BACKGROUND: Severe postoperative pain can delay knee rehabilitation and prolong the duration of convalescence after a total knee replacement (TKR). This study compared a continuous 3-in-1 block using a patient-controlled analgesia (PCA) technique and IV PCA for analgesia after a unilateral TKR.
METHODS: Forty patients scheduled for an elective TKR under spinal anesthesia were randomly divided into two groups. Group 1 received an IV PCA with butorphanol and ketorolac. Group 2 received a continuous 3-in-1 block performed with 20 ml of 0.25% bupivacaine and epinephrine 1 : 200,000, followed by a continuous infusion of 0.125% bupivacaine through a femoral catheter at a rate of 2 ml/h plus 1 ml PCA boluses of a lockout time of 10 min. The level of pain was assessed at rest and during continuous passive motion using a visual analog scale (VAS). The VAS pain scores, nausea and vomiting were recorded in the postanesthetic care unit, at 6 PM on the day of operation, and at 8 AM and 6 PM on postoperative days 1 and 2, respectively. The duration of surgery, anesthesia time, blood loss, and hospital stay were compared.
RESULTS: The patients in Group 2 reported lower VAS pain scores than those in Group 1 (P < 0.05). The duration of surgery, nausea and vomiting, blood loss, and hospital stay were similar in the two groups except for the anesthesia time.
CONCLUSIONS: A continuous 3-in-1 block with a PCA technique provides better pain relief than IV PCA with butorphanol and ketorolac after TKR.