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.     

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.     

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.     

Pilot study to assess increased dialysis efficiency in patients with limited blood flow rates due to vascular access problems

In the last few years, the number of hemodialysis patients with inadequate blood flow (Qb) rates has increased due to vascular access problems. To avoid a clinical status of underdialysis, these patients need long-lasting dialysis sessions. However, other factors aimed to optimize the dialysis dose have to be considered. High-efficiency convective therapies, such as online hemodiafiltration (HDF), are claimed to be superior to high-flux hemodialysis (HF-HD) in improving the dialysis efficacy, but treatment efficacy is strongly related to blood flow rate and infusion volumes. Online mid-dilution (HDF-MD) with the Nephros OL-pure MD190 represents a new HDF concept to increase the removal of middle molecules. In a cross-over clinical trial, 8 patients, with Qb eff <300 mL/min, received either online HDF-MD or HF-HD; Qd was 700 mL/min, the time duration was 240 min, and the filtration volume in HDF-MD was 112+/-7 mL/min. No differences were found for Kt/V, urea, and creatinine clearances. Clearance of both small phosphate (P) large beta(2)-microglobulin (beta(2)m), and leptin (L) solutes was significantly greater for MD (P 217+/-32, beta(2)m 85.5+/-10, L 42.6+/-18 mL/min) than for HF-HD (P 178+/-32, beta(2)m 71.9+/-13, L 32.1+/-12 mL/min). The results of this study indicate that HDF remains the best means of providing increased removal of large-molecular weight solutes even in patients with vascular access problems.     

Effect of an ethanol/trisodium citrate hemodialysis catheter locking solution on isolates of Candida albicans

We conducted an in vitro study to assess the effect of a 30% ethanol/4% trisodium citrate (TSC) catheter locking solution on isolates of Candida albicans. Twelve isolates obtained from human blood cultures were tested in control solutions composed of broth and normal saline, and a test solution of 30% ethanol, 4% TSC, and broth. Colony counts were determined for control and test solutions at baseline and after 1, 24, and 48 hours of exposure. After 48 hours, the remaining test solution was filtered through a sterile filter funnel and rinsed with 10 mL of sterile water. Filters were aseptically transferred to agar plates and incubated for 24 hours. Control solutions grew well over the incubation period, as expected. In contrast, no viable growth was observed in test solutions 1 hour after instillation of the ethanol/TSC locking solution, or throughout the 48-hour study duration. Additionally, filters from test solutions displayed no growth. We conclude that a 30% ethanol/4% TSC catheter locking solution eradicated all isolates of C. albicans within 1 hour of exposure in this in vitro study, and shows promise as a new hemodialysis catheter locking solution.     

Heparin leak from a hemodialysis catheter causing major bleeding,ultimately leading to transplant rejection and death

Leakage of hemodialysis catheter‐locking solutions into the circulation has been reported in in vitro and in vivo studies, although there have been few reports of serious clinical adverse events. We describe a case of heparin leak from a hemodialysis catheter, which caused significant clinical bleeding requiring multiple transfusions and may have ultimately been responsible for the patient's death after transplantation.     

Hemodialysis‐induced bradycardia, “a plumbing issue”: Resolved with catheter repositioning

Sudden cardiac death (SCD) is reported as leading cause of death in patients on chronic hemodialysis. Arrhythmias are proposed to be a major predisposing factor for SCD. However, triggers for potentially lethal arrhythmias are not well understood. Here we describe a case of 72‐year‐old man on chronic hemodialysis via permanent Central venous catheter (CVC) who was admitted for evaluation after unwitnessed fall. Within 10 minutes of his first routine dialysis session in the hospital, he had cardiac‐arrest. He was successfully resuscitated within 3 minutes. The next day, fifteen minutes into the dialysis session, he had bradycardia with telemetry demonstrating long sinus pause and he lost consciousness. After few minutes of Advanced Cardiac Life Support (ACLS) he regained pulse and consciousness. Further review of the chest X‐ray revealed the tip of CVC to be directly touching the distal Superior Vena Cava (SVC) wall. We felt the catheter tip may have migrated after the fall and now is irritating the Sinoatrial node and triggering bradyarrhythmia. Next day, the CVC was exchanged, and the tip was placed higher up in superior vena‐cava. After repositioning, we started him on dialysis under intensive monitoring, and he tolerated well without any arrhythmia. Subsequent dialysis was uneventful. We describe a case of recurrent symptomatic intra‐dialytic bradycardia due to abnormal positioning of CVC that resolved after the repositioning of the catheter. This case in addition to similar case in nondialysis settlings provides additional insights into mechanisms of fatal arrhythmias in hemodialysis patient having CVC.     

Right intra-atrial catheter placement for hemodialysis in patients with multiple venous failure

The purpose of this study is to evaluate the efficacy and safety of direct right atrial catheter insertion for hemodialysis in patients with multiple venous access failure. We retrospectively evaluated the charts of 27 patients with multiple venous access failure who had intra-atrial dialysis catheter placement between October 2005 and October 2010 in our clinic. Permanent right atrial dialysis catheters were placed through a right anterior mini-thoracotomy under intratracheal general anesthesia in all patients. Demographics of the cases, the patency rates of hemodialysis via atrial catheterization, existence of any catheter thrombosis, and catheter-related infections were documented and used in statistical analysis. Seventeen women (63%) and 10 men (37%) with the mean age of 59.0 ± 7.1 years (47-71) were enrolled in this study. Chronic renal failure was diagnosed for the mean of 78.9 ± 24.3 months (33-130). Five patients (18.5%) died. Ventricular fibrillation and myocardial infarction were the causes of death in the early postoperative period in two patients. Two of the remaining three patients died because of cerebrovascular events, and one patient died because of an unknown cause. Ten patients (37%) had been using anticoagulate agents (warfarin) because of concomitant disorders such as deep vein thrombosis, operated valve disease, and arrhythmias. Catheter thrombosis and malfunction was determined in three cases (11.1%). Intra-atrial hemodialysis catheterization is a safe and effective life-saving measure for the patients with multiple venous failure and without any possibility of peritoneal dialysis or renal transplantation.     

Dialysis Staff Time and Supply Cost for the LifeSite System vs. Hemodialysis Catheters

The LifeSite System is a new subcutaneous vascular access option for hemodialysis patients. As the procedure for accessing the LifeSite differs from hemodialysis catheters, we prospectively studied the differences in time required to initiate and discontinue treatments for LifeSite patients compared to patients with hemodialysis catheters. We also collected data on the cost of supplies and the number of alarms during dialysis for both groups. 5 LifeSite and 5 catheter patients were chosen at random for participation in the study. The time required for the ON and OFF procedures was recorded for 3 consecutive dialysis sessions for each patient for a total of 15 observations/group. The average staff time required per session for supply preparation, ON/OFF procedure, dressing changes, and responding to alarms was 15.9 min for the LifeSite and 16.9 min for catheters. Catheter patients experienced 4.5 access-related alarms per session compared to 2.5 access-related alarms per session for LifeSite patients. This increase in the number alarms for catheter patients resulted in an increase in average staff time required to resolve the cause of these alarms vs. LifeSite patients (3.4 vs. 0.87 min/session). There was a minimal difference in the cost of access-related supplies between LifeSite and catheter patients at our center ($3.71 vs. $3.88 per session, respectively) based on dialysis center acquisition costs. This study demonstrates that attaining a critical mass of LifeSite patients in a dialysis unit enables the dialysis staff to develop the skill to initiate and discontinue treatments for patients with the LifeSite in a timeframe similar to that required to do the same for catheter patients. The overall cost of supplies to care for LifeSite patients in a dialysis unit is also similar to those used for catheter patients.     

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.     

Heparin‐induced thrombocytopenia due to heparin lock in a hemodialysis patient: A case report

Heparin‐induced thrombocytopenia (HIT) is a potentially fatal clinical condition which can develop after exposure to unfractionated or low‐molecular‐weight heparins. Even small doses of heparin such as heparin flushes in hemodialysis catheter can induce the development of HIT. However, the true incidence of heparin lock‐related HIT is unknown. We report a 58‐year‐old woman with acute kidney injury because of obstructive uropathy who developed HIT after heparin‐free hemodialysis. She was found to have severe thrombocytopenia with deep vein thrombosis of left lower limb and arterial thrombosis of the right anterior and middle cerebral arteries. The heparin‐platelet factor 4 antibody was positive and she was put on plasmapharesis. However, her condition further deteriorated and succumbed shortly. Heparin lock solution in the hemodialysis catheter was believed to be the cause of HIT in our patient.     

Mycobacterium fortuitum infection of a hemodialysis catheter in a pediatric patient

This case report discusses a pediatric patient who developed a hemodialysis catheter line infection from an uncommon etiology, Mycobacterium fortuitum. The initial presentation revealed a well appearing patient with a slow growing skin lesion near the site of the hemodialysis catheter. The treatment course was complicated by resistance to initial antibiotics leading to continued spread of the lesion. The diagnosis was confirmed via skin biopsy of the lesion that required 2 weeks to grow the atypical Mycobacterium. Treatment was successful after hemodialysis catheter removal, transition to peritoneal dialysis, and a prolonged antibiotic course. Mycobacterium fortuitum is a rare cause of dialysis catheter infections that is resistant to standard antibiotic treatment. Treatment success is improved after removal of the dialysis catheter and prolonged antibiotics based on susceptibilities. This case highlights the importance of keeping atypical Mycobacterium in the differential for patients with slow growing skin lesions near dialysis catheter sites with resistance to initial treatment.     

Heparin albumin priming in a clinical setting for hemodialysis patients at risk for bleeding

Introduction: Intermittent hemodialysis (IHD) is sometimes necessary in patients with a bleeding risk, i.e., before/after surgery or brain hemorrhage. In such case IHD has to be modified to limit the conventional anticoagulation used to avoid clotting of the extracorporeal circuit (ECC). We evaluated if priming using a heparin and albumin (HA) mixture could minimize the exposure to heparin. Methods: Retrospective data from 1995 to 2013 were collected from 1408 acute dialysis treatment protocols that included 321 patients. Comparisons were made between IHD patients that had increased risk for bleeding and were treated by standard anticoagulation (Group‐S), and patients at increased risk of bleeding (Group‐HA). The ECC in Group‐HA was primed with a solution of unfractioned heparin (UFH) (5000 Units/L) and albumin (1 g/L) in saline that was discarded after priming. There were 16 different dialyzers in the material. Findings: Comparing Group‐S (n = 883) with Group‐HA (n = 221), the mean age was 61.6 vs. 62.2 years (P = 0.8), dialysis time was 197 vs. 190 minutes (P = 0.002), and total dose of intravenous anticoagulant/IHD was at median 5000 Units vs. 1200 Units (P = 0.001). Twenty‐four percent of patients were treated without any additional heparin. Clotting resulting in interrupted dialysis was similar in both groups (0.8% for Group‐S vs. 1.0% for Group‐HA, P = 0.8). No secondary bleeding was reported in either group. Discussion: HA priming minimized the risk of clotting and enabled acute IHD in vulnerable patients without increased bleeding, thus allowing completion of IHD to the same extent as for standard HD.     

Fallacies of High‐Speed Hemodialysis

Chronic hemodialysis sessions, as developed in Seattle in the 1960s, were long procedures with minimal intra‐ and interdialytic symptoms. Financial and logistical pressures related to the overwhelming number of patients requiring hemodialysis created an incentive to shorten dialysis time to four, three, and even two hours per session in a thrice weekly schedule. This method spread rapidly, particularly in the United States, after the National Cooperative Dialysis Study suggested that time of dialysis is of minor importance as long as urea clearance multiplied by dialysis time and scaled to total body water (Kt/V_urea) equals 0.95–1.0. This number was later increased to 1.3, but the assumption remained unchanged that hemodialysis time is of minimal importance as long as it is compensated by increased urea clearance. Patients accepted short dialysis as a godsend, believing that it would not be detrimental to their well‐being and longevity. However, Kt/V_urea measures only removal of low molecular weight substances and does not consider removal of larger molecules. Besides, it does not correlate with the other important function of hemodialysis, namely ultrafiltration. Whereas patients with substantial residual renal function may tolerate short dialysis sessions, the patients with little or no urine output tolerate short dialyses poorly because the ultrafiltration rate at the same interdialytic weight gain is inversely proportional to dialysis time. Rapid ultrafiltration is associated with cramps, nausea, vomiting, headache, fatigue, hypotensive episodes during dialysis, and hangover after dialysis; patients remain fluid overloaded with subsequent poor blood pressure control, left ventricular hypertrophy, diastolic dysfunction, and high cardiovascular mortality. Short, high‐efficiency dialysis requires high blood flow, which increases demands on blood access. The classic wrist arteriovenous fistula, the access with the best longevity and lowest complication rates, provides “insufficient” blood flow and is replaced with an arteriovenous graft fistula or an intravenous catheter. Moreover, to achieve high blood flows, large diameter intravenous catheters are used; these fit veins “too tightly,” so predispose the patient to central‐vein thrombosis. Longer hemodialysis sessions (5–8 hrs, thrice weekly), as practiced in some centers, are associated with lower complication rates and better outcomes. Frequent dialyses (four or more sessions per week) provide better clinical results, but are associated with increased cost. It is my strong belief that a wide acceptance of longer, gentler dialysis sessions, even in a thrice weekly schedule, would improve overall hemodialysis results and decrease access complications, hospitalizations, and mortality, particularly in anuric patients.     

Comparison of side hole versus non side hole high flow hemodialysis catheters

Current literature suggests that side holes may be detrimental to dialysis catheter performance. Today, these catheters are primarily available with side holes. The purpose of this study was to compare flow rates, infection rate, and survival of side hole vs. non side hole hemodialysis catheters. Over a 16-month period patients were arbitrarily assigned to either a 14.5 F MAHURKAR MAXID cuffed dual lumen tunneled catheter with side holes or a 14.5 F MAHURKAR MAXID cuffed dual lumen tunneled catheter without side holes ("non side hole catheters"). We performed a retrospective analysis of catheter flow rates, patency, catheter survival, and catheter-related infections. Information was gathered for the life of the catheter or up to 28 weeks. A total of 54 patients were enrolled in the study. Thirty-seven of 54 (68%) patients received a catheter with side holes for a total of 3,930 catheter days and 17/54 (32%) received a similar catheter without side holes for a total of 2,188 catheter days. Catheter infection necessitating removal of the catheter occurred in 10/37 catheters with side holes and 1/17 without side holes. Infection rates per 1,000 catheter days were 2.545 with side holes and 0.254 without side holes (p<0.001). Slightly improved catheter survival (p<0.05) was recorded with the non side hole catheters. No insertion complication (e.g., air embolization, bleeding, or kinking) occurred with either catheter. One catheter without side holes had to be repositioned 5 days after insertion because of poor flows. No significant difference was recorded in mean blood flow rates between the catheters. Results indicate reduced catheter infection rate in hemodialysis patients with the use of non side hole dual lumen tunneled cuffed catheters.     

Hemodialysis catheter insertion using transrenal approach

We report a patient suffering from end‐stage renal disease (ESRD) because of lupus nephritis presented with exhausted vascular access after multiple arteriovenous grafts creation and hemodialysis catheters insertion. A rare percutaneous transrenal approach was finally used for the insertion of dialysis catheter. After 2 years, this hemodialysis catheter was complicated by blockage but was successfully replaced by a new catheter via the same site. Our report shows that the transrenal route of hemodialysis catheter insertion can provide a glimpse of hope for those ESRD patients with exhausted vascular access.     

In‐center hemodialysis attendance: Patient perceptions of risks,barriers, and recommendations

Missed hemodialysis treatments lead to increased morbidity and mortality in the end‐stage renal disease population. Little is known about why patients have difficulty attending their scheduled in‐center dialysis treatments. Semistructured interviews with 15 adherent and 15 nonadherent hemodialysis patients were conducted to determine patients' attitudes about dialysis, health beliefs and risk perception regarding missed treatments, barriers and facilitators to hemodialysis attendance, and recommendations to improve the system to facilitate dialysis attendance. Average time on dialysis was 2.5 years for the nonadherent group and 7.3 years in the adherent group. In both groups, patients felt that dialysis is life‐saving and a necessity. A substantial number of patients in both groups understood that missing hemodialysis treatments is dangerous and several patients could clearly communicate the risk of skipping. The most common barriers to hemodialysis were inadequate or unreliable transportation (mentioned in both groups) and a lack of motivation to get to dialysis or that dialysis is not a priority (typically mentioned by the nonadherent group). Facilitators to hemodialysis attendance included explanations from the health care team regarding the risk of skipping and relationships with other dialysis patients. Patient recommendations to improve dialysis attendance included continued education about the risk of poor attendance and more accessible transportation. Patients did not feel that home dialysis would improve adherence. Hemodialysis patients must adhere to a complex and burdensome regimen. Through the elucidation of barriers and facilitators to hemodialysis attendance and through specific patient recommendations, at least three interventions may be further investigated to improve hemodialysis attendance: Improvement of the transportation system, education and supportive encouragement from the health care team, and peer support mentorship.     

Increased dialyzer reuse with citrate dialysate

Dialyzer reuse is limited by the clotting of blood, which blocks the fibers and reduces the membrane surface area. Clotting during treatment may also reduce dialysis efficiency and potentially decrease delivered dose, Kt/V(urea). A new dialysate containing citric acid, instead of the standard acetic acid, as the acidifying agent has become available and is associated with reduced clotting during acute dialysis treatments. The effect of citric acid dialysate on dialyzer reuse was evaluated in this prospective, controlled, multicenter study involving maintenance hemodialysis patients. A total of 105 patients from five dialysis units were switched to the new dialysate and new dialyzers. Reuse outcome on the new dialysate was compared with the reuse on the regular acetic acid containing bicarbonate dialysate (controls). The overall reuse with citrate dialysate increased significantly from 15.1 +/- 9.4 to 18 +/- 10.0 (mean +/- SD) on regular and citrate dialysate, respectively (p = 0.0003). The most significant increase was seen in those patients who had limited reuse before the switch to citrate dialysate; 51, 59, and 134% increases occurred in those with 10 to 15, 5 to 10, and < 5 reuses at controls, respectively. Interestingly, the 10 patients with 10 or fewer reuses had significantly lower Kt/V(urea) at baseline (before the switch to citric acid dialysate) than those with > 10 reuses (1.23 +/- 0.23 vs. 1.47 +/- 0.23, respectively, p = 0.009). The Kt/V(urea) increased to 1.41 +/- 0.31 after the switch in the low-reuse group but the increase did not reach statistical significance (p = 0.07). The results from this study show that citric acid-containing dialysate is associated with increase in dialyzer reuse and appears to be related to reduced clotting.     

A simple method to create buttonhole cannulation tracks in a busy hemodialysis unit

The preference for fistulae as the hemodialysis access of choice has led to a significant number of accesses that are less than ideal for cannulation. Buttonhole cannulation is ideal for such accesses, but the technique for creation provides major challenges. In 12 patients, buttonhole tunnel tracks were created by leaving the polyurethane catheter of a Clampcath^® hemodialysis needle indwelling for 10 days after the initial cannulation. After each dialysis the catheter was flushed, and dressed with an antibacterial ointment and gauze. Dialysis was carried out via the catheter during that time. After day 10, the catheter was removed, the tunnel track covered with an antibacterial dressing and the tunnel track was cannulated with a dull buttonhole needle at the next dialysis. Successful buttonhole accesses were created in 11 patients after 10 days, the 12th patient required a single sharp needle cannulation before using dull needles. During the first 2 weeks of dull needle cannulation both pain experienced on cannulation and the difficulty cannulating the access were significantly less than in the classical buttonhole technique (P<0.01). Complications during the follow-up period (6 months–1.5 years) included difficulty cannulating with a dull needle (22) and antibacterial agent induced contact dermatitis (4). There was no episode of sepsis or tunnel track infection. Initial cannulation of the fistula using a Clampcath^® hemodialysis needle, leaving the polyurethane catheter indwelling for 10 days, is a simple, safe, and effective technique for the creation of buttonhole tunnel tracks.