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.     

Prevention of Damage to Cuffed Catheters

Cuffed catheters, although not ideal for long-term use, are now used more frequently due to an increase in the aging population, in whom the vessels are not suitable for either arteriovenous fistulas or polytetrafluoroethylene (PTFE) grafts. Infections and thrombosis remain the major causes for removal or change of catheters. We recently identified eight catheter defects that required replacement of catheters. Of these, two were due to patient negligence: one catheter was accidentally severed while the patient was shaving; the other was snipped during a haircut. One was believed to have a manufacturing defect. One catheter sustained needle-prick damage near the hub while irrigating the catheter. Two catheters were lost due to needle pricks during skin closure, and one catheter sustained similar damage while fixing the suture wing to the skin. The other two were damaged by suture material slicing through the lumen of the catheter as it expanded due to increased blood flow during repeated dialyses. Importantly, several of these injuries to the catheters were not immediately obvious and were detected only after repeated use of the catheters. Delayed bleeding of cuffed catheters necessitating change or removal has not been reported. Such bleeding may be due to manufacturing defects, patient carelessness, or iatrogenic causes. Avoiding the use of sutures can minimize the latter. Skin closure strips and a double transparent dressing may serve the same purposes, such as securing the catheter and aiding wound healing. In addition, these dressings have the added advantage of being waterproof, bacteria-proof, and cost effective.     

Catheter‐related bacteremia and mortality in frequent nocturnal home hemodialysis

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

Predictors of steal syndrome in hemodialysis patients

Steal syndrome is a feared complication of dialysis vascular access in a population becoming older and frailer. The aim of this study was to determine the predictor factors of steal syndrome. All proximal arteriovenous fistulas (AVFs), patent at day 30, inserted between January 2008 and December 2009 were studied. Data on age, gender, diabetes mellitus (DM) status, presence of coronary or peripheral artery disease, date of initiation of renal replacement therapy, date of access construction, localization, type of anastomosis, previous interventions, and outcome for AVF and patients were analyzed. There were 324 AVFs placed into 309 individual patients. The mean age was 66.7 ± 15.3 years, and the majority (53.7%) of the patients was male. Mean follow‐up of all 324 fistulas was 18.6 ± 8.5 months. During follow‐up, steal syndrome occurred in 26 (8%) of the AVFs. Univariate analysis revealed correlations between steal syndrome and DM (P = 0.002), brachiomedian fistulas (P = 0.016), and side‐to‐side (STS) anastomosis (P = 0.003). However, in multivariate analysis, the presence of DM, STS anastomosis, and female gender were found to be the independent risk factors. The strongest predictive factor was DM (odds ratio: 6.7; 95% confidence interval: 2.5–17.9). Being diabetic is the factor most predictive of having steal syndrome. In diabetic women, with a proximal access, it seems preferable to construct fistulas with end‐to‐side anastomosis to minimize the risk.     

Carotid-jugular arteriovenous fistula: a case report of an iatrogenic complication following internal jugular vein catheterization for hemodialysis access

We report a case of diabetic end-stage renal disease patient who presented with a right common carotid artery jugular arteriovenous fistula as a complication of the insertion of a polyurethane double-lumen hemodialysis catheter into the right internal jugular vein .On physical examination of the neck, a pulsating mass with a palpable thrill and a bruit was noted in the right subclavicular region. The diagnosis was confirmed by color doppler ultrasonography of the neck and carotid angiography. The review of the literature suggests the occurrence of this complication as rather rare. The fistula was successfully repaired surgically. It is emphasized that while securing the access, a thorough physical examination with a special emphasis on seeking any neck swellings, thrill, and bruit along with routine use of vascular doppler for securing dialysis access is recommended.     

Initial clinical experience with a new heparin-coated chronic hemodialysis catheter

In this paper we wish to report our clinical experience with a new heparin-coated dialysis catheter with a symmetric tip. Over a 16-month period, 60 heparin-coated Tal Palindrome^™ catheters were placed in 57 patients. Catheter patency, catheter-related complications, and reasons for catheter removal were recorded. The patient's initial cause of end-stage renal disease, underlying diseases, and site of access were recorded as well. Patients were specifically followed for development of heparin-induced thrombocytopenia. Patient ages were 34–91 (average 66). Fifty-four percent of patients had a history of diabetes. Sixty catheters were placed for a total of 5353 catheter-days. The average catheter indwell time was 107 days (range of 2–381 days). Catheter-related infection occurred in 6 patients over the study period, with a rate of 1.12/1000 catheter-days. Bacteremia occurred in 3 patients with a rate of 0.56/1000 catheter-days. Six catheters were removed or exchanged due to malfunction. There was no incidence of heparin-induced thrombocytopenia. Initial clinical experience with the heparin-coated Tal Palindrome^™ hemodialysis catheter demonstrated safe, reliable use, and low infection rates.     

A rare complication of hemodialysis catheters: superior vena cava syndrome

Central venous catheters in hemodialysis patients may result in superior vena cava (SVC) syndrome. With the increasing use of these catheters, the SVC syndrome will probably be more common among hemodialysis patients. This report describes 3 cases of SVC syndrome due to central venous catheters that developed in hemodialysis patients with previous multiple catheter placements.     

Air embolism following removal of hemodialysis catheter

Introduction: Air embolism (AE) is a rare, but serious complication that can occur in the practice of hemodialysis. In contrast to careful techniques and meticulous care during insertions and manipulations of the central catheters, awareness of the risk of AE following catheter removal is less. We aimed to analyze the clinical characteristics of the all case reports with AE after catheter removal and summarize the mechanisms, clinical consequences, treatment and prevention of AE. Methods: In addition to our case, MEDLINE database was searched for all case reports with AE following catheter removal, and the clinical, diagnostic and outcome data were analyzed. Findings: A total of 10 patients (including our case) (M/F 6/4; median age 50.5 years) were found for the analysis. Procedures for prevention of AE were reported in a few patients (Trendelenburg position 2, airtight dressing 1). The time that elapsed between catheter removals and onset of AEs was ranged from seconds to 6 hours. The most common findings were dyspnea (90%), hypoxemia (70%), and cerebral dysfunction (70%). The most common sites where air could be detected were the left ventricle (40%), pulmonary artery (30%) and right ventricle (30%). Mortality was reported in 4 (40%) cases and the remaining 6 patients had complete recovery. Blocking of air portal was not reported in any of the fatal cases. Discussion: AE following catheter removal carries a major risk of mortality. Great awareness and attention to preventive procedures and appropriate care after development of AE seem mandatory.     

Dialysis disequilibrium syndrome leading to sudden brain death in a chronic hemodialysis patient

Dialysis disequilibrium syndrome (DDS) is a rare central nervous system (CNS) disease which develops in patients receiving hemodialysis (HD). Although it has been reported in patients receiving chronic HD, DDS is more common during or immediately after the first HD treatment. The exact incidence of DDS is unknown. Death in DDS is an extremely rare phenomenon and to the best of our knowledge only 9 cases have been reported showing this association. We present a unique case of a 42‐year‐old female on chronic HD, and no prior history of CNS disease, who developed brain death in the setting of DDS 2 hours into the dialysis treatment. A literature review of all previously reported cases was performed.     

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.     

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.     

Recognizing misplacement of a dialysis catheter in the azygos vein

Uneventful central venous catheterization for hemodialysis patients may not always result in a correct tip position. A case of inadvertent cannulation of the azygos vein is described. Radiographic features for its early recognition are emphasized and mechanisms related with azygos unintended catheterization are discussed.     

Massive catheter‐related thrombosis of vena cava superior protruding into the right atrium in a hemodialysis patient

A 36‐year‐old man with chronic renal insufficiency secondary to type 1 diabetes mellitus was on hemodialysis via central venous catheter (CVC), newly placed into the right subclavian vein after his arteriovenous fistula became dysfunctional. Seven days after CVC insertion, the patient developed fever and on day 11 echocardiography showed a large nearly occluding thrombus in the superior vena cava (SVC) extending into the right atrium (RA). Emergency surgical thrombectomy was successfully performed and an 11 cm long thrombus extending from the RA cranially into the SVC occupying majority of the vein's lumen was removed. Cultures from the thrombus and CVC were negative, but polymerase chain reaction was positive for Staphylococcus aureus. This particular case was interesting for a marked discrepancy between large SVC occluding thrombosis and a relatively mild clinical presentation with fever, and it highlights the importance of correct timing of echocardiography exam which might prevent potentially fatal consequences such as pulmonary embolism.     

Complications of home hemodialysis

Home hemodialysis is regaining popularity as a treatment choice for end-stage kidney disease. This trend is fueled by numerous reports of better survival and improved quality of life with primarily home-based more frequent and/or longer hours of hemodialysis. Home hemodialysis in the contemporary era is generally very safe. Advances in machine technology have reduced technical complications and longer and more frequent treatments have reduced the risk of hypotension and cardiovascular instability. A successful home hemodialysis program must focus on patient safety to prevent serious hemorrhage from needle dislodgement and enable an aseptic cannulation technique. In addition, vigilance in relation to machine maintenance procedures and attention to water quality are key skills that patients must acquire for optimal outcomes. The possibility of increased septic events with longer and more frequent hemodialysis regimens performed in the home, the long-term psychosocial effects of home hemodialysis, and the best methods for maintaining compliance of patients in the long term are of particular contemporary interest.     

Accidental extravascular insertion of a subclavian hemodialysis catheter is signaled by nonvisualization of catheter tip

Subclavian hemodialysis (HD) catheter placement under fluoroscopy with perforation of the superior vena cava (SVC) is a rare complication that needs to be recognized and treated appropriately. We report the case of a 47-year-old black woman under treatment for end-stage renal disease secondary to HIV-associated nephropathy who sustained an extravascular insertion of fluoroscopy-guided subclavian catheterization for HD. Subsequent successful removal of the extravascularly placed catheter along with repair of the lacerated SVC were effected by open thoracic surgery.     

Subcutaneous defibrillators for dialysis patients

Defibrillation can be successfully provided by the subcutaneous implantable cardioverter defibrillator (ICD) without the leads. In contrast, traditional ICDs require leads that can cause central venous stenosis, lead‐induced endocarditis, and carry the risk of tricuspid regurgitation by valve adhesion, perforation, coaptation interference, or entanglement. Central venous stenosis, infection, and tricuspid regurgitation are all critically important considerations in hemodialysis patients. Recent reports are supporting the use of subcutaneous ICDs in renal patients maintained on long‐term hemodialysis. This article provides the risks associated with leads of traditional defibrillators and raises awareness of the subcutaneous ICD and their benefits for hemodialysis patients.     

The use of vascular access audit and infections in home hemodialysis

Vascular access‐related infection is an important adverse event in home hemodialysis (HHD). We hypothesize that errors in self‐cannulation or manipulation of dialysis vascular access are associated with increased incidence of access‐related infection. We conducted a retrospective cohort study of all prevalent HHD patients at the University Health Network. All vascular access‐related infections were recorded from 2006 to 2013. Errors in dialysis access were ascertained by nurse‐administered vascular access checklist. Ninety‐two patients had completed at least one vascular access audit. Median HHD vintage was 2.3 (0.9–5.0) years in patients with appropriate vascular access technique and 5.8 (1.5–9.4) years in patients with erroneous vascular access technique. The overall rate of infection between patients with and without appropriate vascular access technique was similar (0.27 and 0.28 infections per year, P = 0.166). Among patients who were identified with errors in dialysis access manipulation, patients with five or more errors were associated with higher rate of access‐related infection (mean of 0.47 vs. 0.16 infection per patient‐year, P < 0.001). The use of vascular access audit is a feasible strategy, which can identify errors in vascular access technique. Patients with a longer median HHD vintage are associated with higher risk of inappropriate vascular access technique. Patients with multiple errors in vascular access technique are associated with a higher risk of dialysis access‐related infection. Prospective evaluation of the impact of vascular access audit on adverse vascular access events is warranted.