Addition of low-dose ketamine to propofol-fentanyl sedation for gynecologic diagnostic laparoscopy: randomized controlled trial

Study objective: To assess the feasibility of propofol-fentanyl sedation protocol with ketamine for gynecologic diagnostic laparoscopy.

Design: Prospective, double-blind, randomized study (Canadian Task Force classification I).

Setting: Outpatient operating unit in a university hospital specializing in obstetrics and gynecology.

Patients: Eighty women who underwent outpatient gynecologic diagnostic laparoscopy.

Interventions: Patients were randomly assigned to receive fentanyl, 1 microg/kg, and normal saline solution (group F, n = 40), or fentanyl, 1 microg/kg, and ketamine, 0.5 mg/kg (group FK, n =40), followed by propofol, 2.0 mg/kg, for sedation induction. During surgery, propofol was supplemented to achieve a target Ramsey score of 6, and cardiopulmonary support was required to maintain stable vital signs.

Measurements and main results: Five of 40 patients (12.5%) in group FK reported pain associated with propofol injection compared with 33 of 40 patients (82.5%) in group F. During surgery, 7 patients (17.5%) in group FK required rescue propofol compared with 32 patients (80.0%) in group F (p <.001). The mean (SD) rescue dose of propofol was 0.4 (0.5) mg/kg in group FK compared with 1.6 (0.6) mg/kg in group F (p <.001). In group F, 17 patients (42.5%) required assisted mask ventilation because of respiratory depression, and in 21 patients (52.5%), atropine therapy was necessary to treat bradycardia, compared with 6 patients (15.0%) and 11 patients (27.5%), respectively, in group FK (p <.05). The mean arterial blood pressure at the end of induction, pneumoperitoneum inflation, and trocar insertion was significantly decreased in group F compared with group FK (p <.05). No differences were observed between the 2 groups insofar as operation duration, recovery time, discharge time, intraoperative awareness, incidence of postoperative nausea and vomiting, and postoperative pain. Although patient satisfaction scores were comparable, a higher degree of gynecologist satisfaction was observed in group FK compared with group F (p <.001).

Conclusion: Addition of low-dose ketamine to propofol-fentanyl sedation can provide more stable and satisfactory operation conditions in gynecologic diagnostic laparoscopy.