Cutting the infection risk for dialysis patients
Dialysis Catheter-related blood stream infections (CRBSI) can pose problems for dialysis patients but planning and good care can – and have – cut the incidence of infection.
“Infections which start at the site where the catheter enters the bloodstream of people on dialysis can quickly spread to other parts of the body, causing serious problems such as heart valve infection, spinal or brain abscesses,” says Professor Donal O'Donoghue, consultant renal physician at Salford Royal NHS Foundation Trust and President of the Renal Association.
People can develop multiple infections, and dialysis was until recently the most common cause of blood stream-related MRSA. CRBSI has a mortality rate of between 12 to 25%.
“The good news is that the risk of such bacterial infections has reduced ten-fold in the last decade,” says O'Donoghue. “The risk is now 1.5 per hundred patient years, but we are still working hard to reduce it further.”
The key to reduction mainly lies in prevention, he says. The dialysis process requires vascular access to the bloodstream, either through a fistula or a 'line'.
“The fistula is the gold standard for dialysis patients” Professor O'Donoghue
The fistula is created by re-routing an artery to join a vein, thus increasing its blood flow and 'toughening up' the vein to make it more resistant to repeated needle insertions.
Alternatively, a 'line' is generally a catheter inserted into a large vein, often in the neck. It is often used on a temporary basis but can be used longer-term.
“The fistula is the gold standard for dialysis patients,” says O'Donoghue. “They have lower infection rates than lines, but fistulas need to be prepared at least eight weeks in advance to give them time to mature. That means the medical team and the patient must meet to discuss the patient's needs, options and choices well in advance of dialysis being started, so an optimally-functioning fistula can be fashioned if haemodialysis is chosen.”
For lines infection prevention centres around caring for the line during and between dialysis sessions. “The key is to use a bundle of care approach, which has been proven to reduce line-related infections by two thirds,” says O'Donoghue.
Rather than allowing lines to exit the skin immediately above the vein, they can be 'tunnelled' under the skin for a short distance so that infection at the point of exit or along the tunnel is easier to detect and treat before it gets into the bloodstream.
To minimise infection risk, lines are now inserted by senior doctors in an aseptic environment, using imaging to check correct positioning.
The use of high-quality anti-microbial dressings, based on chlorhexidine to secure and protect the site, such as those approved by NICE for critical care patients, is important. “We always use chlorhexidine dressings, as part of the larger care bundle,” says O'Donoghue.
“This detailed care-bundle approach, plus forward planning of treatment and the use of fistulas rather than lines where possible, has resulted in a seismic shift in the approach to infection prevention. This has cut the risk of CRBSI infection rates for kidney patients on dialysis,” says O'Donoghue.