Observations on the Analgesic Time-effect Regularity of Acupuncture only at Shiqizhui(Extra 18) in Primary Dysmenorrhea Patients

Objective To investigate the analgesic time-effect regularity of acupuncture only at Shiqizhui(Extra 18) in primary dysmenorrhea patients.Methods A needle was inserted into Shiqizhui(Extra 18) only and retained for 30 min.The VAS score was counted just before acupuncture, after 5, 10, 20, and 30 min retention of the needle, and at 30, 60 and 120 min after withdraw of the needle.Statistical analysis was then made.Results During 30 min retention of the needle, the analgesic effect of Acupuncture only at Shiqizhui(Extra 18) improved increasingly until the needle was taken out.The analgesic effect of acupuncture weakened to nearly half of the maximum at 50 min after withdraw of the needle.Conclusion The analgesic effect of acupuncture only at Shiqizhui(Extra 18) will be better in 30 min retention of the needle than in less.The half life time of the analgesic effect of acupuncture only at Shiqizhui(Extra 18) is shorter if the needle is retained for 30 min and therefore, an appropriate frequency of acupuncture is twice a day for patients with dysmenorrhea lasting about or longer than one day.