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.     

Efficacy of preventing hemodialysis catheter infections with citrate lock

Prevalent use of tunneled dialysis catheters can reach 30%. Infection remains the most serious catheter‐related problem. Catheter locks are increasingly used for prevention, but are not yet recommended either by the Food and Drug Association or European Medicines Agency, on the basis of increasing bacterial resistance or lock toxicity. The aim was to test safety and effectiveness of citrate. A prospective, interventional study was conducted to assess the safety and efficacy of a 30% citrate lock in preventing catheter‐related bacteremia (CRB). A total of 157 prevalent tunneled catheters were locked with citrate and prospectively followed during a 1‐year period. The primary endpoint was first CRB diagnosed according to two of the diagnostic criteria for Catheter Infection of Centers for Disease Control and Prevention (CDC), namely definite and probable infection. The CDC criterion of possible but not proved infection was not considered. This citrate lock cohort (n = 157) had 10 episodes of CRB. We observed 0.49 CRB episodes/1000 patient‐days and the mean infection‐free catheter day was 130.6 ± 100.9. No clinically relevant adverse events were observed. No proved tunnel or exit site infection was observed and no patients died because of CRB. Catheter obstruction episodes were reported on 69 occasions out of 14 catheters. These results were compared with an historical cohort from a previous study of catheter locking with low‐dose gentamicin and did not show significant difference in efficacy. Citrate lock is effective in preventing CRB. No toxicity was observed. The use of citrate lock may have advantages over antibiotic locks: No reported bacterial resistance, lower industrial cost, and less manipulation.     

Catheter lock heparin concentration: effects on tissue plasminogen activator use in tunneled cuffed catheters

The optimal cost-effective heparin concentration for locking tunneled cuffed hemodialysis catheters (TCC) is unclear. We performed a retrospective review of tissue plasminogen activator (tpa) use in TCC in 2 hemodialysis units that used different heparin concentrations for TCC lock to evaluate the effectiveness of lower dose heparin as a lock for TCC. Catheter blood flow rate per treatment, units of heparin given during treatments, patient hemoglobin values and use of warfarin, and tpa use were compared for all patients using TCC for at least 3 months in 2 in-center hemodialysis units between 11/04 and 5/05. Both units used the same type of catheters and biocompatible, non-re-use dialyzers. Unit A used heparin 1000 U/mL for catheter locks, and Unit B used heparin 10,000 U/mL for catheter locks. Twelve of 19 Unit A patients, tpa and 14 of 45 Unit B patients received intracatheter during the study period (p=0.0009). There were no differences in the number of patients on warfarin, treatment blood flow rate, or mean hemoglobin levels between the 2 groups. The mean heparin units given during hemodialysis treatments was higher in Unit A patients (3.92+/-2.2 vs. 3.83+/-2.5 1000 U, p=0.05). Assuming a 4.1 mL total catheter lumen volume, the cost of heparin 1000 U/mL lock was 0.20 dollars per treatment and heparin 10,000 U/mL cost 2.67 dollars/treatment; tpa cost 89.02 dollars/use. Using the 10,000 U/mL heparin as a catheter lock was associated with less frequent use of tpa. However, the significantly lower cost of the 1000 U/mL heparin could result in significant savings despite higher tpa use. This retrospective, uncontrolled study of a small number of patients suggests that comparing low and high heparin concentrations as a TCC lock would be worthwhile. Prospective studies would be helpful to define the most appropriate and cost-effective lock for TCC.     

Clinical consequences of heparin-free hemodialysis

Heparin-free hemodialysis (HF-HD) has been increasingly used in patients at risk for bleeding, especially in the intensive care unit (ICU). Lack of heparin can reduce solute clearances in continuous hemofiltration; the effect on HD is undefined. Failure to recognize an effect of the anticoagulation strategy upon delivered clearance could contribute to the known problem of underdialysis in the ICU. In addition, the consequences of "locking" dialysis catheters with concentrated heparin solutions are also unclear. This study was designed to define the clinically relevant consequences of HF-HD and catheter locking. In part I, we performed 200 HD treatments on inpatients, of which 100 were performed with heparin, and 100 were performed as HF-HD. We calculated prescribed and delivered Kt/V and dialysis efficiency. In part II, a separate group of 14 patients undergoing HF-HD via central venous catheters had measurement of activated partial thromboplastin time (aPTT) during the last hour of dialysis, as well as 15, 60, and 240 min after catheters were locked with 1:5000 heparin. The prescribed Kt/V was 1.74+/-0.31 for standard HD with heparin vs. 1.66+/-0.36 for HF-HD (p=ns). The delivered Kt/V was 1.42+/-0.32 vs. 1.36+/-0.38 (p=ns). Efficiency was 0.82 vs. 0.84 (p=ns). Baseline aPTT was 28+/-5 s, and increased to 126+/-54 s, 15 min after locking (p<0.0001) and to 71+/-50 s, 60 min after locking (p=0.005). By 240 min, the mean aPTT had fallen to 33+/-9 s (p=0.03), although individual values were still as high as 50 s. The HF technique does not compromise delivery of dialysis to inpatients. Increased treatment time is not necessary. Locking catheters with heparin after HF-HD resulted in prolonged unintentional anticoagulation.     

Antibiotic lock: In vitro stability of gentamicin and sodium citrate stored in dialysis catheters at 37 °C

Catheter‐related bacteremia (CRB) is a major cause of morbidity and mortality especially among patients receiving hemodialysis. Antibiotic lock therapy represents a promising technique in the treatment of CRB. Several studies have evaluated antibiotics in combination with heparin as an interdialytic locking solution for prophylaxis of CRB. The objective of this study was to evaluate the stability of gentamicin and sodium citrate in hemodialysis catheters as an interdialytic lock. Solutions containing gentamicin 2.5 mg/mL and sodium citrate 40 mg/mL (4%) were prepared individually and in combination. The solutions were instilled into dialysis catheters and stored at 37 °C for 96 h. Samples were withdrawn randomly from catheter lumens at 24‐hour intervals for 4 days and stored at ?20 °C until analysis. The samples were analyzed with validated, stability‐indicating HPLC assays. The luminal concentration of gentamicin 2.5 mg/mL, sodium citrate 40 mg/mL (4%), and the combination was determined on study days 0, 1, 2, 3, and 4. When gentamicin was combined with sodium citrate and stored at 37 °C in dialysis catheters, the solution showed no decrease in either the gentamicin or the sodium citrate concentrations over the 96‐hour study period. The percent of the original concentration at 96 h was 102.4±1.03 for gentamicin and 102.9±1.25 for citrate (P=0.5556). The combination of gentamicin 2.5 mg/mL and sodium citrate 40 mg/mL (4%) can be retained in hemodialysis catheters for at least 96 h at 37 °C with no evidence of degradation.     

Tissue plasminogen activator as a hemodialysis catheter locking solution

Tunneled hemodialysis catheters require a "locking solution" between treatments to prevent catheter thrombosis. Heparin locks can be unsafe in patients with life-threatening bleeding diathesis because of unintentional anticoagulation. This study was designed to define the hematologic consequences of using tissue plasminogen activator (t-PA) as an alternative locking solution after heparin-free hemodialysis (HF-HD). Following HF-HD, t-PA 2 mg was instilled into each lumen of the dialysis catheter in 10 patients. Euglobulin clot lysis time (ECLT), fibrinogen, D-dimer, and fibrin degradation products were measured during the last hour of dialysis, and repeated 15 and 30 minutes after catheter locking. Dialysis catheter performance was reassessed at the time of the next hemodialysis. Fibrinogen, D-dimer, and fibrin degradation products were elevated at all time points, but did not change after t-PA. ECLT decreased significantly from baseline 15 minutes after catheter locking (217+/-64 vs. 132+/-75 min, p=0.016). ECLT values had returned to baseline (202+/-56 minutes) by 30 minutes. No episodes of bleeding or catheter thrombosis occurred, and catheter performance did not deteriorate. A 2 mg t-PA locking solution preserved dialysis catheter performance. ECLT decreased at 15 minutes, but normalized by 30 minutes, and did not enter the range in which bleeding would be likely. No clinical events were seen during this transient increase in systemic fibrinolysis.     

Antibiotic lock: In vitro stability of vancomycin and four percent sodium citrate stored in dialysis catheters at 37°C

Catheter-related bacteremia (CRB) is a major cause of morbidity and mortality especially among patients receiving hemodialysis (HD). Antibiotic lock therapy represents a promising technique in the treatment of CRB. Several studies have evaluated antibiotics in combination with heparin as an interdialytic locking solution as adjunctive therapy for CRB. The objective of this study was to evaluate the chemical stability of the vancomycin in 4% sodium citrate in HD catheters as an interdialytic lock. Vancomycin was prepared and diluted with sodium citrate 4% and stored in polyvinyl chloride syringes, 2 carbothane dialysis catheters (Hemostar^®) and 2 dual floating HD catheters (CardioMed^®). Syringes were stored at 4 °C or 23 °C and the catheters were stored in an incubator at 37 °C for 72 hours. Samples underwent daily chromatographic analysis and the luminal concentration of vancomycn was determined on study days 0, 1, and 3. When vancomycin is reconstituted with normal saline to achieve a concentration of 50 mg/mL, and then further diluted in 4% sodium citrate, to achieve concentrations of either 1 or 3 mg/mL, and then stored at 4 °C, room temperature, or 37 °C, solutions were observed to retain >92% of the initial concentration for the study period of 3 days. Based on the fastest degradation rate determined with 95% confidence interval, >90% is retained for 6.53 days. We conclude that vancomycin—4% citrate solutions stored in polyvinyl chloride syringes or HD catheters are not significantly affected by temperature or concentration within the 72 hours storage period. Therefore, these solutions can be anticipated to be suitable as a HD interdialytic antibiotic lock in standard HD catheters.     

Prevention and Treatment of Thrombosis Associated With Long-Term Hemodialysis Catheters

Soft, cuffed, central vein hemodialysis catheters are used in about 20% of chronic hemodialysis patients in the United States, because long-term arteriovenous blood access cannot be maintained in an aging patient population with a large proportion of diabetics. The most frequent complication of these catheters is thrombosis. The treatment of catheter-related thrombosis is difficult and expensive; thus the emphasis should be on prevention. The preferred material for a long-term catheter is silicone rubber, since it is the least thombogenic. Anticoagulation should be more vigorous during “catheter dialysis” than during “fistula dialysis.” Heparin is the least expensive and most convenient anticoagulant, suitable for over 99% of chronic dialysis patients. The dose of heparin for sufficient anticoagulation depends on many factors, varies widely, and should be established for each patient based on activated clotting time (ACT). ACT should be kept over 270 sec throughout dialysis. Recently we introduced a method of locking catheter lumina with a predetermined amount of heparin; this heparin is not discarded before the next dialysis, but serves as a loading dose. This saves a number of connections/ disconnections and decreases dialysis-associated blood losses. To prevent catheter thrombosis, over 60% of patients require warfarin in sufficient doses to keep the international normalized ratio (INR) between 1.5 and 2.5. The most common catheter-related thrombus is a periluminal fibrin sleeve. Locking the catheter with urokinase to dissolve the clot is of little value, because the bulk of the thrombus is outside the catheter. We have found a high-dose (250 000 U or more) intradialytic urokinase infusion through the venous chamber to be a very efficient and convenient method for dissolving clots. Cumulative success of up to three infusions is over 99%. This obviates the need of catheter stripping or replacement, which is more cumbersome and expensive.     

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.     

Low dose heparin lock (1000 U/mL) maintains tunnelled hemodialysis catheter patency when compared with high dose heparin (5000 U/mL): A randomised controlled trial

Introduction Heparin is commonly used after hemodialysis treatments as a locking solution to prevent catheter thrombosis. The comparative efficacy and safety of different heparin concentrations to maintain catheter patency has been previously reported in retrospective studies. We conducted a prospective, randomised, controlled study of 1000 U/mL heparin (low dose) versus 5000 U/mL heparin (high dose) locking solution to maintain patency of tunnelled catheters. Methods One hundred patients receiving chronic, unit‐based hemodialysis with newly placed tunnelled hemodialysis catheters (less than 1 week) were randomly assigned to either a low dose (n = 48) or high dose heparin (n=52). The primary intention‐to‐treat analysis examined time to malfunction in both groups over a 90 day period. A secondary analysis compared baseline patient characteristics in relation to catheter malfunction. Findings Overall rate of catheter patency loss was 32% of catheters by 90 days. There was no significant difference in time to malfunction of catheters locked with low dose or high dose heparin (P = 0.5770). Time to catheter malfunction was not associated with diabetic, hypertensive or smoking status. There was no difference in mean delivered blood flow rate, venous and arterial pressure, and dialysis adequacy between low dose and high dose groups. No patient suffered a hemorrhagic complication requiring hospitalisation during the study period. Discussion Low dose heparin is adequate to maintain tunnelled hemodialysis catheter patency when compared with high dose heparin. The study also suggests that there is no relationship between catheter malfunction and diabetic, hypertensive or smoking status.     

Recurrent heparin‐induced thrombocytopenia due to heparin rinsing before priming the machine in a hemodialysis patient: A case report

Heparin has remained the most commonly used anticoagulant for patients undergoing hemodialysis. It is usually safe to use but can have severe adverse effects in some cases. Heparin‐induced thrombocytopenia (HIT) is a life‐threatening complication of exposure to heparin. It results from an autoantibody directed against endogenous platelet factor 4 (PF4) in complex with heparin, which activates platelets and can cause catastrophic arterial and venous thromboses. Here, we present the case of an 80‐year‐old woman with a recent diagnosis of chronic renal failure who developed acute HIT (platelet count nadir, 15 × 10⁹/L) on day 7 of hemodialysis performed with routine heparin anticoagulation, who despite subsequent heparin‐free hemodialysis (with argatroban and warfarin) developed recurrent HIT (complicated by acute cerebral infarction) on day 11 that we attributed to “rinsing” of the circuit with heparin‐containing saline (3,000 units of unfractionated heparin, with subsequent saline washing) performed pre‐dialysis as per routine. After stopping heparin rinsing, the platelet count recovered completely, without further thrombotic or other sequelae. Our experience indicates that for patients with acute HIT, besides the well‐known practice of using non‐heparin anticoagulation during dialysis and avoiding heparin “locking” of dialysis catheters, it is also important to avoid inadvertent rinsing of the circuit with heparin during preparation for hemodialysis.     

The CLOCK trial,a double‐blinded randomized controlled trial: Trisodium citrate 30% and minocycline 3 mg/mL plus EDTA 30 mg/mL are effective and safe for catheter patency maintenance among CKD 5D patients on hemodialysis

Introduction: Poor blood flow rate (PF) is highly prevalent among CKD 5D patients with long‐term central venous catheters. Heparin catheter lock solutions are commonly used to maintain catheter patency, however the incidence of PF remains high. The purpose of the CLOCK Trial was to evaluate two catheter lock solutions on reduction of PF incidence. Methods: Seventy‐five CKD 5D patients on high‐efficiency hemodialysis at the Integrated Centre of Nephrology (Guarulhos, Brazil) were randomized 1:1:1 to receive a lock solution combining minocycline 3 mg/mL with the anticoagulant/chelation agent EDTA 30 mg/mL (M‐EDTA) or heparin 1000 IU/mL (H) or trisodium citrate 30% (TSC) vs. Hfor 15 weeks. A total of 68 patients completed the trial in which both investigators and patients were blinded to treatment allocation. The primary end‐point was the occurrence of hydraulic resistance and secondary safety end‐point was adverse drug reactions related to the lock solutions. Findings: At the beginning of the trial, 7 patients were excluded from this trial due to their poor catheter care. The incidence of hydraulic resistance was significantly higher among patients on H (18/23) compared to TSC (4/22) and M‐EDTA (2/23) lock solutions, (P < 0.001). Discussion: The CLOCK Trial suggests TSC and M‐EDTA may preserve catheter patency better than H. TSC may be a better option due the lack of association with long‐term antimicrobial resistance.     

Heparin-induced thrombocytopenia during renal replacement therapy

There is increasing awareness that antibodies to heparin/platelet factor 4 complex can develop in both those with acute renal failure treated with continuous forms of renal replacement therapy and, to a lesser extent, regular hemodialysis patients. Clinical manifestations include premature clotting of the extracorporeal circuit and increased central venous thrombosis with indwelling venous dialysis catheters, associated with thrombocytopenia and increased platelet activation. Nevertheless, a minority of patients who develop heparin/platelet factor 4 antibodies do not have thrombocytopenia or thrombosis. When systemic anticoagulation is also required to treat venous thrombosis, then synthetic heparinoids or the direct thrombin inhibitors argatroban or recombinant hirudins are the agents of choice. Neither the synthetic heparinoids nor hirudin, however, are without their own problems, in that a minority of patients may have cross‐reacting antibodies against the currently available heparinoids, and antibodies may similarly develop against recombinant hirudin, in this case leading to a potentiation of anticoagulant activity and increased risk of hemorrhage.     

Utility of citrate dialysate in management of acute kidney injury in children

Dialysis concentrate acidified with citrate as opposed to acetate has been reported to prevent clotting in hemodialysis circuits, and improve dialysis efficiency in adults. There is no information on its use in children. The purpose of the study was to evaluate the utility of citrate dialysate for renal replacement therapy in a pediatric population with acute kidney injury. We performed a retrospective review of our experience using Citrasate^® concentrate from December 2007 to August 2009. All treatments were provided using the Fresenius 2008 dialysis machine. Citrasate^® was utilized in 7 children aged 60.3±51.0 months (mean±SD), range 13 months to 12 years. The number of treatments varied from 4 to 31 (mean 12±8 treatments) for a total of 89 treatments. Rare sporadic mild hypocalcemia was noted but could not be definitively linked with the use of Citrasate^®. Four children also required low‐dose heparin (3.6–15 U/kg/h) due to clotting. Activated clotting times (when checked) were not affected by this low‐dose heparin therapy. Some degree of clotting occurred in 21 of 89 (23.5%) treatments. Early termination of treatment due to thrombosis was required in 7 of 89 (7.8%) treatments. In summary, use of Citrasate^® dialysis concentrate was well tolerated in critically ill children with acute kidney injury. Citrasate^® reduced but did not completely eliminate the need for heparin in our population. Further study in a more diverse population would be helpful.     

Anticoagulation,delivered dose and outcomes in CRRT: The program to improve care in acute renal disease (PICARD)

Delivered dialysis dose by continuous renal replacement therapies (CRRT) depends on circuit efficacy, which is influenced in part by the anticoagulation strategy. We evaluated the association of anticoagulation strategy used on solute clearance efficacy, circuit longevity, bleeding complications, and mortality. We analyzed data from 1740 sessions 24 h in length among 244 critically ill patients, with at least 48 h on CRRT. Regional citrate, heparin, or saline flushes was variably used to prevent or attenuate filter clotting. We calculated delivered dose using the standardized Kt/V_urea. We monitored filter efficacy by calculating effluent urea nitrogen/blood urea nitrogen ratios. Filter longevity was significantly higher with citrate (median 48, interquartile range [IQR] 20.3–75.0 hours) than with heparin (5.9, IQR 8.5–27.0 hours) or no anticoagulation (17.5, IQR 9.5–32 hours, P < 0.0001). Delivered dose was highest in treatments where citrate was employed. Bleeding complications were similar across the three groups (P = 0.25). Compared with no anticoagulation, odds of death was higher with the heparin use (odds ratio [OR] 1.82, 95% confidence interval [CI] 1.02–3.32; P = 0.033), but not with citrate (OR 1.02 95% CI 0.54–1.96; P = 0.53). Relative to heparin or no anticoagulation, the use of regional citrate for anticoagulation in CRRT was associated with significantly prolonged filter life and increased filter efficacy with respect to delivered dialysis dose. Rates of bleeding complications, transfusions, and mortality were similar across the three groups. While these and other data suggest that citrate anticoagulation may offer superior technical performance than heparin or no anticoagulation, adequately powered clinical trials comparing alternative anticoagulation strategies should be performed to evaluate overall safety and efficacy.     

The Air-Bubble Method of Locking Central-Vein Catheters with Acidified, Concentrated Sodium Chloride as a Bactericidal Agent: In Vitro Studies

Background:  Soft, cuffed indwelling catheters are used for hemodialysis access and intravenous infusions. The majority of these catheters are removed as a result of infection caused by contamination of the catheter hub during the connection/disconnection procedures. To prevent clot formation in the lumen, these catheters are routinely "locked" with heparin or some other anticoagulant. None of the anticoagulants commonly used as locking solutions demonstrates any significant bactericidal properties. The primary goal of this study was the development of a catheter locking method that retains anticoagulant properties at the catheter tip and bactericidal properties at the catheter hub. The second goal was to find a solution that possesses excellent bactericidal properties but is not detrimental in the event of injection into the patient's blood stream. The bactericidal properties of acidified, concentrated saline (ACS) were compared to concentrated trisodium citrate and to commonly used bactericidal agents such as povidone iodine, sodium hypochlorite, and chlorhexidine.
Methods:  In preliminary studies, the rate of diffusion of solutes was measured in glass tubes. In another set of experiments, the mixing of two solutions (anticoagulant and bactericide) separated by an air bubble ("air-bubble method") was observed in stationary and moving systems. The final series of studies compared the bactericidal properties of ACS to other bactericidal solutions mentioned above.
Results:  The solutions diffused swiftly in the glass tubes, and by the third day, both solutions were mixed. The air-bubble method prevented mixing in both stationary and moving systems. The bactericidal properties of ACS were superior to all other tested solutions.
Conclusions:  The proposed method of catheter locking with anticoagulant at the catheter tip and ACS at the catheter hub separated by an air bubble is a promising technique and clinical studies are warranted.     

CQI in the acute dialysis setting

When the acute dialysis program became an in‐house operation, the development and implementation of a CQI program was a priority. Quality indicators were identified. Clotting in the dialyzer, treatment delays, and catheter‐related infections were tracked. Based on our CQI data, it was clear from the beginning that there was a high incidence of dialyzer clotting, particularly on our patients on Extended Daily Dialysis (EDD) who were on heparin‐free dialysis. Heparin‐free dialysis is prescribed for high bleeding risk patients and for patients with heparin‐induced thrombocytopenia. There was a need to explore an effective way to maintain patency and longevity of the extracorporeal circuit as clotting not only results to blood loss but to loss of treatment time, which affects the efficiency and adequacy of the dialysis therapy. Our policy on no‐heparin dialysis was modified. Hourly saline flushes were changed to a more aggressive every‐15‐to‐30 minute flushes. In addition, "heparin rinse" or priming the extracorporeal circuits with 5000 units of heparin added to 1‐liter bag, except for HIT positive patients, was immediately implemented. After 2 months, clotting in the dialyzer on Extended Daily Dialysis was significantly reduced from 24% to 2%. Conclusion:  CQI in the acute dialysis setting is critical for a continuous cycle of evaluating and improving patient outcomes. Through the process of CQI, we were able to identify dialyzer clotting with our EDD as a quality of care problem and implemented a solution that was effective.     

Maintenance of blood flow rate on dialysis with self‐centering CentrosFLO catheter: A multicenter prospective study

Introduction Chronic central venous catheters (CVC) for dialysis lose patency and deliver lower blood flow over time, often due to fibrous sheathing that covers the lumen tips. The CentrosFLO central venous catheter has a shape that directs the arterial and venous tips away from the walls of the vena cava and right atrium, making sheathing of the tips less likely. Methods A prospective, multicenter, single arm, non‐controlled, observational study was conducted at eight sites in the United States. All consenting dialysis patients receiving CentrosFLO catheters through the right or left internal jugular veins were accepted in the study, as long as the catheter was expected to be used for 45 days and was not an over‐the‐wire replacement for a previous CVC. Data were automatically collected on initial and average dialysis blood flow rate and initial arterial and venous pressures, for up to 26 weeks of dialysis therapy. Findings 75 patients were enrolled. Kaplan‐Meier analysis indicated that 87% of patients maintained blood flow rate over 300 mL/min throughout 26 weeks of follow‐up. There was no decline in average dialysis blood flow rate and no significant change in hydraulic resistance of the arterial or venous lumens of the catheters during the study. Discussion The CentrosFLO catheter demonstrates long term patency with good flow rates on dialysis, which, by comparison with previous studies, shows a clinically significant improvement in blood flow rate vs. other catheters. Stable hydraulic resistance of the catheter lumens showed no evidence of tip encroachment by fibrous sheaths.     

Biocompatibility of heparin-grafted hemodialysis membranes: impact on monocyte chemoattractant protein-1 circulating level and oxidative status

This prospective observational study aimed at evaluating efficacy and biocompatibility performances of the new heparin-coated Evodial dialyzers with/without systemic heparin reduction. After a 4-week wash-out period with reference polysulfone F70S dialyzers, 6 hemodialysis patients were sequentially dialyzed with Evodial, F70S, and Evodial dialyzers using 30% heparin reduction, each period of treatment was 4 weeks. Removal rates (RR) (urea, creatinine, and β2-microglobulin), dialysis dose, and instantaneous clearances (urea and creatinine) were measured as well as inflammatory (C-reactive protein, fibrinogen, interleukin 6, tumor necrosis factor α, and monocyte chemoattractant protein-1) and oxidative stress (OS) (superoxide anion, homocysteine, and isoprostanes) parameters at the end of each study period. Patients treated with Evodial or F70S dialyzers for 4 weeks presented comparable dialysis efficacy parameters including urea and creatinine RR, dialysis dose and instantaneous clearances. By contrast, a significantly lower but reasonably good β2-microglobulin RR was achieved with Evodial dialyzers. Regarding biocompatibility, no significant difference was observed with inflammation and OS except for postdialysis monocyte chemoattractant protein-1 which significantly decreased with Evodial dialyzers. Thirty percent heparinization reduction with Evodial dialyzers did not induce any change in inflammation but led to an improvement in OS as demonstrated by a decrease in postdialysis superoxide production and predialysis homocysteine and isoprostane. This bioactive dialyzer together with heparin dose reduction represents a good trade-off between efficacy and biocompatibility performance (improvement in OS with a weak decrease in efficacy) and its use is encouraging for hemodialysis patients not only in reducing OS but also in improving patient comorbid conditions due to lesser heparin side effects.