A comparison of continuous femoral nerve block (CFNB) and continuous epidural infusion (CEI) in postoperative analgesia and knee rehabilitation after total knee arthroplasty (TKA).

BACKGROUND: Postoperative epidural analgesia (EA) and femoral nerve block (FNB) provided effective pain relief However, EA has common side effects such as nausea, vomiting, pruritus, dizziness, and hypotension. Some investigations found that those side effects were less in FNB than in EA. However the analgesic equivalent of both techniques have not been confirmed.

OBJECTIVE: The authors compared continuous epidural infusion (CEI) with continuous femoral nerve block (CFNB) regarding the postoperative analgesic efficacy, side effects, postoperative knee rehabilitation, and hospital length of stay (LOS).

MATERIAL AND METHOD: In this prospective, randomized controlled study, 61 ASA physical status I-III patients scheduled for elective unilateral total knee arthroplasty (TKA) under spinal anesthesia (SA) participated. The patients were allocated into two groups. In the ward, patients in Group I (CEI) were maintained by continuous infusion of 0.125% levobupivacaine with morphine 0.0125 mg/ml (4 ml/hr), Group II (CFNB) were maintained by 0.125% levobupivacaine (8 ml/hr).

RESULTS: Patients in the CFNB group, the VAS scores at PO6-12 hr and tramadol IV requirement were significantly greater than the CEI group (VAS: PO6 hr p-value = 0.001, PO12 hr p-value = 0.004). Patients in the CEI group experienced dizziness, pruritus, and PONV more than the CFNB group significantly. Patient satisfaction was greater with the CFNB group although postoperative knee rehabilitation and the hospital LOS were not different.

CONCLUSION: CFNB represents the optimal analgesia with fewer side effects and greater patient, satisfaction. The rehabilitation indices and duration of hospital stay are comparable in both groups.