Local Inflammation Does Not Correlate With Bacterial Colonization and Contamination of Perineural Catheters
Condition: Catheter Infection
MeSH terms: Inflammation
Study type: Interventional

Summary: 
      The aim of this study was to investigate the influence of alcoholic skin disin-fection before
      PNC (perineural catheter)-removal on the detection of bacteria on the subcutaneous part of
      the PNC or on the tip. Furthermore, the correlation of bacterial colonization with
      PNC-associated local inflammation or infection was evaluated.
    

Detailed description: 
      Two hundred orthopedic patients planned to receive a PNC are prospectively randomized to
      group PNC-removal with alcoholic skin disinfection or group PNC-removal without skin
      disinfection.

      After standardized PNC-placement under sterile conditions, patients receive a perioperative
      antibiotic prophylaxis and clinical signs of local inflammation or infection are periodically
      recorded: The PNC were observed twice daily for clinical signs of local inflammation and
      local infection. Patients were also evaluated for clinical signs of systemic infection. The
      adhesive dressing was changed only if it became dislodged or if blood or secretions made
      visualization of the puncture site impossible. For the dressing change, the anaesthesiologist
      wore a facemask, a cap and sterile gloves.

      Postoperatively, 6 hours after the initial bolus, a local anaesthetic infusion line was
      connected to the micro filter of the PNC. All patients received patient-controlled perineural
      analgesia (basal rate 5 ml/h, bolus 4 ml, lock-out time 20 min) with ropivacaine 0.3% for 24
      hours, and then reduced to ropivacaine 0.2%.

      PNC were removed under sterile conditions after 72h or earlier in the case of signs of
      infection: Removal of the PNC was performed on the surgical ward by an anaesthesiologist
      according to a standardized procedure: Wearing a facemask and a cap, the adhesive skin
      dressing was removed. In the "WITH-group", the skin was now disinfected with an aerosolized
      alcoholic solution (propanol-biphenol). Procedure continued after three minutes, when the
      skin was dry with the anaesthesiologist wearing sterile gloves and using sterile tweezers.

      The distal part of the PNC (directed to the tip of the PNC) was withdrawn for 1 cm at the
      insertion site and then cut distally from the tweezers with a sterile pair of scissors. The
      distal part of the PNC was then totally withdrawn with the sterile tweezers, and with the
      sterile pair of scissors cut in two parts: the tip (defined as the most distal 2 cm) and the
      subcutaneous part, which were placed in separate dry sterile containers.

      Finally, the remaining proximal part of the PNC was thrown away.

      The sterile containers containing the PNC were stored at 4°C and were sent to the laboratory
      the same day for microbiological analysis of the PNC: The PNC were rolled onto sheep blood
      agar plates (Becton Dickinson BD, Basel, Switzerland) similar to the semiquantitative culture
      method for intravenous catheters [10] and thereafter immediately transferred to a liquid
      enrichment medium (thioglycolate medium, BD Basel Switzerland). Sheep blood agar was
      incubated for 2 days and thioglycolate for 5 days. In case of growth in the enrichment media
      only, an aliquot of the liquid was subcultured on solid media. Reports were considered to be
      positive if any growth was present. Identification of the isolated bacteria and
      susceptibility testing were performed according to standard methods.

      All patients were observed for clinical signs of local infection at the PNC insertion site
      and for clinical signs of systemic infection one week after PNC-removal. For the correlation
      of the detection of bacteria on the PNC with clinical signs of in-flammation, the
      sensitivity, specificity, positive and negative predictive values were calculated on the
      basis of the following three categories: 1) any growth of bacteria including enrichment, 2)
      more or equal 5 colonies and 3) more or equal 15 colonies with the semiquantative culture
      technique, respectively.
    

Intervention name(s): propanol-biphenol: Kodan
Intervention type(s): Other
Intervention description(s): WITH-group, the skin is disinfected with an aerosolized alcoholic solutionpropanol-biphenol: Kodan, Schülke & Mayr, Zurich, Switzerland.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Perineural cathether; Catheter infection