Sodium citrate 4% locking solution for central venous dialysis catheters--an effective, more cost-efficient alternative to heparin.

BACKGROUND: Thrombosis of the central venous haemodialysis catheter compromises dialysis adequacy and catheter survival. Heparin containing catheter-locking solution has been associated with bleeding, interferes with INR (prothrombin time/international normalized ratio) measurements and is costly. Sodium citrate has been used successfully as a catheter-locking solution, but long-term experience with its use as the exclusive locking solution has not been published. METHODS: Our haemodialysis unit converted to locking all central venous haemodialysis catheters with sodium citrate 4% instead of heparin 10 000 U/ml. A retrospective analysis compared the outcomes of the year prior and after the conversion. Flow-related catheter exchange rate, prevalence of INR assay interference, tissue plasminogen activator (rt-PA) utilization rate, rate of bacteraemias and annual cost of locking agent were examined. RESULTS: During the study period, 30 925 and 37 139 catheter days were identified during the heparin and citrate years, respectively. The rate of flow-related catheter exchange was not different during the two periods (1.81 vs 1.88 per 1000 catheter days, P = 0.89). Falsely elevated INR values were eliminated with citrate and the rate of rt-PA treatments was similar during the two periods (4.1 vs 3.23 per 1000 catheter days respectively, P = 0.07). The number of bacteraemias was similar during the two periods (0.77 vs 0.94 per 1000 catheter days respectively, P = 0.36) There was an 85% reduction in the costs associated with catheter-locking therapy during the citrate period. CONCLUSIONS: The pharmaco-economic benefits of sodium citrate 4% are well supported by this analysis. Furthermore, citrate offers several clinical advantages over concentrated heparin: citrate lock avoids heparin-associated bleeding complications, improves reliability of INR assays and provides an effective alternative for patients with suspected or confirmed heparin-induced thrombocytopenia.     

Locking of tunneled hemodialysis catheters with gentamicin and heparin

INTRODUCTION: Catheter-related infection (CRI) is a major cause of morbidity and mortality in patients receiving hemodialysis. Antibiotic locking of these catheters has been shown to increase both the success of systemic antibiotic treatment in line sepsis, and to reduce the incidence of sepsis. We have studied the use of gentamicin locking of catheters (in combination with standard heparin rather than previously reported citrate) to reduce CRI rates. Furthermore, we have investigated the effects of this strategy on epoetin requirements and vascular access function. METHODS: Fifty patients were studied. Patients were randomized to catheter-restricted filling with either standard heparin (5000 IU/mL) alone, or gentamicin and heparin (5 mg/mL). Epoetin requirements and hemoglobin response were monitored over the study period. RESULTS: The gentamicin-locked group suffered only one infective episode (0.3/1000 catheter days) compared to 10 episodes in six patients in the heparin alone group (4/1000 catheter days, P= 0.02). The isolated organisms were equally split between Staphylococcal species and coliforms. There were no statistically significant differences in delivered dialysis dose (Kt/V) or QA between the two groups. Use of antibiotic locking was associated with both a higher mean hemoglobin (10.1 +/-0.14 g/dL vs. 9.2 +/- 0.17 g/dL in the heparin group, P= 0.003) and a lower mean epoetin dose (9000 +/- 734 IU/week vs. 10790 +/-615 IU/week in the heparin group, P= 0.04). CONCLUSION: The practice of locking newly inserted tunneled central venous catheters with gentamicin and heparin is an effective strategy to reduce line sepsis rates, and is associated with beneficial effects on epoetin requirements.     

Locking solutions for hemodialysis catheters; heparin and citrate--a position paper by ASDIN

There is wide variation in the use of solutions to "lock" or fill tunneled central venous catheters for dialysis. Some centers use undiluted heparin concentrations ranging from 1000 to 10,000 U/ml and other centers place from 1000 to 10,000 U per lumen. Based on available evidence, it appears that heparin 1000 U/ml, or 4% sodium citrate are suitable choices for lock solution to maintain patency of tunneled central venous catheters for dialysis. Risks from systemic anticoagulation are lower with heparin 1000 U/ml and 4% sodium citrate, compared with higher concentrations of heparin (5000 and 10,000 U/ml). The need for use of tissue plasminogen activator for maintaining catheter patency is increased by using heparin lock at 1000 U/ml, vs. higher concentrations. Higher concentrations of heparin lock should be reserved for patients who have evidence of catheter occlusion or thrombosis when heparin is used at 1000 U/ml. Similar choices for lock solution are sensible for acute hemodialysis catheters. When heparin is used for catheter lock, the injected volume should not exceed the internal volume of the catheter.     

Citrate lock versus heparin lock for the prevention of catheter related infections in hemodialysis patients with tunneled catheters: a Meta-analysis of randomized controlled trials

ObjectiveTo study whether citrate lock is superior to heparin lock in the prevention of catheter related infections, bleeding complications and catheter malfunctions among hemodialysis patients with tunneled catheters. MethodsBy searching in Pubmed, the Cochrane Library, EMBASE, Ovid, WanFang, VIP, CNKI and CBM databases as well as related journals, qualified randomized controlled trials were included in a Meta - analysis using Revman 5.0 and STATA 10.0 software. The endpoints included catheter related infection, bleeding complication, thrombolytic treatment, catheter removal for malfunction, catheter thrombosis and all - cause death. ResultsFifteen randomized controlled trials were included with 1621 patients involved. Eight studies compared citrate alone with heparin lock, while 7 trials focused on citrate in combination with other antimicrobials. Pooled analysis demonstrated that incidence of catheter related infections in patients receiving citrate lock decreased by 47% compared with those on heparin (RR=0.53, 95%CI 0.36-0.77, P＜0.01). Subgroup analysis by types of citrate lock indicated that all combined lock solutions of citrate and other antimicrobials (citrate + gentamicin, citrate + taurolidine, citrate + methylene blue + methylparaben + propylparaben) were superior to heparin lock in preventing catheter-related infections (P＝0.01, 0.04, 0.01, respectively); citrate alone seemed to reduce catheter-related infection risk (RR＝0.68), but no statistically significant difference was observed (95%CI 0.38-1.21, P＝0.19). There were fewer patients with bleeding complications in citrate group (RR＝0.53, 95%CI 0.34-0.84, P＜0.01), while citrate showed no advantage over heparin lock in terms of thrombolytic treatment (P＝0.93), catheter removal for malfunction (P＝0.35), catheter thrombosis (P＝0.64) and all - cause death (P＝0.35). ConclusionsFor hemodialysis patients with tunneled catheters, combined lock solutions of citrate and other antimicrobials, rather than citrate alone, are superior to heparin in preventing catheter related infections. Citrate locks are associated with less bleeding complications, and are comparable to heparin in the maintenance of catheter patency.     

Central venous catheter colonization in critically ill patients: a prospective, randomized, controlled study comparing standard with two antiseptic-impregnated catheters

In this prospective, randomized, controlled, unblinded study, we compared colonization rates of a standard, unimpregnated central venous catheter (CVC) with rates for silver-coated and chlorhexidine-silversulfadiazine (CH-SS)-impregnated CVC. Patient characteristics, CVC insertion site, indwelling time, and colonization detected by semiquantitative and quantitative microbiologic techniques were documented. Two-hundred-seventy-five critically ill patients were included into the study protocol. One-hundred-sixty standard, 160 silver (S)-coated, and 165 externally impregnated CH-SS CVC were inserted. There was a significant difference in CVC colonization rates among study groups (P = 0.029). There was no difference in the colonization rate and the colonization per 1000 catheter days between standard and S-coated (P = 0.564; P = 0.24) or CH-SS-coated CVC (P= 0.795; P = 0.639). When comparing antiseptic CVC with each other, colonization rates were significantly less with CH-SS-impregnated than with S-coated CVC (16.9% versus 7.3%; P = 0.01; 18.2 versus 7.5 of 1000 catheter days; P = 0.003; relative risk, 0.43; 95% confidence interval, 0.21-0.85). Whereas standard and S-coated CVC were first colonized 2 and 3 days after insertion, respectively, CH-SS CVC were first colonized only after 7 days. In conclusion, antiseptic-impregnated CVC could not prevent catheter colonization when compared with standard polyurethane catheters in a critical care setting with infrequent catheter colonization rates and CVC left in place for >10 days.     

Catheter lock solutions: it's time for a change

In recent years, the number of patients on hemodialysis (HD) with central vascular catheters (CVCs) has grown. However, CVC use is often associated with an important risk for catheter related bloodstream infections (CR-BI) and inadequate dialysis due to flow problems. In this study, we reviewed alternative solutions to heparin for locking HD CVCs. Several experiences have demonstrated that trisodium citrate (TSC) (30-47%), citrate (4%) and taurolidine (1.35%) solutions are effective and safe for the prevention of CRBI, while heparin stimulates biofilm formation. High citrate (47%) concentrations can also provide significant advantages in reducing catheter clotting, but controlled studies with larger populations are necessary to confirm and to extend the use of such solutions in clinical practice. Side effects with high sodium citrate concentrations have been reported only immediately after locking, the symptoms are probably caused by a temporary drop in ionized calcium and magnesium, but it is evident that these solutions should only be used by skilled and authorized personnel, with a rigorous protocol.     

Catheter lock solutions influence staphylococcal biofilm formation on abiotic surfaces.

BACKGROUND: Microbial biofilms form on central venous catheters and may be associated with systemic infections as well as decreased dialysis efficiency due to catheter thrombosis. The most widely used anticoagulant catheter lock solution in the US is sodium heparin. We have previously shown that sodium heparin in clinically relevant concentrations enhances Staphylococcus aureus biofilm formation. In the present study, we examine the effect of several alternative catheter lock solutions on in vitro biofilm formation by laboratory and clinical isolates of S. aureus and coagulase-negative staphylococci (CNS). METHODS: Lepirudin, low molecular weight heparin, tissue plasminogen activator, sodium citrate, sodium citrate with gentamicin and sodium ethylene diamine tetra-acetic acid (EDTA) were assessed for their effect on biofilm formation on polystyrene, polyurethane and silicon elastomer. RESULTS: Sodium citrate at concentrations above 0.5% efficiently inhibits biofilm formation and cell growth of S. aureus and Staphylococcus epidermidis. Subinhibitory concentrations of sodium citrate significantly stimulate biofilm formation in most tested S. aureus strains, but not in CNS strains. Sodium EDTA was effective in prevention of biofilm formation as was a combination of sodium citrate and gentamicin. Low molecular weight heparin stimulated biofilm formation of S. aureus, while lepirudin and tissue plasminogen activator had little effect on S. aureus biofilm formation. CONCLUSIONS: This in vitro study demonstrates that heparin alternatives, sodium citrate and sodium EDTA, can prevent the formation of S. aureus biofilms, suggesting that they may reduce the risk of biofilm-associated complications in indwelling catheters. This finding suggests a biological mechanism for the observed improvement in catheter-related outcomes in recent clinical comparisons of heparin and trisodium citrate as catheter locking solutions. A novel and potential clinically relevant finding of the present study is the observation that citrate at low levels strongly stimulates biofilm formation by S. aureus.     

Observational study of need for thrombolytic therapy and incidence of bacteremia using taurolidine-citrate-heparin, taurolidine-citrate and heparin catheter locks in patients treated with hemodialysis

Catheter-related blood stream infections may be reduced by interdialytic locking with Taurolidine, a nontoxic antimicrobial agent. A formulation of 1.35% Taurolidine in 4% citrate (TC) is associated with a greater need for thrombolysis to maintain catheter patency than 5000 U/ml heparin. Our aim was to determine whether addition of 500 Units/ml of heparin to TC reduces the need for thrombolysis. TCH (1.35% taurolidine, 4% citrate and 500 U/ml heparin) was compared to TC and Heparin 5000 U/ml using retrospective data. Hundred and six adult hemodialysis patients with internal jugular tunnelled intravascular catheters using TCH were compared with 34 patients using TC and 34 patients using heparin 5000 U/ml respectively. Outcomes were time to first use of thrombolysis and bacteremia rates.TCH reduced the need for thrombolysis compared to TC (hazard ratio, 0.2; 95%CI: 0.06, 0.5; p < 0.001) and was not significantly different from heparin 5000 U/ml (hazard ratio, 1.4; 95%CI: 0.5, 3.9; p = 0.5). The bacteremia rates from all causes were 1.33, 1.22 and 3.25 per 1000 catheter- days (p < 0.001) in the TCH, TC and heparin groups respectively. Addition of 500 U/ml heparin to TC reduces the need for thrombolysis without increasing bacteremia and may achieve patency comparable to heparin 5000 U/ml.     

Exit of catheter lock solutions from double lumen acute haemodialysis catheters--an in vitro study.

BACKGROUND: Double lumen dialysis catheters are routinely heparin or citrate 'locked' to maintain patency. Heparin lock-related bleeding episodes and antibiotic lock-related toxicity have been reported. The aim of this study is to quantify the amount of leak during 'lock' procedures and to compare leakage for different double lumen dialysis catheters. METHODS: In an experimental, in vitro study at a University research laboratory, five different double lumen dialysis catheters were tested using three different lock volumes. RESULTS: Using the catheter flush volume, leak ratios for Flexxicon II 15 cm and 20 cm catheters were greater than that seen in the Arrow 16 cm catheter (P < 0.05). Using 20% less than the catheter flush volume, the Flexxicon II 20 cm catheter had greater leak than the Duo-flow 15 and 20 cm catheters and Arrow 16 cm catheter (P < 0.05). The Flexxicon II 15 cm catheter had greater leak than the Duo-flow 15 cm and Duo-flow 20 cm catheters with 20% less locking volume (P < 0.05). Using 20% greater than the catheter flush volume, the Duo-flow 20 cm catheter had significantly less leak ratio than the Flexxicon II 20 cm catheter (P < 0.05). There were no other significant differences in leak ratios between the catheters. CONCLUSION: All double lumen dialysis catheters we tested have a substantial amount of leak even when the catheter 'lock' volumes were used, and leak ratio increases significantly with 20% overfill. There is a leak even when using 20% less 'lock' volume. The amount of leak can be clinically important and may explain the reports of bleeding episodes after heparin lock and antibiotic toxicity after antibiotic and anticoagulant combination lock. Some devices have lower leak ratios than others, likely related to catheter design.     

Tunneled catheters' outcome optimization among diabetics on dialysis through antibiotic-lock placement

Efficacy and safety of antibiotic 'locks', in prevention of thrombotic and infectious complication-related morbidity and mortality, among diabetics dialyzed through tunneled-cuffed catheters (TCCs) has not been effectively investigated. This trial was designed to investigate the outcome of TCCs (n = 109), inserted among 96 diabetic end-stage renal disease patients (March 2002-February 2003), by comparing the catheter thrombosis, catheter-related bloodstream infections (CRBSI), catheter survival, and mortality rates, between the cohorts of 49 patients who had TCCs (n = 51) 'locked' with cefotaxime/heparin (group I) and 47 patients with TCCs (n = 58) filled with standard heparin (group II). Thrombosis was defined as the inability to use catheter at a blood flow of 200 ml/min despite intraluminal thrombolysis. Primary end points were catheter thrombosis and CRBSI; elective catheter removal and CRBSI-related death led to sensor of TCCs follow-up. Patients with intraluminal cefotaxime/heparin lock, on cumulative survival analysis, showed a superior thrombosis-free (86.3 vs 63.8%, P = 0.023, log rank), infection-free (72.9 vs 27.1%, P = 0.004, log rank), and thrombosis- and infection-free TCC survival (78.4 vs 37.9%, P = 0.001, log rank) at 365 days, besides having significantly lower incidence of CRBSI (1.56 vs 3.68 episodes/1000 catheter days, P < 0.0001) and CRBSI-related mortality (9.8 vs 23.4%, P = 0.015), compared with the heparin-alone group. Deployment of cefotaxime-heparin 'lock' enhances catheter survival; reduces thrombotic and infectious complications and ensuing mortality, among diabetics on dialysis. However, further studies are needed to define the long-term implications of antibiotic locks in terms of the risk of emergence of antimicrobial resistance.     

维持性血液透析患者其Cuff导管应用不同抗凝剂的封存效果对比评价

目的 讨论在长期带Cuff中心静脉导管的维持性血液透析患者封管时应用肝素钠与枸橼酸钠的临床效果与安全性.方法 选取本院行长期带Cuff中心静脉导管的维持性血液透析患者48例参与本次调查,依据随机对照研究的方式将患者划分为实验组(n=24)和对照组(n=24),分别使用肝素钠与枸橼酸钠进行封管处理,观察6个月,尔后统计比较两组患者透析血流量、导管相关感染(CRIs)、导管内血栓等的差异,并测定观察前后患者血清钙离子(Ca2+)、镁离子(Mg2+)、门冬氨酸氨基转氨酶(AST)、丙氨酸转氨酶(ALT)的变化情况.对比两组观察前后凝血功能、血红蛋白及血小板计数变化情况.同时记录患者不良反应发生情况.结果 进行为期6个月的观察,对照组共行血液透析955次,实验组共行血液透析962次,实验组的CRIs发生次数相较于对照组显著降低(P＜0.05),而尿激酶封管次数则明显高于对照组(P＜0.05),两组在导管内可抽吸血栓次数与导管功能不良发生次数上未见明显差异(P＞0.05);两组观察前后Ca2+、Mg2+、AST及ALT均未见明显变化(P＞0.05);两组观察前PT、APTT、血红蛋白及血小板计数无显著差异.实验组观察后PT及APTT均显著高于对照组(P＜0.05).两组观察后血红蛋白无显著差异.两组血小板计数在观察后显著上升(P＜0.05),但两组观察后血小板计数对比无显著差异(P＞0.05);两组均未见严重不良反应,仅对照组有2例出现胃肠道不适症状,可自行缓解.结论 枸橼酸钠用于维持性血液透析患者长期带Cuff中心静脉导管的封管时有助于减少导管相关感染事件的发生,且不良反应少,安全性较高,但可能增加导管内血栓的形成风险,临床应根据患者的具体情况合理选择,以进一步确保抗凝剂使用的安全性.     

Randomized, clinical trial comparison of trisodium citrate 30% and heparin as catheter-locking solution in hemodialysis patients

Interdialytic hemodialysis catheter-locking solutions could contribute to a reduction of catheter-related complications, especially infections. However, they can cause side effects because of leakage from the tip of the catheter. Recently, trisodium citrate (TSC) has been advocated because of its antimicrobial properties and local anticoagulation. In a multicenter, double-blind, randomized, controlled trial, TSC 30% was compared with unfractionated heparin 5000 U/ml for prevention of catheter-related infections, thrombosis, and bleeding complications. The study was stopped prematurely because of a difference in catheter-related bacteremia (CRB; P < 0.01). Of 363 eligible patients, 291 could be randomized. The study included 98 tunneled cuffed catheters and 193 untunneled. There were no significant differences in patient and catheter characteristics on inclusion. In the heparin group, 46% of catheters had to be removed because of any complication compared with 28% in the TSC group (P = 0.005). CRB rates were 1.1 per 1000 catheter-days for TSC versus 4.1 in the heparin group (P < 0.001). For tunneled cuffed catheters, the risk reduction for CRB was 87% (P < 0.001) and for untunneled catheters was 64% (P = 0.05). Fewer patients died from CRB in the TSC group (0 versus 5; P = 0.028). There were no differences in catheter flow problems and thrombosis (P = 0.75). No serious adverse events were encountered. Major bleeding episodes were significantly lower in the TSC group (P = 0.010). TSC 30% improves overall patency rates and reduces catheter-related infections and major bleeding episodes for both tunneled and untunneled hemodialysis catheters. Flow problems are not reduced.     

Plasma clearance of fat emulsion during continuous heparin infusion

Intravenous fat tolerance was tested in two groups of patients given a continuous i.v. infusion of heparin for several days. One group of 11 patients with deep vein thrombosis (DVT) of the leg was given 25,000-35,000 IU heparin daily for 4-5 days. The other group comprised 10 patients who had central venous catheters (CVC) for total parenteral nutrition. These patients were given 20,000 IU heparin daily for 6 days as prophylaxis against CVC-related thrombosis. In the DVT group heparinization was associated with a 44% decrease in plasma fat removal capacity (P less than 0.05). This reduction persisted for 2 days after the discontinuation of heparin therapy. In the CVC group the plasma fat removal capacity decreased by 29% during heparinization (P greater than 0.05, NS). During heparinization activated partial thromboplastin time was more than three times the basal value in the DVT group but less than twice those in the CVC group. One week after the heparin therapy the serum triglyceride levels were higher in both groups compared with initial values (DVT group: 1.2 +/- 0.2 s.e. mean vs. 1.7 +/- 0.3 mmol/l; P less than 0.05. CVC group: 1.0 +/- 0.1 vs. 1.4 +/- 0.2 mmol/l; NS). The possibility that full-dose heparinization reduces plasma fat removal capacity and that this may be due to a partial depletion of lipoprotein lipase stores is discussed.     

Prevention of tunneled hemodialysis catheter-related infections using catheter-restricted filling with gentamicin and citrate: a randomized controlled study

Tunneled catheters are widely used for the provision of hemodialysis. Long-term catheter survival is limited by tunneled catheter-related infections (CRI). This study assesses the efficacy of catheter-restricted filling with gentamicin and citrate in preventing CRI in hemodialysis patients. A double-blind randomized study was conducted to compare heparin (5000 U/ml) with gentamicin/citrate (40 mg/ml and 3.13% citrate; ratio 2:1) as catheter-lock solutions. A total of 112 tunneled catheters in 83 patients were enrolled at the time of catheter insertion for commencement or maintenance of hemodialysis. The primary end point was CRI. Catheter malfunction, defined as blood flow rate of <200 ml/min for three consecutive dialyses and/or the use of urokinase, was also assessed as a secondary end point. Infection rates per 100 catheter-days were 0.03 in the gentamicin group versus 0.42 in the heparin group (P = 0.003). Kaplan-Meier survival analyses showed mean infection-free catheter survival of 282 d (95% CI, 272 to 293 d) in the gentamicin group versus 181 d (95% CI, 124 to 237 d) in the heparin group (log rank, 9.58; P = 0.002). Cox regression analyses showed a relative risk for infection-free catheter survival of 0.10 (95% CI, 0.01 to 0.92) in the gentamicin group when adjusted for gender, race, diabetes mellitus, catheter malfunction, and hemoglobin (P = 0.042). The incidence of catheter malfunction was not significantly different between groups. Predialysis gentamicin levels were significantly higher in patients randomized to gentamicin (gentamicin/citrate: median 2.8 mg/L [range, 0.6 to 3.5 mg/L], n = 5; heparin: median <0.2 mg/L [range <0.2 to 0.2 mg/L], n = 5; P = 0.008). Tunneled hemodialysis catheter-restricted filling with gentamicin and citrate is a highly effective strategy for prevention of CRI. Although citrate as a catheter-lock solution provides adequate anticoagulation for the interdialytic period, gentamicin levels suggest significant risk for chronic aminoglycoside exposure and associated ototoxicity. Before this technique is adopted, these preliminary observations warrant replication in future studies that will examine the efficacy and safety of lower doses of gentamicin or alternative agents with a reduced potential for toxicity.     

Catheter outcomes in the short-term inpatient setting: a controlled quality improvement study comparing citrate and heparin lock

Heparin and citrate are used as catheter lock solutions to reduce risk of catheter dysfunction and infection in hemodialysis. There is a paucity of data comparing these two locks in the short-term, inpatient setting. We compared the efficacy of 2.2% acid citrate dextrose (ACD) versus 5000 U/ml heparin as catheter lock in the inpatient setting. The study was conducted at two sites within our system, with ACD locks used at site 1 and heparin locks at site 2. We assessed catheters for catheter dysfunction and infection. Both nontunneled dialysis catheters (NTDC) and tunneled dialysis catheters (TDC) were evaluated. We studied 250 catheters and 139 met inclusion criteria: 90 catheters in the ACD group and 49 in the heparin group. ACD had superior outcomes for NTDC; event rate was 0.052 for NTDC/ACD and 0.125 for NTDC/heparin (p = 0.032). There was no difference for TDC. Univariate (odds ratio [OR]: 1.88, confidence interval [CI]: 0.931, 3.82) and multivariate (OR: 1.35, CI: 0.64, 2.87) analyses demonstrated a trend toward increased odds of event with heparin. Catheter lock with 2.2% ACD has lower risk of catheter dysfunction as compared with that of 5000 U/ml heparin in the short-term inpatient setting in NTDC and similar risk in TDC.     

The incidence and costs of bacteremia due to lack of gentamicin lock solutions for dialysis catheters

The use of antibiotic lock solutions as prophylaxis for catheter‐associated blood stream infection (CRBSI) has been shown to be effective in previous randomized controlled trials. However, the cost‐effectiveness of this approach had not been studied. In 2012, the routine gentamicin‐heparin lock solution used in Auckland City Hospital was withdrawn from the market, leading to a change to heparin‐only lock. This was then replaced with gentamicin‐citrate lock in 2014. This situation allowed review of the CRBSI rate and financial impact of different catheter lock solutions. A retrospective audit was performed from 1 January 2011 to 31 December 2015 to investigate the rate of culture‐proven CRBSI in patients with tunneled cuffed dialysis catheters. There were 89 cases of CRBSI involving 64 patients in the 5‐year period. In comparison with the heparin‐only lock, both gentamicin‐heparin and gentamicin‐citrate locks had a significantly lower rate of bacteremia, with rate ratios of 0.46 (confidence interval 0.30‐0.72) and 0.11 (confidence interval 0.05‐0.22), respectively. The inpatient costs as a consequence of the CRBSI were NZ$27 792 per 1000 catheter days for heparin‐only lock, NZ$10 608.56 per 1000 catheter days for gentamicin‐heparin lock, and NZ$ 1898.45 per 1000 catheter days for gentamicin‐citrate lock. The lack of antibiotic lock solutions led to an increase in bacteremia rates and higher financial cost for inpatient management of bacteremia. Our findings highlight the importance of consistent supply of pharmaceuticals.     

Effect of ethanol/trisodium citrate lock on the mechanical properties of carbothane hemodialysis catheters

AIMS: The objective of this study was to investigate the effect of three locking solutions on the mechanical properties of carbothane hemodialysis catheters. METHODS: Catheters were exposed in vitro to one of three locking solutions (heparin 5000 U/ml; 4% trisodium citrate (TSC) or 30% ethanol/4% TSC). Each solution was locked in six catheters and bathed at 37 degrees C for 9 weeks. Changes in the mechanical properties namely, force at break, elongation at break and elastic modulus of the catheters were determined by tensile testing. RESULTS: The ethanol/TSC lock has an effect on the properties of carbothane hemodialysis catheters. The force at break was significantly lower in the ethanol/TSC group compared to the heparin and TSC groups (113.26 N, 191.97 N and 229.72 N, respectively, p < 0.01). Similarly, elongation at break was lower in the ethanol/TSC group, compared to the heparin and TSC groups (stretched 21.97, 38.29, and 42.42 times original length respectively, p < 0.01). The elastic modulus was not significantly different. CONCLUSIONS: The effect of the ethanol/TSC lock on the catheters is unlikely to prohibit clinical use. After 9 weeks of exposure to the solution, the catheter segments could still be stretched to 22 times their length and withstand 11.5 kg (113 N) of force. Clinically produced forces during dialysis are many times smaller than the force required to break the catheters examined in this study. Therefore, the ethanol/TSC lock shows promise as a new catheter locking solution for the treatment of catheter-related infections. Further clinical studies are required.     

A prospective clinical audit of central venous catheter use and complications in 1000 consecutive patients

We conducted a prospective audit of central venous catheter (CVC) use in 1000 consecutive patients to better define the rates of postoperative complications (particularly vascular perforation) and the pattern of CVC and pulmonary artery catheter (PAC) usage (particularly the number of lumens inserted and utilized). Details of CVCs, complications, and the number of lumens in place and used, were recorded daily until all CVCs were removed. A total of 1546 CVCs and 223 PACs were placed in study patients. Two non-fatal perforations occurred: a perforated right atrium in a patient who received an Arrow triple-lumen CVC (previously reported), and a perforated pulmonary artery in a patient upon withdrawal of a Baxter PAC. The risk per patient of any CVC-related perforation was 0.2% (95% confidence interval (CI): 0.02% to 0.7%). The rates of CVC-related sepsis and local infection were 3% (95% CI: 2% to 4%) and 2% (95% CI: 1% to 3%) respectively. At the peak of CVC use (day 1 in the ICU) the overall number of lumens placed was significantly correlated with lumens used (r = 0.53), endorsing clinical judgement in the anticipation of the needs of the patient. The modal number of lumen uses in adults and children was four. However, in children, fewer catheters were inserted per patient than in adults (1.28 vs 1.63, P = 0.01), and placed lumens were used more intensively (P < 0.001). Data appear to justify the routine selection of a triple-lumen CVC in adult patients, but not of a quad-lumen CVC.     

Filling Hemodialysis Catheters in the Interdialytic Period: Heparin Versus Citrate Versus Polygeline: A Prospective Randomized Study

Heparin and saline are commonly used to fill hemodialysis central venous catheters to prevent their thrombosis during the interdialytic period. The purpose of this prospective clinical study was to evaluate whether replacing heparin with citrate or polygeline could ensure satisfactory catheter function without exposing patients to the risk of systemic heparinization. Thirty end-stage renal disease (ESRD) patients with subclavian or jugular single lumen catheters as temporary vascular access for hemodialysis were enrolled. After the insertion of the catheters, the patients were randomly assigned to one of the following three filling groups: Group A, heparin; Group B, citrate; Group C, polygeline. Before each dialysis, the filling solution was aspirated and clot volume, if present, was measured. The catheter usage time and the clot volume were 23 ± 24 days and 0.052 ± 0.035 ml in Group A, 51 ± 36 days and 0.059 ± 0.032 ml in Group B, and 32 ± 10 days and 0.056 ± 0.038 ml in Group C, respectively. Our results indicate that citrate or polygeline can replace heparin effectively as a filling solution for single lumen temporary hemodialysis catheters.     

Effect of different sterile barrier precautions and central venous catheter dressing on the skin colonization around the insertion site

AIM: The purpose of this prospective, randomized, controlled study was the comparison of maximal sterile barrier (consisting of mask, cap, sterile gloves, gown, large drape) vs control precautions (mask, cap, sterile gloves, small drape) and of transparent polyurethan film vs gauze dressing for use on central venous (CVC) nontunneled catheters, inserted via the jugular vein. Skin colonization at the insertion site (defined by quantitative skin cultures performed at the time of insertion and in days 2 and 5) was used as a primary endpoint. Catheter tip colonization was also assessed through qualitative culture and CVC related sepsis was defined by the isolation of the same organism from the catheter tip and the blood, with clinical sepsis of no other apparent source. METHODS: Eighty-two consecutive patients were enrolled, admitted to a mixed medical-surgical ICU, aged 72+/-12 years, 58% male, SAPS II 42+/-13. One-hundred and seven CVCs were studied (presenting 750 catheter in situ days); CVCs were in place for a mean period of 6.9+/-4.7 days and 5 episodes of central catheter-related bloodstream infection were detected (6.6 per 1000 catheter days). RESULTS: A multiple logistic regression detected an increased risk of skin colonization in male gender (OR=2.5) and control precautions (OR=3.4) and no difference with regard to age, dressing and diagnostic group. CONCLUSIONS: Maximal sterile barrier proved to be an effective and recommended practice. However surveillance skin cultures revealed the common and changing nature of colonization of skin at the insertion site.