Influence of the menstrual cycle on the incidence of nausea and vomiting after laparoscopic gynecological surgery: a pilot study.

STUDY OBJECTIVE To investigate whether the phase of menstrual cycle influences the incidence of postoperative nausea and vomiting (PONV) in women undergoing general anesthesia for elective laparoscopic gynecological surgery. DESIGN Prospective, observational, blinded study. SETTING General hospital, Postanesthesia Care Unit, and gynecologic floor room. PATIENTS 111 ASA physical status 1 and 2 women, aged 18 to 53 years. INTERVENTIONS Patients were classified into three groups according to the phase of menstrual cycle at the time of anesthesia: Group F1: follicular phase (menstrual days 1-8; n = 34); Group O2: ovulatory phase (days 9-15; n = 40); and Group L3: luteal phase (days 16 to end of cycle; n = 37). Anesthetic, postoperative pain management, and antiemetic regimens were standardized. MEASUREMENTS Frequency of nausea, vomiting, or both were assessed for early (0-2 hrs). Late PONV (2-24 hrs) along with the use of rescue antiemetic, severity of nausea, and pain. MAIN RESULTS In the follicular (n = 34), ovulatory (n = 40) and luteal phase (n = 37) groups, the frequencies of PONV over 24 hours were 35%, 38%, and 14% (P = 0.04), respectively. This was due to differences in the early postoperative period where the frequencies were 21%, 25%, and 3% (P = 0.02), respectively, as frequencies were similar in the late period (15%, 20% and 14%, P = 0.71), respectively. Nausea scores, rescue antiemetic usage, pain scores, and opioid consumption were similar in the groups. CONCLUSION Patients in the luteal phase of their menstrual cycle may have a decreased risk of PONV after laparoscopic gynecological surgery in the early postoperative period.