GUIDELINES [ back to index ]
7. Placement and routine management of tunneled catheter
*1 Patients with severe peripheral arterial obstructive disease, chronic cardiac failure, or chronic hypotension
• Central venous catheters for dialysis are necessary in patients in whom adequate access blood flow cannot be sustained without steal syndrome or deleterious effects on the general circulation.
*2 Subcutaneous devices
• Although some papers indicate that infectious complications might also be reduced by subcutaneously implantable port-systems 1, data in the literature does not suggest that infection rates are lower in ports than in Tunneled catheters.
• In addition, these systems may suffer from mechanical complications (see appendix III) and are also expensive.
*3 Place permanent tunneled catheter
• Permanent central venous catheters should only be placed by trained and experienced staff. The procedure should be performed in a dedicated clean area under aseptic conditions 2. Surgical asepsis includes hand washing at least for two minutes, sterile gloves, facial mask, and an assistant required to support the procedure.
*4 Preference for the right internal jugular vein
• The right internal jugular vein is preferred for catheter placement due to its direct continuity into the superior vena cava and the right atrium 3, and catheter length is shorter.
• In acute catheters, blood flow rates achieved in the left internal jugular vein were lower than those obtained in the right internal jugular vein 4.
• A left internal jugular catheter can also produce left brachiocephalic vein stenosis and occlusion
• If an A/V fistula or graft is planned to be used in the future, the cuffed catheter should be placed in the internal jugular vein contralateral to the planned or developing A/V fistula or PTFE graft.
• Thrombosis of the central vein after catheter insertion is a serious problem. Catheter placement in the subclavian vein must be avoided 3 due to higher complication rates and a higher incidence of developing central vein stenosis (42 –50 % with subclavian vein catheters vs. 0 - 10% with internal jugular vein catheters) 5 6 or thrombosis (13 % with subclavian vein catheters vs. 3 % with internal jugular vein catheters) 7.
• Central vein stenosis often remains asymptomatic until creation of an ipsilateral arteriovenous access. G. Jean investigated 51 patients by upper limb phlebography while or after being dialysed on internal jugular vein tunneled CVC during a mean period of 28 months. 24 patients (47 %) had one or more central vein, from the subclavian vein to the superior and the inferior vena cava, high grade stenosis >50%, or complete occlusion . 5 of the 12 patients with subclavian vein stenosis had never had any subclavian catheter 8.
*5 Consider alternative sites for catheter placement
• Other potential catheter placement sites include the femoral vein, inferior vena cava through a translumbar approach and transhepatic placement. Femoral catheters have been reported to require more interventions and to cause more infections than thoracic ones 9. In a prospective study 80% of femoral catheters required anticoagulation compared to 16 % of jugular catheters 10. Nevertheless a median survival of tunneled femoral catheters of 166 days was reported 11.
*6 Choose appropriate catheter size
• Catheters used should be designed to provide blood flow rates > 350 ml/min 12. Catheters with a size of 10 to 12 French generally allow a blood flow up to 250 ml/min 13, as the main determinant of flow is the diameter of the catheter (Poiseuille's Law) 14.
• Longer catheters provide less blood flow at the same inflow pressure compared to shorter catheters of the same diameter. Consequently, in larger patients, where longer catheters are used, the blood flow rate may be lower than in smaller patients, making it more difficult to administer the appropriate dialysis dose 15.
• When the femoral vein is used for haemodialysis access, the length of the catheter must be 20 cm or more, and the catheter tip should at least be positioned in the common iliac vein although preferably in the inferior vena cava. With the tip of a shorter catheter positioned in the external iliac vein, high rates of recirculation will be encountered 16 17.
*7 Use ultrasound guidance
• Due to the anatomic variability of the venous system and the high rate of complications (5.9 %) including pneumo- and haemothorax, arterial puncture, air embolism, atrial perforation, recurrent laryngeal nerve palsy and cardiac arrest 13, real-time ultrasonic guidance is strongly recommended 15.
• In internal jugular vein catheters, the use of ultrasound-guidance increases the rate of successful placement (100 % with compared to 88.1 % without ultrasound guidance) 18 and decreases the rate of complications including haematoma and carotid artery puncture 18 19 20.
• Kwon et al.. compared cannulation of the femoral vein with ultrasound guidance to the cannulation by the landmark technique. They described a 100 % success rate in 28 patients using the ultrasound guidance compared to 89.5 % success in 38 patients using the landmark technique 21.
*8 Assure correct position of the catheter
• Blood flow, which should reach > 300 ml/min, depends on the catheter tip location, the status of the patient’s central circulation 13 and the catheter design. The catheter tip should be positioned in the mid right atrium to allow adequate flow 22 23.
• Be aware of the retraction of the catheter tip by as much as 1 to 2 cm, when the patient adopts an upright position, as the chest wall is pulled downward 3, particularly in obese patients or women with large breasts.
• Advancing the catheter into the lower atrium must be avoided, as this may cause dysrhythmias 3.
*9 Dialysis via catheter
• In order to minimise the risk of infection the catheter should only be used for dialysis 2.
• Only trained dialysis staff should perform catheter connection, disconnection and interventions under aseptic conditions. The patient and staff member should wear a surgical mask 2.
*10 Assure correct dressing
• The dressing should be changed only by trained dialysis staff 2. Conly et al.. found less infection with gauze than with transparent dressing 24, but the question whether gauze should be preferred to transparent dressings remains unsolved 13.
• Especially in high-risk S. aureus nasal carriers (see below), topical povidone iodine ointment reduces exit site infections (0 % vs. 24 %), catheter tip colonisation (12 % vs. 42 %) and bacteraemia (0 % vs. 29 %) compared to the control group without povidone iodine ointment 25. This ointment, however, might degrade catheters made of silicone 26.
• The use of povidone is contraindicated with silicone catheters due to the risk of damaging the silicone.
*11 Catheter Lock
• Locking the catheter, e.g. by heparin, to preserve patency between the dialysis sessions is routinely performed 27.
• An elevated risk of bleeding has been described, especially if the volume of the heparin lock was not adapted to the catheter size 28.
• Some authors recommend the use of a heparin lock as loading dose for the next dialysis session, reducing not only costs but also avoiding blood wastage 29. In general, this procedure is performed without any complications, but it might risk embolisation of thrombus or of infected catheter content.
• Sodium citrate, polygeline, or urokinase are possible alternatives to heparin 28 30 . In a comparison of heparin to 30 % trisodium citrate solution both were found to be equally effective in preventing thrombus formation in the catheter during the interdialysis period 31.
• There are potential risks to concentrated sodium citrate, e.g. bleeding, sodium overload, alkalosis due to the degradation of citrate by the liver, and changes in calcium concentration.
• In using an antimicrobial lock solution (Neutrolin®), blood stream infections were 0.2 / 1,000 catheter days, and no catheter was lost in 41 patient-years of treatment due to infection 32.
• To prevent both catheter thrombosis and infection, the combination of heparin with antibiotics was studied in vitro by Vercaigne et al.. 33. A mixture of heparin 5000 IU/ml with 10 mg/ml of cefazolin or 5 mg/ml of gentamycin retains bactericidial activity for 72 hours. Ciprofloxacin cannot be mixed with heparin, as it precipitates immediately. A mixture of 10 - 20 % trisodium citrate plus 2.3 mg/ml gentamicin used for locking the catheter was also successfully tested 34.
• Nevertheless the routine use of a prophylactic antibiotic lock solution cannot be recommended because of the potential risk of encouraging bacterial resistance. The prophylactic use of antimicrobial lock solutions such as Neutrolin needs further investigation.
*12 Treat nasal carrier of S. aureus
• About 52 - 57 % of all dialysis patients are nasal carrier of S. aureus 35 36. As they are at increased risk for catheter infection, all patients with catheters should be screened for S. aureus and eradication should be considered 2.
• The risk of infection can be reduced by the application of mupirocin at the exit site or by intranasal application 37. Nasal mupirocin treatment in unselected dialysis patients led to eradication of nasal S. aureus in 96.3 % of the patients. The incidence of S. aureus bacteraemia was reduced fourfold.
*13 Monitor catheter
• Catheter monitoring is mandatory to ensure dialysis efficacy and to prevent catheter-related hazards (see algorithm: ”Identification and management of permanent Tunneled catheter dysfunction”).
• In order to detect catheter-related infections early, the skin exit site should be examined at each haemodialysis treatment for signs of inflammation or tunnel track infections (erythema, pain, secretions, crusts, abscess). Regular measurement of body temperature, CRP and white blood cell counts are required to detect latent catheter contamination, which may be revealed by acute onset of bacteraemia during the dialysis session. Some experts also recommend periodic blood cultures through the catheter.
• Catheter dysfunction should be detected early and corrected to prevent dialysis inadequacy. Several observations may indicate a catheter dysfunction: a reduction in effective blood flow delivered (computed from the dialysis monitor), in the total amount of blood processed and dialysis dose delivered during the session, permanently or intermittently reduced blood flow rates and/or higher or lower than expected arterial or venous pressures. These signs may be caused by partial or complete catheter obstruction by host vein thrombosis or fibrin sleeves wrapping around the catheter tip. A catheterogram and/or venography are required to identify and visualise the precise cause.
• Inversion of the inlet and outlet lines of a twin central venous catheter leads to an increase in recirculation, thus reducing dialysis efficiency 38.