Comparison Of The Immediate Analgesic Effect Of Perpendicular Needling And Transverse Needling At Sp6 In Primary Dysmenorrhea Patients

Background:A recent review on acupuncture treatment advances for primary dysmenorrhea(PD)showed that acupuncture had a satisfied result with less complication.Clinical researches on acupuncture treatment for PD started with comparing the effects of different points,and then focused on the relationship between the patterns of PD and treatment result,and the effect of needling technique on the pain-relief result as well.According to traditional acupuncture theory and the latest research articles,getting a good result in acupuncture treatment,Deqi sensation(needling sensation)is needed.SP6,an intersecting point of three yin channels of foot and closely related to the uterus,is known as one of the best point with immediate analgesic effect for PD.Previous studies showed that acupuncture at SP6,particularly perpendicular Deqi needling,had showed more satisfied immediate analgesic effect on PD compared to perpendicular non-Deqi needling.Although Deqi is essential for attaining the effect,some needling techniques such as transverse needling without Deqi sensation which was used in Wrist-Ankle Acupuncture(WAA),can help for treatment of some diseases.The characteristics of this needling technique include subcutaneous transverse needling without Deqi sensation,and the tip of the needle towards to the injured site.Transverse needling without needling sensation is a technique which is easier to be accepted by patients who dislike Deqi sensation,and it also has certain effect on some diseases.This study aims to compare the immediate analgesia effect of perpendicular Deqi needling and transverse non-Deqi needling at SP6 in primary dysmenorrhea patients by analyzing of VAS-P,and to explore the underlying mechanism by observing changing of skin temperature in related acupoints.Objectives:This study aims to compare the immediate analgesia effect of perpendicular Deqi needling and transverse non-Deqi needling at SP6(Sanyinjiao)in primary dysmenorrhea patients with cold and dampness stagnation pattern.Methods:Design and Setting:A pilot randomized controlled clinical trial(RCT)was designed and performed at the School of Acupuncture-Moxibustion and Tuina in Beijing University of Chinese Medicine(BUCM),China,between March 2017 and March 2018.Patients:A total of 59 patients diagnosed with primary dysmenorrhea were screened in this study.Among them,45 patients were diagnosed as cold-dampness stagnation pattern at their first visit.Nineteen(19)of them were excluded due to menstrual pain below 40 on a 100-mm visual analogous scale(VAS-P)(n=10),use of analgesic medications(n=3),cycle irregularity(n=3)and personal circumstances(n=3).The final number of participants who recruited in the study was 26 patients.The trial followed the ethical principles of the human research ethics committee of BUCM.All participants should be signed an informed consent from before their enrollment and could exit from this study at any time.Randomization:Twenty-six(26)participants were finally recruited and randomly allocated to perpendicular Deqi needling group(PN group,n=13)and transverse non-Deqi needling group(TN group,n=13)in a 1:1 ratio by random numbers generated with the SPSS software(version 23.0).Interventions:The participants assigned in both groups received suspended needling treatment.Study started on the first day of menstruation just one session for 30 min when the VAS-P score of the menstrual pain was more than 40.In PN Deqi group,perpendicular needling with tube at SP6 bilaterally in a depth of 1-1.2 cun by using single used filiform needle(0.25 X 40mm)with even manipulation to induce Deqi sensation was used.In TN non-Deqi group,transverse needling with tube at SP6 bilaterally in same depth by using same sized single used filiform needle with direction through spleen channel toward the abdomen without manipulation was used.During needling in both groups,needling sensation intensity(Deqi sensation)by patients was assessed in both legs separately by using Acupuncture Deqi Clinical Assessment Scale(ADCAS),which is developed by our research group with good reliability and validity.Outcome measurements:Primary outcomes were menstrual pain assessed by VAS-P,and skin temperature at Guanyuan(CV4)area and at three acupoints(SP6,SP8 and SP10)on the spleen channel measured by thermal infrared imaging camera(FLIR SC640,FLIR system,America).Secondary outcomes included anxiety intensity checked by VAS-A,blood pressure(BP)and pulse rate(PR).The values of VAS-P,VAS-A,and skin temperature at lower abdomen(CV4)and spleen channel(SP6,SP8 and SP10)in both groups were assessed before needling,30min after needling and 10min after removal of needles.The blood pressure and pulse rate were assessed before needling and 30min after needling.Statistical analysis:Final data analysis was done by a separated specialist analyzer in Tehran university of Iran and was independent from research team by using SPSS software Version 23(IBM Corporation,Armonk,New York,USA).The data were expressed as Mean and Standard Deviation(SD).All data were analyzed based on per protocol subjects,the subject completed the follow up.So,ITT didn’t need to be applied.Two-sample T-test(as a parametric test)or Mann-Whitney U test(as a non-parametric test)was performed for comparison of patients’ baseline features,Friedman test or paired sample T-test was used.One-way ANOVA repeated measure was applied after parametric assumptions being established(e.g.normality and homogeneity of variance)for comparison of VAS-A,VAS-P,and skin temperature of acupoints.Mann-Whitney U test or Independent T-test was applied for comparison of VAS-A,VAS-P,and skin temperature of same acupoint at each time point between 2 groups.All statistical test P<0.05 was considered as statistically significant,highly significant if P<0.01,and no significant if P>0.05.Results:All 26 participants completed the study and their data were included in the final analysis.The baseline characteristics including age,BMI,age of menarche,onset of pain after menarche,menstrual cycle,menstrual days,menstrual pain and anxiety among participants were similar in two group(P>0.05).Thus the randomization process was effective in producing groups with equivalent variable outcomes at baseline.Within-group comparison showed that the severity of dysmenorrhea was significantly decreased at 30min after intervention and 10min after needle removal in both perpendicular Deqi needling group(35.77mm and 39.62mm less pain respectively on VAS-P,P<0.001)and transverse non-Deqi needling group(22.69mm and 30.38mm less pain respectively on VAS-P,P<0.001).When the severity of dysmenorrhea was analyzed at three times in each group,there were significant reduction in VAS-P scores in both groups in a time-dependent manner(P<0.001)and statistic difference in a time-intervention effect(P=0.045).However,there was no significant difference in VAS-P after intervention between two groups(P=0.553).Skin temperature at CV4 in perpendicular Deqi needling group was significantly increased at 30min after intervention and 10min after removal of needle compared to those before intervention(0.69℃ and 1.01℃ raising of skin temperature respectively,P<0.001).However,in transverse non-Deqi needling group there was no significant raising in skin temperature at CV4 after intervention(P=0.067).When changing of skin temperature at CV4 was analyzed at three times in longitudinal analysis,there were significant increase in a time-dependent manner(P<0.001)and in time-intervention(P=0.018),however there was no significant difference between two group(P=0.519).Temperature elevation at left-SP8 was significant in both transverse non-Deqi needling group and perpendicular Deqi needling group(P<0.001,P=0.025 respectively),but there was no significant difference between 2 groups(P=0.413).Temperature elevation at left-SP10 was significant in both groups(P<0.001 in TN group,P=0.008 in PN group),but there was no significant difference between 2 groups(P=0.605).Temperature elevation at right-SP10 was significant in both groups(P=0.012 in TN group,P=0.019 in PN group),but there was no significant difference between 2 groups(P=0.603).There was no significant difference in skin temperature at SP6 in both sides and right-SP8 after intervention within each group and between two groups(P>0.05).Within-group comparison showed that the anxiety intensity was significantly decreased at 30min after intervention and 10min after needle removal in both perpendicular Deqi needling group(35.39mm and 38.08mm less anxiety respectively on VAS-A,P<0.001)and transverse non-Deqi needling group(25.77mm and 30.77mm less anxiety respectively on VAS-A,P<0.001),however,there was no significant difference between two groups(P=0.140).Regarding the changes of blood pressure,significant reduction were only found in diastolic blood pressure in both groups after intervention(in PN group,71.92±8.85 vs 65.92±6.17,P=0.018;and in TN group,72.69±5.48 vs 66.92±4.71,P=0.009),but there was no significant difference between two groups(P=0.647).Systolic blood pressure had no significant changes in both groups after intervention(in PN group,P=0.069 and in TN group,P=0.111).Regarding the change of pulse rate,in transvers non-Deqi needling group,there was highly significant reduction in PR after treatment(78.69±8.84 vs 69.15±6.27,P<0.001).In perpendicular Deqi needling group,there was statistically significant reduction in PR after needling(75.15±14.23 vs 66.15±10.95,P=0.021).However,there was no significant difference between two groups(P=0.400).Conclusions:Data of this pilot trial preliminarily showed that both perpendicular Deqi needling and transverse non-Deqi needling at SP6 had effect for the immediately analgesia in primary dysmenorrhea patients with cold and dampness stagnation pattern,however there was no significant difference in pain relieve between two groups.The changes of skin temperatures at CV4 and three points on spleen channel(SP6,SP8 and SP10)were variable in both groups.In perpendicular Deqi needling group,skin temperature was significantly increased at CV4 after needling.In transverse non-Deqi needling group,increasing of skin temperature at points in spleen channel was better than that at CV4.These may suggest different mechanisms and pathway of those two needling techniques with the theory of channel and layers for relieving menstrual pain in terms of skin temperature.Both needling techniques showed effects in relieving anxiety,reduction of diastolic BP and PR,but transverse needling group showed a tendency of more positive effects in reduction of diastolic BP,PR.The results of this study might help the acupuncture practitioner apply proper needling techniques at SP6 according to the tolerance of needling sensation of patients as well as their autonomic nervous system condition in the treatment of primary dysmenorrhea.There is a need to get more reliable evidence to compare the effects of those two needling techniques on PD by performing larger sample size RCTs and the mechanism in terms of more objective measurements in future studies.