GUIDELINES [ back to index ]
2. Patient with acute need for dialysis access
*1 Place temporary catheter
• Haemodialysis vascular access catheters are at high risk of infection, thrombosis and other complications 1. However in emergency cases, they are essential to enable dialysis. Depending on the predicted duration that the catheter is needed, two different kinds of catheters can be used:
a) Catheter placement for up to 2 weeks
Temporary or acute catheters are used in three settings: in patients with acute renal failure, for “in and out” use in patients with temporary loss of permanent access and in critically ill, bed-bound patients 2. Blood flow ranges from 200 – 250 ml/min 1 to almost 350 ml/min 2. For temporary use, soft catheters should be preferred because they are believed to be less traumatic to the vessel wall. The choice between silicone and one of the new polyurethanes is still unresolved.
The femoral route should be the preferred site in an emergency in order to preserve the thoracic venous system. Femoral catheters can be left in place for at least one week. Reported success rates for femoral vein catheterisation are in the range of 95-100% in patients with palpable femoral arterial pulses 3. In prospective studies the mean duration of placement was 1 week for temporary polyurethane catheters 3 4 if ambulation was allowed 4. The incidence of bacteraemia was 5.4% after 3 weeks of placement in the internal jugular vein and 10.7% after one week in the femoral vein 5. The risk of iliofemoral vein thrombosis may be high: tube-shaped thrombi were detected with colour-coded duplex-ultrasound in 95.7% cases in a study with a mean catheter dwell time of 17.9 + /-11.2 days 6. There are no data reported for temporary soft silicone catheters.
b) Catheter placement for more than 2 weeks
Tunneled cuffed catheters should be inserted in situations when the catheter access is required for more than 2 weeks. Thus they may be preferred to bridge the period until an A/V fistula has matured, until a PD catheter can be used or until an anticipated living-related donor transplantation is performed. Finally, they are used as a last resort in patients with no possibility of other dialysis access.
• The right internal jugular vein should be preferred to the left internal jugular vein and to the subclavian veins (see Algorithm: Placement and Routine Management of Tunneled Catheter, *4). It is also possible to use the femoral vein for Tunneled cuffed catheters, in order to preserve the central venous system.
• In the case of unexpected long access maturation time, due to borderline quality of the vessels, a decision has to be taken on an individual basis, as to whether the catheter should be used for several weeks or even months, whether the patients should be treated by CAPD during maturation, or whether an AV graft fistula is the better alternative.
*2 Monitor catheter
• Temporary and Tunneled cuffed catheters should be monitored clinically for adequate blood-flow delivery, occlusion and potential infection at each treatment. Pre-pump arterial pressures < -250 mm Hg indicate the inability of the catheter to deliver the prescribed blood flow (Qb) and may be indicative of catheter malfunction. With a pre-pump pressure of 180 to 220 mm Hg, roller pump blood flow readings overestimate blood flow by approximately 10 % 7.
• In most cases, early malfunction of the catheter is due to technical problems (e.g. kinking), incorrect placement or secondary dislocation of the catheter tip, which should be placed in the right atrium or at its junction with the superior vena cava. Late dislocation may also occur.
• Clotting of the catheter decreases blood flow and endangers adequacy of dialysis if treatment time is not adjusted, or stops blood flow.
Catheter infection is common with an incidence of catheter-related bacteraemia of approximately 3.4-5.5/1000 patient days 8 9 10. Catheter care must be performed using aseptic technique (see algorithm “Placement and routine management of permanent Tunneled catheters“). Signs of potential infection are erythema, discharge and pain around the catheter tract with increased WBC or fever. Infection should be evaluated and treated promptly (see algorithm “Management of permanent Tunneled Catheter Infection”).