Keita Sato1, Takehiko Adachi, Naoto Shirai, Noriko Naoi. 1. From the *Department of Anesthesiology, Tokyo Women's Medical University, Tokyo; and †Department of Anesthesiology, Kitano Hospital, Osaka, Japan.
Abstract
BACKGROUND AND OBJECTIVES: The benefit of adding sciatic nerve block (SNB) to femoral nerve block to improve analgesia after total knee arthroplasty (TKA) is uncertain. We hypothesized that the effective duration of single-injection SNB is too short to improve postoperative analgesia and that this contributes to conflicting results on the efficacy of SNB after TKA. We evaluated this hypothesis in a prospective double-blind randomized controlled trial. METHODS:Sixty patients undergoing TKA were randomly allocated to a continuous SNB group or a single-injection SNB group. All patients received femoral nerve block (0.5% ropivacaine 20 mL) and SNB (0.2% ropivacaine 20 mL) and catheters were inserted into both peripheral nerve block sites before surgery. Both groups received continuous femoral nerve block and patient-controlled intravenous analgesia with morphine. Continuous SNB (0.2% ropivacaine 5 mL/h; continuous SNB group) or sham continuous SNB (0.9% normal saline 5 mL/h; single-injection SNB group) was provided after surgery. The primary outcome was total morphine consumption for 48 hours after surgery. RESULTS:Total morphine consumption in the 48-hour period after surgery was significantly lower in the continuous SNB group compared with the single-injection SNB group [4.9 (5.9) vs 9.7 (9.5) mg, P = 0.002]. Visual analog scale pain scores at rest were also significantly lower in the continuous SNB group (P = 0.035). CONCLUSIONS: The combination of continuous femoral and SNB provides a superior opioid sparing effect and improves analgesia after TKA.
RCT Entities:
BACKGROUND AND OBJECTIVES: The benefit of adding sciatic nerve block (SNB) to femoral nerve block to improve analgesia after total knee arthroplasty (TKA) is uncertain. We hypothesized that the effective duration of single-injection SNB is too short to improve postoperative analgesia and that this contributes to conflicting results on the efficacy of SNB after TKA. We evaluated this hypothesis in a prospective double-blind randomized controlled trial. METHODS: Sixty patients undergoing TKA were randomly allocated to a continuous SNB group or a single-injection SNB group. All patients received femoral nerve block (0.5% ropivacaine 20 mL) and SNB (0.2% ropivacaine 20 mL) and catheters were inserted into both peripheral nerve block sites before surgery. Both groups received continuous femoral nerve block and patient-controlled intravenous analgesia with morphine. Continuous SNB (0.2% ropivacaine 5 mL/h; continuous SNB group) or sham continuous SNB (0.9% normal saline 5 mL/h; single-injection SNB group) was provided after surgery. The primary outcome was total morphine consumption for 48 hours after surgery. RESULTS: Total morphine consumption in the 48-hour period after surgery was significantly lower in the continuous SNB group compared with the single-injection SNB group [4.9 (5.9) vs 9.7 (9.5) mg, P = 0.002]. Visual analog scale pain scores at rest were also significantly lower in the continuous SNB group (P = 0.035). CONCLUSIONS: The combination of continuous femoral and SNB provides a superior opioid sparing effect and improves analgesia after TKA.
Authors: Lajla Kadic; Frank G van Haren; Oliver Wilder-Smith; Jorgen Bruhn; Jacques J Driessen; Maarten C de Waal Malefijt Journal: J Anaesthesiol Clin Pharmacol Date: 2016 Oct-Dec