Iliopsoas abscess as a complication of tunneled jugular vein catheterization in a hemodialysis patient

Iliopsoas abscess is a rare complication in hemodialysis patients that is mainly due to adjacent catheterization, local acupuncture, discitis, and bacteremia. Herein, we report a 47‐year‐old woman undergoing regular hemodialysis via a catheter in the internal jugular vein who presented with low back pain and dyspnea. A heart murmur suggested the presence of catheter‐related endocarditis, and this was confirmed by an echocardiogram and a blood culture of methicillin‐resistant Staphylococcus aureus. A computed tomography indicated a pulmonary embolism and an incidental finding of iliopsoas abscess. Following surgical intervention and intravenous daptomycin, the patient experienced full recovery and a return to usual activities. This case indicates that an iliopsoas abscess can be related to a jugular vein catheter, which is apparently facilitated by infective endocarditis. The possibility of iliopsoas abscess should be considered when a hemodialysis patient presents with severe low back pain, even when there is no history of adjacent mechanical intervention.     

Approach to prophylactic measures for central venous catheter‐related infections in hemodialysis: A critical review

Vascular access is the major risk factor for bacteremia, hospitalization, and mortality among hemodialysis (HD) patients. The type of vascular access most associated with bloodstream infection is central venous catheter (CVC). The incidence of catheter‐related bacteremia ranges between 0.6 and 6.5 episodes per 1000 catheter days and increases linearly with the duration of catheter use. Given the high prevalence of CVC use and its direct association with catheter‐related bacteremia, which adversely impacts morbidity and mortality rates and costs among HD patients, several prevention measures aimed at reducing the rates of CVC‐related infections have been proposed and implemented. As a result, a large number of clinical trials, systematic reviews, and meta‐analyses have been conducted in order to assess the effectiveness, clinical applicability, and long‐term adverse effects of such measures. In the following article, prophylactic measures against CVC‐related infections in HD patients and their possible advantages and limitations will be discussed, and the more recent literature on clinical experience with prophylactic antimicrobial lock therapy in HD CVCs will be reviewed.     

Daptomycin antibiotic lock therapy for hemodialysis patients with Gram‐positive bloodstream infections following use of tunneled,cuffed hemodialysis catheters: retrospective single center analysis

Catheter‐related blood stream infection (CRBSI) is a major complication in hemodialysis patients. We assessed the efficacy of systemic daptomycin (DPT) plus DPT antibiotic lock therapy (DPT‐ALT) for catheter salvage in patients with Gram‐positive CRBSIs. This is a retrospective study of hemodialysis patients with tunneled and cuffed hemodialysis catheters. All patients were from a single institution in Taipei and received systemic DPT plus DPT‐ALT for the treatment of Gram‐positive CRBSI. Successful resolution of CRBSI was implemented. Resolution of fever within 48 hours, negative result of repeated blood cultures after resolution of fever, no clinical evidence of CRBSI relapse and no need for catheter removal were measured. Fifteen hemodialysis patients received DPT‐ALT for CRBSI, nine with coagulase‐negative Staphylococcus (CONS), two with methicillin‐resistant Staphylococcus aureus (MRSA), three with methicillin‐sensitive Staphylococcus aureus (MSSA) and one with polymicrobial infections. Systemic DPT plus DPT‐ALT cured 11 patients (73.3%). Treatment failed in all three MRSA cases (two with MRSA and one with MRSA + Enterococcus faecalis). Retrospective design and small sample size were the limitations of this study. Systemic DPT plus DPT‐ALT appears to be a promising treatment for CRBSI from CONS and MSSA, but not for MRSA CRBSI. Systemic DPT plus DPT‐ALT should be considered for patients with CRBSIs caused by certain species.     

High‐dose cefazolin on consecutive hemodialysis in anuric patients with Staphylococcal bacteremia

Methicillin‐sensitive Staphylococcus aureus (MSSA) bacteremia is a leading cause of infection in hemodialysis (HD) patients. Cloxacillin, cefazolin, and vancomycin are the mainstay antimicrobials. Cloxacillin administration leads to frequent drug dosing, longer length of stay (LOS), and higher cost, while resistance and poorer outcomes are associated with vancomycin use. Dosing cefazolin during HD allows for prolonged blood therapeutic levels. We assessed the outcomes and safety of a strategy of treating MSSA bacteremia with 2–3 g cefazolin on HD only. All HD patients with MSSA bacteremia admitted in June–December 2009 at our center and receiving this regime were compared with historical controls who received cloxacillin. Demographic characteristics and outcome measures like mortality, LOS, cost, recrudescence, and adverse drug reactions were assessed. Of 27 consecutive episodes reviewed, 14 and 13 patients received cefazolin and cloxacillin, respectively. Baseline demographics were comparable between the 2 treatment groups. More than one‐third of the bacteremia was related to tunneled catheter infection. The 30‐day mortality of cloxacillin‐ and cefazolin‐treated patients was 15% and 7%, respectively (P=0.14). Two of the 11 survivors treated with cloxacillin (18%) had recrudescent bacteremia while none was observed in cefazolin‐treated survivors. Cefazolin was associated with shorter LOS (10 vs. 20 days, P<0.05) and lower cost (US$8262.00 vs. US$15,367.00, P<0.05). Cefazolin use resulted in 3 idiosyncratic adverse drug reactions. Cefazolin dosed on each HD in MSSA bacteremia leads to earlier discharge and less cost. Larger prospective studies are, however, warranted to fully assess its safety and efficacy.     

Air-Bubble Method of Locking Central-Vein Catheters for Prevention of Hub Colonization: A Pilot Study

Background: The major source of catheter‐associated bacteremia is contamination of the catheter hub during connection–disconnection procedures. A new method of catheter locking has been developed wherein anticoagulant is injected first, followed by a 0.1‐mL air bubble and 0.9 mL of bactericidal solution. The anticoagulant is then located at the catheter tip and the bactericidal solution is located at the catheter hub. The air bubble prevents mixing of the two solutions. The bactericidal solution was acidified concentrated saline (ACS). The 27% saline solution has a pH of 2.0. ACS was chosen because it is theoretically harmless if injected in the amount used to lock the catheter lumens. The goals of this pilot study were to determine whether the new method of catheter locking is easy to perform with available syringes and whether eventual injection of the experimental solution is well tolerated. Methods: Ten patients were randomly assigned, either to heparin lock (5 patients, 62 treatments) or air‐bubble method (5 patients, 56 treatments). In the control group, the catheters were locked with heparin, 5000 U/mL. In the experimental group, the catheters were locked with heparin, air bubble, and ACS. Altogether, the lumens were overfilled by 0.2 mL. Results: Compared to the routine method, the experimental method required a 1‐ to 2‐min‐longer procedure time. There were no errors in proper sequence of injections into the lumina. There were no episodes of bacteremia related to hub contamination in either group. In the air‐bubble group, there was one case of bacteremia associated with purulent drainage from the exit and the same organism in both cultures. In three instances in each group, the locking solution could not be aspirated and was injected without any subjective symptoms or objective signs. Conclusion: We conclude that the air‐bubble method of locking central‐vein catheters is easy to perform. In three instances of air‐bubble and ACS injection, there were no adverse effects. A full‐scale prospective randomized study is feasible and warranted.     

Ten‐year study of bacteremia in hemodialysis patients in a single center

Background: The incidence of infection in patients on chronic hemodialysis in higher than that of the general population. Infection is known to be a major cause of morbidity and mortality in these patients. The vascular access is important for hemodialysis, but infection through this route is the most common source of bacteremia and can be lethal to the patients. Despite the high morbidity and mortality of bacteremia in patients on chronic hemodialysis, the clinical characteristics of bacteremia in hemodialysis patients is rarely reported yet in Korea. Methods: We included 696 hemodialysis patients from January 1993 to December 2003 at Uijongbu St. Mary's Hospital. We investigated incidence, source, causative organisms, clinical manifestations, complication, and mortality of bacteremia. We compared clinical factors, morbidity, and mortality between arteriovenous fistula and central venous catheter groups. Results: Total 52 cases of bacteremia occurred in 43 patients. The major source of infection was vascular access (48%). Staphylococcus aureus was most common organism isolated. Major complications were septic shock (9.6%), pneumonia (9.6%), infective endocarditis (3.8%), and aortic pseudoaneurysm (1.9%). Nine patients died from septic shock (n = 4), aspiration pneumonia (n = 2), hypoxic brain injury (n = 1), gastrointestinal bleeding (n = 1), and rupture of aortic pseudoaneurysm. The central venous catheter group (n = 22) had higher incidences of vascular access as a source of infection (81.8% vs 23.3%, p < 0.001) and staphylococcus as a causative organism (77.2% vs 50.0%, p = 0.042) than the arteriovenous group. Conclusion: This data shows that bacteremia causes high incidence of fatal complications and mortality. Therefore, careful management of vascular access as well as early detection of bacteremia is an important factor for the prevention of infection and proper antibiotic therapy should be started early.     

Relation between Access-Related Infection and Preinfection Serum Albumin Concentration in Patients on Chronic Hemodialysis

Background: Hemodialysis (HD) access‐related infection is a major cause of morbidity and mortality in HD patients. We tested whether hypoalbuminemia is a risk factor for HD access infection and whether mortality of HD catheter infection is affected by removal of the infected catheter. Methods: We analyzed the records of 87 patients on chronic HD who were hospitalized for HD access‐related infection. We obtained data on age, sex, preinfection serum albumin level, comorbidities, complications, infecting organism, type of infection, mode of management, and mortality. We compared preinfection serum albumin levels in 79 patients with HD access infection with the serum albumin levels of 198 control patients on chronic HD without HD access infection admitted to the hospital during the same time for other reasons. In the HD catheter infection subgroup, we compared mortalities between patients treated with catheter removal plus antibiotics as the primary mode of management and those treated initially with antibiotics alone. Results: Preadmission serum albumin level was lower in the HD access infection group (2.4 ± 0.6 g/dL) than in the control group (3.2 ± 0.6 g/dL, P < 0.0001). Logistic regression identified preadmission serum albumin level as a strong independent predictor of HD access infection. In a logistic regression model, with age, sex, HIV status, diabetes, and type of HD vascular access (excluding arterovenous fistula) as the covariates, the odds ratio of HD access infection was 9.8 (95% confidence interval [CI] 4.9–19.7) for a serum albumin level ≤ 3.0 g/dL (P < 0.0001), 10.4 (95% CI 4.97–21.6) for a serum albumin level ≤ 2.5 g/dL (P < 0.0001), and 28.0 (95% CI 5.8–135.9) for a serum albumin level ≤ 2.0 g/dL (P < 0.0001). Case mortality was 25.0% (4/16) in patients with tunneled HD catheter infection initially treated with antibiotics alone and 2.8% (2/71) in those treated with catheter removal plus antibiotics at the time of presentation (P = 0.0096). Conclusion: Hypoalbuminemia is associated with increased risk of HD access infection. Treatment of HD access infection with antibiotics alone is associated with increased risk of death.     

Complications associated with the development of bacteremia with Staphylococcus aureus

Access-related infections are a leading cause of morbidity and mortality among hemodialysis patients. Staphylococcus aureus bacteremia accounts for 25% of these episodes. Nissenson et al., found that 20.7% of the patients developing S. aureus bacteremia had infectious complications as well as hospital readmissions related to the S. aureus bacteremia. This retrospective analysis did not determine whether the S. aureus bacteremia was access related, nor how each episode was treated. We have prospectively collected a database of all access-related S. aureus bacteremia developing in our unit between 1/1/03 and 8/31/05, including the management of the access. Episodes of S. aureus bacteremia with an identifiable source other than the vascular access were excluded. Seventy-two episodes of S. aureus bacteremia were identified; 54 developed in patients using a catheter and 18 developed in patients using an arteriovenous graft/fistula. The mean age was 64+/-15 years, and 56% of the patients were Caucasian. All patients were treated with 4 weeks of antibiotics. A total of 6 (8%) deaths and 15 (20.8%) infectious complications related to the S. aureus bacteremia were identified. Infectious complications included endocarditis (4), metastatic infection (7), discitis (3), and a myocardial abscess (1). Seventeen (23.6%) of the patients were readmitted within 30 days of the episode of S. aureus bacteremia; 4 readmissions were related to the S. aureus bacteremia. Five of the 54 catheter patients who developed S. aureus bacteremia expired and 14 developed infectious complications despite the catheter being removed/exchanged in all but one patient. One of the arteriovenous graft patients who developed S. aureus bacteremia expired. We conclude that infectious complications from S. aureus bacteremia are common, as 23.6% of the patients in our study developed an infectious complication. Eight percent of the patients who developed S. aureus bacteremia expired. Strategies to avoid S. aureus bacteremia are needed.     

Safety of arteriovenous fistulae and grafts for continuous renal replacement therapy: The Michigan experience

Introduction: Arteriovenous fistula or graft (AVF/AVG) use is widely considered contraindicated for continuous renal replacement therapy (CRRT), yet insertion of hemodialysis (HD) catheters can carry high complication risk in critically ill end‐stage renal disease (ESRD) patients. Methods: Single‐center analysis of 48 consecutive hospitalized ESRD patients on maintenance HD who underwent CRRT using AVF/AVG from 2012 to 2013. Primary outcome was access‐related complications. Findings: Mean age was 60 years, 48% were male, and 88% required vasopressor support. Median duration of AVF/AVG use for CRRT was 4 days (range 1–34). Ten (21%) patients had access complications (5 bleeding, 5 infiltration, 1 thrombosis); 5 (10.4%) required catheter placement. Overall 31 (65%) patients survived to hospital discharge and AVF/AVG access was functional at the time of discharge in 29 (94%) patients. Discussion: In our experience, use of AVF/AVG for CRRT can be performed with a low serious complication rate and low risk of access loss, potentially avoiding catheter‐related complications.     

Catheter‐related bacteremia and mortality in frequent nocturnal home hemodialysis

Frequent nightly home hemodialysis (NHHD) has emerged as an attractive alternative to thrice weekly in‐center hemodialysis, albeit with preponderant long‐term hemodialysis catheter used. Sixty‐three NHHD patients from University of Virginia Lynchburg Dialysis Facility were matched 1:2 with 121 conventional hemodialysis patients admitted to Fresenius Medical Care North America facilities from January 1, 2007 to December 31, 2010. Matching considered age (± 5 years), gender, race, dialysis vintage, and diabetes. The primary end‐point was the combined incidence of bacteremia/sepsis, for up to 20 months or upon changing to a fistula/graft (with catheter removal), transferring to peritoneal dialysis (PD), or at the time of kidney transplant or death. No significant differences were observed in rate of fistula/graft conversion, transfer to PD, transplant, or death between NHHD and in‐center hemodialysis (IHD) groups. For the first catheter used, the rate of catheter‐related sepsis was not significantly different between the NHHD (1.77 per 100 patient months) and IHD (2.03 per 100 patient months; P = 0.21). Combining all catheters, the rate of bacteremia/sepsis per 100 patient months in the NHHD group was 1.51 and in the IHD group was 2.01 (P = 0.35). Median catheter lifespan for the first catheter was 5.6 (1.7～19.0) for NHHD and 4.6 (2.7～7.8) for the IHD group (P = 0.64), and for all catheters used was 5.2 (Q1～Q3 = 1.5～15.2) months in NHHD group, and 4.1 (2.0～6.8) months in IHD group (P = 0.20). The rate of bacteremia and death is not different for up to 20 months in catheter users who dialyze via frequent NHHD vs. thrice weekly IHD.     

Synergistic Chemotherapy and Photodynamic Therapy of Endophthalmitis Mediated by Zeolitic Imidazolate Framework‐Based Drug Delivery Systems

Endophthalmitis, derived from the infections of pathogens, is a common complication during the use of ophthalmology‐related biomaterials and after ophthalmic surgery. Herein, aiming at efficient photodynamic therapy (PDT) of bacterial infections and biofilm eradication of endophthalmitis, a pH‐responsive zeolitic imidazolate framework‐8‐polyacrylic acid (ZIF‐8‐PAA) material is constructed for bacterial infection–targeted delivery of ammonium methylbenzene blue (MB), a broad‐spectrum photosensitizer antibacterial agent. Polyacrylic acid (PAA) is incorporated into the system to achieve higher pH responsiveness and better drug loading capacity. MB‐loaded ZIF‐8‐PAA nanoparticles are modified with AgNO₃/dopamine for in situ reduction of AgNO₃ to silver nanoparticles (AgNPs), followed by a secondary modification with vancomycin/NH₂‐polyethylene glycol (Van/NH₂‐PEG), leading to the formation of a composite nanomaterial, ZIF‐8‐PAA‐MB@AgNPs@Van‐PEG. Dynamic light scattering, transmission electron microscopy, and UV–vis spectral analysis are used to explore the nanoparticles synthesis, drug loading and release, and related material properties. In terms of biological performance, in vitro antibacterial studies against three kinds of bacteria, i.e., Escherichia coli, Staphylococcus aureus, and methicillin‐resistant S. aureus, suggest an obvious superiority of PDT/AgNPs to any single strategy. Both in vitro retinal pigment epithelium cellular biocompatibility experiments and in vivo mice endophthalmitis models verify the biocompatibility and antibacterial function of the composite nanomaterials.     

Necrotizing fasciitis and infective endocarditis caused by Escherichia coli in a hemodialysis patient

Patients with uremia are often immunocompromised and uremia patients undergoing maintenance dialysis are often vulnerable to uncommon infections. We report a 40‐year‐old man who was undergoing maintenance hemodialysis and was initially diagnosed with monomicrobal necrotizing fasciitis of the lower limbs, based on blood and pus cultures that yielded Escherichia coli. His condition improved after surgical debridement and antibiotic therapy. However, he eventually died of intracranial hemorrhage related to septic emboli. Concurrent infective endocarditis was diagnosed based on an echocardiogram that indicated vegetation in the left ventricular region. Escherichia coli‐related necrotizing fasciitis and infective endocarditis is rarely seen in clinical practice. There should be a high index of suspicion for multiple infections when a hemodialysis patient presents with an uncommon infection.     

Infective spondylodiscitis in patients on high‐flux hemodialysis and on‐line hemodiafiltration

Infective spondylodiscitis (ISD) is a rare but potentially devastating condition in hemodialysis (HD) patients. Reports are limited especially in patients receiving high‐flux HD and hemodiafiltration (HDF). In a retrospective analysis, 13 patients on our maintenance high‐flux HD/HDF program were identified as having has infective spondylodiscitis over a 10‐year period (1997–2006), an incidence of approximately 1 episode every 215 patient‐years. The incidence was around 3 times higher in patients dialyzing with tunnelled central venous catheters (TCVC) than in those with arteriovenous fistulae. Affected patients were elderly (mean age 70 years) and had multiple comorbidities. Access problems, particularly TCVC infection, were common in the months preceding it's onset. Tunnelled central venous catheter removal during these episodes did not necessarily prevent it. Diagnosis was based on a history of back pain, raised C‐reactive protein, positive blood cultures, and characteristic magnetic resonance findings. Many patients were apyrexial and had normal white cell counts. In our patients on high‐flux HD/hemodiafiltration, its incidence appears comparable to that in conventional HD settings. No patients had infection with waterborne organisms. Blood cultures were positive in 77%. Gram‐positive organisms predominated, particularly Staphylococcus aureus. The major route of infection was hematogenous, with the most likely source the venous access. All received antibiotics for 6 to 12 weeks or until death. Only 2 patients underwent surgical drainage. Mortality was high (46%) and predicted by the development of complications, and by pre‐existing cardiovascular comorbidity. Prevention, using strategies to reduce the prevalence of bacteremia, including limiting the use of TCVC, should be an overriding aim.     

The economics and practicality of t‐PA vs tunnel catheter replacement for hemodialysis

Introduction: Thrombolytic therapy is an important treatment modality for thrombosis‐related catheter occlusion. Central venous access devices (CAVDs) are essential tools for the administration of many therapeutic modalities, especially for patients requiring lifetime therapy like hemodialysis. There are several reasons to salvage the occluded catheter. Catheter replacement results in an interruption of therapy delivery. This interruption may result in complications such as life‐threatening metabolic and physiologic states. In addition, the patient's future access sites for CAVDs may be affected. The data released in the 2001 Annual Report – ESRD Clinical Performance Measures Project (Department of Health and Human Services, December 2001) shows 17% of prevalent patients were dialyzed with a chronic catheter continuously for 90 days or longer. In the pediatric population the data shows that 31% were dialyzed with a chronic catheter. The most common reasons for catheter placement included: no fistula or graft created (42%) and fistula and graft were maturing, not ready to cannulate (17%). Five percent of patients were not candidates for fistula or graft placement as all sites had been exhausted. Methods: A short study was done in our medical center to evaluate the results of t‐PA vs. changing the tunnel catheter. On an average a catheter costs about $400.00. If you add the cost of specialty personnel such as an interventional radiologist, radiology technician, radiology nurse, and the ancillaries such as the room, sutures, gauze, and tape, the total could reach $2000.00 easily. Cathflo? Activase® costs around $60.00 for a single dose. T‐PA was reconstituted by pharmacy personnel in single vials containing 2 mg/2 ml. Now with Cathflo, vials are stored in the renal clinic's refrigerator and when the need arises, the RN reconstitutes the medication. The RN, using established protocols, will instill Cathflo in the catheter following the volume requirements of the various tunnel catheters. After the t‐PA is placed, the patient is sent home with instructions to return to their dialysis center the next day (arrangements are made by the RN as needed). In seventeen patients (17) with tunnel catheter malfunctions due to inadequate flow, not related to placement, t‐PA was used. Of those 17 patients 2 were unable to use their catheter on their next dialysis treatment date, yielding an 88% success rate. This compares with clinical trials in which there is an 83% success rate with a dwell time of 4 hours, or an 89% rate on patients having a 2 hour dwell time (t‐PA was repeated a second time if flow was not successfully restored. Results: 15/17 patients in our retrospective study showed that Cathflo worked successfully in restoring blood flow. Two catheters needed to be exchanged. The cost savings were significant when we compared the average cost of an exchange ($2000) versus using t‐PA ($170 including nursing time). Conclusion: Cathflo is not just safe and practical to use but also cost effective.     

Ethanol combined with heparin as a locking solution for the prevention of catheter related blood stream infections in hemodialysis patients: A prospective randomized study

Introduction: Ethanol lock solution has been mainly administered in paediatric and home parenteral nutrition patients in order to prevent catheter related blood stream infections (CRBSI). Its utility in hemodialysis (HD) patients with non‐tunneled‐uncuffed catheter (NTC) has been poorly explored. Methods: We conducted a prospective randomized study in chronic HD patients requiring a newly inserted NTC‐while awaiting for the maturation of an already established arteriovenous fistula (AVF) or arteriovenous graft (AVG) or tunneled‐cuffed catheter insertion. Patients were randomized in two groups: Group A, where the lock solution was ethanol 70% + unfractionated heparin 2000 U/mL and group B, that received only unfractionated heparin 2000 U/mL. Primary end point was CRBSIs whereas exit site infections, thrombotic and bleeding episodes were the secondary end points. Findings: One hundred three HD patients were enrolled in the study (group A, n = 52; group B, n = 51). The median number of catheter days was 32 for group A (range: 23–39) and 34 (range: 27–40) for group B with no statistically significant difference between the two groups. Group A (ethanol + heparin) demonstrated 4/52 episodes (7.69%) of CRBSI whereas Group B (heparin) 11/51 episodes (21.57%) (P = 0.04). CRBSI rates per 1000 catheter days were 2.53/1000 catheter days for group A and 6.7/1000 catheter days for group B (P = 0.04). Mean cumulative infection‐free catheter survival in the ethanol group did not differ significantly compared to the heparin group (log‐rank test = 2.99, P = 0.08). Thrombotic episodes did not differ between the two groups. Discussion: Locking of NTCs in HD patients with ethanol 70% + unfractionated heparin reduces CRBSI rates without increasing the thrombotic episodes.     

Single Fe Atom on Hierarchically Porous S,N‐Codoped Nanocarbon Derived from Porphyra Enable Boosted Oxygen Catalysis for Rechargeable Zn‐Air Batteries

Iron–nitrogen–carbon materials (Fe–N–C) are known for their excellent oxygen reduction reaction (ORR) performance. Unfortunately, they generally show a laggard oxygen evolution reaction (OER) activity, which results in a lethargic charging performance in rechargeable Zn–air batteries. Here porous S‐doped Fe–N–C nanosheets are innovatively synthesized utilizing a scalable FeCl₃‐encapsulated‐porphyra precursor pyrolysis strategy. The obtained electrocatalyst exhibits ultrahigh ORR activity (E_1/2 = 0.84 V vs reversible hydrogen electrode) and impressive OER performance (E_{j = 10} = 1.64 V). The potential gap (ΔE = E_{j = 10} ? E_1/2) is 0.80 V, outperforming that of most highly active bifunctional electrocatalysts reported to date. Furthermore, the key role of S involved in the atomically dispersed Fe–Nx species on the enhanced ORR and OER activities is expounded for the first time by ultrasound‐assisted extraction of the exclusive S source (taurine) from porphyra. Moreover, the assembled rechargeable Zn–air battery comprising this bifunctional electrocatalyst exhibits higher power density (225.1 mW cm^?2) and lower charging–discharging overpotential (1.00 V, 100 mA cm^?2 compared to Pt/C + RuO₂ catalyst). The design strategy can expand the utilization of earth‐abundant biomaterial‐derived catalysts, and the mechanism investigations of S doping on the structure–activity relationship can inspire the progress of other functional electrocatalysts.     

Relationship of Hypoalbuminemia to Multiple Clinical Factors in Hemodialysis Patients

Research shows that low albumin is correlated with higher morbidity and mortality in the dialysis population. The reasons for this are multi‐factorial and may be related to inadequate protein intake, infection and sepsis, inadequate dialysis, or catabolism of uremia. USRDS data show that ESRD Network 16 tends to have lower albumins compared to other ESRD Networks. Objective: To evaluate albumin status of HD patients at Puget Sound Kidney Centers, Everett, WA (ESRD Network 16) and identify potential factors that may put patients at risk of hypoalbuminemia. Methods: Clinical and biochemical data were collected for 3 months on 221 HD patients. Data included serum albumin (bromcresol purple), calcium, phosphorus, CO₂, Hct, % saturation, ferritin, PTH, BUN, Kt/V, URR, nPCR, hours of HD treatment, interdialytic fluid weight gains, DW changes, incidence of infection and hospitalization, catheter use for dialysis access, presence of diabetes and other co‐morbidities, dialyzer reuse, social/psychological status, and use of nutrition supplements. All biochemical data were collected after the longest interdialytic period and analyzed at the same reference laboratory. Data were averaged for each patient for the 3 months and correlations between parameters were determined using Chi‐square analysis. Results: 25% of all patients had albumins <3.2 g/dL (reference range for normal population 3.5–5.0 g/dL). Patients with lower albumins were significantly more likely to have DM (p < 0.02), use catheters for HD access (p < 0.001), had infections during the previous month (p < 0.001), been hospitalized during the previous month (p < 0.002), have co‐morbid issues (p < 0.001), and use nutrition supplements (p < 0.002). No other factors were significantly correlated with lower albumin. Conclusion: Factors other than nutrition seem to be related to hypoalbuminemia. This study has prompted improved protocols for catheter care and use, infection control, and early intervention for nutrition supplement use. Increased screening and monitoring at‐risk patients (those with diabetes and other co‐morbid conditions) has resulted in improved patient care.     

Concentrated Sodium Citrate (23%) for Catheter Lock

For chronic central venous dialysis catheters, the standard method for maintaining catheter patency between treatments is to instill (lock) catheters with 5000 – 10 000 units of heparin in each lumen. Sodium citrate (citrate) is an anticoagulant with intrinsic antibacterial activity (at 20% concentration or higher). Citrate has only transient anticoagulant effects if accidentally infused to the patient. Prior studies of citrate as a catheter lock solution have utilized citrate concentrations of 1% in combination with 27 mg/mL gentamicin. We changed clinical protocols for catheter locks using various solutions, including concentrated citrate, in a dialysis unit with 50% of patients having chronic central venous catheters [40 catheters total, mostly Ash Split Cath (Medcomp, Harleysville, PA, U.S.A.) but some Tesio (Medcomp) and Hickman (BARD, Salt Lake City, UT, U.S.A.) catheters]. At 3‐ to 4‐month intervals, the standard catheter lock solution for the unit was varied on the following schedule: heparin; 10% citrate with 3 mg/mL gentamicin; 20% citrate with 3 mg/mL gentamicin; heparin; and 23% citrate. Catheters were not routinely removed during treatment of bacteremia. Incidence of bacteremia in patients with catheters using heparin as catheter lock was 4.32 episodes per 3000 patient‐days (equivalent to percent of patients with catheters having bacteremia per month). The incidence of bacteremia decreased to 1.68 using 20% citrate/gentamicin as catheter lock (p < 0.05) and to 0% with 47% citrate (p < 0.05). Incidence of bacteremia increased on return to heparin and decreased again with use of 23% citrate to 1.79 (p < 0.05). Use of urokinase for occluded catheters also significantly decreased with citrate during the time that it was available (p = 0.02). Life table analysis indicated an 83% survival of Ash Split Cath catheters at 1 year, in this unit. Concentrated citrate is an effective catheter lock solution that may provide prolonged central venous catheter use with a diminution in catheter‐related infections and occlusion.     

Normalization of Dialysis Dose for Daily Dialysis

The equilibrated Kt/V (eKtV) is widely used in hemodialysis (HD) as a measure of the intensity (magnitude) of an individual dialysis treatment. Adequate eKt/V for thrice‐weekly hemodialysis (twHD) has been extensively studied, and a value in the range 1.0 – 1.1 per treatment (3.0 – 3.3 weekly) is generally considered to represent adequate therapy for this specific frequency of dialysis. However, for other schedules, summing eKt/V's and time‐averaging the clearance is not appropriate. This was first demonstrated several years ago by the observation that a weekly eKt/V of 2.0 in continuous ambulatory peritoneal dialysis (CAPD) is therapeutically equal to a weekly eKt/V of 3.0 in twHD. That paradox has been resolved by the standard Kt/V (stdKt/V), which accounts for the first order nature of solute removal by dialysis, and which correctly predicts a normalized weekly stdKt/V of 2.0 for both CAPD and twHD. The equivalent renal clearance (EKR) has also been advanced as a method to normalize dose for varying treatment schedules. However, mathematical consideration shows that EKR is an exact time‐averaged clearance. Analysis of data reported for daily dialysis by Piccoli et al. in the present issue of Hemodialysis International shows that the EKR_ct/V calculated for daily dialysis is identical to the sum of eKt/V's for the individual dialyses. We therefore conclude that EKR is not a suitable parameter for normalizing the dialysis dose, because it fails to reflect the effect of dialysis frequency in HD therapy.