Pain control after knee arthroplasty: intraarticular versus epidural anesthesia

The current study compared the effectiveness of a pain control infusion pump with patient-controlled epidural anesthesia in managing pain after primary total knee arthroplasty. Two protocols using the infusion pump or epidural anesthesia were reviewed retrospectively. Eighty-six consecutive patients (91 knees) treated with the infusion pump were compared with 82 consecutive patients (91 knees) treated with epidural anesthesia. The infusion pump delivered bupivacaine (0.5%) at 2 mL/hour after the knee was infiltrated with 20 mL of 0.5% bupivacaine in the operating room. The patient-controlled epidural anesthesia delivered fentanyl (2 microg/mL) and bupivacaine (0.125%) at 15 mL/hour, with a demand bolus of 5 mL available every 30 minutes. Both methods were discontinued on the first postoperative day, and each allowed on-demand oral, intravenous, or intramuscular narcotics, intramuscular ketorolac, and acetaminophen. No drain was used for patients with an infusion pump. A reinfusable drain was used for patients with epidural anesthesia. Significantly more acetaminophen, propoxyphene napsylate, and ketorolac were used by patients with an infusion pump. Similar amounts of other analgesics were used in each group. Prolonged wound drainage (> 3 days) was more common in the patients with an infusion pump (four patients; five knees) versus patients with epidural anesthesia (no patients).