Double-blind randomized comparison of epidural co-analgesics on the postoperative analgesic consumption

ABSTRACT

Pain mediators are responsible for the peripheral and central sensitization. Preempetive treatment will prevent the establishment of hypersensitivity by blocking the sensory input that induces the central sensitization. This prospective double blind study was carried out on 45 adult patients who underwent upper abdominal operations. All patients were assigned into 3 groups according to the drug injected epidurally. [Plain bupivacaine [group I], Ketamine + plain bupivacaine [group II]. and clonidine + plain bupivacaine [group III]],. 15 minutes before the general anesthesia. The purpose of this study was to evaluate and compare the effects of epidural ketamine and clonidine as co-analgesics on postoperative analgesic consumption for upper abdominal surgery Measurements for efficacy of preemptive analgesia evaluated by visual analogue scale [VAS] and Prince Henry score [PHS]. sedation score, mood state, cumulative postoperative analgesic consumption and the time of the first need of fentanyl Monitoring of vital signs and recording of possible side effects were performed on the postanesthesia care unit VAS was significantly less in group III at most times of measurements until 2 hr postoperatively. PHS showed less significant reading in groups I and III compared to group II at 15 min and 6 hr postoperatively. Sedation score was significantly higher in group III compared to group II, I and II at 15, 30 min. respectively. Mood score was significantly high in group II and III. No significant side effects and respiratory rate, oxygen saturation, and ECG were within normal range in the three groups. The total amount of fentanyl requirements in the first 24 hrs postoperatively was significantly less in group III compared to group I and II. The time of first need of fentanyl was't changed significantly between the three groups. In conclusion the preemptive analgesic effect of epidural clonidine combined with plain bupivacaine with lack of vcnak ventilatory effects makes clonidine a potenlially useful drug for the reduction of postoperative narcotic consumption or in other words for the postoperative pain management