HEMATOLOGY: ISSUES IN THE DIALYSIS PATIENT: The Safety of Heparins in End-Stage Renal Disease

Application of Extracorporeal Apheresis in Treatment of COVID-19: a Rapid Review

Spread of a novel coronavirus infection in 2019 caused by SARS-CoV-2 virus has become a real threat to public health all around the world. The new pandemic required the mobilization of all resources for effective treatment of COVID-19 patients. Extracorporeal apheresis methods were suggested as an addition to the therapy of severe COVID-19 patients, especially when there is a threat of cytokine storm. Cytokine storm has a complex and not fully understood mechanism, and it can result in the multiple organ failure syndrome, associated with high mortality. The main cytokines that play the key role in the cytokine storm are IL-6, IL-10, and TNF-alpha. Removal of the target pro-inflammatory cytokines from the bloodstream can be beneficial in reducing the risk of complications as well as the mortality rate. We describe and compare different methods of extracorporeal apheresis: hemoadsorption, selective plasma filtration, and plasma exchange therapy in the context of their potential use in COVID-19 treatment.

AHPBA guidelines for managing VTE prophylaxis and anticoagulation for pancreatic surgery

BACKGROUND

Major abdominal surgery and malignancy lead to a hypercoagulable state, with a risk of venous thromboembolism (VTE) of approximately 3% after pancreatic surgery. No guidelines exist to assist surgeons in managing VTE prophylaxis or anticoagulation in patients undergoing elective pancreatic surgery for malignancy or premalignant lesions. A systematic review specific to VTE prophylaxis and anticoagulation after resectional pancreatic surgery is herein provided.

METHODS

Six topic areas are reviewed: pre- and perioperative VTE prophylaxis, early postoperative VTE prophylaxis, extended outpatient VTE prophylaxis, management of chronic anticoagulation, anti-coagulation after vascular reconstruction, and treatment of VTE. A Medline and PubMED search was completed with systematic medical literature review for each topic. Level of evidence was graded and strength of recommendation ranked according to the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system for practice guidelines.

RESULTS

Levels of evidence and strength of recommendations are presented.

DISCUSSION

While strong data exist to guide management of chronic anticoagulation and treatment of VTE, data for anticoagulation after reconstruction is inconclusive and support for perioperative chemoprophylaxis with pancreatic surgery is similarly limited. The risk of post-pancreatectomy hemorrhage often exceeds that of thrombosis. The role of universal chemoprophylaxis must therefore be examined critically, particularly in the preoperative setting.

Osteogenic and Angiogenic Properties of Heparin as a System for Delivery of Biomolecules for Bone Bioengineering: a Brief Critical Review

The review considers complex, controversial, and individual effects of heparin and its derivatives on the bone and circulatory systems in dependence of the dose, the state of the cells and tissues of the recipient. General data on the anticoagulant activity of heparin and its derivatives are presented; special attention is paid to the effect of heparin on mesenchymal cells and tissues and its role in angiogenesis. We also discuss the ability of heparin to bind osteogenic and angiogenic biomolecules in the context of the development of systems for their delivery and sustained controlled release and propose a schematic representation of the positive and side effects of heparin as a delivery system for biomolecules in tissue engineering.

[Osteogenic and angiogenic properties of heparin as a system of biomolecule delivery for bone bioengineering: a brief critical review]

The review discusses the complex, ambiguous and individual effects of heparin and its derivatives on the bone and circulatory systems, in dependence of the dosage, the state of the cells and tissues of recipients. General data on the anticoagulant activity of heparin and its derivatives are presented; aspects of the effect of heparin on mesenchymal cells and tissues and its role in angiogenesis are considered in details. Particular attention is paid to the ability of heparin to bind osteogenic and angiogenic biomolecules: thus us especially important for the development of systems for their delivery and sustained controlled release. A schematic representation of the positive and side effects of heparin as a delivery system for biomolecules in tissue engineering is proposed.

Low Concentration Trisodium Citrate as a Non-inferior Locking Agent for Non-tunneled Dialysis Catheters in the Asian Setting

Introduction

Unfractionated heparin is the commonly used catheter lock solution in patients with temporary dialysis catheters as hemodialysis access. The effectiveness of trisodium citrate as an alternate catheter lock agent has not been studied in Asian population.

Methods

In this prospective quasi-experimental study, which included 180 patients with central venous dialysis catheter, patients were randomly allotted to citrate 4.67% and heparin 5000 units/ml arms in the ratio of 2:1. Baseline demographic and dialysis related data, incidence of catheter-related bloodstream infections, and mean catheter days in both the study cohorts were collected and compared. Formal cost analysis for citrate 4.67% use as catheter lock was done.

Results

The mean age of the total study population was 50.49 ± 14.87 years. Sixty-six females (36.7%) and 80 (44.4%) diabetic patients were included in the study. The overall incidence of catheter-related bloodstream infection (CRBSI) was 11.11%. The majority had nontunneled dialysis catheters (95%; n = 114). On analyzing the data of patients with nontunneled catheters, it was found that the total number of catheter days for the citrate and heparin groups were 4,795 and 2,419 days, respectively. The number of CRBSI episodes per 1,000 catheter days for the citrate and heparin groups were 2.711 and 2.89, respectively. Citrate catheter lock cost only 6% of that of heparin lock.

Conclusions

The incidence of catheter related bloodstream infections was comparable between the heparin and citrate 4.67% lock cohorts. The use of low concentration citrate as catheter lock was cost-effective when compared with heparin.

Heparin: An essential drug for modern medicine

Heparin is a life-saving drug, which belongs to few clinically used drugs without defined molecular structures in modern medicine. Heparin is the mostly negatively charged biopolymer with a broad distributions in molecular weight, charge density, and biological activities. Heparin is mainly composed of repeating trisulfated disaccharide units, which is made by mast cells that are enriched in the intestines, lungs or livers of animals. Porcine intestines and bovine lungs are two mostly used sources for heparin isolation. Heparin is well known for its anticoagulant and antithrombotic pharmacological effects. The anticoagulant activity of heparin is attributable to a 3-O-sulfate and 6-O-sulfate containing pentasaccharide sequence or a minimum eight-repeating disaccharide units containing the pentasaccharide sequence that catalyzes the suicidal inactivation of factor Xa or thrombin by a serpin or serine protease inhibitor named antithrombin III, respectively. Thus, heparin is responsible for the simultaneous inhibition of both thrombin generation and thrombin activity in the blood circulation. Moreover, heparin has many pharmacological properties such as anti-inflammatory, anti-viral, anti-angiogenesis, anti-neoplastic, and anti-metastatic effects though high affinity interactions with a variety of proteases, protease inhibitors, chemokines, cytokines, growth factors, and their respective receptors. The one drug multiple molecular targeting properties make heparin a very special drug in that various clinical trials are still conducting worldwide even 100 years after its discovery. In this review, we will summarize the structure-function relationship and the molecular mechanisms of heparin. We will also provide an overview of different clinical and potential clinical applications of heparin.

Effects of Long-Term Low-Molecular-Weight Heparin on Fractures and Bone Density in Non-Pregnant Adults: A Systematic Review With Meta-Analysis

BACKGROUND

Adults who require long-term anticoagulation with low-molecular-weight heparin (LMWH) such as cancer patients or the elderly may be at increased risk of fractures.

OBJECTIVE

To determine the effects of LMWH therapy of at least 3 months' duration on fractures and bone mineral density (BMD) in non-pregnant adult populations.

METHODS

We systematically reviewed electronic databases (e.g., MEDLINE, EMBASE), conferences and bibliographies until June 2015 and included comparative studies in non-pregnant adult populations that examined the effects of LMWH (≥3 months) on fractures and BMD. We synthesized evidence qualitatively and used random-effects meta-analysis to quantify the effect of LMWH on fractures.

RESULTS

Sixteen articles reporting 14 studies were included: 10 clinical trials (n = 4865 participants) and four observational cohort studies (3 prospective, n = 221; 1 retrospective, n = 30). BMD and fractures were secondary outcomes in the majority of trials, while they were primary outcomes in the majority of observational studies. In participants with venous thromboembolism and underlying cardiovascular disease or cancer (5 RCTs, n = 2280), LMWH for 3-6 months did not increase the relative risk of all fractures at 6-12 months compared to unfractionated heparin, oral vitamin K antagonists or placebo [pooled risk ratio (RR) = 0.58, 95 % CI: 0.23-1.43; I(2) = 12.5 %]. No statistically significant increase in the risk of fractures at 6-12 months was found for cancer patients (RR = 1.08, 95 % CI: 0.31-3.75; I(2) = 4.4 %). Based on the data from two prospective cohort studies (n = 166), LMWH for 3-24 months decreased mean BMD by 2.8-4.8 % (depending on the BMD site) compared to mean BMD decreases of 1.2-2.5 % with oral vitamin K antagonists.

CONCLUSIONS

LMWH for 3-6 months may not increase the risk of fractures, but longer exposure for up to 24 months may adversely affect BMD. Clinicians should consider monitoring BMD in adults on long-term LMWH who are at increased risk of bone loss or fracture.

Pharmacology of Heparin and Related Drugs

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use. However, it is increasingly recognized that heparin has many other pharmacological properties, including but not limited to antiviral, anti-inflammatory, and antimetastatic actions. Many of these activities are independent of its anticoagulant activity, although the mechanisms of these other activities are currently less well defined. Nonetheless, heparin is being exploited for clinical uses beyond anticoagulation and developed for a wide range of clinical disorders. This article provides a "state of the art" review of our current understanding of the pharmacology of heparin and related drugs and an overview of the status of development of such drugs.

Hemodialysis with end-stage renal disease did not raise the risk of intracranial hemorrhage after a head injury

BACKGROUND

Hemodialysis (HD) treatment for end-stage renal disease (ESRD) (HD(+ESRD)) may increase the risk of intracranial hemorrhage (ICH) after a head injury (HI) for which heparin is used. However, the results of noncontrast head computed tomography (CT) in such patients are not always clear. We aimed to evaluate the effect of HD on the risk of ICH in ESRD patients and in controls without ESRD with HD (HD(-ESRD)), and to determine whether to lower the threshold of head CT in HD(+ESRD) patients after HI.

METHODS

In this nationwide population-based study using Taiwan's National Health Insurance Research Database, we enrolled 6938 HD(+ESRD) HI patients for the case group and 13,876 randomly selected HD(-ESRD) HI patients for the control group. Measures of the post-HI association between HD(+ESRD) and ICH determined using conditional logistic regression.

RESULTS

Five hundred sixty-eight (2.74 %) patients had post-HI ICH: 185 in the HD(+ESRD) group (2.67 % of cases) and 383 were from the HD(-ESRD) group (2.76 % of controls). Conditional logistic regression analysis revealed that after adjusting for age, gender, diabetes, hypertension, congestive heart failure, stroke, cancer, and liver disease, HD(+ESRD) patients had no higher odds of ICH (adjusted odds ratio [AOR]: 0.91; 95 % confidence interval [CI]: 0.75-1.11) than did HD(-ESRD) patients. In the subgroup analysis of immediate ICH, HD(+ESRD) patients had lower odds than did HD(-ESRD) patients (AOR: 0.73; 95 % CI: 0.56-0.94).

CONCLUSIONS

HD(+ESRD) did not increase the post-HI risk of ICH. Therefore, it may not be necessary to lower the threshold of head CT in HD(+ESRD) patients.

Renal replacement therapy: implications for the surgeon

Renal replacement therapy comprises peritoneal dialysis, haemodialysis and renal transplantation. Patients undergoing renal replacement therapy often require surgery for a number of different reasons. This review summarizes likely surgical procedures for these patients and some of the common complications.

Free thyroxine level as an independent predictor of infection-related mortality in patients on peritoneal dialysis: a prospective multicenter cohort study

BACKGROUND

Previous studies have reported the relationship between thyroid hormone levels and mortality in dialysis patients. However, little is known about the association of free thyroxine (fT4) and mortality in patients on peritoneal dialysis (PD). This study investigated the association between basal and annual variation in fT4 level and mortality in PD patients.

METHODS

Patients on maintenance PD were enrolled from a prospective multicenter cohort study in Korea; their serum triiodothyronine, fT4, and thyroid-stimulating hormone levels were measured 12 months apart. Patients with overt thyroid disease and those receiving thyroid hormone replacement therapy were excluded from the analysis. Patients were divided into two groups based on the median levels of fT4. The differences of all-cause, infection-related, and cardiovascular mortalities were analyzed between the two groups. The association of basal levels and annual variation with mortality was investigated with Kaplan-Meier curves and Cox proportional hazard models.

RESULTS

Among 235 PD patients, 31 (13.2%) deaths occurred during the mean follow-up period of 24 months. Infection (38.7%) was the most common cause of death. Lower basal fT4 levels were an independent predictor of all-cause and infection-related death (hazard ratio [HR] = 2.74, 95% confidence interval [CI] 1.27-5.90, P = 0.01, and HR = 6.33, 95% CI 1.16-34.64, P = 0.03, respectively). Longitudinally, patients with persistently lower fT4 levels during the 12-month period had significantly higher all-cause mortality than those with persistently higher levels (HR = 3.30, 95% CI 1.15-9.41, P = 0.03). The area under the receiver operating characteristic curve of fT4 for predicting all-cause and infection-related mortality was 0.60 and 0.68, respectively.

CONCLUSIONS

fT4 level is an independent predictor of mortality and is especially attributable to infection in PD patients. This predictor was consistent when considering both baseline measurements and annual variation patterns. Close attention to infection in PD patients with relatively lower fT4 levels should be considered.

Tinzaparin versus dalteparin for periprocedure prophylaxis of thromboembolic events in hemodialysis patients: a randomized trial

BACKGROUND

Low-molecular-weight heparin (LMWH) is cleared predominantly by the kidneys and hence there is uncertainty about the safety of its use in hemodialysis (HD) patients. Our primary objective was to compare whether tinzaparin and dalteparin differentially accumulate in HD patients.

STUDY DESIGN

Open-label randomized controlled trial.

SETTING & PARTICIPANTS

HD patients undergoing periprocedure bridging anticoagulation.

INTERVENTION

After warfarin therapy was discontinued, participants were randomly assigned to either 3 daily doses of tinzaparin (175 IU/kg) or dalteparin (200 IU/kg), with 2 intervening HD treatments between the first dose of study drug and their procedure.

OUTCOMES

The primary outcome was predialysis anti-Xa levels 20 to 24 hours after the third LMWH dose (therapeutic target, <0.2 IU/mL). Secondary outcomes included thromboembolic events and major bleeding.

RESULTS

Of 29 eligible and consenting patients, 17 patients received tinzaparin and 12 patients received dalteparin. Mean predialysis anti-Xa level 20-24 hours after the third LMWH dose was 0.37 ± 0.23 (SD) IU/mL for tinzaparin and 0.62 ± 0.41 IU/mL for dalteparin (P = 0.1), indicating clinically important accumulation for both drugs. No invasive procedures were canceled due to study drug accumulation. 4 patients experienced serious adverse events (1 major bleed after traumatic arteriovenous fistula puncture in the tinzaparin arm, 2 non-ST-elevation myocardial infarctions [1 in each group], and 1 upper-extremity deep venous thrombosis [dalteparin group]).

LIMITATIONS

Small sample size.

CONCLUSIONS

Dalteparin and tinzaparin significantly accumulate in HD patients at therapeutic doses. "Bridging therapy" with LMWHs at therapeutic doses in HD patients who require temporary interruption of warfarin therapy has the potential for complications and is of uncertain benefit. Other anticoagulation strategies, including no bridging therapy or intravenous heparin, need comparative evaluation in this unique patient population.

Management of the dialysis patient in general intensive care

The incidence of end-stage renal disease (ESRD) is rising and represents an important group of patients admitted to intensive care units (ICU). ESRD patients have significant co-morbidities and specific medical requirements. Renal replacement therapy (RRT), cardiovascular disease, disorders of electrolytes, drug metabolism, and sepsis are discussed. This review provides a practical approach to problems specific to the ESRD patient and common problems on ICU that require special consideration in ESRD patients. ESRD patients are at risk of hyperkalaemia. I.V. insulin and nebulized salbutamol lower serum potassium until definitive treatment with RRT is instituted. ESRD patients are prone to hypocalcaemia, which requires i.v. replacement if associated with complications. Midazolam has delayed metabolism and elimination in renal impairment and should be avoided. Morphine and its derivatives accumulate in renal failure and shorter-acting opiates are preferable. The use of diuretics is limited to patients with residual urine output. When required, therapeutic systemic anticoagulation should be achieved with unfractionated heparin as it is reversible and its metabolism and clearance are independent of renal function. The risk of sepsis is higher among ESRD patients when compared with patients with normal renal function. Empiric treatment should include both Gram-positive and Gram-negative cover, and methicillin-resistant Staphylococcus aureus cover if the patient has a dialysis catheter. Cardiovascular events account for the majority of deaths among ESRD patients. Troponin-I and CK-MB in combination should be used as markers of acute myocardial damage in the appropriate context, whereas B-type natriuretic peptide and troponin-T values are of less value.

Anticoagulation and dialysis access practice in home haemodialysis in the UK

Anticoagulation is an important component of haemodialysis treatment in all settings. The therapeutic options available for anticoagulation of home haemodialysis are similar to those for haemodialysis in other settings. However, dialysis sessions with a wide range of treatment durations are undertaken at home, which can require different approaches to anticoagulation. Conference delegates were asked about the types of anticoagulation used in home dialysis and about surveillance strategies for monitoring vascular access, and the results are presented and discussed.

Therapeutic apheresis: a review of complications and recommendations for prevention and management

Therapeutic apheresis procedures are a form of extracorporeal therapy that use different techniques to separate blood into the different components out of which the part containing the etiological agent in a disease process is discarded and the rest of the components of blood are re-infused into the patient, frequently with the addition of a replacement fluid or volume. These complex procedures have inherent risks of adverse events and factors that may impact on the incidence these events include the underlying disease state, anticoagulation techniques, replacement fluid type including the volume, issues related to the vascular access used, and the therapeutic apheresis procedure type and technique. We present a representative case based review of common complications of therapeutic apheresis and suggestions about how to prevent or manage these as presented at the 2010 Therapeutic Apheresis Academy.

Reduced expression of perlecan in the aorta of secondary hyperparathyroidism model rats with medial calcification

BACKGROUND

Vascular calcification is an important complication that worsens the prognosis for dialysis patients, although its detailed molecular mechanisms are still unknown.

METHODS

We produced a rat model for vascular calcification with hyperphosphatasemia and hyperparathyroidism, performing a 5/6 nephrectomy and providing a high-phosphorus, low-calcium diet for eight weeks. We examined mRNA obtained from the calcified aortae using microarray analysis, and searched for alterations in gene expression specifically in the calcified lesions.

RESULTS

Medial calcification was demonstrated in the abdominal aorta of 12 out of 42 hyperparathyroidism rats. In the aortae of hyperparathyroid rats with vascular calcification, the genes for heparan sulfate proteoglycans, including perlecan, were found to be down-regulated using microarray analysis and real time PCR. Immunohistochemistry also demonstrated reduced production of perlecan in the aortae of hyperparathyroid rats.

DISCUSSION

Perlecan is a major component of the vascular wall basement membrane and may play a role in protecting vascular smooth muscle cells from inflammatory cells and various toxins. It has also been reported that heparan sulfate chains may inhibit osteogenesis. Our findings indicate that perlecan may protect vascular smooth muscle cells from various factors that promote vascular calcification.

CONCLUSIONS

It may be that reduced expression of perlecan in the calcified aortae of hyperparathyroid rats is a risk factor for vascular calcification.

Pharmacodynamics of unfractionated heparin during and after a hemodialysis session

BACKGROUND

Anti-Xa activity is used as a clinical guide to anticoagulation with heparin, but heparin dosing regimens for hemodialysis were established before anti-Xa assays were developed; thus, the optimal regimen for heparin dosing was not determined. The aim is to confirm the interesting characteristics of unfractionated heparin pharmacokinetics for hemodialysis anticoagulation, provide insight into the hemorrhagic risk of hemodialysis patients, and determine the dose of unfractionated heparin and its adequate mode of administration.

STUDY DESIGN

Cross-sectional study of the pharmacokinetics of unfractionated heparin performed during and after a 4-hour midweek hemodialysis session.

SETTING & PARTICIPANTS

35 long-term hemodialysis patients at the Sainte-Marguerite Unit of the Marseille University Hospital, Marseille, France.

PREDICTOR

Hemodialysis anticoagulation with continuous unfractionated heparin infusion at a dose of 50 IU/kg/session (25 IU/kg/h during the first hour, 12.5 IU/kg during the second and third hours, and stop during the last hour).

OUTCOME & MEASUREMENTS

Anti-Xa activity was monitored during the 10 hours after the beginning of the hemodialysis session. Levels of 0.3 to 0.7 IU/mL are considered sufficient for anticoagulation. Pharmacokinetics was determined by using a population approach (nonlinear mixed-effects modeling). The final model and corresponding parameter values (including interindividual and residual variability) were used to simulate 1,000 replicates.

RESULTS

No case of clotting was recorded. A pharmacokinetic model with 1 compartment and first-order elimination best fitted the data. Terminal half-life was 54 minutes. Median anti-Xa activities were 0.55 IU/mL at peak, 0.25 IU/mL at end of the 4-hour session, and less than 0.1 IU/mL at 90 minutes after the session. We simulated a continuous infusion of the dose of 50 IU/kg for 1, 2, 3, and 4 hours. Peak values were 1.1, 0.8, 0.6, and 0.5 IU/mL, respectively. Values at the end of the session were 0.12, 0.18, 0.3, and 0.5 IU/mL, respectively. Values became less than 0.1 IU/mL at 15, 60, 105, and 120 minutes after the session, respectively.

LIMITATIONS

Interindividual variability in unfractionated heparin pharmacokinetics.

CONCLUSIONS

Unfractionated heparin administered by means of a 3-hour continuous infusion for hemodialysis anticoagulation provided an efficient and safe effect that quickly disappeared after the end of the session.

Management of Uremic Patients With Heparin-Induced Thrombocytopenia Requiring Hemodialysis

Medical records of 122 patients with suspected heparin-induced thrombocytopenia on dialysis were reviewed. Method of dialysis in heparin-induced thrombocytopenia patients with bleeding from various causes (including surgical interventions) and how to cope with blood access occlusion induced by heparin-induced thrombocytopenia were studied. Of 122 patients, 17 who met the criteria of >30% thrombocytopenia, clots in the extracorporeal circulation, positive for heparin/PF4 complex antibodies, and improvement from heparin-induced thrombocytopenia with the use of an alternative anticoagulant or another strategy for heparin-induced thrombocytopenia were chosen. Argatroban was uneventfully introduced in 12 patients having neither bleeding nor blood access failure. In all, 2 of 5 patients were treated with peritoneal dialysis. The others requiring a regional anticoagulant were given nafamostat mesilate. Argatroban as an alternative provides effectively anticoagulation in patients with heparin-induced thrombocytopenia on dialysis. In patients with heparin-induced thrombocytopenia with bleeding and its associated risk, nafamostat mesilate was an alternative. Peritoneal dialysis also was applied in cases of blood access failure due to heparin-induced thrombocytopenia.

Clinical and biochemical implications of low thyroid hormone levels (total and free forms) in euthyroid patients with chronic kidney disease

OBJECTIVES

In this study, we explore the associations of decreased thyroid hormone levels with inflammation, wasting and survival in biochemically euthyroid patients with end-stage renal disease (ESRD).

DESIGN

After exclusion of 23 patients with thyroid-stimulating hormone (TSH) values outside the normal range (0.1-4.5 mIU L(-1)), 187 clinically and biochemically euthyroid incident ESRD stage 5 patients starting dialysis were followed for a median of 20 (range 1-60) months. Measurements of total and free forms of thyroid hormones, s-albumin, hs-CRP, interleukin (IL)-6, vascular adhesion molecule (VCAM)-1 and insulin-like growth factor 1 (IGF-1) were performed at baseline.

RESULTS

In this population, 17 out of 210 patients (8%) were defined as subclinically hypothyroid. Multivariate analysis, according to receiver operating characteristic (ROC) curves, showed that mortality was best predicted by total triiodothyronine (T3). When using the cut-off levels derived from ROC, low T3 levels were associated with increased inflammation (higher hs-CRP, IL-6 and VCAM-1) and lower concentration of both s-albumin and IGF-1. Finally, low T3 but not low free triiodothyronine was associated with worse all-cause (Likelihood ratio = 45.4; P < 0.0001) and cardiovascular mortality (Likelihood ratio = 47.8; P < 0.0001) after adjustment for confounding factors.

CONCLUSION

This study showed that low T3 levels are independent predictors of all-cause and also cardiovascular disease mortality in biochemically euthyroid patients, perhaps due to an intimate association with inflammation. Based on these results, the use of T3 levels in studies assessing the relationship between thyroid dysfunction and mortality risk is recommended.

Current management of vascular access

Optimizing vascular access outcomes remains an ongoing challenge for clinical nephrologists. All other things being equal, fistulas are preferred over grafts, and grafts are preferred over catheters. Mature fistulas have better longevity and require fewer interventions, as compared with mature grafts. The major hurdle to increasing fistula use is the high rate of failure to mature of newly created fistulas. There is a desperate need for enhanced understanding of the mechanisms of failure to mature and the optimal type and timing of interventions to promote maturity. Grafts are prone to frequent stenosis and thrombosis. Surveillance for graft stenosis with preemptive angioplasty may reduce graft thrombosis, but recent randomized clinical trials have questioned the efficacy of this approach. Graft stenosis results from aggressive neointimal hyperplasia, and pharmacologic approaches to slowing this process are being investigated in clinical trials. Catheters are prone to frequent thrombosis and infection. The optimal management of catheter-related bacteremia is a subject of ongoing debate. Prophylaxis of catheter-related bacteremia continues to generate important clinical research. Close collaboration among nephrologists, surgeons, radiologists, and the dialysis staff is required to optimize vascular access outcomes and can be expedited by having a dedicated access coordinator to streamline the process. The goal of this review is to provide an update on the current status of vascular access management.