bluuebunny/crossref_metadata_2025_split huggingface dataset:
Projected shifts in fish species dominance in Wisconsin lakes under climate change
Authors: Hansen Gretchen J. A. , Read Jordan S. , Hansen Jonathan F. , Winslow Luke A. 
Published: September 2016

AbstractTemperate lakes may contain both coolwater fish species such as walleye (Sander vitreus) and warmwater fish species such as largemouth bass (Micropterus salmoides). Recent declining walleye and increasing largemouth bass populations have raised questions regarding the future trajectories and management actions for these species. We developed a thermodynamic model of water temperatures driven by downscaled climate data and lake‐specific characteristics to estimate daily water temperature profiles for 2148 lakes in Wisconsin, US, under contemporary (1989–2014) and future (2040–2064 and 2065–2089) conditions. We correlated contemporary walleye recruitment and largemouth bass relative abundance to modeled water temperature, lake morphometry, and lake productivity, and projected lake‐specific changes in each species under future climate conditions. Walleye recruitment success was negatively related and largemouth bass abundance was positively related to water temperature degree days. Both species exhibited a threshold response at the same degree day value, albeit in opposite directions. Degree days were predicted to increase in the future, although the magnitude of increase varied among lakes, time periods, and global circulation models (GCMs). Under future conditions, we predicted a loss of walleye recruitment in 33–75% of lakes where recruitment is currently supported and a 27–60% increase in the number of lakes suitable for high largemouth bass abundance. The percentage of lakes capable of supporting abundant largemouth bass but failed walleye recruitment was predicted to increase from 58% in contemporary conditions to 86% by mid‐century and to 91% of lakes by late century, based on median projections across GCMs. Conversely, the percentage of lakes with successful walleye recruitment and low largemouth bass abundance was predicted to decline from 9% of lakes in contemporary conditions to only 1% of lakes in both future periods. Importantly, we identify up to 85 resilient lakes predicted to continue to support natural walleye recruitment. Management resources could target preserving these resilient walleye populations.
Successful Long‐Term Central Venous Access
Authors: Tesio Franco , Baz Hamurabi De , Panarello Giacomo 
Published: September 2016

Daily home hemodialysis (DHHD) requires simple, vascular access to minimize patients' discomfort but also to guarantee tolerance and long‐term efficiency. The arteriovenous fistula is not ideal for DHHD because of the double puncture required every day; in addition, the rate of dysfunction is probably greater because of the more frequent use. Central venous catheters may be a good alternative to the arteriovenous fistula as long‐term vascular access for DHHD. In this study we report our experience with the internal jugular vein two‐catheter access for long‐term dialysis and evaluate its possible use for DHHD.Since 1988, Tesio's twin catheters have been positioned in 908 patients with exhausted peripheral vascular bed. In all patients hemodialysis could be performed a few minutes after the surgical procedure.The survival rate of catheters, in a selected group of 46 patients, at 1, 2, and 5 years was, respectively, 92%, 87%, and 82%. The mean blood flow was 282±29 mL/min at 1 month, 286±36 mL/min at 1 year, and 274±37 mL/min at 5 years. Venous pressure in the inlet side was 102±31 mm Hg at 1 month, 126±36 mm Hg at 1 year, and 132±58 mm Hg at 5 years. Catheter clotting was treated either with thrombolytic agents or with catheter (one or both) replacement. Sepsis was treated with systemic antibiotic therapy or catheter removal.Data support the potential role of the internal jugular vein two‐catheter system for DHHD.
A Brief History of Daily Hemodialysis
Authors: Kjellstrand Carl M. 
Published: September 2016

Daily hemodialysis has been in uninterrupted practice since its introduction in California in 1967. Early trials were stopped for technical, logistical, and economical problems, but a rapidly increasing number of centers now perform it on close to 200 patients, either as long nightly or short daytime hemodialysis.Increasing the frequency of dialysis appears much more important in improving patient well‐being than increasing the Kt/V dose, and patients quickly experience much more vigor, energy, and improved quality of life when starting daily hemodialysis. Blood pressure improves, and medications can often be discontinued. Similarly, the need for erythropoietin decreases, and nutrition and dry body mass increase.While the cost of dialysis increases, the total cost for a patient decreases as medications and hospitalizations decrease. Technical innovation will solve the logistical problems by letting a machine do the labor necessary to begin and end a dialysis session. Access problems have decreased for native fistula, and the other access types have not been studied enough.
A Proposed Peritoneal‐Based Wearable Artificial Kidney
Authors: Roberts M. , Lee D.B.N. 
Published: September 2016

Ideally, an artificial kidney should simulate the normal kidney in providing continuous metabolic control, removal of toxins, and unrestricted patient freedom. Of the dialysis procedures available, continuous ambulatory peritoneal dialysis (CAPD) comes the closest to this ideal but provides inadequate dialysis and fails to remove protein‐bound toxins.A continuous, wearable, peritoneal‐based artificial kidney is proposed in which the spent peritoneal dialysate is regenerated using a REDY sorbent cartridge one‐tenth the size of the present cartridge, with the urease chemically bound to an inert support to eliminate the possibility of its displacement by protein in the spent dialysate. To simplify the flow path and to increase clearance, the dialysate flow will be through the peritoneal cavity using a dual lumen catheter instead of the traditional in/outflow through a single catheter. At a flow rate of 4 L/hour through the peritoneal cavity, of which 2 L/hour will pass through the sorbent cartridge, it is estimated that the weekly Kt/V will be 6.5 and the creatinine clearance will be 250 L. In addition, any protein in the spent peritoneal dialysate will be stripped of toxins by the sorbents and returned to the patient, thereby minimizing protein loss. The only disposables will be the sorbent cartridge and infusate, which will be changed every 8 hours.
Outpatient High‐Dose Urokinase Infusion Improves Dialysis Catheter Longevity: A Prospective Observational Study
Authors: Saran Rajiv , Venkataraman Vijaya , Leavey Sean F. , Usovsky Ron , Usha Kumari , Twardowski Zbylut J. 
Published: September 2016

Catheter thrombosis is a major limiting factor affecting catheter survival in hemodialysis (HD). A previous retrospective study highlighted the utility of outpatient intradialytic high‐dose urokinase (HDU) infusion in the treatment of HD catheter thrombosis. The present study was designed to prospectively evaluate the effectiveness of 250 000 IU urokinase given as a 3‐hour infusion during HD. The infusion would follow detection of a drop in blood flow thought to be secondary to thrombosis [a "thrombotic event" (TE)] after exclusion of nonthrombotic causes of drop in blood flow [a "nonthrombotic event" (NTE)], such as systemic hypotension or suboptimal position of the catheter on x ray. An “event” was defined as a drop in pump blood flow by greater than or equal to 20% of the prescribed blood flow. Twenty patients (mean age 57.7 years; 13 males) with documented or potentially long‐term catheters were recruited (total catheters used, 30) from an outpatient HD unit. A variety of catheter types were used. Catheter position was confirmed on x ray. Hemodialysis sessions were monitored for 6 months or until catheter removal (whichever was earlier). Thrombotic and NTEs (mostly related to drop in blood flow) were noted. The use of intradialytic HDU infusions was monitored. Improvement was defined as reestablishment of blood flow to within 10% of prescription.There were 24 TEs in 11 patients and 15 NTEs in 7 patients. Twenty‐one of 22 (95%) TEs responded to HDU, with complete restoration of blood flow; in 1/22 HDU‐treated instances there was a partial response. For 2/24 TEs the patients underwent catheter stripping with good results. Twelve of 15 NTEs occurred in the first 2 weeks of catheter placement versus 6/24 TEs (p = 0.001, chi‐square). Catheter survival was longer than 24 weeks in 12/30 catheters. Nine catheters were lost to NTEs. No catheter was lost secondary to a TE. It is therefore concluded that intradialytic outpatient HDU is useful for the treatment of HD catheter thrombosis. It may obviate/reduce the need for catheter stripping or replacement. Randomized controlled trials with this approach are needed. A higher proportion of NTEs tended to occur earlier after catheter placement compared to TEs.
Stepwise Anticoagulation with Warfarin for Prevention of Intravenous Catheter Thrombosis
Authors: Twardowski Zbylut J. 
Published: September 2016

Warfarin is the most commonly used anticoagulant for prevention and therapy of thrombosis. Warfarin is a vitamin K antagonist and inhibits synthesis of clotting factors II, VII, IX, and X, and anticoagulant proteins C and S. Whereas there is extensive information about the efficacy of warfarin and target International Normalized Ratio (INR) for patients with artificial heart valves, atrial fibrillation, pulmonary emboli, deep venous thrombosis, and lupus anticoagulant, there is little in the literature on the role of warfarin in maintaining the patency of hemodialysis catheters. Much more is reported about the value of minidose warfarin in maintaining the patency of infusion catheters. Many centers have tried low‐dose warfarin (1 mg per day), and found this not to be effective in preventing catheter thrombosis in many patients. Although most support the use of warfarin following catheterproblems, individual units have their own guidelines, with doses ranging from 2 mg per day (normal INR) to formal systemic anticoagulation with INR from 1.5 to 3.0.Stepwise anticoagulation with warfarin is emerging as useful in preventing catheter‐associated thrombosis. With this method, patients are placed on low‐dose warfarin after the first clotting episode. With each subsequent episode, the dose is increased, raising INR by 0.5 until clotting episodes do not recur. Warfarin doses similar to those in patients with artificial heart valves have been used in selected patients (target INR 3.0 – 4.0) to prevent clotting.
What Went Wrong with Home Hemodialysis in the United States and What Can Be Done Now?
Authors: Blagg Christopher 
Published: September 2016

In 1973, almost 40% of the more than 10 000 dialysis patients were treated by home hemodialysis. Today, with more than a quarter of a million dialysis patients in the United States, fewer than 2000 are on home hemodialysis. A number of factors have contributed to this change. First, many nephrologists and administrators who were developing new dialysis units had little or no practical experience with dialysis for chronic renal failure. Second, more elderly and diabetic patients were admitted to treatment. Home hemodialysis was more difficult for such patients, and often their helpers were themselves were elderly. Third, hemodialysis machines were difficult to learn and operate. Fourth, following publication of the results of the National Cooperative Dialysis Study, there developed the erroneous concept that a Kt/V equal to 1.0 was “adequate dialysis.” As bigger dialyzers became available, there was a widespread shortening of dialysis time. This decrease in time was embraced by for‐profit dialysis facilities and inadequately educated patients, and assembly‐line dialysis became generally accepted. Finally, continuous ambulatory peritoneal dialysis, with its simplicity and short training time, began to fill the need of many patients for home dialysis and independence, at least temporarily.Fortunately, the trend is now reversing. Two developments clearly have benefits for home hemodialysis. The first is an increasing interest in the use of more frequent dialysis. The second is the development of new equipment designed specifically for use by the patient, and requiring a minimum of effort on the patient's part.
Volume Control in Hemodialysis Patients
Authors: Charra Bernard , Chazot Charles , Hurot Jean-Marc , Jean Guillaume , Terrat Jean-Claude , Vanel Thierry , Laurent Guy 
Published: September 2016

Cardiovascular disease is the main cause of the high mortality of dialysis patients and is largely due to poor control of blood pressure. Establishing and maintaining normal extracellular volume (ECV) is required to achieve normotension. The dry weight concept links ECV and blood pressure by a simple clinical relationship. Dry weight is the ideal postdialysis weight that allows a constantly normal blood pressure to be maintained without using antihypertensive medications.Maintenance of normal ECV requires control of salt intake to reduce interdialytic weight gain ( i.e., saline overload) combined with the diffusive and convective removal of salt and water from the body during dialysis sessions.Several problems are to be faced when using the dry weight method. Clinical evaluation must take into account the following confounding factors: weight varies with nutrition, clinical symptoms are unspecific and sometimes discordant, and there is a lag time between ECV and blood pressure changes. On the other hand, achievement of dry weight is hampered by dialysis times that are too short (and weight gains that are too high), by antihypertensive medications, and by poor heart conditions. A longer session time allows for a slower, easier, and more comfortable ultrafiltration.
Tunneled Catheter–Associated Atrial Thrombi: Successful Treatment with Chronic Anticoagulation
Authors: Kung Shiang-Cheng , Aravind Bonapally , Morse Stephen , Jacobs Larry E. , Raja Rasib 
Published: September 2016

Tunneled dialysis catheter–associated right atrial thrombus (RAT) is a rarely reported complication. We reviewed hospital records of 10 patients from a teaching hospital dialysis unit, in whom RAT was diagnosed by trans‐esophageal echocardiography (TEE). Patients were treated with chronic anticoagulation (heparin followed by warfarin) and followed over time. The group included 7 women; 6 patients were African American, 3 were Caucasian, and 1 was Hispanic. The average age was 52.1 ± 15.3 years. The most common presenting symptom was poor catheter flow on hemodialysis followed by fever and chills. On average, the patients had had 3.4 ± 2.7 catheter insertions before diagnosis of RAT, and the tunneled dialysis catheter (TC) had been in place for a mean of 91 ± 89.4 days when the thrombi were diagnosed. Trans‐thoracic echocardiography (2‐D echo) was done in 4 patients, but it identified RAT in only 1 patient. The catheter tip was at the junction of the superior vena cava and right atrium (SVC/RA) in most patients.Thrombolysis (unsuccessful) was attempted with urokinase in 3 patients, complicated in 2 patients by hemorrhage. After anticoagulation, 90% of the RAT resolved on repeated TEE. One patient had persistent RAT for 23 weeks and underwent surgical thrombolysis, but died postoperatively.We conclude that RAT is a frequently missed complication of a TC. Positioning the tip of the TC at the SVC/RA junction may not prevent RAT. Trans‐esophageal echocardiography is a more sensitive diagnostic tool than 2‐D echo and should be obtained early. Most patients can be successfully treated with anticoagulation alone. Thrombolytic therapy and surgical thrombolysis have high morbidity and mortality.
A Comparative Study of C‐Reactive Protein Plasma Levels in Patients on Hemodialysis and Peritoneal Dialysis
Authors: Fernández–Reyes M. José , Hevia Covadonga , Bajo M. Auxiliadora , Peso Gloria Del , Costero Olga , Diez Juan J. , Selgas Rafael 
Published: September 2016

In dialysis patients, C‐reactive protein (CRP), a well‐recognized marker of inflammation, predicts mortality. Higher levels have been described in hemodialysis (HD) patients as compared with peritoneal dialysis (PD) patients. Our aim was to determine, based on CRP plasma levels, the degree of inflammation in HD patients using low‐permeability polysulfone membranes and relatively pure dialysate, and that in PD patients. A secondary objective was to study factors associated with hypoalbuminemia and inflammation in both populations.We studied 69 stable patients on dialysis (32 on HD and 37 on PD). The mean age was 69.9 ± 8.2 years, and the mean time on dialysis was 27 months. The two populations were comparable for overall and cardiovascular comorbidities. Nephelometry was used to measure CRP plasma levels (normal levels < 0.6 mg/dL). The Kt/Vurea, corrected for residual renal clearance, and the equivalent of protein nitrogen appearance (PNA) were also calculated.Of the patients studied, 53% showed CRP plasma levels higher than 0.6 mg/dL; in 36%, the levels were higher than 1 mg/dL. No significant differences in these percentages were noted between the two dialysis groups. Patients with CRP levels higher than 1 mg/dL showed lower serum albumin, iron, hemoglobin, and transferrin levels, and higher ferritin values and leukocyte counts. Under logistic regression analysis, CRP levels higher and lower than 1 mg/dL were significantly associated with serum albumin [p = 0.01; odds ratio (OR): 0.15], iron (p = 0.006; OR: 0.96), transferrin (p = 0.004; OR: 0.97), and hemoglobin (p = 0.02; OR: 0.67). Serum albumin levels were significantly lower in PD patients. Under regression analysis, serum albumin levels correlated with cholesterol (r: 0.25; p = 0.04), serum iron (r: 0.5; p = 0.0001), transferrin (r: 0.3; p = 0.015), ultrafiltration capacity (r: 0.42; p = 0.008), and CRP values above 0.6 mg/dL (r: –0.65; p = 0.001).In conclusion, the frequent elevation of CRP plasma levels observed in both HD and PD patients suggests the presence of a silent inflammatory state. Hemodialysis performed with biocompatible, low‐permeability membranes is not associated with higher CRP plasma levels than those seen in PD. In both groups, hypoalbuminemia is related to CRP level. Levels of serum albumin, slightly lower in PD patients, are also related to peritoneal ultrafiltration capacity.
Arterial Hypertension Is Associated with Increased Serum Lipoprotein(a) Levels in End‐Stage Renal Disease Patients
Authors: Fytili Christina I. , Passadakis Ploumis S. , Progia Euaggelia G. , Kambouromiti Georgia L. , Panopoulou Maria I. , Sombolos Kostas I. , Vargemezis Vassilis A. 
Published: September 2016

In addition to disorders in lipoprotein metabolism, several other factors are involved in the development of atherosclerotic changes in end‐stage renal disease (ESRD) patients. One of these is arterial hypertension.We evaluated serum lipids—total cholesterol (TC), triglycerides (TG), apolipoproteins (AI , A II , B, E), lipoprotein(a) [Lp(a)]—in 109 ESRD patients on dialysis [46 on hemodialysis (HD); 63 on continuous ambulatory peritoneal dialysis (CAPD)] and in 45 hyperlipidemic patients without renal failure (HL group). Dialysis patients were divided in two groups. Group A included 42 hypertensive patients (mean age: 62.3 ± 15.5 years) whose blood pressure (BP) was satisfactorily controlled with anti‐hypertensive medications. Group B included 67 non hypertensive patients (mean age: 66.6 ± 11.9 years).Levels of Lp(a) were significantly higher in both the HD (p = 0.001) and the CAPD (p < 0.05) patients as compared with the HL group. When the HD and CAPD groups were divided into hypertensive and non hypertensive patients, Lp(a) levels were significantly higher in the hypertensive patients; this difference was not observed among non renal failure patients.These results indicate that arterial hypertension is associated with elevated Lp(a) serum levels in ESRD patients undergoing either HD or CAPD.
Mechanism and Clinical Presentation of Heparin‐Induced Thrombocytopenia
Authors: Fischer Karl-Georg 
Published: September 2016

Heparin‐induced thrombocytopenia (HIT) is a potentially life‐threatening complication of heparin anticoagulation, occurring in approximately 3% of patients treated with unfractionated heparin.Heparin and platelet factor 4 (PF4) are capable of forming multimolecular complexes. Given stoichiometric concentrations of heparin and platelet factor 4 (PF4), heparin may induce conformational changes in the PF4 molecule, rendering it antigenic. The subsequent immune response generates antibodies against heparin–PF4 complexes (HIT antibodies). Binding of these antibodies to FcγIIA receptors on the surface of platelets results in potent platelet activation. Binding of HIT antibodies to heparan sulfate–PF4 complexes on the surface of endothelial cells (ECs) causes EC activation with subsequent expression of tissue factor. Activation of platelets and of ECs together leads to marked thrombin generation, resulting in the hypercoagulable state in HIT.Clinically, HIT presents with two major sequelae: thrombocytopenia and thrombosis. Thrombocytopenia—that is, a platelet count below 150×10 9 /L—is present in 85% – 90% of HIT patients and typically occurs between day 5 and day 10 of heparin treatment. The mean platelet count nadir is approximately 60×10 9 /L. Alternatively, HIT may be associated with a marked fall in platelet count (≥50% of the initial value) whose nadir is not below 150×10 9 /L. Despite the low platelet count, thrombosis rather than bleeding predominates. In HIT, the risk for thrombosis is 5% – 10% in the first 2 days; the 30‐day cumulative risk is approximately 50%. Thromboses most often occur in deep veins of the lower limbs, frequently leading to pulmonary embolism. If thrombosis is severe or if it is detected in an unusual location in heparintreated patients, HIT should be suspected.
Management of Heparin‐Induced Thrombocytopenia During Renal Replacement Therapy
Authors: Davenport Andrew 
Published: September 2016

Awareness is increasing concerning the development of antibodies to heparin–platelet factor 4 complex in both regular hemodialysis patients and those treated with continuous forms of renal replacement therapy. Although the development of antibodies does not result in thrombocytopenia or thrombosis in some patients, most patients present with thrombocytopenia, premature platelet activation, and clotting of the extracorporeal circuit. When systemic anticoagulation is also required to treat venous thrombosis, then synthetic heparinoids or recombinant hirudin will be the agents of choice. However, neither the synthetic heparinoids nor hirudin are without problems. A few patients may have cross‐reacting antibodies against the currently available heparinoids. Similarly, antibodies may develop against recombinant hirudin, leading to a potentiation of anticoagulant activity and increased risk of hemorrhage.In the future, thrombin inhibitors such as recombinant hirudin and the arginine derivative argatroban will probably be the agents most widely used to prevent thromboembolic complications. However, anti‐platelet agents used alone or in combination with hirudin or synthetic heparinoids may provide adequate treatment by inhibiting both platelet and clotting cascade activation.