Postoperative Analgesia for Total Knee Replacement: Comparing between Pre-and Postoperative “3-in-1” Femoral Nerve Block
Pavena Bunburaphong MD*, Supranee Niruthisard MD*, Thewarug Werawatganon MD*, Worasak Keeyapaj MD*, Anantachote Vimuktanandana MD*, Kusonsri Toleb BN*
Affiliation : * Department of Anesthesiology, Faculty of Medicine, Chulalongkorn University
Background : Total Knee Replacement (TKR) produces severe postoperative pain. Pre- and postoperative
single-shot “3-in-1” Femoral Nerve Block (FNB) were reported to improve analgesia and reduce morphine
consumption post TKR.
Objective : To find out the most beneficial time for injection of single shot “3-in-1” FNB for TKR between
preoperative and postoperative in a prospective controlled trial.
Materials and Methods : In a Randomized, double-blind Controlled Trial (RCT), 48 patients undergoing TKR
received either pre- or postoperative “3-in-1” FNB using 30 mL of bupivacaine 0.25% after a standardized
general anesthesia. Morphine consumption, Numeric Pain-Rating Scale (NPRS) at rest and during movement,
tension in the back of the knee, nausea/vomiting, pruritus, sedation, and respiratory depression at 1, 4, 24 and
48 hr after TKR were compared.
Results : There were no significant differences in 48-hr morphine consumption [46.5 (20.0) vs 45.0 (23.6) mg,
p = 0.809], NPRS both at rest and during movement, tension in the back of knee, nausea/vomiting, pruritus,
sedation, and respiratory depression at any time during 48-hr postoperative TKR between groups.
Conclusion : Preoperative single-shot “3-in-1” FNB using 30 mL of bupivacaine 0.25% is not better than
postoperative single-shot “3-in-1” FNB using the same drug in postoperative pain and morphine reduction in
patients undergoing elective TKR under general anesthesia.
Keywords : Analgesia, Total knee replacement, “3-in-1” Femoral nerve block, Bupivacaine, RCT
