Role of epidural ketamine for postoperative analgesia after upper abdominal surgery

Ketamine, aN-methyl-D-aspartate receptor antagonist inhibits central sensitization due to peripheral nociception thus potentiating the analgesic effect of morphine. The purpose of our study was to evaluate the effect of adding small-dose ketamine in a multimodal regimen of postoperative patient-controlled epidural analgesia (PCEA). One hundred patients of American Society of Anesthesiologists physical status I-II, undergoing major upper abdominal surgery were randomly allocated to two groups. Group I received PCEA device containing bupivacaine hydrochloride 0.0625% and morphine sulphate (preservative free) 0.05mg/ml. Group II received PCEA device containing bupivacaine hydrochloride 0.0625%, morphine sulphate (preservative free) 0.05 mg/ml and ketamine hydrochloride (preservative free) 0.2 mg/ml. The mean morphine consumption in group I after 1 st and 2 nd postoperative day was 8.38±2.85 and 7.64±1.95 mg, respectively, compared to 6.81±1.35 and 6.25±1.22 mg (P