based on the previous researches 70% of post - surgical patients are facing with moderate to severe pain . post - operative nausea and vomiting ( ponv ) are also distressing with a prevalence of 20 - 30% , depending the type of surgery and patient - related factors . these problems are not only discomforting , but also may cause dehydration , electrolyte disturbances , delayed recovery , and delayed hospital discharge , if prolonged . opioids and non - steroidal anti - inflammatory drugs remain the most common treatments for post - operative pain . however , many of these drugs are expensive , and all are associated with complications . ondansetron is associated with headache , diarrhea , and transient increase in hepatic transaminase level . to avoid these side effects , there are certain points in the body , which are known as pressure points and are capable to transmit the energy . by pressing these points , muscle spasm goes away , blood circulation and the body 's vital energy improve , and calm the nerves . several studies have been conducted on the effects of acupressure on post - operative pain , nausea , and vomiting in variety of surgeries . ( 1991 ) in children undergoing strabismus correction , studied the effect of p6 acupressure on ponv . however , fan et al . has reported that this method reduced the severity of ponv . felhendler and lisander ( 1996 ) have also reported that acupressure was effective for pain relief after arthroscopy . lanwei acupoint also known as le7 acupoint or the extra point33 is located below the right knee with a distance of 2 cun from the st . this point had been known as a useful acupoint for reducing pain of acute and chronic appendicitis . however , no study on the effect of le7 acupressure on post - appendectomy pain is available . we assumed that acupressure on this point may be effective in reliving post - appendectomy pain , nausea , and vomiting . therefore , the present study was conducted with the aim of assessing the effect of acupressure on le7 acupoint on pain , nausea , and vomiting of patients after appendectomy which is the most common emergency abdominal surgery . if effective , this method may be suggested as a complementary treatment to reduce post - appendectomy pain , nausea , and vomiting . a single - blind randomized controlled trial was undertaken to evaluate the effects of le7 acupressure in relieving pain , nausea , and vomiting post appendectomy . the study was conducted on 70 post - appendectomy patients referred to a general surgical ward in a university hospital in the first half of 2012 . sample size was calculated based on data obtained from a pilot study on 14 patients ( 7 in each group ) . after 1 h acupressure on le7 point and measuring the pain intensity , the difference between experimental and control groups was 0.44 ( sd = 1.181 ) . based on the above parameters and selecting the significance level to be less than 0.05 and a power of 0.8 , 34 subjects were estimated to be needed in each group . then , we selected 35 patients in each group . samples were selected consecutively among the patients admitted for appendectomy and patients who entered the study were randomly assigned into the groups [ figure 1 ] . the overall design of the study ( without specifying the allocated group ) explained to the patients . the criteria for inclusion of the participants were : the desire to participate in the research , no injury or lesion in the region of the acupoint of le7 , aged between 15 years and 70 years , being in the list of appendectomy surgery , and receiving general anesthesia . those with the following conditions were not selected : a recent history of disorders associated with acute or chronic nausea and vomiting ( such as gastrointestinal and ear disorders ) , experiencing nausea and vomiting during the last 24 h , the drug and alcohol addiction , a known neurological or psychiatric disease , and the previous use of acupressure or acupuncture techniques . the exclusion criteria were : occurring unforeseen complications during surgery and anesthesia , prolonged surgical time ( more than 2 h ) , receiving drugs outside anesthesia protocol for the routine appendectomy patients , and fever above 38c . the first section was the demographic data form and had six questions about the patient 's age , gender , height , weight , level of education , and the study group the patient was belonged to . it also had two questions about the length of surgical incision ( in millimeters ) and the duration of anesthesia ( in minutes ) . second section was a visual analog scale ( vas ) used for recording the severity of nausea . descriptors were placed at each end of the line ( 0 = absence of nausea and vomiting and 100 = the worst condition ) . the observer asked the patient about the severity of nausea and marked an x on place that corresponded with severity of nausea . nausea with a score of 70 was classified as severe , between 35 and 70 as moderate , and less than 35 as mild . if there was retch or vomiting more than 5 times each hour , it was considered as severe vomiting , between 3 times and 5 times as the average and less than 3 times as mild . a vas was also included in the third part for recording the severity of pain . descriptors are placed at each end of the line ( 0 = no pain and 100 = the most unimaginable pain ) . patients were asked to mark an x on place that corresponded with severity of pain . acupressure was applied using a special band called acuband ( psiband , american design , made in china ) . the technique was started after the full patient 's consciousness ( so that the patient is aware of the location , time , and person ) . all the patients were anesthetized using thiopental sodium ( 5 mg / kg ) , atracurium ( 0.6 mg / kg ) , and fentanyl ( 2 mcg / kg ) and then the anesthesia continued using a gas mixture of o2 + n2o ( each : 50% ) , morphine ( 0.1 mg / kg ) and isofeluran ( 1 mac [ minimum alveolar concentration ] ) . all the patients were transferred to the surgical ward by a specially trained team to eliminate the effect of patient movement and handling of pain , nausea , and vomiting . initially , the severity of pain , nausea , and vomiting were assessed and recorded . then the acuband was fastened by the second researcher . in the experimental group the acuband was fastened on the right leg in such a way that the button located exactly on the le7 acupoint . then , the pulses below the point were checked to ensure that the acuband would not interfere with the blood flow . the patient 's foot was also examined for the possibility of impaired venous return . in order to keep the patients and the staff blind to the group the patient was belonged to , an acuband also used in the control group , but the band was fasten loosely and in a way that the button placed right in opposite side of the le7 point ( as sham point ) . the occurrence and the severity of pain , nausea , and vomiting were assessed and recorded in the two groups hourly and up to 7 h. the acubands was preserved for 7 h. however , they were loosened for 10 min every 2 h and then tightened . for patients who suffered from severe nausea and vomiting during this period , anti - emetic medication ( metoclopramid , 10 mg ) was administered and the nausea was considered as severe one . an analgesic medication ( pethidine , 1 mg / kg ) also administered if the pain score was six or higher . this study was approved by the research council and the research ethics committee in our university of medical sciences . all the subjects had been informed about voluntary participation in the research , non - disclosure of personal information , and offered a written informed consent form to be signed before entering the study . all subjects have been assured that they will receive all the necessary care and pain medications if the intervention had no effect . the researchers were mindful of the need to pay close attention to ethical considerations and the welfare of the participants . the spss software ( statistical package for the social sciences ) version 11.5 used for data analysis . independent sample t - test was used to compare the mean of pain and nausea severity of two groups . the mean of pain intensity before the intervention was compared to the average of pain intensity in the next 7 h. also the mean of the nausea intensity was compared with average of nausea intensity in the next 7 h. paired t - test was used to compare the mean of pain intensity of each group before and total mean of pain at post intervention hours . a p value of less than 0.05 was considered to be significant for all tests . a single - blind randomized controlled trial was undertaken to evaluate the effects of le7 acupressure in relieving pain , nausea , and vomiting post appendectomy . the study was conducted on 70 post - appendectomy patients referred to a general surgical ward in a university hospital in the first half of 2012 . sample size was calculated based on data obtained from a pilot study on 14 patients ( 7 in each group ) . after 1 h acupressure on le7 point and measuring the pain intensity , the difference between experimental and control groups was 0.44 ( sd = 1.181 ) . based on the above parameters and selecting the significance level to be less than 0.05 and a power of 0.8 , 34 subjects were estimated to be needed in each group . samples were selected consecutively among the patients admitted for appendectomy and patients who entered the study were randomly assigned into the groups [ figure 1 ] . the overall design of the study ( without specifying the allocated group ) explained to the patients . the criteria for inclusion of the participants were : the desire to participate in the research , no injury or lesion in the region of the acupoint of le7 , aged between 15 years and 70 years , being in the list of appendectomy surgery , and receiving general anesthesia . those with the following conditions were not selected : a recent history of disorders associated with acute or chronic nausea and vomiting ( such as gastrointestinal and ear disorders ) , experiencing nausea and vomiting during the last 24 h , the drug and alcohol addiction , a known neurological or psychiatric disease , and the previous use of acupressure or acupuncture techniques . the exclusion criteria were : occurring unforeseen complications during surgery and anesthesia , prolonged surgical time ( more than 2 h ) , receiving drugs outside anesthesia protocol for the routine appendectomy patients , and fever above 38c . the first section was the demographic data form and had six questions about the patient 's age , gender , height , weight , level of education , and the study group the patient was belonged to . it also had two questions about the length of surgical incision ( in millimeters ) and the duration of anesthesia ( in minutes ) . second section was a visual analog scale ( vas ) used for recording the severity of nausea . descriptors were placed at each end of the line ( 0 = absence of nausea and vomiting and 100 = the worst condition ) . the observer asked the patient about the severity of nausea and marked an x on place that corresponded with severity of nausea . nausea with a score of 70 was classified as severe , between 35 and 70 as moderate , and less than 35 as mild . if there was retch or vomiting more than 5 times each hour , it was considered as severe vomiting , between 3 times and 5 times as the average and less than 3 times as mild . a vas was also included in the third part for recording the severity of pain . descriptors are placed at each end of the line ( 0 = no pain and 100 = the most unimaginable pain ) . patients were asked to mark an x on place that corresponded with severity of pain . acupressure was applied using a special band called acuband ( psiband , american design , made in china ) . the technique was started after the full patient 's consciousness ( so that the patient is aware of the location , time , and person ) . all the patients were anesthetized using thiopental sodium ( 5 mg / kg ) , atracurium ( 0.6 mg / kg ) , and fentanyl ( 2 mcg / kg ) and then the anesthesia continued using a gas mixture of o2 + n2o ( each : 50% ) , morphine ( 0.1 mg / kg ) and isofeluran ( 1 mac [ minimum alveolar concentration ] ) . all the patients were transferred to the surgical ward by a specially trained team to eliminate the effect of patient movement and handling of pain , nausea , and vomiting . initially , the severity of pain , nausea , and vomiting were assessed and recorded . then the acuband was fastened by the second researcher . in the experimental group the acuband was fastened on the right leg in such a way that the button located exactly on the le7 acupoint . then , the pulses below the point were checked to ensure that the acuband would not interfere with the blood flow . the patient 's foot was also examined for the possibility of impaired venous return . in order to keep the patients and the staff blind to the group the patient was belonged to , an acuband also used in the control group , but the band was fasten loosely and in a way that the button placed right in opposite side of the le7 point ( as sham point ) . the occurrence and the severity of pain , nausea , and vomiting were assessed and recorded in the two groups hourly and up to 7 h. the acubands was preserved for 7 h. however , they were loosened for 10 min every 2 h and then tightened . for patients who suffered from severe nausea and vomiting during this period , anti - emetic medication ( metoclopramid , 10 mg ) was administered and the nausea was considered as severe one . an analgesic medication ( pethidine , 1 mg / kg ) also administered if the pain score was six or higher . this study was approved by the research council and the research ethics committee in our university of medical sciences . all the subjects had been informed about voluntary participation in the research , non - disclosure of personal information , and offered a written informed consent form to be signed before entering the study . all subjects have been assured that they will receive all the necessary care and pain medications if the intervention had no effect . the researchers were mindful of the need to pay close attention to ethical considerations and the welfare of the participants . the spss software ( statistical package for the social sciences ) version 11.5 used for data analysis . independent sample t - test was used to compare the mean of pain and nausea severity of two groups . the mean of pain intensity before the intervention was compared to the average of pain intensity in the next 7 h. also the mean of the nausea intensity was compared with average of nausea intensity in the next 7 h. paired t - test was used to compare the mean of pain intensity of each group before and total mean of pain at post intervention hours . a p value of less than 0.05 was considered to be significant for all tests . this study was undertaken on 70 patients in the age range 15 - 70 years . no significant difference was observed between the two groups in terms of age , body mass index , duration of anesthesia and the incision length [ table 1 ] . demographic data of study groups the mean of pain intensity in the le7 group was less than the control group after the intervention ( p = 0.02 ) [ table 2 ] . a significant deference was also observed between the mean pain severity of the le7 group before the intervention and the total mean of pain severity in the seven post - operative hours ( p = 0.018 ) . however , such difference was not significant in the control group ( p = 0.32 ) . figure 2 also shows that the mean of pain intensity was lower in le7 group till the 6 h after the surgery . mean ( sd ) , estimated difference ( 95% confidence interval ) and p values for pain intensity in the two groups before and after the intervention the mean and standard deviation of the pain severity in the seven post - operative hours in total , 35 patients ( 18 in the le7 group and 17 in the control group ) experienced post - operative nausea . also , no significant difference was observed between the means severity of post - operative nausea in the two groups [ table 3 and figure 3 ] . mean ( sd ) , estimated difference ( 95% confidence interval ) and p values for severity of nausea in the two groups before and after the intervention the mean and standard deviation of the nausea severity in the seven post - operative hours also 31 patients ( 16 in the le7 group and 15 in the control group ) experienced post - operative vomiting . from the total patients who experienced vomiting , four ones in the le7 group and 7 patients in the control group had mild vomiting while the severity of vomiting was moderate in the other ones . in the present study the intensity of post - operative pain was lower in le7 group than the control groups . studies have been conducted on the effects of acupressure on pain have reported different results . however , another study reported that the method was not successful on pain reduction after abdominal surgeries . it is noteworthy that in previous studies on the effect of acupressure on pain , researchers applied the method on points that were fully known to be effective in traditional chinese medicine . for example , lee stimulated the sp6 point that painless labor is one of its applications in acupuncture . in the present study we examined the effect of pressure on le7 acupoint that had been reported to be effective in reducing pain of acute and chronic appendicitis but , no study was available to assess its acupressure on post appendectomy patients . on the other hand , the effects observed in this study , may be due to the connections between the skin 's dermatomes . in the present study , the incidence and the severity of post - operative nausea did not significantly differ in the two groups . several studies have been conducted to evaluate the effects of acupressure on ponv ( although not in post - appendectomy patients ) . two studies have reported that this technique was not effective for nausea and vomiting after cholecystectomy and strabismus correction . however , some of the studies showed that this method has significantly reduced the severity of nausea and vomiting after adeno - tonsillectomy and laparoscopic surgeries . while no study on the effects of acupressure on le7 point is available , the studies that used p6 or other acupoints for ponv have not been reached to a definitive conclusion . the present study showed that acupressure on le7 acupoint was effective on post - appendectomy pain while its effect on ponv did not differ with the control group . it seems that nurses can be trained to use acupressure on le7 acupoint as a remedy for post - appendectomy pain . however , further investigations are recommended to confirm the results of the present study . in the present study , acupressure was started when the patients recovered from anesthesia and findings showed a considerable reduction in the severity of post - operative pain . however we suggest further studies with starting acupressure at the onset of pain or nausea and vomiting . second , we assessed the patients pain , nausea and vomiting only for 7 h. third , our study was single blinded . therefore , it is recommended to repeat a larger , double - blind study with longer period of assessment of pain and ponv . also amount of medication received in each group did not check in the present study . it is suggested that the amount of medication to be controlled in the future studies .
background : the le7 acupoint had been known as an acupoint for reducing pain of appendicitis . however , no study on the effect of its acupressure on post - appendectomy pain is available . 
 the objective of this study was to evaluate the effects of acupressure of le7 acupoint on pain , nausea , and vomiting after appendectomy.materials and methods : a single - blind randomized controlled trial was conducted on 70 post - appendectomy patients in a general surgical ward . 
 patients with inclusion criteria were selected consecutively and were randomly assigned into two groups . 
 the intervention group received acupressure to the le7 acupoint and the second group was the control group . 
 the severity of post - operative pain , nausea , and vomiting measured hourly till the seventh post - operative hour . 
 t - test was used to compare the mean of pain and nausea severity of two groups . 
 paired t - test was used to compare the mean of pain intensity of each group before and total mean of pain at post - intervention hours . 
 chi - squared test and fisher exact test were used for nominal data.results:the mean of pain intensity in the intervention group was 5.10  3.52 before intervention and decreased to 3.53  0.75 in the post - operative hours ( p = 0.018 ) . 
 the mean of pain intensity in the control group was 4.45  3.16 before intervention and changed to 4.01  0.92 in the post - operative hours ( p = 0.32 ) . 
 however , the mean of pain intensity in the intervention group was less than the control group till 6th h after the surgery . 
 no significant differences were observed between the two groups in terms of nausea and vomiting ( p = 0.74).conclusion : acupressure on le7 acupoint was effective on post - appendectomy pain but did not affect nausea and vomiting . 
 further investigations are suggested with starting acupressure at the onset of pain or nausea and vomiting .