Current Concepts in Hemodialysis Vascular Access Infections

A nomogram for predicting central venous catheter-related infections in maintenance hemodialysis: A 4-year single-center study

OBJECTIVE

To develop and validate a nomogram model for predicting central venous catheter-related infections (CRI) in patients with maintenance hemodialysis (MHD).

METHODS

MHD patients with central venous catheters (CVCs) visiting the outpatient hemodialysis (HD) center of Xuzhou Medical University Affiliated Hospital from January 2020 to December 2023 were retrospectively selected through a HD monitoring system. Patient data were collected, and the patients were divided into training and validation sets in a 7:3 ratio. The training set was used to establish the model, which was verified using the validation set. Multiple logistic regression analysis was performed to identify risk factors for central venous CRI and develop a nomogram prediction model.

RESULTS

A total of 300 MHD patients were enrolled. Multivariate analysis showed that catheter duration, catheter site, catheter reinsertion, history of catheter infection, diabetes, and albumin <35 g/L were risk factors for central venous CRI. The area under the receiver operating characteristic (ROC) curve (AUC) for the training set was 0.902 (95% confidence interval (CI) = 0.862-0.941), with a sensitivity of 85.7%, specificity of 80%, and a Youden index of 65.7%, and that for the validation set was 0.826 (95% CI = 0.726-0.905), with a sensitivity of 80.5%, specificity of 77.9%, and a Youden index of 58.4%. The model demonstrated good discrimination and calibration (Hosmer-Lemeshow goodness-of-fit test statistics: training set: χ2 = 4.709, p = 0.788; validation set: χ2 = 7.171, p = 0.518).

CONCLUSION

This study identified six risk factors associated with central venous CRI in MHD patients. This predictive model demonstrates good prognostic performance and can be used by clinicians to screen for high-risk patients with central venous CRI, thereby enabling the early implementation of risk management strategies.

Comparative evaluation of BacT/ALERT VIRTUO and BACTEC FX400 blood culture systems for the detection of bloodstream infections

Bloodstream infections (BSI) pose significant threats to patient health, necessitating timely and accurate diagnostics to reduce mortality and morbidity. This study aimed to evaluate the clinical performance of the BacT/ALERT VIRTUO blood culture system with FANPlus bottles compared to the BACTEC FX400 system in detecting bloodstream pathogens. A total of 1,772 blood specimens were collected from various hospital wards. Specimen selection criteria were based on clinical suspicion of bloodstream infections, ensuring the inclusion of relevant and representative patient samples. These blood samples, collected from the same suspected sepsis patients, were cultured in parallel using both the BacT/ALERT VIRTUO and BACTEC FX400 systems. The diagnostic efficiency of both systems, including detection rates, time to detection (TTD), and sensitivity across different bacterial species, was assessed. In various application scenarios, the VIRTUO system demonstrates a higher positive detection rate, whether in the intensive care unit (ICU) (8.5% vs 6.4%, P = 0.028) or in general wards. Additionally, for different types of bacteria, the TVIRTUO system exhibits superior detection rates for anaerobic bacteria (5.9% vs 3.2%, P < 0.001) and aerobic bacteria (9.1% vs 7.2%, P = 0.043). Furthermore, it boasts a shorter median TTD of 14 hours compared to 16 hours, and a higher sensitivity for Gram-positive bacteria (2.8% vs 1.6%, P < 0.001). These findings emphasize VIRTUO's effectiveness in enhancing diagnostic accuracy, achieving faster time to detection, and expanding the spectrum of detected organisms, thereby facilitating the quicker initiation of appropriate therapies, supporting precise clinical decision-making, and ultimately improving patient outcomes.IMPORTANCEOur study conducted a critical evaluation of advanced blood culture technologies for managing bloodstream infections (BSI). A distinctive strength of our research is the large sample size and the concurrent testing of the same patients with two systems, a methodology rarely achieved in other studies. BSIs present severe health threats, necessitating prompt and accurate diagnostics to mitigate morbidity and mortality. The BacT/ALERT VIRTUO system, in comparison to the BACTEC FX400 system, demonstrated superior detection capabilities, emphasizing the critical role of advanced diagnostics in clinical settings.

Involvement of healthcare staff in hospital hygiene during emergency hemodialysis

BACKGROUND

Healthcare-associated infections are still a worrying health problem that complicates patient care and increases morbidity and mortality. The incidence of infections in hemodialysis patients is still high and they constitute the second cause of hospitalization and death in this category.

AIMS

The study's objective was to evaluate nursing and medical staff's involvement in hospital hygiene.

METHODS

This is an observational study that took place within the hemodialysis unit of a Moroccan university hospital from March 2021 to June 2021. A surface swabbing technique for bacteriological examination was also carried out.

RESULTS

The study revealed some shortcomings regarding hand hygiene which was respected by the nurses in only 17.5% of sessions and in 42.2% by the doctors. Other shortcomings in asepsis measures, were also noted such as the non-change of gloves after skin preparation (1.03%) and before manual compression. The serological status of patients concerning HBV, HVC, and HIV was also not always known (31.1%). The bacteriological samples from the surfaces also showed colonization of the medical devices and the ultrasound scanner used for the ultrasound-guided introduction of the central catheters. The results of the study showed some deviations concerning the recommendations; however, they are comparable to other studies conducted internationally, especially in terms of hand hygiene.

CONCLUSION

Our study results highlight some shortcomings adherence to hygiene measures like inconsistent disinfection of medical devices and dialysis stations, as well as insufficient hand hygiene practices among some staff members. However, we observed an improvement in practices following the implementation of awareness-raising sessions. To maintain improved hygiene practices and prevent infections, it is crucial to provide ongoing training for staff, ensure adequate resources, and regularly monitor compliance with hygiene standards.

Infective Endocarditis in Patients Receiving Hemodialysis: A Current Review

Background

Cardiovascular and infective complications are commonly observed in patients receiving hemodialysis (HD) with cardiovascular events and infection-related complications being the first and second leading causes of death. Infective endocarditis (IE) is characterized by inflammation of the endocardium caused by infection, typically affecting the cardiac valves and can be in acute, subacute, or chronic forms. It is a serious complication within the HD population due to their predisposition for both infection and valvular damage. Considering the frailty and burden of comorbidities in those receiving HD, management of IE in the HD population is very challenging. There has been continuous discussion and debate on optimizing the diagnostic and treatment approach of IE in this patient group to improve their clinical outcomes. Currently, reported outcomes are relatively poor and there are updates from numerous guidelines relating to advances in IE management.

Summary

In this review, we will evaluate the evidence in relation to the epidemiology of HD-associated IE and discuss the important risk factors of IE in patients requiring dialysis. We will also evaluate the current recommendations regarding diagnosis and treatment for suspected or confirmed IE cases amongst HD patients and present the updated data regarding clinical outcomes relating to HD-associated IE.

Key Messages

The incidence of IE in HD patients is expected to increase going forward as HD becomes more easily accessible alongside an emerging uptake of home HD. A more thorough insight into this topic is required to improve clinical practice relating to IE prevention and management in the HD population, given relatively poor clinical outcomes.

Poor mid-term functional patency and post-operative outcomes in diabetic patients who undergo arteriovenous graft creation

INTRODUCTION

Diabetes mellitus is a leading cause of renal failure in the US and has been associated with higher mortality when compared to nondiabetic patients. This remains true despite initiation of renal replacement therapy. As such, we were interested in identifying any potential differences in access durability and postoperative outcomes in diabetic patients who receive arteriovenous fistulas versus grafts for hemodialysis.

METHODS

Diabetic patients undergoing their first arteriovenous (AV) access creation surgery in the Vascular Quality Initiative from January 2011 to January 2022 were included in our study. After exclusions, the study included two groups: those receiving AV fistulas and those receiving AV grafts for hemodialysis. Demographic characteristics were summarized and compared between these two groups using chi-square analysis or unpaired t-test. After propensity score matching was conducted, the effect of procedure type on functional patency, along with secondary outcomes including wound infection were assessed using chi-square analysis.

RESULTS

A total of 20,159 diabetic patients who used their hemodialysis access were included in our study; 16,205 received AV fistulas while 3954 received AV grafts. Patients receiving AV grafts were more likely to be older, female, and have higher pre-operative catheter usage. After propensity score matching, patients who received AV grafts had a shorter time-to-use their conduit (50 vs 166 days, p < 0.0001), however, patients who received AV fistulas were more likely to have longer functional patency use for hemodialysis when compared to those who received AV grafts (mean survival time: 3.3 vs 2.9 years, p < 0.0001). These results were consistent between diabetics with insulin-dependent or insulin-independent diabetes.

CONCLUSION

Patients diagnosed with diabetes mellitus had an increased risk for significantly inferior clinical outcomes related to newly created AV grafts, including lower rates of mid-term functional patency and higher rates of worse post-operative outcomes when compared to diabetics who received AV fistulas.

Meticulous catheter care and aseptic approach reduce catheter-related bloodstream infections significantly in hemodialysis patients: A 5-year single center study

AIM

The use of central venous catheters as hemodialysis vascular access is a major contributor to high bloodstream infection rate. In our dialysis unit in Shenzhen Guangdong Province China, we have developed and used our own dialysis catheter care protocol since May 2013 with good results. In this study, we would like to share our experience with the other units.

METHODS

We have undertaken a 5-year retrospective analysis to determine our tunneled dialysis catheter-related blood stream infection rate by adding the number of infections divided by total number of catheter days × 1000. The results were compared with another study carried out in Henan Province China. Demographic data were summarized using descriptive statistics. Continuous and categorical variables were compared using t-test and χ2 test respectively.

RESULTS

Between 2017 and 2021, a total of 216 tunneled dialysis catheters were managed by following our own dialysis access pathway and catheter care protocol. The tunneled dialysis catheter-related bloodstream infection rate was 0.0229 per 1000 catheter days in the 5-year period.

CONCLUSION

Comparing with other published studies in China, our unit has achieved a very low rate of tunneled dialysis catheter-related bloodstream infection which has been sustained over time. This paper explores how our protocol and implementation might have contributed to the results.

Antibiotic lock solutions as adjunct therapy for catheter-related blood stream infections in pediatric hemodialysis patients

The predominant use of intravenous catheters as primary access type in the pediatric hemodialysis population is associated with an increased risk of catheter related blood stream infections. While strict adherence to catheter placement and long-term care guidelines have helped to decrease the incidence of these infections, blood stream infections remain an infection burden in pediatric patients with long term hemodialysis catheters. The formation of biofilms on the surfaces of these catheters has been shown to be a source of microbes causing blood stream infections. One of the strategies for preventing bacterial colonization, inhibiting microbial multiplication, and suppressing the seeding of these microbes from biofilms upon maturation, has been the use of antibiotic-based lock solutions in-between dialysis treatments. Although clinical guidelines for the use of antibiotic lock solutions are yet to be developed, available evidence suggests a beneficial role of antibiotic lock solutions in the management of catheter related blood stream infections. Additionally, a clear understanding of how biofilms are formed and their role in the pathogenesis of catheter related bloodstream infection will facilitate the development of solutions that can prevent biofilm formation and inhibit their multiplication, maturation and seeding into the bloodstream.

Comparison between transposed arteriovenous fistulas and arteriovenous graft for the hemodialysis patients: A meta-analysis and systematic review

It is challenging for a surgeon to determine the appropriate vascular access for hemodialysis patients whose cephalic vein is usually inaccessible. The purpose of the study is to compare the complications and patency rates between transposed arteriovenous fistulas (tAVF) and arteriovenous graft (AVG) for the hemodialysis patients. Studies were recruited from PubMed, Cochrane library, EMBASE, the web of science databases, and reviewing reference lists of related studies from the inception dates to September 2, 2021. Statistical analyses were conducted using the statistical tool Review Manager version5.3 (Cochrane Collaboration, London, UK). I2 > 50% was defined as a high degree of heterogeneity, and then a random-effects model was used. Otherwise, the fixed-effects model was used. Odds ratio with its 95% confidence interval (95% CI) was used. Thirty-three trials (26 retrospective studies, four randomized controlled trials, two prospective trials, and one controlled-comparative study) with 6430 enrolled participants were identified in our analysis. The results showed that tAVF was accompanied with lower thrombosis rate (103/1184 (8.69%) vs 257/1367 (18.80%); I2 = 45%; 95% CI, 0.34 (0.26, 0.45)) and infection rate (43/2031 (2.12%) vs 180/2147 (8.38%); I2 = 0%; 95% CI, 0.20 (0.14, 0.30)) than arteriovenous graft. The significantly better primary patency rates, secondary patency rates, and primary assisted patency rates during follow-up were found in tAVF. However, the failure rate and the prevalence of hematoma were significantly lower in AVG group. No evidence showed the rate of overall mortality, steal syndrome, and aneurysm reduced in tAVF. Our results showed that tAVF is a promising vascular access technique for hemodialysis patients whose cephalic vein is inaccessible. Our data showed that tAVF has less thrombosis, infection risk, and better patency rates when compared with AVG. However, more attentions need to be paid to transposed arteriovenous fistulas maturation and hematoma.

Definition and clinical management of haemodialysis central venous catheter local infections (exit site and tunnel infection): An international consensus assessment

AIM

To evaluate the relevance of signs and symptoms for the clinical identification of ESI and TI in HD-CVC, by means of international expert consensus, and to reach a consensus on a definition and clinical management (CM) for these infections.

BACKGROUND

A recent systematic review showed a high heterogeneity in the signs/symptoms used for determining exit site infection (ESI) and tunnel infection (TI) of haemodialysis central venous catheter (HD-CVC).

DESIGN

A modified Delphi ranking process was carried out between November 2020 and March 2021, consisting of four rounds using an online questionnaire with a panel of 26 experts from 12 countries.

METHODS

Experts responded on the level of relevance for the identification of ESI and TI, based on a list of 22 signs/symptoms obtained from a previous systematic review, using a 4-point Likert-type scale. After reaching consensus on the signs/symptoms, they followed the same method to reach consensus on the CM. The STROBE Checklist was used to report this study.

RESULTS

A high degree of consensus was reached to identify the presence of ESI based on nine signs/symptoms: presence of pain at the exit site (ES) during interdialysis period, with fever ≥38°C do not suspect other cause, local signs at the ES (inflammation, induration, swelling, hyperemia/erythema ≥2 cm from ES) and obvious abscess or purulent exudate at ES; and of TI. Likewise, 5 cm were agreed upon.

CONCLUSION

This Delphi study provides international expert consensus definitions of ESI and TI in HD-CVC, laying the groundwork for the validation of an HD-CVC ES clinical assessment scale for early identification of ESI.

RELEVANCE TO CLINICAL PRACTICE

In addition, this study provides a series of attitudes to consensual clinics regarding signs/symptoms of local infections in HD-CVC, which may be useful as expert opinion in clinical practice guidelines, when there is insufficient scientific evidence.

Compliance with good practice guidelines for the prevention of vascular access infections: the multi-centre PHYDEL survey in French haemodialysis units

BACKGROUND

French guidelines for the prevention of vascular access infections in a haemodialysis setting were released in 2005. Compliance with these guidelines is currently unknown. The aim of this study was to assess compliance with the guidelines for vascular access infection prevention in French haemodialysis units, and to describe the difficulties reported.

METHODS

A cross-sectional survey was conducted between March and December 2019 in 200 haemodialysis units in France, selected at random. Data were collected via questionnaire, completed by telephone interview with an infection control practitioner. A practice was deemed compliant when >85% of units declared that they always complied with the guidelines.

RESULTS

In total, 103 units (51.5%) agreed to participate. Most practices complied with the guidelines; however, some practices did not reach the 85% compliance threshold for working in pairs when connecting central venous catheter (CVC) lines, performing hand hygiene before disconnecting lines, rinsing antiseptic soap before painting CVC exit site or arteriovenous fistula (AVF) puncture site, allowing antiseptic paint to dry, handling CVC branches with antiseptic impregnated gauze, performing hand hygiene after AVF compression with gloves, wearing protective eyewear when connecting/disconnecting CVC or when puncturing AVF, and wearing a gown when puncturing AVF. The most frequently reported difficulties were understaffing, difficulties with skin preparation because of exit site skin damage, and lack of buttonhole technical expertise.

CONCLUSIONS

Despite good overall compliance, this survey highlights some shortcomings in compliance with infection prevention guidelines, which could be associated with either higher risk of vascular access infection or increased blood-borne virus transmission.

VasQ U.S. pivotal study demonstrates the safety and effectiveness of an external vascular support for arteriovenous fistula creation

OBJECTIVE

Arteriovenous fistula (AVF) creation is a commonly performed vascular operation that reports 6-month functional success rates as low as 50%. Recently, a nitinol external vascular support device, VasQ, has shown potential in studies outside the United States (U.S.) to improve AVF outcomes when implanted at creation. Here, the pivotal study results of this novel technology in treating patients in the U.S. are described.

METHODS

VasQ was implanted in 144 patients at 16 centers across the U.S. who were referred for creation of a new AVF and consented for enrollment in a 2-year, prospective, multicenter, single-arm, open-label study. Brachiocephalic (n = 129) and radiocephalic (n = 15) AVFs were analyzed. The primary endpoint was primary patency at 6 months compared against a performance goal of 55% derived from a systematic literature search. Safety endpoints included device-related events, ischemic steal, infection, aneurysm, and seroma at up to 6 months. Minimum arterial size was 2.0 mm; target veins were required to measure 2.5 to 6 mm. Key exclusion criteria were patients <18 or >80 years, those with known ipsilateral central venous occlusion, target cannulation zone venous depth greater than 8 mm, and New York Heart Association class 3 or 4.

RESULTS

Patients were 61% male, 53% White, 35% African American, and 14% Hispanic. Mean age was 60 years, and median body mass index was 30.4. Of the patients, 69% were diabetic, 66% were on dialysis at the time of creation, and 70% had a prior access surgery. At 6 months, steal was observed in 2.1%, infection in 0.7%, and no aneurysms or seromas were seen. Primary patency at 6 months was 66% (P < .021 vs performance goal). Physiological maturation was achieved in 92.4% of patients. Successful two-needle cannulation for patients that entered the study on dialysis was achieved in 88% of VasQ AVFs at a median of 56 days. Pre-dialysis patients who initiated dialysis during the study achieved two-needle cannulation in 81.6% VasQ AVFs. Interventions were required at a rate of 1.07 per patient year over the entire study period. Two-year cumulative patency was 76.6% (95% confidence interval, 67.9%-83.4%) with no statistical difference between patients requiring interventions and those that did not. No patency differences were observed between brachiocephalic and radiocephalic AVFs.

CONCLUSIONS

The U.S. pivotal study results demonstrated improved AVF outcomes and an excellent safety profile with VasQ use relative to traditional AVFs. Under the conditions of this trial, VasQ shows great promise in expeditiously and efficiently enhancing AVF functional success.

Survival of Tunneled Double Lumen-Cuffed Catheters in Children on Maintenance Hemodialysis - A Retrospective Cohort Study

Introduction

Survival of tunneled cuffed catheters (TCC), used widely in children, is complicated by infections and catheter dysfunction. In resource limited settings, where risk of complications could be higher and waiting period for transplantation longer, catheter survival determines patient survival. This study was conducted to determine infection free catheter survival rates, incidence of catheter failure and associated risk factors.

Methods

Children <18 years of age receiving maintenance hemodialysis through TCC at nephrology division of a pediatric hospital, over a period of 6 years. Data was collected with consecutive selection by a complete enumeration technique from pre-collected data sheets in the records. Exposure detected were catheter infections, thrombosis, and mechanical complications.

Results

Forty-five TCCs in 36 children studied for 12,590 catheter days showed catheter failure in 36%, due to catheter related infections in 75% and mechanical complications in 25%. The incidence of complications per 1000 catheter days was 1.19 infection, 1.03 thrombus, and 0.39 mechanical. Catheter-related blood stream infection (CRBSI) (15/36) was associated with thrombus in nine and led to mortality in three. The mean infection free catheter survival was 449 ± 42 days for cohort with 388 ± 38 days in Group A (premature catheter removal) and 593 ± 43 days in Group B (elective removal) (P = 0.03). Catheterization duration of 267 days predicted CRBSI (sensitivity 93%, specificity 66.7%) with area under the curve of 0.808.

Conclusions

Median infection free catheter survival was 449 days with catheter failure in 36%. CRBSI was the main cause of failure. Duration of catheterization greater than 267 days was a predictor of CRBSI.

Topical gentamicin for the prevention of tunneled hemodialysis catheter-related infections: a randomized double-blind study

INTRODUCTION

Infection is the second leading cause of death in dialysis patients, with catheter-related bloodstream infection being the most serious. Exit Site Infection and Tunnel Infection are also related to the catheter.

OBJECTIVE

To compare the infection rates achieved with the application of either topical gentamicin or placebo to the exit-site of tunneled catheters filled with locking solution in chronic hemodialysis patients.

METHODS

This randomized double-blind clinical trial compared the application of 0.1% gentamicin versus placebo to the exit site of tunneled hemodialysis catheters filled with a prophylactic locking solution. A total of 91 patients were randomly allocated to 2 groups: placebo or 0.1% gentamicin.

RESULTS

Mean patient age was 60.4 (+ 15.3) years, with predominance of males (60.4%). The main cause of chronic kidney disease was diabetes (40.7%). The rates of exit site infection (placebo = 30% vs. gentamicin = 34.1%, p = 0.821), and bloodstream infection (placebo = 22% vs. gentamicin = 17.1%, p = 0.60), as well as both exit site infection and bloodstream infection incidence density per 1000 catheter-days (p = 1) did not differ between groups. The infection-free curve was also similar in both groups.

CONCLUSION

The application of topical 0.1% gentamicin to the exit site of tunneled catheters filled with lock solution did not reduce infectious complications when compared to topical placebo in patients on chronic hemodialysis.

Early identification of bloodstream infection in hemodialysis patients by machine learning

Background

Bloodstream infection (BSI) is a prevalent cause of admission in hemodialysis (HD) patients and is associated with increased morbidity and mortality. This study aimed to establish a diagnostic, predictive model for the early identification of BSI in HD patients.

Methods

HD patients who underwent blood culture testing between August 2018 and March 2022 were enrolled in this study. Machine learning algorithms, including stepwise logistic regression (SLR), Lasso logistic regression (LLR), support vector machine (SVM), decision tree, random forest (RF), and gradient boosting machine (XGboost), were used to predict the risk of developing BSI from the patient's clinical data. The accuracy (ACC) and area under the subject working curve (AUC) were used to evaluate the performance of such models. The Shapley Additive Explanation (SHAP) values were used to explain each feature's predictive value on the models' output. Finally, a simplified nomogram for predicting BSI was devised.

Results

A total of 391 HD patients were enrolled in this study, of whom 74 (18.9%) were diagnosed with BSI. The XGboost model achieved the highest AUC (0.914, 95% confidence interval [CI]: 0.861-0.964) and ACC (86.3%) for BSI prediction. The four most significant co-variables in both the significance matrix plot of the XGboost model variables and the SHAP summary plot were body temperature, dialysis access via a non-arteriovenous fistula (non-AVF), the procalcitonin levels (PCT), and neutrophil-lymphocyte ratio (NLR).

Conclusions

This study created an effective machine-learning model for predicting BSI in HD patients. The model could be used to detect BSI at an early stage and hence guide antibiotic treatment in HD patients.

Microneedle-Integrated Sensors for Extraction of Skin Interstitial Fluid and Metabolic Analysis

Skin interstitial fluid (ISF) has emerged as a fungible biofluid sample for blood serum and plasma for disease diagnosis and therapy. The sampling of skin ISF is highly desirable considering its easy accessibility, no damage to blood vessels, and reduced risk of infection. Particularly, skin ISF can be sampled using microneedle (MN)-based platforms in the skin tissues, which exhibit multiple advantages including minimal invasion of the skin tissues, less pain, ease of carrying, capacity for continuous monitoring, etc. In this review, we focus on the current development of microneedle-integrated transdermal sensors for collecting ISF and detecting specific disease biomarkers. Firstly, we discussed and classified microneedles according to their structural design, including solid MNs, hollow MNs, porous MNs, and coated MNs. Subsequently, we elaborate on the construction of MN-integrated sensors for metabolic analysis with highlights on the electrochemical, fluorescent, chemical chromogenic, immunodiagnostic, and molecular diagnostic MN-integrated sensors. Finally, we discuss the current challenges and future direction for developing MN-based platforms for ISF extraction and sensing applications.

Central Line-Associated Bloodstream Infections: Effect of Patient and Pathogen Factors on Outcome

Introduction

Patients on central lines are often having multiple morbidities, and invasive devices provide a niche for biofilm formation, which makes central line-associated bloodstream infections (CLABSIs), a serious concern in health-care settings, as the infections difficult to treat. In this study, we evaluated the common bacteria causing CLABSI, and various patient and pathogen factors affecting the clinical outcome.

Methods

In the prospective observational study, patients diagnosed with CLABSI were recruited. Extensive clinical, microbiological, and other laboratory workup was done, and observations were recorded. Congo red agar method, tube test, and microtiter plate assay were used for eliciting the biofilm-forming attributes of the bacterial pathogens.

Results

Klebsiella pneumoniae was responsible for 48% of CLABSI, followed by Coagulase-negative Staphylococci (16%) and Staphylococcus aureus and Acinetobacter baumannii (12% each). Fifty-six percent of the isolates produced biofilms. The median (interquartile range) duration of hospital stay till death or discharge was 30 (20, 43) days. The all-cause mortality was 44%. Patients having a deranged liver function on the day of diagnosis (P value for total bilirubin 0.001 and for aspartate transaminase 0.02), and those infected with multidrug-resistant organisms (P value = 0.04) had significantly poor prognosis. The difference in the demographic, clinical, laboratory profile, and outcome of patients infected with biofilm producers and nonproducers was not found to be statistically significant.

Conclusion

The study throws light on various host and pathogen factors determining the cause and outcome of CLABSI patients. To the best of our knowledge, this is the first study trying to decipher the role of biofilm formation in the virulence of pathogens and the prognosis of CLABSI.

Urokinase-based lock solutions for catheter salvage: A case of an upcoming kidney transplant recipient

Catheter-related bloodstream infection (CRBSI) is a significant complication among patients on haemodialysis (HD) who are dependent on a central venous catheter (CVC) for an extended period. Catheter removal as first-line treatment can induce accelerated venous access site depletion in patients on HD who rely on it to survive. It is possible to retain the catheter in stable patients without septic syndrome while administering systemic antibiotics and antibiotic lock therapy. Herein, we report the case of a patient on HD with CRBSI who was successfully treated with intravenous levofloxacin- and urokinase-based antibiotic lock, without catheter removal prior to kidney transplantation. The use of urokinase in combination with antibiotics in lock solutions for treating catheter infections is rare. We verified the physical compatibility of levofloxacin and urokinase by visual inspection, turbidimetric measurements, and particle count. To our knowledge, this was a rare case demonstrating the effective use of urokinase and levofloxacin in a catheter lock for CRBSI in a patient on HD. Considering the need for highly concentrated antimicrobials and the availability of various antibiotics, the compatibility and stability of the lock solution is a matter of concern. Further studies are warranted to assess the stability and compatibility of various antibiotics in combination with urokinase.

Causes of Emergency Department Visits Among End-Stage Kidney Disease Patients on Maintenance Hemodialysis in Pakistan: A Single-Center Study

Background In this study, we aimed to determine the causes of emergency department (ED) visits by end-stage kidney disease (ESKD) patients on maintenance hemodialysis (MHD) in Karachi, Pakistan. Methodology We conducted a cross-sectional study that included 194 visits of ESKD patients on MHD aged ≥18 years of both genders presenting at the ED of The Kidney Centre Postgraduate Training Institute, Karachi, Pakistan between February 2021 and May 2021. The study investigated the causes behind ED visits. Frequencies were calculated for categorical variables, and a bar graph was used for the graphical representation of the causes. Results In total, 194 visits included 151 patients of whom 88 (58.3%) were males while 63 (41.7%) were females, with a mean age of 51.68 ± 15.8 years. The most common comorbidity among the ED visits was hypertension 182 (93.8%). The majority of the visits 129 (66.5%) were undergoing regular three dialysis sessions per week, 101 (52.1%) were registered for MHD at our Institute, and 69.1% of visits reported arteriovenous fistula (AVF) as the current access for hemodialysis. Around 111 (57.2%) of the visits had infection-related complications, followed by electrolyte abnormalities 74 (38.1%), cardiovascular 53 (27.3%), and pulmonary complications 41 (21.1%). Overall, 19 (9.8%), 16 (8.2%), and 14 (7.2%) patients reported access-related, neurological, and gastrointestinal complications, respectively. Conclusions Infection-related complications are a significant cause of ED visits among ESKD patients, followed by electrolyte abnormalities and systemic complications, many of which are related to the existing comorbid conditions. Risk identification of preventable causes and surveillance of existing comorbidities would help mitigate ED visits among ESKD patients.

Pre-Emptive Antimicrobial Locks Decrease Long-Term Catheter-Related Bloodstream Infections in Hemodialysis Patients

This study aimed to prove that pre-emptive antimicrobial locks in patients at risk of bacteremia decrease infection. We performed a non-randomized prospective pilot study of hemodialysis patients with tunneled central venous catheters. We drew quantitative blood cultures monthly to detect colonization. Patients with a critical catheter colonization by coagulase-negative staphylococci (defined as counts of 100−999 CFU/mL) were at high risk of developing a catheter-related bloodstream infection. We recommended antimicrobial lock for this set of patients. The nephrologist in charge of the patient decided whether to follow the recommendation or not (i.e., standard of care). We compared bloodstream infection rates between patients treated with antimicrobial lock therapy versus patients treated with the standard of care (i.e., heparin). We enrolled 149 patients and diagnosed 86 episodes of critical catheter colonization by coagulase-negative staphylococci. Patients treated with antimicrobial lock had a relative risk of bloodstream infection of 0.19 when compared with heparin lock (CI 95%, 0.11−0.33, p < 0.001) within three months of treatment. We avoided one catheter-related bloodstream infection for every ten catheter-critical colonizations treated with antimicrobial lock [number needed to treat 10, 95% CI, 5.26−100, p = 0.046]. In conclusion, pre-emptive antimicrobial locks decrease bloodstream infection rates in hemodialysis patients with critical catheter colonization.

Validity of a catheter exit site clinical assessment scale for the early detection of exit site infections in patients on haemodialysis with a central venous catheter: protocol for a multicentre validation study in Spain (EXITA Study)

INTRODUCTION

Haemodialysis patients with central venous catheter (HD-CVC) are at increased risk of exit site infections (ESIs) and catheter-related bloodstream infections, causing an increase of hospitalisation, morbidity and mortality rates. The main aim of the EXITA Study is to develop and validate an instrument for the early detection of HD-CVC ESIs.

METHODS AND ANALYSIS

EXITA is a multicentre prospective cohort study to validate the proposed instrument with a sample of 457 HD-CVCs: 92 in the ESI group and 365 in the non-ESI group. Sample size was calculated using Epidat V.4.2 software, with 95% and 90% expected sensitivity and specificity, respectively, an ESI incidence around 20% and 5%-10% precision range. During each haemodialysis session, the absence or presence of each item will be assessed by nurses. If any item is present, a microbiological study of pericatheter skin smears and/or exit site exudate will be carried out. HD-CVC ESI will be diagnosed when the pericatheter skin smears and/or exit site exudate culture are positive (≥15 CFU/mL by semiquantitative Maki's technique or ≥1000 CFU/mL by Cleri's technique). To validate the scale, a logistic regression analysis will be performed: the β coefficients of each of the signs/symptoms of the scale to be validated will be estimated. We will use logit function and calculate ESI probability=elogit ESI/1+elogit ESI.

ETHICS AND DISSEMINATION

The study has been approved by the Research Ethics Committee with Medical Products of Cantabria (approval code 2019.146). We will obtain informed consent from all participants before data collection. We will publish the study results in a peer-reviewed scientific journal.

Challenging, Safe, and Effective Use of External Iliac Vein for Insertion of Tunneled Cuffed Hemodialysis Catheters: A Single-Center Prospective Study

Background

Providing well-functioning vascular access is crucial for patients undergoing chronic hemodialysis. Peripheral arteriovenous fistulas and grafts are the preferred accesses in hemodialysis patients. Patients with bilateral obstruction of internal jugular veins and subclavian veins require a suitable vascular access. Thus, the insertion of iliac vein tunneled cuffed catheters (TCCs) by interventional nephrologists may be a good option for these patients. We aimed to evaluate the outcomes of iliac vein TCCs in patients lacking other vascular options.

Methods

80 tunneled cuffed hemodialysis catheters were inserted through the iliac veins of 80 patients with an end-stage kidney disease. Catheter insertion was guided by Doppler ultrasonography followed by plain radiography to detect the catheter tip and exclude complications.

Results

The insertion success rate was 100%. 25 patients developed catheter-related infections. The mean survival time per catheter was 328 days. At the end of the study, 40 catheters were still functioning, 15 patients were shifted to continuous ambulatory peritoneal dialysis and 5 patients were referred to the interventional radiology department for insertion of transhepatic inferior vena cava tunneled catheters. Resistant catheter-related infection was the main cause of catheter removal in 11 patients (17.5%) in this study. Catheter malfunction was the second most common cause of catheter removal in 9 patients (11.25%).

Conclusion

This study concluded that iliac vein TCCs can provide suitable vascular access in hemodialysis patients with bilateral obstruction of internal jugular veins and subclavian veins.

Iatrogenic Infective Endocarditis in Hemodialysis Patients: A Case Report and Review of the Literature

Foreign bodies such as implanted cardiac devices are susceptible to infections and may be involved in infective endocarditis. Exposure to pathogens, by frequent use of intravascular accesses for hemodialysis (i.e., catheters or fistulas), combined with high rates of degenerative heart valve diseases in hemodialysis patients, both favor the development of infective endocarditis in this population. The mitral and aortic valves are predominantly implicated in endocardial infections. The involvement of both mitral and tricuspid valves is rare in the general population but can occur in hemodialysis patients with implanted cardiac devices. Infective endocarditis is associated with high morbidity and mortality rates among hemodialysis patients, mostly because of the complications of septic emboli. Prevention, prophylaxis, and early diagnosis of endocarditis can be lifesaving in this fragile population. We report a case of right and left heart methicillin-sensitive Staphylococcus aureus endocarditis with cerebral septic emboli in an elderly hemodialysis patient carrier of an arteriovenous fistula and an ipsilateral nonleadless pacemaker.

Aeromonas and Human Health Disorders: Clinical Approaches

The genus Aeromonas comprises more than 30 Gram-negative bacterial species and naturally inhabitants from aquatic environments. These microorganisms, commonly regarded as pathogens of fish and several other animals, have been gaining prominence on medical trial due to its ability to colonize and infect human beings. Besides water, Aeromonas are widely spreaded on most varied sources like soil, vegetables, and food; Although its opportunistic nature, they are able to cause infections on immunocompromised or immunocompetent patients. Aeromonas species regarded as potential human pathogens are usually A. hydrophila, A. caviae, and A. veronii biovar sobria. The main clinical manifestations are gastrointestinal tract disorders, wound, and soft tissue infections, as well as septicemia. Regarding to antibiotic responses, the bacteria present a diversified susceptibility profile and show inherence resistance to ampicillin. Aeromonas, as an ascending genus in microbiology, has been carefully studied aiming comprehension and development of methods for detection and medical intervention of infectious processes, not fully elucidated in medicine. This review focuses on current clinical knowledge related to human health disorders caused by Aeromonas to contribute on development of efficient approaches able to recognize and impair the pathological processes.

Coronary stent infection: a systematic review

Coronary stent infection (CSI) is the rarest complication associated with the percutaneous coronary intervention, occurring in less than 0.1% of cases. So far, all reported instances are limited to case reports. CSI presents itself in various, often confusing, ways in clinical settings. Therefore, the current systematic review summarizes reports of CSI's clinical presentations, causative pathogens, diagnoses and treatments. This systematic review considered three online databases, using reference lists as an additional source. All case reports or case series with stent infection in the coronary artery were included - however, reviews or commentaries, articles not published in English, and articles mentioning a history of hemodialysis or any surgery were excluded. Thirty-two studies on 34 CSI patients were included in the final qualitative analysis. CSI predominantly affected males of a wide range of ages. The most common symptoms were chest pain and fever with various onsets. Interestingly, CSI usually occurred during the first stent implantation. Cultures and coronary angiography were the most common methods used to diagnose CSI. Furthermore, drug-eluting stents had a higher risk of infection than bare-metal stents. Aneurysms were the most frequent abnormalities observed in infected stents. The bacteria that most often caused CSI were Staphylococcus aureus and Pseudomonas aeroginosa. More than 90% of the reports mentioned using various antibiotics, and 74% mentioned carrying out surgery. Finally, a mortality rate of 26.47% among CSI patients was calculated.

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.

Exposure to b-LED Light While Exerting Antimicrobial Activity on Gram-Negative and -Positive Bacteria Promotes Transient EMT-like Changes and Growth Arrest in Keratinocytes

While blue LED (b-LED) light is increasingly being studied for its cytotoxic activity towards bacteria in therapy of skin-related infections, its effects on eukaryotic cells plasticity are less well characterized. Moreover, since different protocols are often used, comparing the effect of b-LED towards both microorganisms and epithelial surfaces may be difficult. The aim of this study was to analyze, in the same experimental setting, both the bactericidal activity and the effects on human keratinocytes. Exposure to b-LED induced an intense cytocidal activity against Gram-positive (i.e, Staphylococcus aureus) and Gram-negative (i.e., Pseudomonas aeruginosa) bacteria associated with catheter-related infections. Treatment with b-LED of a human keratinocyte cell line induced a transient cell cycle arrest. At the molecular level, exposure to b-LED induced a transient downregulation of Cyclin D1 and an upregulation of p21, but not signs of apoptosis. Interestingly, a transient induction of phosphor-histone γ-H2Ax, which is associated with genotoxic damages, was observed. At the same time, keratinocytes underwent a transient epithelial to mesenchymal transition (EMT)-like phenotype, characterized by E-cadherin downregulation and SNAIL/SLUG induction. As a functional readout of EMT induction, a scratch assay was performed. Surprisingly, b-LED treatment provoked a delay in the scratch closure. In conclusion, we demonstrated that b-LED microbicidal activity is associated with complex responses in keratinocytes that certainly deserve further analysis.

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.

Survival Analysis of Tunneled Cuffed Central Venous Catheters in Maintenance Hemodialysis Patients: A Retrospective Study in China

AIM

The study aimed to investigate the clinical epidemiological data and the survival rate of maintenance hemodialysis patients with tunneled cuffed central venous catheters (TCCs) in a single hemodialysis center in China.

METHODS

We retrospectively investigated the general clinical characteristics (including sex, age, primary causes, and catheter outcome) of 316 patients undergoing maintenance hemodialysis (MHD) via TCC for >3 months at Wannan Medical College Affiliated Yijishan Hospital, Wuhu, China, from July 2011 to June 2021. The long-term survival rate of the catheters was determined by Kaplan-Meier survival analyses.

RESULTS

A total of 316 patients (137 males, 179 females) were included, with a mean age of 65.0 ± 15.5 years. The right internal jugular vein was the most commonly used central vein, accounting for 89.1% of catheterizations. After censoring for noncatheter-related events leading to the removal of the catheter, the mean survival time of the TCCs was 26.2 ± 19.8 smonths and the median survival time was 58.0 (95% CI, 54.0-62.0) months. Seventy patients had catheter loss-of-function events, with an incidence of 22.2%. Moreover, 97.3% of TCCs survived 1 year and 43.3% survived 5 years, respectively. The sex and age of the patients were not related to the survival rate (p > 0.05). There were also no statistical differences between the primary diseases of patients and the survival rate of TCCs (p > 0.05).

CONCLUSION

In this study, we provide evidence of the mean TCC survival time beyond 2 years. We found that TCC is an effective alternative for MHD patients with poor vessel status or limited survival time or become a bridge waiting for arteriovenous fistula to mature, regardless of age, sex, and primary diseases.

Unconventional T cells and kidney disease

Unconventional T cells are a diverse and underappreciated group of relatively rare lymphocytes that are distinct from conventional CD4⁺ and CD8⁺ T cells, and that mainly recognize antigens in the absence of classical restriction through the major histocompatibility complex (MHC). These non-MHC-restricted T cells include mucosal-associated invariant T (MAIT) cells, natural killer T (NKT) cells, γδ T cells and other, often poorly defined, subsets. Depending on the physiological context, unconventional T cells may assume either protective or pathogenic roles in a range of inflammatory and autoimmune responses in the kidney. Accordingly, experimental models and clinical studies have revealed that certain unconventional T cells are potential therapeutic targets, as well as prognostic and diagnostic biomarkers. The responsiveness of human Vγ9Vδ2 T cells and MAIT cells to many microbial pathogens, for example, has implications for early diagnosis, risk stratification and targeted treatment of peritoneal dialysis-related peritonitis. The expansion of non-Vγ9Vδ2 γδ T cells during cytomegalovirus infection and their contribution to viral clearance suggest that these cells can be harnessed for immune monitoring and adoptive immunotherapy in kidney transplant recipients. In addition, populations of NKT, MAIT or γδ T cells are involved in the immunopathology of IgA nephropathy and in models of glomerulonephritis, ischaemia-reperfusion injury and kidney transplantation.

Risk factors for infection-related hospitalization in end-stage renal disease patients during peri-dialysis period

Infection-related hospitalization during the peri-dialysis period (PDP) in patients with end-stage renal disease (ESRD) has received less attention. Considering the limited data, we explored the risk factors in this population. Retrospective analysis using the data system to examine factors for infection in ESRD during PDP between January 2012 and December 2017. Patients were divided into infected group and non-infected group according to the history of infection. Binary Logistic Regression Model was used to search for risk factors. A total of 478 patients were hospitalized during their PDP. One hundred and ninety patients developed infection (39.75%). Thirty-six patients (18.95%) had two or more infection events, all due to recurrent respiratory infections. The respiratory system was the main site of infection (63.68%), followed by the urinary system and digestive system. Compared with the non-infected group, the infected group had more patients with hypoproteinemia and coronary heart disease. The following factors: C-reactive protein >15 mg/L, procalcitonin >1 ng/L, neutrophil percentage >75%, age >52.5 years, platelet >300 × 10⁹ /L, neutrophil to lymphocyte ratio, and concomitant coronary heart disease were associated with the occurrence of infection in ESRD patients during PDP. Patients with ESRD have a high incidence of infection during the PDP, with respiratory infection most commonly seen. This research identified several factors associated with risk for infection, which should guide the design of infection prevention strategies.

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.

Association Between Lighting Level to Subjective Complaints of Visual Fatigue on Operators in the Auto Welder Section

Introduction: Good intensity of light dramatically affects the eyes. If there is less intensity of light. the eye muscles contract as much as possible to see objects or vice versa. If this happens continuously, it will cause damage to the eyes. Based on the preliminary study, it was found that as the auto welder operators have the task to observe the results of the auto welder engine to determine the quality of the welder, this type of work needs accuracy so that the right lighting intensity is required. This study aimed to determine the association between the lighting level and subjective visual fatigue complaints on operators in the auto welder section. Methods: The research method used was quantitative, with a cross- sectional approach and observational method. The samples in this study were 18 respondents from the total sampling technique. The instrument used was the Visual Fatigue Index (VTI) questionnaire. Moreover, the analysis of the study results used the one sample T-test statistical test to determine the association between the dependent and independent variables. Results: The one sample T-test results showed p-value = 0.012 < α = 0.05. This result showed an association between the lighting leveland subjective visual fatigue complaints on operators in the auto welder section. Conclusion: In this research, it was found that the majority of lighting levels that did not meet the standards had an association with subjective complaints of visual fatigue on the operators in the auto welder section.Keywords: auto welder, lighting, visual fatigue

Hypoalbuminemia as Surrogate and Culprit of Infections

Hypoalbuminemia is associated with the acquisition and severity of infectious diseases, and intact innate and adaptive immune responses depend on albumin. Albumin oxidation and breakdown affect interactions with bioactive lipid mediators that play important roles in antimicrobial defense and repair. There is bio-mechanistic plausibility for a causal link between hypoalbuminemia and increased risks of primary and secondary infections. Serum albumin levels have prognostic value for complications in viral, bacterial and fungal infections, and for infectious complications of non-infective chronic conditions. Hypoalbuminemia predicts the development of healthcare-associated infections, particularly with Clostridium difficile. In coronavirus disease 2019, hypoalbuminemia correlates with viral load and degree of acute lung injury and organ dysfunction. Non-oncotic properties of albumin affect the pharmacokinetics and pharmacodynamics of antimicrobials. Low serum albumin is associated with inadequate antimicrobial treatment. Infusion of human albumin solution (HAS) supplements endogenous albumin in patients with cirrhosis of the liver and effectively supported antimicrobial therapy in randomized controlled trials (RCTs). Evidence of the beneficial effects of HAS on infections in hypoalbuminemic patients without cirrhosis is largely observational. Prospective RCTs are underway and, if hypotheses are confirmed, could lead to changes in clinical practice for the management of hypoalbuminemic patients with infections or at risk of infectious complications.

Targeting COVID-19 prevention in hemodialysis facilities is associated with a drastic reduction in central venous catheter-related infections

BACKGROUND

In hemodialysis (HD) patients, central venous catheter (CVC) related bloodstream infections are a major cause of morbidity and mortality. Hygienic precautions are a key aspect of dialysis care for infection prevention, but they are not sufficient to completely avoid the occurrence of CVC related infections. During the COVID-19 pandemic, hygienic precautions for preventing viral transmission have been markedly reinforced. We evaluated their effects on CVC-related infection rates.

METHODS

An observational retrospective study was conducted in two hemodialysis units of the same institution treating 215 chronic hemodialysis patients, 71 of whom are currently (33%) using a CVC. In the CVC cohort, we compared data on catheter-related infection rates during the maximum spread of the COVID-19 pandemic in Italy (February to May 2020) with data from the same period of the previous year and with the whole of 2019.

RESULTS

In 2019, we recorded a catheter-related bloodstream infection (CRBSI) rate of 1.19 (95% CI 0.81-1.68)/1000 days [2.07 (95% CI 1.12-3.52)/1000 days in the Feb-May 2019 period] and a tunnel and exit-site infection rate of 0.82 (95% CI 0.51-1.24)/1000 days [1.04 (95% CI 0.41-2.15)/1000 days in the Feb-May 2019 period]. Infection rates drastically decreased during the COVID-19 pandemic, with just one catheter-related bloodstream infection being recorded. Catheter-related bloodstream infection rates showed a significant reduction to 0.20 (95% CI 0.01-0.9)/1000 days (p < 0.05 and p < 0.005 compared to 2019 and to Feb-May 2019, respectively) and a non-significant reduction in tunnel and exit-site infections to 0.6 (95% CI 0.15-1.6)/1000 days.

CONCLUSIONS

The observed 91% reduction in catheter-related bloodstream infections compared to the same period in 2019 [IRR 0.09 (95% CI 0.002-0.64)] and the 83% reduction compared to the whole of 2019 [IRR 0.17 (95% CI 0.004-1.009)] suggest that a stricter implementation of hygienic precautions in the dialysis setting can markedly improve the problem of CVC-related infections.

Patency and functionality of radiocephalic arteriovenous fistulas with an external support device (VasQ™): Real-world single-center experience

BACKGROUND

The VasQTM device was designed to improve the outcome of arteriovenous fistulae by optimizing the hemodynamics of the flow in the juxta-anastomotic region of the arteriovenous fistulae through tailored external support. The aim of the study was to evaluate the impact of the VasQ on outcome of radiocephalic arteriovenous fistulae in a real-world setting.

METHODS

This was a single-center, retrospective analysis of patients with either fistula creation before or after dialysis initiation with implantation of the VasQ device during creation of end-to-side radiocephalic arteriovenous fistulae between June 2018 and May 2019. The flow rate and vein diameter were evaluated intraoperatively, at discharge within 48 h postprocedure and at a follow-up of 1, 3, 6, 9, and 12 months.

RESULTS

Thirty-three VasQ devices were implanted during 33 radiocephalic arteriovenous fistula procedures. The study population comprised mostly of men, with an average age of 66 years. Mean intraoperative flow was 428 mL/min (range: 130-945). All patients were discharged with patent arteriovenous fistulae and mean fistula flow of 740 mL/min (range: 230-1300 mL/min). The primary patency was 100% and 79% at 3 and 6 months, respectively. Cumulative/secondary patency was 100% and 90% at 3 and 6 months, respectively.

CONCLUSION

Data presented here suggest that the VasQ device has the potential to provide benefit to the functionality of radiocephalic arteriovenous fistulae.

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.

Bioengineered human blood vessels

Since the advent of the vascular anastomosis by Alexis Carrel in the early 20th century, the repair and replacement of blood vessels have been key to treating acute injuries, as well as chronic atherosclerotic disease. Arteries serve diverse mechanical and biological functions, such as conducting blood to tissues, interacting with the coagulation system, and modulating resistance to blood flow. Early approaches for arterial replacement used artificial materials, which were supplanted by polymer fabrics in recent decades. With recent advances in the engineering of connective tissues, including arteries, we are on the cusp of seeing engineered human arteries become mainstays of surgical therapy for vascular disease. Progress in our understanding of physiology, cell biology, and biomanufacturing over the past several decades has made these advances possible.

Post-antibiotic era in hemodialysis? Two case reports of simultaneous colonization and bacteremia by multidrug-resistant bacteria

The emergence of resistance mechanisms not only limits the therapeutic options for common bacterial infections but also worsens the prognosis in patients who have conditions that increase the risk of bacterial infections. Thus, the effectiveness of important medical advances that seek to improve the quality of life of patients with chronic diseases is threatened. We report the simultaneous colonization and bacteremia by multidrug-resistant bacteria in two hemodialysis patients. The first patient was colonized by carbapenem- and colistin-resistant Klebsiella pneumoniae, carbapenem-resistant Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus (MRSA). The patient had a bacteremia by MRSA, and molecular typing methods confirmed the colonizing isolate was the same strain that caused infection. The second case is of a patient colonized by extended-spectrum beta-lactamases (ESBL)-producing Escherichia coli and carbapenem-resistant Pseudomonas aeruginosa. During the follow-up period, the patient presented three episodes of bacteremia, one of these caused by ESBL-producing E. coli. Molecular methods confirmed colonization by the same clone of ESBL-producing E. coli at two time points, but with a different genetic pattern to the strain isolated from the blood culture. Colonization by multidrug-resistant bacteria allows not only the spread of these microorganisms, but also increases the subsequent risk of infections with limited treatments options. In addition to infection control measures, it is important to establish policies for the prudent use of antibiotics in dialysis units.

Lipoteichoic Acid as a Potential Noninvasive Biomarker of Biofilm in Dialysis Access

Tunneled central venous catheters (TCVCs) are colonized by Gram-positive organisms and form biofilm. Lipoteichoic acid (LTA) is a Gram-positive cell wall component that can be measured in serum. The purpose of this pilot study was to characterize LTA concentrations in hemodialysis (HD) patients with TCVCs compared to other access types and to evaluate biofilm morphology and microbiology in TCVCs removed by clinical decision. The study enrolled patients with TCVCs (18), grafts (19), and fistulas (18). Blood samples were collected before HD, at 30 minutes, 2 hours, and end of HD. Catheters removed by clinical decision were evaluated by scanning electron microscopy (SEM) for biofilm morphology, and portions of the catheter were cultured. LTA was detectable in all samples and concentrations increased significantly in all access types during HD (p < 0.05 for all comparisons). Patients with TCVCs that had a >30% increase in LTA concentration from baseline also had the greatest rate of increase (slope) compared to grafts and fistulas (p = 0.03 and p = 0.04, respectively). Catheters removed by clinical decision (n = 7) and examined by SEM had deposition of fibrin. Cultures revealed polymicrobial colonization. TCVCs had the highest rate of increase of LTA during HD. Further studies to determine the source of LTA in patients with AVG and AVF are warranted.

Incidence and risk factors of sepsis in hemodialysis patients in the United States

BACKGROUND

Sepsis is one the most serious and life-threatening complication in patients with chronic hemodialysis (HD) access. Arteriovenous fistula (AVF) use is associated with a lower risk of infection. However, several prior studies identified significantly higher number of patients initiating HD using a catheter (HC) or arteriovenous graft (AVG). The aim of this study was to use a large national renal database to report the incidence and risk factors of sepsis in patients with end-stage renal disease (ESRD) initiating HD access using AVF, AVG, or HC in the United States.

METHODS

All patients with ESRD initiating HD access (AVF, AVG, HC) between January 1, 2006, and December 31, 2014, in United States Renal Data System were included. International Classification of Diseases, 9th edition-Clinical Modification diagnosis code (038x, 790.7) was used to identify patients who developed first onset of sepsis during follow-up. Standard univariate (Students t-test, χ², and Kaplan-Meier) and multivariable (logistic/Cox regression) analyses were performed as appropriate.

RESULTS

A total of 870,571 patients were identified, of whom, 29.8% (n = 259,686) developed sepsis. HC (31.2%) and AVG (30.6%) were associated with a higher number of septic cases compared with AVF (22.9%; P < .001). The incident rate of sepsis was 12.66 episodes per 100 person-years. It was the highest among HC vs AVG vs AVF (13.86 vs 11.49 vs 8.03 per 100 person-years). Patients with sepsis were slightly older (mean age 65.09 ± 14.49 years vs 63.24 ± 15.17 years) and had higher number of comorbidities including obesity (40.7% vs 37.7%), congestive heart failure (36.6% vs 30.8%), peripheral arterial disease (15.6% vs 12.4%), and diabetes (59.6% vs 53.5%) (all P < .001). After adjusting for potential confounders, compared with AVF, patients with AVG (hazard ratio [HR], 1.35 [95% confidence interval [CI], 1.31-1.40) and HC (HR, 1.80 [95% CI, 1.77-1.84) were more likely to develop sepsis at 3 years (both P < .001). Compared with patients with no sepsis, sepsis was associated with a three-fold increase the odds of mortality (odds ratio, 3.16; 95% CI, 3.11-3.21; P < .001). Additionally, in patients who developed sepsis, AVF use was associated with significantly lower mortality compared with AVG and HC (73.7% vs 78.7% vs 78.0%; P < .001). After adjusting for significant covariates, compared with AVF, mortality at 1 year after sepsis was 21% higher in AVG (HR, 1.21; 95% CI, 1.15-1.28; P < .001) and nearly doubled in HC (HR, 1.94; 95% CI, 1.88-2.00; P < .001).

CONCLUSIONS

Sepsis risk in HD patients is clearly related to access type and is associated with dramatic increase in mortality. Initiating HD access with AVF to meet the National Kidney Foundation Kidney Disease Outcomes Quality recommendations should be implemented to reduce the incidence of sepsis and improve survival in patients with ESRD.

Catheter-related bloodstream infections in a nephrology unit: Analysis of patient- and catheter-associated risk factors

BACKGROUND

Central venous catheter use is rising in chronic and acute hemodialysis. Catheter-related bloodstream infections are a major complication of central venous catheter use. This article examines clinical factors associated with catheter-related bloodstream infections incidence.

METHODS

In this retrospective, single-center study, 413 patients undergoing extracorporeal treatments between 1 February 2014 and 31 January 2017 with 560 central venous catheters were recruited. Clinical parameters, such as gender, age, kidney disease status, diabetes, immunosuppression, and vintage dialysis, were collected at study entry. An incidence rate ratio (95% confidence interval) was calculated to assess the association between catheter-related bloodstream infections incidence rate and each clinical variable/central venous catheter type. Significant associations at the univariate analyses were investigated with multivariate Cox models.

RESULTS

During a cumulative time of 66,686 catheter-days, 54 catheter-related bloodstream infections (incidence rate: 0.81) events occurred. Gram negative bacteria were more frequent in patients with age < 80 years (16 (36%) vs. 0, p = 0.02). At the univariate analyses, male sex (incidence rate ratio: 1.9 (1.1-3.5), p = 0.03), age < 80 years (incidence rate ratio: 2.4 (1.1-5.5), p = 0.016) and acute kidney injury (incidence rate ratio: 5.6 (3.1-10), p < 0.0001) were associated with higher catheter-related bloodstream infections incidence rate. Compared with tunneled jugular central venous catheter, higher catheter-related bloodstream infections incidence rate was associated with non-tunneled jugular (incidence rate ratio: 6.45 (2.99-13.56), p < 0.0001) and non-tunneled femoral (incidence rate ratio: 12.90 (5.87-27.61), p < 0.0001) central venous catheter use; tunneled femoral central venous catheter was associated with higher non-significant incidence rate (incidence rate ratio: 2.45 (0.93-5.85), p = 0.07). The multivariate analyses showed that acute kidney injury (hazard ratio: 3.03 (1.38-6.67), p = 0.006), non-tunneled (hazard ratio: 3.11 (1.30-7.41), p = 0.01) and femoral (hazard ratio: 2.63 (1.36-5.07), p = 0.004) central venous catheter were associated with higher catheter-related bloodstream infections incidence rate.

CONCLUSION

Central venous catheter characteristics and acute kidney injury are independently associated with higher catheter-related bloodstream infections rate.

Arteriovenous access in hemodialysis: A multidisciplinary perspective for future solutions

In hemodialysis, vascular access is a key issue. The preferred access is an arteriovenous fistula on the non-dominant lower arm. If the natural vessels are insufficient for such access, the insertion of a synthetic vascular graft between artery and vein is an option to construct an arteriovenous shunt for punctures. In emergency situations and especially in elderly with narrow and atherosclerotic vessels, a cuffed double-lumen catheter is placed in a larger vein for chronic use. The latter option constitutes a greater risk for infections while arteriovenous fistula and arteriovenous shunt can fail due to stenosis, thrombosis, or infections. This review will recapitulate the vast and interdisciplinary scenario that characterizes hemodialysis vascular access creation and function, since adequate access management must be based on knowledge of the state of the art and on future perspectives. We also discuss recent developments to improve arteriovenous fistula creation and patency, the blood compatibility of arteriovenous shunt, needs to avoid infections, and potential development of tissue engineering applications in hemodialysis vascular access. The ultimate goal is to spread more knowledge in a critical area of medicine that is importantly affecting medical costs of renal replacement therapies and patients’ quality of life.