INTRODUCTION — Hemodialysis requires access to the central veins that can provide rapid extracorporeal blood flow ranging from 300 to 400 mL/min for three to four hours three times a week with minimal complications.
Hemodialysis catheters are appropriate when there is an acute need for hemodialysis (eg, acute kidney injury, thrombosed hemodialysis arteriovenous [AV] access, poisoning). In the inpatient setting, a nontunneled (temporary) hemodialysis catheter is often used, but if the duration of hemodialysis with a catheter is likely to exceed two weeks or if the patient will need chronic outpatient hemodialysis, a tunneled hemodialysis catheter should be placed instead, unless there is concern about infection risk. Ideally, if the patient's anatomy and physiology can support it, an AV access can be created, and once the AV access can be used reliably, the hemodialysis catheter is removed. Of note, compared with an AV access, hemodialysis catheters are associated with inferior clinical outcomes and may also generate higher costs [1].
The general features of nontunneled and tunneled hemodialysis catheters and the basic principles governing their use are reviewed here. Complications of central venous access and placement are discussed separately. (See "Central venous catheters: Overview of complications and prevention in adults" and "Vascular complications of central venous access and their management in adults".)
HEMODIALYSIS CATHETERS — The broad categories of catheters used for hemodialysis vascular access are nontunneled hemodialysis catheters and tunneled hemodialysis catheters, frequently referred to as simply tunneled dialysis catheters. Many hemodialysis catheter designs are available, and there are no convincing data that any one is superior to another. The selection of the appropriate catheter type is at the discretion of the practitioner. The operator should consider the need, requirements, and duration of the catheter as well as access site location. Often, the catheter type used in a dialysis program is based on historical practice, availability, and cost [1]. (See "Central venous access: Device and site selection in adults", section on 'Heparin bonding'.)
Hemodialysis catheters are composed of polyurethane, poly(carbonate)urethane, or silicone. Both nontunneled and tunneled catheters are mostly made of polyurethane, but the formation of polyurethane used for chronic hemodialysis catheters is purposefully designed to be softer due to the longer dwell times within the patient. Nontunneled hemodialysis catheters are designed to be slightly stiffer for ease of insertion but will soften upon exposure to body temperature.
●Nontunneled hemodialysis catheters – Nontunneled catheters, which are often referred to as temporary catheters, have a conically pointed tip and can have two or three lumens.
●Tunneled hemodialysis catheters – Tunneled hemodialysis catheters are designed to be inserted into the vein and then tunneled subcutaneously on the chest wall for the internal jugular site and thigh for the femoral site. A polyester cuff on the tunneled hemodialysis catheter provides a point for tissue ingrowth inside the resulting subcutaneous tunnel to secure the catheter and reduce the risk of infection. This cuff can effectively seal the intravascular portion of the catheter from the skin, providing a point of fixation to help prevent migration or accidental dislodgement and to reduce infection rates [2].
Catheter design — Hemodialysis catheters have two lumens for the dialysis circuit, attached to two ports (blue and red colored). By convention, the red port identifies the "arterial" lumen that draws blood from the patient, and the blue port identifies the "venous" lumen for return of blood from the dialysis machine back to the patient. This direction of flow may be reversed on dialysis if blood flow is limited in the conventional direction, although at the risk of increased recirculation, reduced clearance, and possibly inadequate dialysis depending on the configuration of the catheter tip [3-6].
Compared with a typical catheter used for central venous access, the hemodialysis catheter is larger to provide a higher rate of blood flow in the 300 to 375 mL/min range for most catheters [7]. Nontunneled hemodialysis catheters range in size from 8 to 14 Fr, while tunneled catheters range from 10 to 16 Fr. Catheters are available in a variety of configurations and tip designs, including double D, coaxial, shotgun, step tip, symmetric, and split tip, among others. Separation of the tips of the catheter can be achieved with a staggered tip design, use of a septum extruding beyond the openings, or splitting the catheter lumens distally. Some catheters are self-centering with a built-in curvature designed to push the tip of the catheter away from the wall of the vessel or heart chamber [5,8]. These designs are intended to maximize flow and, in some cases, reduce recirculation when used in a reverse configuration. Some randomized studies show some statistical differences in blood flow, clearance, or thrombolytic use, but the clinical significance of these differences is not clear, and other endpoints including patency are similar [3,9-11].
Surface-coated catheters — A variety of surface coatings (eg, silver, chlorhexidine, rifampin, and minocycline) have been used to prevent infection. In early studies, antimicrobial-coated hemodialysis catheters appeared to be effective in preventing intravascular catheter infections in the dialysis setting [12-21]. However, in a systematic review that evaluated 29 trials with 2886 patients and 3005 hemodialysis catheters, the incidence of catheter-related bacteremia and exit-site infections was similar for antimicrobial-coated hemodialysis catheters compared to noncoated catheters [19]. (See "Central venous access: Device and site selection in adults", section on 'Antimicrobial-impregnated catheters'.)
Heparin-coated catheters have also been used to decrease the incidence of catheter-related thrombosis. In observational studies, the frequency of catheter malfunction and overall catheter survival was similar [21,22]. (See "Central venous access: Device and site selection in adults", section on 'Coated and impregnated catheters'.)
INDICATIONS AND DURATION OF USE
Nontunneled hemodialysis catheters — Nontunneled catheters are indicated when there is an acute need to establish vascular access for hemodialysis, including acute kidney injury, thrombosed hemodialysis arteriovenous (AV) access, and to treat poisoning. Nontunneled femoral catheters are often used in bedbound critically ill patients. The nonavailability of vascular surgeons or interventional radiologists or nephrologists after hours or on weekends may also dictate temporary catheter use. Nontunneled femoral catheters should be avoided in ambulatory patients to avoid damage or thrombosis of the femoral vein and kinking of the catheter.
In general, nontunneled catheters should be used for less than two weeks to avoid bacteremia. Outpatient use is discouraged [23]. In a study of 318 new hemodialysis catheter insertions, at the end of one, two, three, and four weeks, the incidences of bacteremia for femoral vein catheters were 3, 11, 18, and 29 percent, respectively, and for internal jugular catheters, the incidences were 2, 5, 5, and 10 percent, respectively [24]. Rarely, femoral catheter may be required for a single dialysis session in ambulatory patients, inserted before and removed after the dialysis session, but this practice should be avoided to minimize patient discomfort [25-28].
Tunneled hemodialysis catheters — Tunneled hemodialysis catheters are frequently used to establish acute vascular access for hemodialysis and can be used in the outpatient setting. Given the risk of catheter-related bloodstream infections with nontunneled devices, it is our practice to recommend placement of a tunneled hemodialysis catheter for inpatients without bacteremia if the duration of hemodialysis is expected to be longer than two weeks (even in the intensive care unit setting), unless the patient is unstable or otherwise cannot be transported to a procedure room for catheter placement. Ideally, when permanent hemodialysis access is required, an AV fistula or graft is placed, though this typically requires a maturation period before use. Once the AV fistula or AV graft can be used reliably, the hemodialysis catheter is removed. (See "Approach to the adult patient needing vascular access for chronic hemodialysis", section on 'Strategy for lifelong hemodialysis access'.)
However, a tunneled central venous catheter can be used for indefinite periods of time in some patients, such as those with multiple failed AV accesses with no available options, limited life expectancy, or anatomic issues that prevent appropriate combinations of inflow artery and outflow veins or those who simply opt, after being well informed, not to have an AV access created and choose instead long-term catheter-based hemodialysis [23].
Patients should be informed that the risk of catheter complications is cumulative over time. In a prospective multicenter study from Canada, at one year, risks for tunneled hemodialysis catheter-related bacteremia, malfunction, and symptomatic central stenosis were 9, 15, and 2 percent, respectively [29]. The risk for any catheter-related complications at one and two years was 30 and 38 percent, respectively. These risks are from Canadian programs in which catheter use is generally high [30,31]. Each hemodialysis program should assess its local catheter-related risk with long-term use to inform patients.
Catheter life — The overall survival of tunneled hemodialysis catheters is highly variable because while studies may report primary or assisted patency, they vary in outcomes that terminate patency (eg, dysfunction only versus any catheter event including infection) and treat inclusion or exclusion or exiting events such as transplantation, death, or conversion to AV access differently. With these considerations, one randomized trial of 302 tunneled catheters reported six-month assisted patency ranging from 77 to 87 percent and 12 month patency ranging from 72 to 76 percent [11]. In another trial of 86 catheters, dysfunction-free survival, excluding other causes of catheter removal, was high at 92 to 98 percent at three months [10].
CATHETER PLACEMENT — Central venous catheters, including nontunneled and tunneled hemodialysis catheters, are placed using a stepwise approach under sterile conditions. When placed by experienced practitioners, periprocedural complications are uncommon. Catheter placement and complications related to placement are reviewed separately. (See "Placement of jugular venous catheters" and "Placement of femoral venous catheters" and "Central venous catheters: Overview of complications and prevention in adults" and "Vascular complications of central venous access and their management in adults".)
Access site — The right internal jugular vein is the preferred vein for hemodialysis access (nontunneled and tunneled hemodialysis catheters) in ambulatory patients because the vein takes a straight path directly into the superior vena cava (figure 1), leading to improved blood flow rates [7]. If the right internal jugular vein cannot be used, then placement into the left internal jugular vein may be necessary. Insertion can be more difficult on the left, and there is a higher incidence of catheter dysfunction (image 1) [32,33]. This is because placement of catheters into the left internal jugular vein requires that the catheter negotiate significant angulations present at the transition from the left internal jugular vein to the left brachiocephalic vein and then again when arriving at the superior vena cava. The femoral vein is a common location for nontunneled catheter placement in the intensive care setting for patients who cannot get up from bed. Tunneled catheters are placed into the femoral vein usually when central venous thrombosis or stenosis prevents internal jugular placement. The subclavian vein should be avoided to prevent subclavian stenosis, which would compromise future ipsilateral upper extremity arteriovenous hemodialysis access if the patient has or is at risk for developing end-stage renal disease [34]. In rare cases, catheter placement using a translumbar or transhepatic approach is possible if no other access is possible [35-37]. (See "Central vein obstruction associated with upper extremity hemodialysis access".)
To determine the appropriate length, the practitioner should consider the height of the patient and the location from which the catheter is being inserted. Catheters inserted from the left internal jugular vein need to be longer than right-sided internal jugular catheters as they have a greater distance to traverse. Catheters inserted from the groin are also longer to reach the inferior vena cava.
●For nontunneled catheters, right internal jugular (precurved) catheters range from 12 to 15 cm. Left internal jugular catheters range from 20 to 24 cm. While short catheters that are 12 to 20 cm in length can be placed in the femoral position, lengths of at least 24 cm are commonly required to reach the inferior vena cava.
●Tunneled hemodialysis catheters usually need to be longer to account for the tunneled portion. Typical lengths from the tip to the cuff are as follows: right internal jugular 19 to 23 cm, left internal jugular 23 to 31 cm, and femoral 35 cm or greater.
Imaging guidance — Ultrasound imaging is critical to ensure safe performance of hemodialysis catheter placement. Ultrasound is used to assess vein size and patency prior to venous puncture. In a study of 143 hemodialysis patients with a history of prior hemodialysis catheter placement, 25.9 percent had jugular vein thrombus, and 62 percent of these were occluded [38]. Ultrasound guidance during venipuncture minimizes the incidence of venous access-related complications, decreases procedure time, and increases the rate of initial technical success [39]. Ultrasound-guided venous access also decreases the likelihood of arterial puncture or pneumothorax in patients undergoing hemodialysis catheter placement [39-43].
●Nontunneled (temporary) catheters are placed at the bedside or in a procedure room using local anesthesia. Ultrasound guidance during venous cannulation should be used.
●Tunneled catheters are placed in an angiography suite or appropriately equipped operating room using local anesthesia with or without sedation. Ultrasound guidance for venous cannulation should be used, and fluoroscopic guidance is necessary to guide proper catheter positioning due to their larger caliber. Catheter malposition is a common problem (25 to 40 percent) when fluoroscopy is not used for guidance; accurate catheter positioning can be achieved in 95 to 100 percent of cases with fluoroscopy [44]. Fluoroscopy also allows direct imaging of the wires and dilators to minimize the potential for injury.
Catheter positioning — Confirmation of the catheter tip position, removal of the guidewire, and absence of a pneumothorax must be documented using fluoroscopy or chest radiography prior to use of the catheter. The ideal position of the catheter is as follows:
●The tip of nontunneled internal jugular hemodialysis catheters should be positioned in the distal superior vena cava. Because of the stiffness of short-term access catheters and risk for complications, atrial placement should be avoided [45].
●The tip of tunneled hemodialysis catheters should be positioned within the right atrium when placed with the patient supine. As the patient transitions to the upright position, the catheter will tend to retract 2 to 4 cm. Retraction of the catheter is greater for left-sided placement. In a retrospective review of 532 internal jugular hemodialysis catheters, left-sided catheters initially terminating in the superior vena cava or peri-cavoatrial junction had significantly more episodes of catheter dysfunction or infection compared with left-sided catheters terminating in the mid- to deep right atrium (0.84 versus 0.35), whereas no significant difference was identified for right-sided catheters based on tip position [33].
●The tip of femoral hemodialysis catheters (nontunneled or tunneled) should be placed in the inferior vena cava.
ROUTINE CARE AND ACCESS FOR HEMODIALYSIS — The routine care and maintenance of hemodialysis catheters is similar to that of other central venous catheters (nontunneled, tunneled) with any differences noted below. (See "Routine care and maintenance of intravenous devices".)
After catheter insertion, nontunneled catheters are secured to the skin with a suture. Tunneled catheters should be secured with sutures to prevent migration and facilitate ingrowth into the subcutaneous cuff. The catheter is flushed with saline to clear any residual blood and is often locked with a heparin or citrate-based solution to prevent thrombosis unless a contraindication exists (eg, heparin-induced thrombocytopenia [HIT]). A sterile dressing is placed at the catheter exit site. The catheter exit site is then sterilely dressed. (See "Routine care and maintenance of intravenous devices", section on 'Dressing and securement'.)
Subsequently, the hemodialysis catheter is accessed for hemodialysis using established routines that aim to prevent thrombosis and catheter-related bacteremia and bloodstream infection.
Access, flushing, and catheter locking — All hemodialysis personnel accessing the catheter should be trained in proper techniques for handling or manipulating vascular access catheters. Universal care strategies should be used to prevent infection and include hand hygiene and using an aseptic no-touch technique. Hemodialysis catheters should not be accessed by nonhemodialysis personnel, except in an emergency. (See "Routine care and maintenance of intravenous devices", section on 'Universal care strategies'.)
To initiate hemodialysis using a hemodialysis catheter, a disinfecting agent (eg, chlorhexidine) should be used to clean the catheter hubs. Once the hubs are removed, the lock solution is aspirated from each hub, and the catheter is flushed with saline. The catheter hubs should then be immediately connected to the dialysis machine to avoid prolonged exposure to air. The connection of the blood lines to the catheter hubs should remain visible during the dialysis treatment.
Once hemodialysis is complete, the catheter is flushed with saline to clear any residual blood. The usual rinse with saline at the end of dialysis is important to clear blood from the blood lines and dialyzer, but it is not very efficient in completely clearing all blood from the catheter or dislodging any small thrombi that might be present. A turbulent method of flushing with saline using the push-pause technique can be used, but practice may vary among hemodialysis units to clear the catheter walls and lumen of residual blood prior to instilling a locking solution. (See "Routine care and maintenance of intravenous devices", section on 'Hubs, needleless connectors, and line access'.)
The catheter is often locked with a heparin- or citrate-based solution to prevent thrombosis; other solutions including saline, other antithrombotic agents, and antimicrobial agents have also been used. Taurolidine-containing catheter lock solutions may be chosen when chlorhexidine-coated catheter caps (ClearGuard) cannot be used. (See 'Dressings' below and "Tunneled hemodialysis catheter-related bloodstream infection (CRBSI): Management and prevention", section on 'Methods we use'.)
Typical hemodialysis catheter volumes are 1.2 to 1.8 mL for short nontunneled catheters and 1.9 to 3.1 mL for larger tunneled catheters. When heparin is used, the catheters should not be overfilled. When citrate is used, 10 percent overfill is recommended. In vitro studies demonstrate leaking of the locking solution can occur after instillation of the catheter [46].
●Heparin concentrations vary from 10 to 10,000 units per mL. The American Society of Diagnostic and Interventional Nephrology position paper recommends a heparin lock concentration of 1000 units/mL [47,48]. Some acute hemodialysis programs prefer to use a heparin concentration of 100 units per mL. Higher heparin concentration levels have been associated with inadvertent systemic anticoagulation and clinical episodes of bleeding due to leaking of the anticoagulant into the patient, particularly if the catheter lumen was overfilled with heparin [47,49,50].
●Citrate provides an effective alternative for patients with suspected or confirmed heparin-induced thrombocytopenia and may help avoid heparin-associated bleeding complications [51-54]. In Canada, 4% citrate is the most commonly used locking solution. High-dose citrate (30 to 47 percent) should be avoided because if inadvertently injected, it can cause severe hypocalcemia, cardiac dysrhythmias, and death [55].
Antithrombotic agents other than heparin or citrate have also been used. In addition, agents meant to reduce infection include sodium citrate, hypertonic saline, ethanol (30 to 100 percent), methylene blue, ethylene diamine tetra-acetic acid (EDTA), antibiotics like gentamicin alone or with other agents (cefazolin or vancomycin), trimethoprim/sulfamethoxazole (TMP-SMX; also known as co-trimoxazole), and minocycline. The Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline for Vascular Access: 2019 Update states that selective use of specific prophylactic antibiotic locks can be considered in patients in need of long-term central venous catheters who are at high risk of catheter-related bloodstream infection [23]. Despite these benefits and guidelines, concerns still persist about antimicrobial resistance with long-term use and possible ototoxicity from catheter leakage with gentamicin [56]. In the United States, reimbursement policies do not provide payment for these agents, thereby placing a financial burden on dialysis units.
●A systematic review identified 27 trials [56-79] assessing alternative locking solutions or systemic agents for the prevention of catheter malfunction (defined as a catheter blood flow of ≤200 mL/minute or as defined by the study authors) or for the occurrence of bacteremia [80]. In a meta-analysis of 16 of these, the incidence of catheter malfunction was not significantly different for alternative anticoagulant locking solutions, systemic agents, or low- or no-dose heparin compared with conventional care, which predominantly consisted of instilling a heparin solution into each catheter port.
●One trial demonstrated that once-weekly instillation of tissue plasminogen activator (tPa, alteplase) significantly lowered catheter malfunction (20 versus 35 percent) and catheter-related bacteremia (4.5 versus 13 percent). The reduction in bacteremia from thrombolytic locks indicates a relationship between thrombosis and infection [76]. Use is likely limited due to cost, but it may be useful for patients at high risk for dysfunction or bacteremia and with limited access to options.
●A review that included 1350 hemodialysis catheters showed that use of a gentamicin-heparin lock was associated with a significantly reduced risk of all-cause mortality compared with standard heparin locks (hazard ratio 0.36, 95% CI 0.22-0.58) [81]. The reduction was primarily due to reduction of sepsis events that resulted in death.
The available data from randomized trials and observational studies do not support routine systemic antithrombotic agents to prevent hemodialysis catheter dysfunction, due to increased risks of harm and unclear benefit with respect to patency [23,80,82,83]. The KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update recommends against the use of systemic anticoagulants for the sole purpose of maintaining central venous catheter patency [23].
Dressings — Catheter dressings should be changed weekly or if they are dislodged, unclean, or stained with blood or discharge. Routine dressing changes are reviewed separately. (See "Routine care and maintenance of intravenous devices", section on 'Dressing and securement'.)
Antibiotic ointment may be applied at the catheter exit site to prevent infection [19,84-90]. Based on low-to-moderate quality evidence, antibiotic ointment is included as a core intervention by the Centers for Disease Control and was endorsed in the KDOQI Vascular Access Guidelines to prevent infection [23,91]. A joint working group led by the Society of Critical Care Medicine and the Infectious Diseases Society of America recommends the use of povidone-iodine ointment or triple antibiotic (bacitracin/gramicidin/polymyxin B) ointment at the exit site after catheter insertion and at the end of each hemodialysis session, provided the ointment does not adversely interact with the catheter material according to manufacturer recommendations [92]. In meta-analyses of trials comparing various antibiotic ointments (eg, mupirocin, Polysporin, povidone-iodine) with no ointment or placebo, the use of exit-site antimicrobial agents significantly reduced catheter-related bacteremia (five trials; relative risk [RR] 0.26, 95% CI 0.15-0.46), exit site infection (four trials; RR 0.20, 95% CI 0.09-0.45), and requirement for catheter removal (four trials; RR 0.35, 95% CI 0.25-0.5) [84]. However, concerns have been raised about the emergence of mupirocin resistance and the occurrence of fungal infections, so antibiotic ointment may not be used by all programs consistently [93,94]. Exit-site antibiotic ointment may be more commonly used after catheter placement, during exit site healing, after catheter exchange, or if signs of infection are present.
Two large, multicenter, cluster randomized studies have shown a benefit of an antibacterial barrier cap device (ClearGuard) that contains a rod coated with chlorhexidine compared with standard best-use practices/policies for central venous catheters [95,96]. The two studies were carried out in multiple dialysis units at the two largest dialysis providers in the United States. In both studies, there was a significant decrease in the rate of catheter-related bloodstream infections and hospitalizations for the chlorhexidine-coated catheter cap. There was no reported improvement in other complications or dysfunctions such as thrombosis rates. (See "Tunneled hemodialysis catheter-related bloodstream infection (CRBSI): Management and prevention", section on 'Methods we use'.)
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Venous access" and "Society guideline links: Dialysis" and "Society guideline links: Hemodialysis vascular access".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
●Beyond the Basics topics (see "Patient education: Dialysis or kidney transplantation — which is right for me? (Beyond the Basics)" and "Patient education: Hemodialysis (Beyond the Basics)")
SUMMARY AND RECOMMENDATIONS
●Hemodialysis catheters – Hemodialysis catheters are designed to maximize flow and, in some cases, reduce recirculation. There are no convincing data that any one catheter is superior to others. Selection is at the discretion of the clinician or institution based on familiarity, cost, and availability. (See 'Hemodialysis catheters' above and 'Indications and duration of use' above.)
There are two main types of hemodialysis catheters: nontunneled (temporary) hemodialysis catheters and tunneled hemodialysis catheters, which are frequently referred to as simply tunneled dialysis catheters.
•Acute hemodialysis – Nontunneled hemodialysis catheters are appropriate when there is an acute need for hemodialysis (eg, acute kidney injury, thrombosed hemodialysis arteriovenous [AV] access, poisoning). Nontunneled hemodialysis catheters are often used in the inpatient setting.
•Chronic hemodialysis – Unless there is concern about infection, a tunneled hemodialysis catheter should be placed if the duration of hemodialysis will be for more than two weeks or if the patient will be maintained chronically as an outpatient. For some patients, a tunneled hemodialysis catheter may be needed for an indefinite period.
●Catheter placement – Central venous catheters, including nontunneled and tunneled hemodialysis catheters, are placed under sterile conditions with a stepwise approach that uses a modified Seldinger technique. Nontunneled (temporary) catheters are inserted at the bedside or in a procedure room using local anesthesia. Tunneled catheters are inserted in an angiography suite or appropriately equipped operating room using local anesthesia with or without sedation. When placed by experienced practitioners, complications are uncommon. (See 'Catheter placement' above.)
•Access site selection – (See 'Access site' above.)
-For ambulatory patients, the right internal jugular vein (IJV) is the preferred access site for hemodialysis access (nontunneled and tunneled hemodialysis catheters). Placement into the left IJV may be necessary if the right internal jugular vein cannot be used; however, insertion can be more difficult on the left, and there is a higher incidence of catheter dysfunction.
-For nonambulatory patients, the femoral vein is a common location for nontunneled catheter placement, particularly in the intensive care unit setting if central venous thrombosis or stenosis prevents internal jugular vein placement.
-The subclavian veins should be avoided. Subclavian venous access is associated with a high incidence of subclavian venous stenosis and thrombosis, which compromises subsequent access options.
•Ultrasound guidance – Prior to venous puncture, ultrasound should be used to assess vein size and patency. Ultrasound guidance should also be used during venipuncture, which increases the rate of initial technical success, decreases procedure time, and minimizes the incidence of access-related complications, including arterial puncture. (See 'Imaging guidance' above.)
•Catheter tip positioning – (See 'Catheter positioning' above.)
-The tip of nontunneled internal jugular hemodialysis catheters should be positioned in the distal superior vena cava; atrial placement is avoided due to the stiffness of nontunneled catheters.
-The tip of tunneled hemodialysis catheters should be positioned within the right atrium when placed with the patient supine. The catheter tip will retract 2 to 4 cm with upright positioning.
-The tip of femoral hemodialysis catheters (nontunneled or tunneled) should be placed in the inferior vena cava.
●Routine care and maintenance – The routine care and maintenance of hemodialysis catheters is similar to that of other central venous catheters (nontunneled, tunneled). Hemodialysis catheters are accessed using established routines to prevent thrombosis and catheter-related bacteremia or bloodstream infection. These include adherence to an aseptic no-touch technique when connecting and disconnecting from the dialysis machine and to flushing, locking, and access site dressing protocols. Hemodialysis catheters should not be accessed by nonhemodialysis personnel, except in an emergency. Catheter dressings should be changed weekly and whenever they become loose or soiled. (See 'Routine care and access for hemodialysis' above.)
•Hemodialysis catheters are often locked with a heparin- or 4% citrate-based solution to prevent thrombosis; other solutions such as saline, other antithrombotic agents, and antimicrobial agents have also been used. Heparin is typically dosed at a concentration of 1000 IU/mL, but other concentrations, sometimes as low as 10 IU/mL, have also been used. When heparin is used, the catheters should not be overfilled, to avoid systemic anticoagulation.
•We suggest using antibiotic ointment at the exit site after catheter insertion and at the end of each hemodialysis session, rather than no such application (Grade 2C). Application of these agents reduces the risk of exit-site and catheter-related bloodstream infection. It is also reasonable to limit their use to after catheter insertion while the exit site is healing, after catheter exchange, or if signs of infection are present.
•Concerns about the emergence of resistant organisms and fungal infections have been raised with both antimicrobial locking solution and exit-site ointments, which may limit their use in some hemodialysis programs.
ACKNOWLEDGMENTS — The editorial staff at UpToDate acknowledges Steve J Schwab, MD, Karen Woo, MD, and Steven J Bander, MD, who contributed to earlier versions of this topic review.
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