We investigated the effects of group III mechanoreceptors to cardiovascular responses in both pre-menopausal woman and post-menopausal woman during passive ankle dorsiflexion (PAD).

Twenty healthy volunteers (10 post-menopausal women and 10 pre-menopausal women) were recruited for this study. Stroke volume (SV), heart rate (HR), cardiac output (CO), and total vascular conductances (TVC) were measured continuously throughout the experiment. To stimulate the group III mechanoreceptors, PAD was performed for one minute.

The results showed that mean arterial pressure (MAP) mediated by the mechanoreflex activation was significantly increased in both groups. However, this pressor response was significantly higher in post-menopausal women. This reflex significantly increased both SV and CO in pre-menopausal women, while there were no differences in post-menopausal women. There was no difference in HR in either group. The mechanoreflex significantly decreased TVC in post-menopausal woman, while there was no difference in pre-menopausal woman.

The results indicate that the excessive pressor response mediated by the mechanoreflex occurs due to overactivity of group III mechanorecptors and the mechanism is produced mainly via peripheral vasoconstriction in post-menopausal women.

This study was performed to identify effects of pneumoperitoneum on hemodynamic changes of hypertensive patients undergoing laparoscopic colectomy under general anesthesia.

Data collection was done from January 2 to June 10, 2008. Seventy-six patients, including 38 hypertensive patients, who had taken antihypertensive drugs more than 1 month and 38 normotensive patients undergoing laparoscopic colectomy were enrolled in this study. The hemodynamic parameters were heart rate (HR), mean arterial pressure (MAP) and cardiac output (CO) which were measured 7 times from before induction of anesthesia to 5 min after deflation of the pneumoperitoneum. Collected data were analyzed using Repeated Measures ANOVA and Bonferroni comparison method.

HR in the hypertensive group was significantly decreased at deflation of the pneumoperitoneum and 5 min after deflation of the pneumoperitoneum (p=.012). MAP in the hypertensive group was not different from the normotensive group (p=.756). CO in hypertensive group was significantly lower than normotensive group (p<.001) from immediately after pneumoperitoneum to 5 min after deflation of the pneumoperitoneum.

The results indicate that pneumoperitoneum during laparoscopic surgery does not lead to clinically negative hemodynamic changes in heart rate, mean arterial pressure or cardiac output of hypertensive patients, who have taken antihypertensive drugs for more than 1 month.