Effect of the menstrual cycle on circulation during combined spinal-epidural anaesthesia

BACKGROUND: From adolescence to menopause, hormone levels during the menstrual cycle affect various body systems, from the cardiovascular system to the water and electrolyte balance. This study investigated the effect of different phases of the menstrual cycle on circulatory function relative to changes in body position and combined spinal-epidural anaesthesia (CSEA). METHODS: Forty-six women were selected who underwent scheduled gynaecological surgery, were classified as American Society of Anesthesiology (ASA) I-II, and met the test criteria. The sample was divided into the follicular and corpus luteal groups. Preoperative heart rate and blood pressure measurements were taken from the supine and standing positions. Heart rate measurements as well as systolic, diastolic, and mean blood pressure measurements were taken upon entering the operating room, at the beginning of the spinal-epidural anaesthesia, and 10, 20, and 30 min after anaesthesia was administered. RESULTS: The heart rates of patients in the corpus luteal group were higher than those of patients in the follicular group both before and after anaesthesia (P < 0.05). Significantly more ephedrine was used during the first 30 min of CSEA in the corpus luteal group than in the follicular group (P < 0.05). CONCLUSIONS: Although the effect was slight, women in the follicular phase were better able to compensate and tolerate circulatory fluctuations than those in the luteal phase.