Ear Plaster Therapy as a Safe and Effective Treatment for Gestational Vomiting

Summary

The presented protocol describes a traditional Chinese medicine treatment procedure known for its safety and effectiveness in managing gestational vomiting.

Abstract

Nausea and vomiting in pregnancy (NVP) are common symptoms that often complicate early pregnancy for many women. While clinical treatments such as fasting, fluid infusion, and nutritional support are conventionally applied to manage NVP, their effectiveness varies. However, traditional ear plaster therapy offers a promising alternative that effectively relieves symptoms and poses no known risk to the development of embryos or fetuses. This therapy is known for its ease of application, cost-effectiveness, and favorable outcomes. Previous studies have demonstrated the efficacy of combining ear plaster therapy with conventional treatments in alleviating symptoms of nausea and vomiting in pregnant women, surpassing the results achieved with conventional treatment alone. The protocol presented herein describes a method to relieve NVP using round, smooth, and hard cowherb seeds applied to specific ear points. These seeds are gently rubbed onto the surface of the ear, utilizing the principles of acupressure. By stimulating the designated ear points, this procedure aims to regulate the body's energy flow and restore balance, thereby reducing the severity and frequency of NVP. The application of cowherb seeds on specific ear points is a straightforward technique that healthcare professionals can easily implement or self-administered by pregnant women under appropriate guidance. Overall, ear plaster therapy presents a safe, effective, and economical approach for managing gestational vomiting, offering women a potential solution to alleviate their discomfort during pregnancy.

Introduction

Nausea and vomiting during pregnancy (NVP) are common, affecting approximately 50%-80% of pregnant women to varying degrees¹. When NVP progresses to moderate or severe levels, it increases the risk of adverse pregnancy outcomes for both the mother and the fetus. Therefore, early intervention for NVP may be beneficial in preventing the development of hyperemesis gravidarum². The exact cause of NVP is not well understood in modern biomedicine, but it is believed to be associated with factors such as changes in the serum level of human chorionic gonadotropin during pregnancy and deficiencies of certain vitamins³. Current treatments for NVP include fasting, fluid infusion, and correction of electrolyte imbalances, but none of these approaches are considered reliable⁴. Consequently, finding an effective treatment that does not impact the development of the embryo or fetus is a significant clinical challenge.

Ear plaster therapy is a traditional Chinese medicine treatment method that involves the use of small, rounded objects, typically the seeds of cowherb, to stimulate specific points on the ear for disease prevention and treatment⁵. The dried and mature seeds of Vaccaria hispanica, also known as cowherb, are used in this therapy as they are believed to regulate blood and channels, enhance blood circulation, and promote lactation. The auricle (outer part of the ear) is rich in nerves, containing numerous acupuncture and sensitive points⁶. By stimulating these points, the soft tissues of the ear may produce localized aseptic inflammation, which in turn may regulate the neuroendocrine system, including the pituitary-adrenal cortex and sympathetic-adrenal cortical glands. Additionally, this therapy can potentially invigorate the body's non-specific immune response, leading to therapeutic effects⁷. Ear plaster therapy effectively treats NVP by targeting specific points on the ear that primarily regulate autonomic dysfunction, reduce gastrointestinal responses, and alleviate the sensation of vomiting. It can also increase the level of Motilin, a hormone that promotes intestinal motility⁸, and restore the appetite of pregnant women. Moreover, some previous studies suggest that ear plaster therapy may have a favorable impact on NVP-related mood disturbances⁹, as it exhibits similar actions to sedatives in relieving anxiety.

Ear plaster therapy is a simple and easily administered treatment method. It can be used in conjunction with conventional treatments to alleviate the symptoms of NVP while minimizing the potential risks associated with medication use for both the mother and the fetus. This protocol provides detailed instructions on how to perform this therapy and what to consider during the process. We hope ear plaster therapy will receive increased attention and be promoted and utilized in clinical practice.

Protocol

All procedures of this study were conducted by clinical trial registration and were approved by the ethical institution of the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine (Filing No. 2022SL-015). All patients in this study were fully provided with informed consent and consented to the investigators' use of data, images, and related video filming during the trial. Eligible patients were recruited (from January 2023 to April 2023) through leaflets, word communication, and doctors' recommendation in the inpatient department of the Hospital of Chengdu University of Traditional Chinese Medicine.

1. Patient selection

1. Inclusion criteria
   1. Confirm intrauterine pregnancy. Identify early pregnancy vomiting as the main complaint, referring to the Guidelines for the Diagnosis and Management of NVP published by the American College of Physicians in 2018¹⁰, and ensure that the participants meet the diagnostic criteria for clinical NVP.
   2. Verify that participants are not currently participating in other clinical trials.
2. Exclusion criteria
   1. Exclude individuals with other pathological conditions causing NVP, such as hyperemesis gravidarum, pregnancy-associated viral hepatitis, or pregnancy-associated acute gastroenteritis.
   2. Exclude participants who refuse treatment with ear plaster therapy.
   3. Exclude individuals with severe NVP or allergies to the medication or its excipients and participants with auricular injuries.
   4. Exclude those who have been treated for NVP within the last 2 weeks.
3. Disposal of dropout cases
   1. Withdraw participants from the trial if they are unable to sustain adherence to the treatment. Allow participants to voluntarily withdraw from the study if they choose to do so.
4. Criteria for termination of the trial
   1. Terminate the participants who develop serious complications or experience disease progression during the study. Cease the trial if participants develop serious adverse reactions.

2. Patient grouping and treatment plan

1. Recruit twenty patients and randomly assign them to either the experimental group or the control group.
2. Provide the control group with a controlled diet and administer conventional treatment, including rehydration and vitamin supplementation (see Results section for details).
3. For the experimental group, administer ear plaster therapy in addition to conventional treatment.
4. Ensure that the rest management for both groups remains the same until the patients are discharged from the hospital.

3. Preparation for ear plaster therapy procedure

1. Gather the necessary items (Figure 1): scissors, sterile cotton swabs, tweezers, medical tape, 75% alcohol, and cowherb seeds (see Table of Materials).
2. Preparation of the ear plaster
   1. Cut the adhesive tape into square pieces measuring 0.6 cm x 0.6 cm.
   2. Take 1 or 2 smooth cowherb seeds (seeds of B. Wang, obtained from a pharmaceutical company, see Table of Materials) and place them at the center of each tape square, as shown in Figure 2.
3. Patient preparation
   1. Instruct the patient to sit in a comfortable position.
   2. Inspect the condition of the skin on the ear.
      NOTE: Ensure that the skin of the ear is intact and free from any abnormalities (e.g., inflammation, ulceration, frostbite, etc.) before proceeding with the treatment. Ear plaster therapy should not be performed on areas with auricular trauma or inflammation. It should only be carried out after these abnormalities have subsided and the trauma has healed. If the patient is allergic to adhesive tape, use alternative materials.
4. Selection of acupoints
   1. Locate points/sensitive areas on the ear. Stabilize the ear auricle by using the thumb and index finger of one hand to pinch and lift the ear helix backwards and upwards, fully exposing the area.
   2. With the sterile swab in the other hand, gently probe the patient's ear to identify sensitive pressure points near the six auricular points of the stomach (CO4), cardia (CO3), belly (AH8), shenmen (TF4), subcortex (AT4), and liver (CO12) (Figure 3).
      NOTE: Sensitive points refer to areas where there is significant soreness, numbness, swelling, or pain compared to other areas when applying pressure. These sensitive points have demonstrated better therapeutic effects compared to other common auricular points⁷. Based on previous clinical studies, the six auricular points (CO4, CO3, AH8, TF4, AT4, and CO12) are commonly used in the treatment of NVP and have prominent antiemetic and calming effects^11,12,13. If sensitive points on the ear are not detected, the six mentioned points can be selected for the subsequent treatment round.
5. Disinfection
   1. Disinfect the hands of the operator using an alcohol-soaked cotton ball.
   2. Disinfect the patient's auricle using a sterile cotton swab dipped in 75% alcohol.
      ​NOTE: The disinfection area should cover approximately 1-2 cm² of the auricular skin surrounding the target point. Alcohol helps remove oil from the skin surface, ensuring better adhesive properties of the tape. If the patient is allergic to alcohol, iodophor can be used as an alternative.

4. Ear plaster therapy

1. Once the area is dry, stabilize the auricle by pinching the ear helix with the thumb and index finger of one hand, lifting it backward and upward.
2. Using forceps, take the prepared ear plaster (step 3.2) and place the central seeds of the cowherb onto the selected point, as shown in Figure 4. Confirm with the patient that the seed placement corresponds to a sensitive point or sore area.
3. Position the thumb and index finger in front of and behind the auricle, applying moderate and tolerable pressure with a rhythmic pressing and relaxing motion to stimulate the cowherb seeds at the auricular site. Press and release for 3-5 min at each site, maintaining an even rhythm.
   NOTE: Adjust the intensity of pressure based on communication with the patient, ensuring that soreness, numbness, swelling, and pain are felt without excessive force.
4. Monitor the patient's overall condition for 15 min following the treatment.
   NOTE: In case of panic, chest distress, dizziness, or profuse sweating, promptly remove the adhesive tape.
5. Instruct the patient or their family to rub the seeds three times a day: morning, midday, and evening.
   NOTE: Emphasize the need for additional stimulation of the seeds when the patient experiences nausea.
6. Remove the ear plaster after three days and repeat the above steps on the opposite ear, alternating treatment between the two ears.
   ​NOTE: Continue treatment until the patient meets the discharge criteria: PUQE score ≤4 and urinary ketone bodies turn negative. If the ear plaster becomes dislodged, reapply it.

5. Patient diagnosis

1. Starting from the first day of hospitalization, collect fresh urine every 2 days to measure and record urinary ketone levels. Note the duration from the start of treatment to the time when the urinary ketone levels turn negative.
   NOTE: Urinary ketone levels serve as an important indicator for assessing patients with NVP. A positive urine ketone level indicates ongoing starvation and dehydration^14,15. Ensure timely testing of urine samples to prevent low values caused by ketone body evaporation.
2. Instruct patients to complete the Pregnancy-Unique Quantification of Emesis and Nausea (PUQE) scale (see Table 1) on a daily basis. Record the scores based on their actual symptoms each day until the day of discharge.
   ​NOTE: The PUQE scale is widely used in various practice guidelines globally to measure the severity of NVP symptoms in patients¹⁶. A higher PUQE score indicates a more severe condition.

6. Post-operative care

1. Advise the patient to keep the ear clean and dry.
   NOTE: The placement of the seed patch does not interfere with daily activities such as washing and bathing.
2. Provide reassurance and support to alleviate the patient's nervousness and fear.
3. Instruct the patient to perform swallowing movements or take deep breaths when experiencing feelings of nausea and vomiting.
4. If the patient experiences local allergic reactions such as itching, redness, or exudation on the skin during treatment, immediately remove the adhesive tape and apply anti-allergy ointment topically to alleviate these symptoms.
5. If an infection occurs, manage it as a common infection. Use topical antibiotics (appropriate for pregnant women) or anti-inflammatory and analgesic ointments for treatment.
6. Monitor the frequency and amount of vomiting, assess for signs of dehydration, and regularly measure urinary ketone levels.
   NOTE: In cases where conditions affecting fetal development and maternal safety are present and cannot be effectively addressed, consider termination of the pregnancy.

Representative Results

All twenty participants in this clinical study successfully completed the trial. Four patients met the discharge criteria and were discharged on day 5, while the remaining 16 patients met the discharge criteria and were discharged within 2 weeks of hospitalization.

During the trial, the control group received a controlled diet and intravenous drips, which included the following components: vitamin C 2g + 0.9% sodium chloride injection 500 mL, vitamin B6 0.2 g + 0.9% sodium chloride injection 500 mL, potassium magnesium menadione 20 mL + 5% glucose injection 500 mL, potassium chloride 15 mL + glucose injection 500 mL, 0.9% sodium chloride injection 500 mL, and vitamin B1 200 mg (see Table of Materials) intramuscularly once daily. The amount of fluid infusion was gradually decreased when food intake increased^{10,17,18,19,20}.

Patients in the experimental group received ear plaster therapy in addition to the same fluid infusion treatment as the control group until they were discharged. The duration of treatment, time to negative urine ketone bodies, and daily PUQE scores were analyzed. The measures were expressed as (x¯± s), and t-tests were used to compare the two groups.

Pregnancy-Unique Quantification of Emesis (PUQE) is used to measure the severity of nausea and vomiting during pregnancy (NVP) (Table 1). The total PUQE score is categorized as follows: Mild NVP with a score of ≤6, moderate NVP with a score of 7-12, and severe NVP with a score of ≥13.

The comparison of maternal age and gestational weeks between the two groups is presented in Table 2. The table indicates that there were no statistically significant differences in maternal age and gestational weeks between the two groups (p > 0.05). The ages of the pregnant women and the duration of their pregnancies were similar in both groups.

Table 3 displays the comparison of hospitalization duration and the time taken for ketone bodies to turn negative between the two groups of pregnant women (x¯± s). The experimental group had a significantly shorter average hospital stay by 2.5 days compared to the control group. Similarly, the time for ketone bodies to turn negative was 2.4 days shorter in the experimental group. Both differences were statistically significant (p < 0.05). These results suggest that ear plaster therapy can effectively reduce the treatment time for NVP.

The PUQE scores of the two groups of pregnant women are presented in Table 4. Prior to treatment, there were no statistically significant differences in PUQE scores between the groups (p > 0.05). However, after five days of treatment, both the experimental and control groups showed a significant reduction in PUQE scores compared to their initial scores (p < 0.05). In the experimental group, the mean PUQE score decreased from 12.6 to 5.0, while in the control group, it decreased from 12.5 to 6.9. Additionally, during the treatment period, the scores of the experimental group were consistently lower than those of the control group, and this difference was statistically significant (p < 0.05). These findings suggest that the treatment was effective in both groups, with the experimental group demonstrating better efficacy than the control group.

Figure 1: The items required for ear acupuncture therapy. It includes various items: (A) Scissors, (B,C) Sterile cotton swabs and tweezers, (D) Medical tape, (E) 75% alcohol, and (F) Cowherb seeds. Please click here to view a larger version of this figure.

Figure 2: Prepared ear patches used in the treatment. The figure displays pictures of the ear patches that are utilized in the therapy. Please click here to view a larger version of this figure.

Figure 3: The location of auricular points used in the treatment. The diagram is based on the National Standard of the People's Republic of China "Names and Positioning of Ear Points" (GB/T13734-2008)²¹. It highlights six specific ear points: stomach (CO4), cardia (CO3), belly (AH8), shenmen (TF4), subcortex (AT4), and liver (CO12). The diagram includes red circles to indicate the corresponding locations of these points. Please click here to view a larger version of this figure.

Figure 4: The key steps involved in the ear acupuncture procedure. The steps are as follows: (1) and (2) represent disinfection operations, (3) indicate probing for ear pressure points, (4), (5), and (6) represent the ear needling operations. Please click here to view a larger version of this figure.

Pregnancy-Unique Quantification of Emesis (PUQE)
Circle the answer that best fits your situation below
1. How long did you feel nauseous and vomit the day before?
never	≤1h	2-3h	4-6h	≥6h
1 point	2 point	3 point	4 point	5 point
2. How many times did you vomit the day before?
never	1-2 times	3-4 times	5-6 times	≥7 times
1 point	2 point	3 point	4 point	5 point
3. How many times did you dry heave the day before?
never	1-2 times	3-4 times	5-6 times	≥7 times
1 point	2 point	3 point	4 point	5 point

Table 1: Pregnancy-Unique Quantification of Emesis (PUQE) scoring system used to assess the severity of nausea and vomiting during pregnancy (NVP). The total score is categorized as follows: mild NVP with a score of ≤6, moderate NVP with a score of 7-12, and severe NVP with a score of ≥13.

Group A	Group B	n	Age/year	Gestational weeks/week
Experimental group	Experimental group	10	25.4 ± 1.57762	7.9 ± 2.46982
Control group	Control group	10	25.5 ± 1.84089	8.2 ± 1.98886

Table 2: Comparison of maternal age and gestational weeks between the two groups.

Group	n	Length of stay in hospital/day	Time to negative ketone body/day
Experimental group	10	6.2 ± 1.13529	6.0 ± 0.94281
Control group	10	8.7 ± 1.49443	8.4 ± 1.50555

Table 3: Comparison of the duration of hospitalization and the time to turning negative of ketone bodies between the two groups of pregnant women. The average duration of hospitalization and the time taken for ketone bodies to turn negative are represented by x¯± s in Group A and Group B. x¯± s represents the mean and standard deviation values for the respective measurements in each group.

Group	n	PUQE Score
		Before treatment	Treatment day 1	Treatment day 2	Treatment day 3	Treatment day 4	Treatment day 5
Experimental group	10	12.6 ± 0.84327	9.7 ± 0.82327	8.6 ± 1.17379	7.0 ± 1.26930	5.9 ± 1.44914	5.0 ± 1.69967
Control group	10	12.5 ± 0.84984	10.9  ± 1.10050	10.0 ± 1.41421	9.0 ± 1.41421	8.1 ± 1.52388	6.9 ± 1.19722

Table 4: Comparison of PUQE scores between the two groups of pregnant women. The average PUQE scores are represented by x¯± s in Group A and Group B. x¯± s represents the mean and standard deviation values for the respective measurements in each group.

Discussion

Nausea and vomiting in pregnancy (NVP) is a common condition that can pose risks to the health of pregnant women, even leading to complications despite terminating pregnancies. Clinical drugs often used for antiemetic/antinauseant effects, such as ondansetron and promethazine, carry potential risks for pregnant women, including dystonia, sedation, and lowered seizure thresholds²². Consequently, pharmacological treatments come with their own set of dangers. On the other hand, the symptom-centered treatments commonly employed today lack specificity and are sometimes ineffective²³. Therefore, obstetricians should pay closer attention to this disorder.

This article introduces ear plaster therapy, a traditional Chinese medicine technique used for treating NVP. This therapy is simple, cost-effective, and safe, and has gained acceptance from patients in clinical practice. Our trial results also support the notion that when combined with conventional treatment, ear plaster therapy effectively alleviates NVP.

This article presents a retrospective clinical observation with limited patients and some limitations. However, it is believed that the effectiveness of ear plaster therapy will be fully demonstrated through randomized studies with larger sample sizes. Currently, several challenges are associated with using ear plaster therapy in NVP treatment. Firstly, the selection of ear points relies on the patients' subjective perceptions, which can lead to imprecise identification of sensitive points due to variations in patients' descriptions or perceptions. Secondly, there is a lack of quantitative indicators for the method, duration, and intensity of acupoint stimulation, and operators employ different techniques and levels of stimulation, potentially resulting in under or over-stimulation.

In our practice, we have observed that post-therapeutic care following this therapy is often overlooked. Post-operative care is crucial for treatment outcomes, prevention of complications, and patient satisfaction. The subcutaneous tissue of the ear is thin and contains numerous superficial blood vessels. Therefore, the use of adhesive tape and its removal can cause skin lesions or infection, necessitating careful handling. For this reason, specific post-operative care instructions are provided, including observing the skin of the auricle after treatment, maintaining cleanliness and dryness of the ear, and advising patients to avoid contact with liquids and contaminants on the day of needling. As nerve endings are widely distributed in the ear, some patients may experience pain when pressing the seeds. Treatment can proceed if the pain is tolerable and there is no harm to the ear. Furthermore, it is important to make adjustments based on post-operative assessments. If NVP relief is not sufficiently pronounced after two weeks of treatment, it may indicate inaccurately chosen ear acupuncture points, which should be adjusted by adding new points as needed.

Although the use of ear plaster therapy for NVP treatment is still being explored, the benefits demonstrated thus far are impressive. With accumulating clinical experience, we believe this therapy will increasingly prove effective in alleviating the pain experienced by pregnant women.

Materials

Name	Company	Catalog Number	Comments
Alcohol cotton ball	Yangzhou Longhu Medical Instrument Co., Ltd	20172142183
Cowherb seeds	Anhui Kangyunnuo Biotechnology Co., Ltd	SC10334161107893
Disposable tweezers	Yangzhou Guilong Medical Instrument Co., Ltd	20182010440
Glucose Injection	Jichuan Pharmaceutical Group Co., Ltd	H32024826
Omnifilm	Paul Hartmann AG	20210605
Potassium Aspartate and Magnesium Aspartate Injection	Hangzhou Minsheng Pharmaceutical Co., Ltd	H33020038
Potassium Chloride Injection	Shandong Qidu Pharmaceutical Co., Ltd	H20153283
Scissor	BERNAL DENTAS	20190961
Sodium Chloride Injection	Chenxin Pharmaceutical Co., Ltd	H20056758
Swab	Bicon,LLC	20151479
Vitamin B1 Injection	Chengdu Beite Pharmaceutical Co., Ltd	H32021525
Vitamin B6 Tablets	Gansu Chengji Biopharmaceutical Co., Ltd	H62020314
Vitamin C Tablets	Xinxiang Changle Pharmaceutical Co., Ltd	H41021516