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 (TO),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 TO 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.