Postoperative analgesia for total knee replacement: comparing between pre-and postoperative "3-in-1" femoral nerve block.
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.


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.


CONCLUSIONS
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.
Bunburaphong
Pavena
P
Department of Anesthesiology, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand. bpavenal@yahoo.com
Niruthisard
Supranee
S
Werawatganon
Thewarug
T
Keeyapaj
Worasak
W
Vimuktanandana
Anantachote
A
Toleb
Kusonsri
K
D000368:Aged; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D002045:Bupivacaine / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005267:Femoral Nerve / Q000187:drug effects*; D006801:Humans; D007267:Injections; D008297:Male; D009020:Morphine / Q000627:therapeutic use*; D009407:Nerve Block; D010149:Postoperative Pain / Q000188:drug therapy*; D011182:Postoperative Care; D011300:Preoperative Care; D013997:Time Factors
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009020:Morphine; D002045:Bupivacaine