Effects of preoperative ketamine on the endocrine-metabolic and inflammatory response to laparoscopic surgery.

BACKGROUND: Ketamine is hypothesized to reduce perioperative endocrine-metabolic and inflammatory responses in cardiac surgery patients. This randomized, placebo-controlled, double-blind study was performed to determine whether perioperative endocrine-metabolic and inflammatory responses are attenuated by preoperative administration of ketamine to healthy females receiving elective laparoscopic surgery. METHODS: Forty female patients with American Society of Anesthesiologist classification I or II who elected to receive gynecological laparoscopic surgery were randomly assigned to the ketamine-treated (group K; n = 20) or control (group C; n = 20) group. At 2 minutes prior to induction patients in group K received ketamine (0.25 mg/kg) whereas those in group C received normal saline. All patients received standardized general anesthesia. Serum glucose and cortisol values were measured before ketamine administration (T0), 2 minutes after tracheal intubation (T1), 30 minutes after skin incision (T2), 2 minutes after tracheal extubation (T3) and 1 hour postoperatively (T4). Serum interleukin-6 and tumor necrosis factor-α values were determined at T0 and T4. Postoperative analgesic efficacy, side effects of administered drugs, and time to discharge were recorded. RESULTS: Compared with subjects in group C, those in group K had lower serum glucose values at T1, T2, T3 and T4 and lower serum cortisol values at T4 (P < 0.05). Postoperative interleukin-6 and tumor necrosis factor-α concentrations for group K were lower than those for group C (P < 0.05). Postoperative visual analog scale scores at rest, cumulative fentanyl consumption, and time to discharge were lower in group K as compared to group C (P < 0.05). No significant differences in drug side effects were observed postoperatively between the two groups. CONCLUSION: Endocrine-metabolic and inflammatory responses to laparoscopic surgery are attenuated in part by pre-incisional administration of ketamine.