Epidural Morphine Plus Ketamine for Upper Abdominal Surgery

Abstract

Increased postoperative pain may be caused by central nervous system plasticity, which may be related to actions of N-methyl-D-aspartic acid (NMDA) receptors on neurons in the dorsal horn of the spinal cord. Opioids act mainly on presynaptic receptors and reduce neurotransmitter release, while ketamine antagonizes NMDA receptors and prevents wind-up and long-term potentiation. Thus, we postulated that central nervous system sensitization would be prevented more effectively by the preoperative use of these two drugs simultaneously, and the effect of preemptive analgesia would be demonstrated. Ketamine, 60 mg, and morphine, 2 mg, were injected epidurally through an indwelling catheter that was inserted at the T7-8 interspace in 60 ASA physical status class 1-2 patients. The drugs were injected before induction of anesthesia (Group 1; n = 30) or immediately after removal of a surgical specimen (Group 2; n = 30). An additional 2 mg of morphine was injected when the patients complained of resting pain. The analgesic effect was assessed by the time from first analgesic injection to second dose and the number of patients who needed supplemental injections. Complications were also noted. The duration of analgesia was longer (P < 0.01) in Group 1 (31.1 +/- 16.0 h) than in Group 2 (21.1 +/- 12.0 h), and the proportion of patients who needed supplemental injections was decreased (P < 0.05) in Group 1 (56.7%) compared with Group 2 (90.0%). The incidence of adverse effects was not different between the two groups. In conclusion, preoperative administration of morphine and ketamine is more effective in reducing postoperative pain than it is when given during the operation.

Quality of post-operative analgesia after epidural dexmedetomidine and ketamine: A comparative pilot study

“…Furthermore, epidural ketamine as pre-emptive analgesic increased the time between first and second analgesic dose thus prolonging the duration of post-operative analgesia. [ 10 11 ] Number of patients requiring rescue analgesia in Group K was more as compared to Group D but the difference was insignificant. Reduced rescue analgesia requirement resulted in decreased amount of local anaesthetics and other systemic analgesics consumed postoperatively.…”

Preemptive epidural analgesia for postoperative pain relief revisited: Comparison of combination of buprenorphine and neostigmine with combination of buprenorphine and ketamine in lower abdominal surgeries, a double-blind randomized trial

“…who used a combination of epidural morphine and ketamine. [ 5 ] Wong et al . also concluded that ketamine potentiates analgesic effect of morphine in postoperative epidural pain control.…”

“…in a similar study reported that 56.7% (17 out of 30) patients required supplemental analgesic injections. [ 5 ]…”

“…in a similar study reported the incidence of complications such as nausea and vomiting, urinary retention, pruritus, somnolence, respiratory depression, and hallucination as 1, 5, 2, 4, 0, and 0, respectively. [ 5 ] Wong et al . also reported reduced incidence of side effects when combination of morphine and ketamine was used.…”

“…It provides analgesia by inhibiting the breakdown of acetylcholine, an endogenous spinal neurotransmitter. [ 4 5 ]…”