[Frequency of bacterial contamination of epidural and plexus catheters in postoperative analgesia].

OBJECTIVE: There is little available information regarding contamination of perineural catheters. Incidence ranges from 5% to 57%, depending on the location of the catheter. The objective of this prospective study was to evaluate the incidence and predisposing factors of bacterial contamination of these catheters. PATIENTS AND METHODS: The study included 47 patients who had an epidural (24 patients) or perineural (23 patients) catheter inserted for a minimum of 48 hours. We recorded details of the patients' characteristics, difficulty of insertion and duration of placement of the catheter, antibiotic treatment received, and signs of local or systemic infection immediately after surgery. When the catheters were removed, cultures were prepared using the Maki method. A descriptive analysis was performed and the frequency of contamination was determined using various parameters. RESULTS: The incidence of contamination was 28% (13 patients): 5/24 (21%) in epidural catheters, 6/17 (35%) in femoral catheters, and 2/6 (33%) in brachial and sciatic plexus catheters. Colonization was not influenced by the patients' characteristics, technical difficulties in placing the catheter, prophylactic antibiotic treatment, or the characteristics of the infusion administered. None of the patients presented clinical signs of infection. The most commonly isolated microorganism was Staphylococcus epidermidis, found in 10 patients (69% of the colonized catheters). CONCLUSIONS: Although infection of perineural catheters is exceptional when they are placed for 2 or more days, contamination is very common. Epidemiological studies are required to evaluate the variables involved.