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.