The importance of aseptic procedure

Meticulous aseptic technique during catheter placement and catheter care is essential to avoid catheter-associated infections. The infusion system must be checked in the same careful way as the catheter since numerous possibilities exist for pathogenic germs to enter the catheter via the luminal pathway.

Depending on the indication, central venous catheters can be used on a short- term basis (1-2 days) or over a longer period of up to several weeks. A longer indwelling time increases the risk of the patient acquiring a catheter-associated infection (Raad, et al.). Such an infection is present when clinical signs of a local infection at the puncture site (redness, tenderness, pain, heat) or a systematic infection (feber, chills, low blood pressure) occur. The diagnosis is confirmed when at the same time, bacteria-positive blood cultures from two different sites have been taken for which other infection sources have been ruled out (Garner).

The top priority of catheter management is to reduce the number of bacteria settling on the catheter´s outer surface or invading the bloodstream via the catheter lumens. Bacteria can attach to the catheter surface during placement if it has not been possible to adhere properly to aseptic technique during placement, e.g. during an emergency catheterization. Inadequate disinfection of the patient´s skin makes it possible for bacteria to enter the bloodstream by migrating along the exterior of the catheter.

Clinical studies have documented that careful observance of aseptic procedures during catheter placement can lower the risk of infection. This means wearing a mask, cap, gloves and gown for the physician and a large sterile drape and broad disinfection at the puncture site (Pearson, et al.).

After catheter placement, the puncture site is covered by a wound dressing. In the worst case, bacteria can proliferate rapidly beneath this dressing and then migrate along the catheter into the bloodstream if the catheter does not have an anti-bacterial surface. Careful inspection of the puncture site and the wound dressing are necessary on a daily basis to block this potential infection pathway. Blood residues or wound secretion must be removed using sterile physiological solution. If signs of a local infection occur, the puncture site must be carefully disinfected. Experts do not recommend the use of topical antibiotics at the puncture site (Raad, et al.).

An alternative to the immediate removal of the catheter is the possibility of filling all of the catheter lumen for a short period with a highly concentrated antibiotic solution. This antibiotic treatment should kill the bacteria present in the lumen of the catheter. The success rate of this method varies considerably. The risk that the catheter-associated infection will continue to develop in the event of an unsuccessful "antibiotic lock" must be carefully weighed when considering the use of this method.

Careful catheter care also includes all measures related to the infusion regimen. Any connection point within the infusion system that opens to the exterior (such as stopcocks or when infusion lines are exchanged) can lead to the infiltration of bacteria in the event of insufficient disinfection. Bacteria that have entered into the infusion line will then quickly migrate with the flow of solution into the catheter and proliferate there.

An important measure to avoid catheter-induced infections is the regular exchange of infusion lines. If lipid-containing solutions are being applied, it is recommended that the infusion lines be changed every 12 hours. With the administration of drugs or other infusion solutions, the lines should be exchanged after 24 hours.