Infections are the second most common cause of death among kidney dialysis patients so tackling infection is a priority.

“Infections such as MRSA and septicaemia are a hundred times more common in people on dialysis than in the general population. We must seek ways to cut infection risk,” says Richard Fluck, consultant nephrologist at Derby Teaching Hospitals NHS Foundation Trust.

Infection rates can be reduced - over the last ten years the rate of Methicillin resistant Staphylococcus aureus (MRSA) among haemodialysis patients has dropped by 90%.

However, there is still work to be done. A Renal Association survey shows that the most common infections among haemodialysis patients are Methicillin sensitive Staphylococcus aureus (MSSA) with 526 cases from May1, 2013 to April 30, 2014, followed by Escherichia coli (E.coli) with 352 cases, Clostridium difficile (CDI) with 247 and MRSA, with 35.

Rates of MSSA and CDI infection are rising slightly while E.coli and MRSA are more stable.

Reducing risk starts with understanding where it lies, explains Fluck. Risk rates are higher in patients on haemodialysis than in those on peritoneal dialysis.

 

What's the difference between haemodialysis and peritoneal dialysis?

 
  • Haemodialysis involves cleaning and filtering the blood using a machine, usually in a specialist centre.
  • Peritoneal dialysis uses the peritoneal membrane as the dialysis filter. It is done at home by patients, who access the membrane through a tube in the abdomen.

“Haemodialysis carries a risk of blood-borne infections such as MRSA as it directly accesses the blood stream,” says Fluck. “With peritoneal dialysis, risks are lower, but there also is a risk of infection in the tube and the belly cavity.”

In haemodialysis the rate of infection risk depends partly on how the blood vessels are accessed. This could be by joining an artery to a vein to make a fistula; inserting a plastic tube to join an artery and a vein (a 'graft'); or using a central venous catheter (CVC), a plastic tube inserted into a vein. CVCs are usually used on a temporary basis but sometimes they are the best long-term option.

"Infections can spread into the heart and bones leading to many complications and great suffering for patients"
- Richard Fluck

In terms of infection, the least risky access method is the fistula, followed by the graft and the CVC. The number of patients with fistulas varies among dialysis centres, from under 50% to around 85%. Fluck says: “An overall strategy of increasing fistulas could reduce infections, though they are not suitable for everyone.”

Around 25% of patients have CVCs, which carry ten times the risk of a fistula. “With CVCs the infection can enter the blood via the dialysis machine or through the tunnel carrying the tube,” says Fluck. Patients with CVCs also have a higher risk of internally-originating infection. The tube and the fibrous tissue created by the body around it allow bacteria to hide more effectively from antibiotics, so they are less likely to fully clear infections.

Fluck explains: “A haemodialysis patient with a CVC is likely to suffer a worse outcome from pneumonia than someone with a fistula. Centres should be working to reduce the use of CVCs, though sometimes they are the best option.”

Regardless of source, infections in dialysis patients can cause major suffering. Fluck says: “Infections can spread into the heart and bones leading to many complications and great suffering for patients.”

Using antibiotic or antimicrobial solutions to wash out the CVC tube after dialysis helps. “Studies show a statistically significant reduction in infections,” says Fluck. “Antibiotic solutions may be more effective than antimicrobials, but the theoretical risk of antibiotic resistance means some centres use antimicrobials. Benefits must be balanced against unintended consequences.”

Regular training for patients and staff also reduces risk, he says. “Care plans must include initial training and regular update training for staff and patients to ensure they are as meticulous as possible when it comes to procedures such as inserting needles into fistulas, care of exit sites and connecting to dialysis machines.”

“We have successfully reduced the level of MRSA. The fight against infection now needs to be broadened out”
- Richard Fluck

A project to get patients receiving dialysis in renal centres to take part in their own care  has proved that patient training can pay off.

 

The shared haemodialysis care project

 

The shared haemodialysis care project, led by Dr Martin Wilkie, Consultant Nephrologist at Sheffield Teaching Hospitals NHS Foundation Trust, trained dialysis nurses to educate and support patients to take on greater responsibility for their own care. Patients reported greater control of their illness and increased confidence. “One of the eventual outcomes will be an examination of the effect on infection rates,” says Fluck.

Some haemodialysis patients treat themselves at home. “These community haemodialysis patients need the same level of training as centre staff,” Fluck says.

Work to reduce infections is already paying off, but more must be done. Fluck says: “We have successfully reduced the level of MRSA. The fight against infection now needs to be broadened out.”