Accupressure of P6 to Reduce Nausea During Cesarean Section

The Use of P6 Acupressure for the Reduction of Intraoperative and Postoperative Nausea and Vomiting in Women Undergoing Cesarean Delivery: a Randomized Trial

The purpose of this study is to evaluate if the addition of P6 pressure point stimulation as opposed to sham-point stimulation will decrease intraoperative and postoperative nausea and vomiting (IONV and PONV) for patients undergoing non-emergent cesarean delivery. We hypothesize that the addition of stimulation of the P6 pressure point to our institutional current standard of care (phenylephrine infusion, intravenous fluid bolus, and as needed intraoperative ondansetron) will decrease the occurrence of intraoperative emesis.

Study Overview

• Status: Completed
• Conditions: Nausea; Vomiting; Pregnancy Related; Cesarean Delivery
• Intervention / Treatment: Other: Magnet at P6; Other: Magnet applied to arm not at P6 pressure point.

Detailed Description

After obtaining written informed consent from the subject. They were then randomized to either the P6 acupressure or a sham acupressure group. Envelopes containing group assignment information were prepared prior to the start of the study by research personnel not involved in this study. Randomization occurred by selecting a sealed envelope that contained the group assignment, two acupressure 0.09-inch by 0.2-inch diameter devices, and a diagram of where to place the device from a pool of 200 envelopes. The acupressure devices used in this study are also used in clinical practice by Northwestern Medicine Osher Center for Integrative Medicine (Plaster - Accu Band 800 NP Magnets, Japan). Prior to the commencement of the study, the Center for Integrative Medicine acupuncturists educated study personnel on the placement of the devices and the proper patient-initiated stimulation method when the subject began to perceive nausea. Device placement took place in the preoperative room, prior to walking to the operating room for the surgical procedure, by research personnel not involved in the clinical care of study subjects. In the P6 acupressure group, the devices were placed two inches proximal to the flexor retinaculum, between the flexor carpi radialis and palmaras longus bilaterally. The small protrusion on the device was placed on the skin and held in place using an adhesive sticker at the stimulation point. In the sham acupressure group, the devices were placed distal and lateral to the P6 acupoint site, like in prior studies comparing the effectiveness of P6 acupressure to sham. This method of sham acupoint placement when compared to P6 acupoint placement has shown superiority of the P6 acupoint placement in 70% of studies that have used this point for sham.15 The devices are designed to maintain pressure at the point of placement without additional force applied. Research personnel also instructed subjects to apply additional pressure at the acupressure site for a period of 30 s-2 min if they perceived nausea. Subjects were then taken to the operating room where they received neuraxial anesthesia consisting of either a spinal anesthetic dosed with hyperbaric bupivacaine 12 mg plus fentanyl 15 mcg and morphine 150 mcg, or a combined spinal epidural with the same intrathecal dosing per institutional standard practice. Co-loading with a crystalloid solution occurred upon the start of the neuraxial procedure, and a phenylephrine infusion was started immediately after the cerebrospinal fluid was obtained. Maternal hypotension was defined as a systolic blood pressure less than 100 mmHg, mean arterial pressure less than 65 mmHg, or mean arterial pressure less than 20% of the baseline mean arterial pressure. The baseline blood pressure was considered the average value of three blood pressure readings obtained by the nursing staff in the preoperative area. Subjects were asked to report any nausea, retching, or vomiting to the anesthesia care team. In addition, the anesthesia provider asked the study subject about nausea or vomiting at intervals corresponding to events that are associated with a greater prevalence of nausea and vomiting (e.g. neuraxial dose administration, uterine exteriorization, and following uterotonic administration) as well as when the anesthesia provider observed the subject massaging the acupressure point. After the first complaint of nausea, subjects were encouraged to apply additional pressure to the devices, an intravenous (IV) fluid bolus was administered, and phenylephrine or ephedrine was administered by IV bolus and/or by increasing the infusion rate of phenylephrine if hypotension was present. At the second complaint of nausea or emesis, study subjects were again encouraged to apply additional pressure on the devices. Following delivery of the fetus, ondansetron 8 mg IV and dexamethasone 8 mg IV were administered. If intraoperative nausea and/or vomiting continued, study subjects were again encouraged to apply additional acupressure. If this was ineffective, prochlorperazine, promethazine, metoclopramide, fentanyl, or propofol were administered at the anesthesiologist's discretion. If these antiemetic agents were ineffective, the anesthesiologist could provide additional medications.

Routine postoperative orders, including antiemetic medications as needed, were placed by the anesthesiology team for postpartum use per our institution's current standard of care. Postoperative medications were administered and documented by the nursing staff. Study subjects were also encouraged to use additional acupressure as needed throughout their postoperative course, for up to 48 h or until discharge, whichever came first. A study team member replaced devices that were lost or removed the device if the study subject requested it. Prior to discharge, subjects were visited by study personnel and asked to complete a survey asking them to describe the incidence, duration, and severity of nausea and vomiting, interference of nausea/vomiting with the ability to care for themselves, and their rating and satisfaction of the acupressure therapy.

Baseline data collected were age, weight, height, body mass index, American Society of Anesthesiologists physical status classification, race, ethnicity, history of nausea and vomiting, parity, and the number of prior cesarean delivery. Intraoperative data included the type of neuraxial anesthesia, initial blood pressure in the operating room, the lowest recorded blood pressure intraoperatively, total vasopressor use (expressed as phenylephrine equivalents),18 the number of hypotensive episodes, crystalloid administered, and duration of anesthesia. Intraoperative nausea and vomiting outcomes included the number of subjects with nausea and/or vomiting, the number of emesis episodes, and the need for rescue antiemetic administration in the operating room. Post delivery emesis and antiemetic treatments were recorded in the post anesthesia care unit (PACU) in 0-24 h and 24-48 h periods. Study subject questionnaires were collected at the end of the study period.

• Study Type: Interventional
• Enrollment (Actual): 200
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Northwestern Memorial Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• ≥18 years of age
• English-speaking
• Pregnant patients presenting for scheduled cesarean delivery of a full-term fetus (>37 weeks' gestation)
• Patients scheduled as ERAC
• Parturients undergoing spinal anesthesia

Exclusion Criteria:

• Patients requiring emergent delivery,
• Fetal demise
• Patients with adhesive allergy/sensitivity
• Patients with allergy/sensitivity to nickel,
• Patients with inability to consent,
• Patients with known abnormal placentation
• Patients with pacemakers/defibrillators
• Patients with positive COVID-19 tests

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: P6 Accupressure Group; The pressure point will be stimulated by the presence of the magnet when positioned properly on the P6 acupressure point. Additional pressure may be applied as desired by the study subject but is not necessary for P6 stimulation.	Other: Magnet at P6; Magnet applied at P6 and attached with adhesive tape. The P6 pressure point is 2 inches proximal to the flexor retinaculum, between the flexor carpi radialis and palmaras longus.
Sham Comparator: Sham Pressure Point; The sham pressure point (distal to the P6 acupressure point).	Other: Magnet applied to arm not at P6 pressure point.; Magnet applied to arm not at P6 pressure point and affixed with adhesive tape.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Presence of Intraoperative Vomiting	Presence of intraoperative vomiting during scheduled cesarean delivery (intraoperative period).	Intraoperative Period
Presence of Intraoperative Nausea	Presence of intraoperative nausea during scheduled cesarean delivery (intraoperative period).	Intraoperative period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Emesis Episodes in the Intraoperative Period Period	The number of emesis episodes during the cesarean section intraoperative period.	Intraoperative period
Number of Rescue Antiemetic Doses Administered for the Treatment of Intraoperative Nausea and Vomiting	Reported total number (count) of rescue antiemetics administered per group during the intraoperative period. Rescue antiemetics are defined as the use of intravenous administered prochlorperazine, promethazine, or metoclopramide.	Intraoperative period

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Number of Emesis From Post Anesthesia Care Unit to Discharge.	Reported total number (count) of emesis episodes per group from admission to the post anesthesia care unit after the operative procedure to discharge from the hospital.	96 hours
Antiemetic Medication Administered From the PACU Through Discharge	The number(count) of antiemetic medication administered per group in the post anesthesia care unit through discharge from the hospital	96 hours
Patient Questionnaire: Have You Experienced Dry Retching or Vomiting	Patient recovery questionnaire administered prior to discharge from the hospital. Have you experienced dry retching or vomiting?	96 Hours
Patient Questionnaire: Number of Times Vomited	Patient recovery questionnaire administered prior to discharge from the hospital. (of those who indicated vomiting) How many times did you vomit.	96 Hours
Number of Participants With Nausea	Patient recovery questionnaire administered prior to discharge from the hospital. Have you experienced nausea?	96 Hours
Patient Questionnaire: Describe the Pattern of Your Nausea?	Patient recovery questionnaire administered prior to discharge from the hospital. (of those who had nausea)Describe the pattern of your nausea (2 choices).	96 Hours
Patient Questionnaire: Did the Nausea Interfere With You Ability to Care for Yourself?	Patient recovery questionnaire administered prior to discharge from the hospital. (of those who had nausea) How did the nausea interfere with your ability to care for yourself.	96 Hours
Patient Questionnaire: Duration of Nausea.	Patient recovery questionnaire administered prior to discharge from the hospital. (of those who had nausea) How many hours did the nausea last.	96 Hours
Patient Questionnaire: Severity of Nausea.	Patient recovery questionnaire administered prior to discharge from the hospital. (of those who had nausea).Severity of nausea based on a 0 (none) -100 (very severe).	96 Hours
Patient Questionnaire: Do You Think the Magnet Improves Nausea?	Patient recovery questionnaire administered prior to discharge from the hospital. Does the magnet improve nausea response yes or no.	96 Hours
Patient Questionnaire: Do You Think the Magnet Improves Vomiting?	Patient recovery questionnaire administered prior to discharge from the hospital. Does the magnet improve vomiting response yes or no.	96 Hours
Patient Questionnaire: Are You Satisfied With Acupressure?	Patient recovery questionnaire administered prior to discharge from the hospital. Are you satisfied with acupressure response yes or no.	96 Hours
Intraoperative Lowest BP (mmHg)	Lowest systolic and diastolic blood pressure during the intraoperative period.	Intraoperative period
Intraoperative Total Vasopressor (VPE) [1]	Measure Description: Total vasopressor units expressed as phenylephrine units using an 80:1 ratio for ephedrine in micrograms.	Intraoperative period
Intraoperative Hypotension Episodes (n)	Number of hypotension episodes experienced during the intraoperative period.	Intraoperative
Intraoperative Crystalloid Co-load (mL)	Amount of crystalloid fluids given as a co-load in milliliters during the intraoperative period.	Intraoperative period
Intraoperative Fluids Administered (mL)	Total number of milliliters of fluids administered during the intraoperative period.	Intraoperative
Duration of Intraoperative Anesthesia (Min)	Duration of administration of intraoperative anesthesia in minutes.	Intraoperative period

Collaborators and Investigators

• Sponsor: Northwestern University
• Investigators: Principal Investigator: Feyce Peralta, MD, Northwestern University

Publications and helpful links

General Publications

• Chooi C, Cox JJ, Lumb RS, Middleton P, Chemali M, Emmett RS, Simmons SW, Cyna AM. Techniques for preventing hypotension during spinal anaesthesia for caesarean section. Cochrane Database Syst Rev. 2017 Aug 4;8(8):CD002251. doi: 10.1002/14651858.CD002251.pub3.
• Wengritzky R, Mettho T, Myles PS, Burke J, Kakos A. Development and validation of a postoperative nausea and vomiting intensity scale. Br J Anaesth. 2010 Feb;104(2):158-66. doi: 10.1093/bja/aep370. Epub 2009 Dec 26.
• Lee A, Fan LT. Stimulation of the wrist acupuncture point P6 for preventing postoperative nausea and vomiting. Cochrane Database Syst Rev. 2009 Apr 15;(2):CD003281. doi: 10.1002/14651858.CD003281.pub3.
• Balki M, Carvalho JC. Intraoperative nausea and vomiting during cesarean section under regional anesthesia. Int J Obstet Anesth. 2005 Jul;14(3):230-41. doi: 10.1016/j.ijoa.2004.12.004.
• Allen TK, Habib AS. P6 stimulation for the prevention of nausea and vomiting associated with cesarean delivery under neuraxial anesthesia: a systematic review of randomized controlled trials. Anesth Analg. 2008 Oct;107(4):1308-12. doi: 10.1213/ane.0b013e31816d1864.
• Boogaerts JG, Vanacker E, Seidel L, Albert A, Bardiau FM. Assessment of postoperative nausea using a visual analogue scale. Acta Anaesthesiol Scand. 2000 Apr;44(4):470-4. doi: 10.1034/j.1399-6576.2000.440420.x.
• Habib AS, Itchon-Ramos N, Phillips-Bute BG, Gan TJ; Duke Women's Anesthesia (DWA) Research Group. Transcutaneous acupoint electrical stimulation with the ReliefBand for the prevention of nausea and vomiting during and after cesarean delivery under spinal anesthesia. Anesth Analg. 2006 Feb;102(2):581-4. doi: 10.1213/01.ane.0000189217.19600.5c.
• Ho CM, Tsai HJ, Chan KH, Tsai SK. P6 acupressure does not prevent emesis during spinal anesthesia for cesarean delivery. Anesth Analg. 2006 Mar;102(3):900-3. doi: 10.1213/01.ane.0000195553.82409.00.
• Tan JY, Suen LK, Wang T, Molassiotis A. Sham Acupressure Controls Used in Randomized Controlled Trials: A Systematic Review and Critique. PLoS One. 2015 Jul 15;10(7):e0132989. doi: 10.1371/journal.pone.0132989. eCollection 2015.
• Albooghobeish M, Mohtadi A, Saidkhani V, Fallah H, Behaein K, Nesionpour S, Nikbakht R. Comparison Between Effects of Acupuncture and Metoclopramide on Postoperative Nausea and Vomiting after Gynaecological Laparoscopy: A Randomized Controlled Trial. Anesth Pain Med. 2017 Aug 22;7(5):e12876. doi: 10.5812/aapm.12876. eCollection 2017 Oct.
• Matthews A, Haas DM, O'Mathuna DP, Dowswell T. Interventions for nausea and vomiting in early pregnancy. Cochrane Database Syst Rev. 2015 Sep 8;2015(9):CD007575. doi: 10.1002/14651858.CD007575.pub4.
• El-Deeb AM, Ahmady MS. Effect of acupuncture on nausea and/or vomiting during and after cesarean section in comparison with ondansetron. J Anesth. 2011 Oct;25(5):698-703. doi: 10.1007/s00540-011-1198-0. Epub 2011 Jul 15.
• Sheldon RR, Loughren MJ, Marenco CW, Winters JR, Bingham JR, Martin MJ, Eckert MJ, Burney RO. Microdermal Implants Show No Effect on Surrounding Tissue During Surgery With Electrocautery. J Surg Res. 2019 Sep;241:72-77. doi: 10.1016/j.jss.2019.03.039. Epub 2019 Apr 19.
• A DM, A K. Effect of acupressure on post-operative nausea and vomiting in cesarean section: a randomised controlled trial. J Clin Diagn Res. 2013 Oct;7(10):2247-9. doi: 10.7860/JCDR/2013/5702.3485. Epub 2013 Oct 5.

Study record dates

Study Major Dates

• Study Start (Actual): May 26, 2021
• Primary Completion (Actual): August 31, 2023
• Study Completion (Actual): September 30, 2023

Study Registration Dates

• First Submitted: February 26, 2021
• First Submitted That Met QC Criteria: March 11, 2021
• First Posted (Actual): March 16, 2021

Study Record Updates

• Last Update Posted (Actual): June 6, 2025
• Last Update Submitted That Met QC Criteria: May 20, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: Nausea; Vomiting; Cesarean Delivery; Accupressure
• Additional Relevant MeSH Terms: Signs and Symptoms, Digestive; Nausea; Vomiting
• Other Study ID Numbers: STU#: 00213854

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No