h for seven-day regimens (P < 0.05). However, none of the regimens reached 45% RI within seven days of therapy.

CONCLUSION

According to our in-vitro data, an ethanol-based lock solution with 40% ethanol + 60 IU heparin administered daily for 72 h is sufficient to almost eradicate the metabolic activity of bacterial and fungal biofilms. Future studies are needed to study cell regrowth after LT.

In vitro assessment of the anti-biofilm activity of ethanol alone and in combination with enoxaparin 60IU

INTRODUCTION

Catheter-related bloodstream infection (C-RBSI) can sometimes be managed without catheter removal by combining systemic therapy with catheter lock therapy. Most antiseptic lock solutions are made up of ethanol combined with an anticoagulant. However, data regarding the anti-biofilm activity of ethanol combined with enoxaparin are scarce. We aimed to assess the efficacy of ethanol at different concentrations combined with enoxaparin 60IU as a lock solution for eradication of the biofilm of different microorganisms.

METHODS

Using a static 96-well plate in vitro model, we tested 30%, 35%, and 40% ethanol alone and combined with 60IU of enoxaparin against 24-h-old biofilm from the following microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, and Candida albicans. Time of exposure was assessed during a 2-h and 24-h regimen. We analysed the percentage reduction in metabolic activity using the XTT assay. We considered therapy to be successful when metabolic activity was reduced by >90%.

RESULTS

In the 2-h regimen, the therapy was successful against all microorganisms at 35% and 40% ethanol without enoxaparin (p<0.001). In the 24-h regimen, the therapy was successful against all microorganisms at all ethanol solutions without enoxaparin (p<0.001). When ethanol was combined with enoxaparin, the therapy was only successful in the 24-h regimen in biofilms of S. epidermidis, C. albicans and E. coli at all concentrations of ethanol assessed.

CONCLUSIONS

Our in vitro model demonstrated that when ethanol is combined with enoxaparin in a lock solution, it negatively affects ethanol anti-biofilm activity after both short and long exposures.

Pneumothorax Secondary to Septic Pulmonary Emboli in a Long-term Hemodialysis Patient with Psoas Abscess

Pneumothorax secondary to septic pulmonary embolism (SPE) is rare but life-threatening. We herein report a long-term hemodialysis patient with psoas abscess caused by methicillin-resistant Staphylococcus aureus, associated with other muscle and splenic abscesses and SPE. Intravenous vancomycin treatment and percutaneous drainage of the psoas abscess rapidly improved her condition. However, the SPE lesions continued to increase, and right-sided pneumothorax occurred 10 days after treatment. The pneumothorax resolved after two months and SPE and all abscesses after four months of treatment. Since late-onset pneumothorax caused by SPE can occur despite successful treatment of the primary infection, care should be taken with such patients.

Role of vancomycin in the treatment of bacteraemia and meningitis caused by Elizabethkingia meningoseptica

Elizabethkingia meningoseptica, a Gram-negative pathogen once deemed clinically insignificant, tends to cause infections among low-birth-weight infants and immunocompromised patients. Previously, vancomycin was reported to cure several patients with bacteraemia caused by E. meningoseptica. Nevertheless, some laboratory investigations also showed considerable discordance between in vitro vancomycin susceptibility results obtained by the disk diffusion and broth microdilution methods against clinical E. meningoseptica isolates as determined using the criteria for staphylococci recommended by the Clinical and Laboratory Standards Institute (CLSI). In this review, the PubMed database (1960-2017) was searched for studies that reported mainly cases with E. meningoseptica bacteraemia or meningitis treated with vancomycin alone or with regimens that included vancomycin. In addition, the in vitro synergy between vancomycin and other agents against isolates of E. meningoseptica was reviewed. Elizabethkingia meningoseptica bacteraemia appears not to universally respond to intravenous (i.v.) vancomycin-only therapy, especially in patients who require haemodialysis. If i.v. vancomycin is the favoured therapy against E. meningoseptica meningitis, the addition of ciprofloxacin, linezolid or rifampicin might be an option to effectively treat this difficult-to-treat infection. Further clinical studies are needed to determine the clinical efficacy of these combination regimens for the treatment of E. meningoseptica meningitis.

Venous Hemodialysis Catheters and Cardiac Implantable Electronic Devices: Avoiding a High-Risk Combination

End-stage renal disease is frequently accompanied by cardiac comorbidity that warrants treatment with a cardiovascular implantable electronic device (permanent pacemaker or implantable cardioverter-defibrillator). In the United States, chronic hemodialysis (HD) population, cardiac implantable devices are present in up to 10.5% of patients; a venous HD catheter is utilized for blood access in 18% of prevalent patients. The concomitant presence of a venous HD catheter and cardiovascular implantable device creates a high-risk circumstance, with potential for causing symptomatic central venous stenosis, and for developing complicated endovascular infection. This dangerous combination may be avoided for many patients by utilizing nondialysis methods for management of advanced chronic kidney disease, initiating dialysis without venous catheter access, or managing cardiac rhythm disorders without use of transvenous cardiac implantable electronic devices. In those situations where the combination of a venous HD catheter and cardiac implantable device is unavoidable, there are strategies to minimize duration of venous catheter access, and to reduce risks for infectious complications. It is essential for nephrologists and cardiologists to understand the indications, alternatives, and risks involved with venous HD access and cardiac implantable devices. Coordinated management of renal disease and cardiac rhythm disorders has potential to minimize risks, improve outcomes, and substantially reduce the cost of care.