Use of a chlorhexidine-impregnated patch does not decrease the incidence of bacterial colonization of femoral nerve catheters: a randomized trial.

PURPOSE

Femoral nerve catheter (FNC) insertion is commonly performed for postoperative analgesia following total knee arthroplasty (TKA). A wide range of rates has been reported relating to the bacterial colonization of catheters complicating FNC insertion. The BIOPATCH® is a chlorhexidine (CHG) impregnated patch designed to inhibit bacterial growth for days. The BIOPATCH has proven to be effective at decreasing bacterial colonization in epidural and vascular catheters. We hypothesized that the BIOPATCH would be effective at decreasing the rates of FNC bacterial colonization.

METHODS

Following Institutional Review Board approval and written informed consent, 100 patients scheduled for TKA were prospectively enrolled in the study. Patients at elevated risk for infection were excluded from analysis. Femoral nerve catheters were inserted and tunneled under sterile conditions using ultrasound guidance following CHG skin cleansing. Participants were then randomized either to have the BIOPATCH applied to the catheter exit site or not to have the patch applied. All patients received pre/postoperative antibiotic therapy. The FNC tip and catheter exit site were cultured for bacterial growth at the conclusion of therapy.

RESULTS

No differences were observed between groups in regards to catheter exit site. Catheter colonization was observed in three of 48 (6.3%) BIOPATCH patients and two of 47 (4.3%) non-BIOPATCH patients (risk ratio [RR] = 1.5; 95% confidence interval [CI] 0.3 to 8.4; P = 1.0). Colonization of the catheter exit site was observed in 12 BIOPATCH and 14 non-BIOPATCH patients (RR = 0.8; 95% CI 0.4 to 1.6; P = 0.65). Local skin inflammation (non-BIOPATCH 10.6% vs BIOPATCH 2.1%) and colonization of the FNC exit site by more than one type of bacteria trended towards increased values in the non-BIOPATCH group.

CONCLUSIONS

The baseline rate of bacterial colonization of FNCs is quite low in the setting of short-term use, CHG skin decontamination, ultrasound guidance, subcutaneous tunneling, and perioperative antibiotic therapy. No benefit was shown by using the BIOPATCH in this patient population. (ClinicalTrials.gov number: NCT01411891).