Comparison of Continuous Femoral Nerve Block Using Ultrasound Versus Ultrasound and Nerve Stimulation Using Stimulating Catheter in Patients Undergoing Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

Continuous femoral nerve block (cFNB) is a widely used regional anesthetic technique for many lower limb operations, such as total knee arthroplasty (TKA), anterior cruciate ligament repair, tibial osteotomy and patellar surgery. It provides superior pain relief, faster ambulation, shorter hospital stays and less risk of side effects in comparison to patient controlled analgesia (PCA), local anesthetic wound infiltration, or single shot femoral nerve block (FNB).

Stimulating catheters were introduced in 1999 to provide an objective end point to guide continuous nerve block catheter position by maintaining the desired evoked muscle response with nerve stimulation (NS). The main advantages of stimulating catheters are faster onset of sensory and motor block and reduction of local anesthetic drugs consumption. In recent years the precise insertion of continuous catheters has improved especially with the introduction of ultrasound (US)-guided imaging to regional anesthesia practice and advances in scanning techniques. That led to a call to reduce cost by switching to non-stimulating catheters. However, most studies comparing both catheters lacked anesthetic technique standardization and adequate sample size.

In this prospective randomized controlled trial, we compared postoperative analgesic efficacy and opioids consumption in patients having cFNB insertion using US alone and that of US combined with NS.