A Traditional Chinese Medicine Characteristic Therapy for Bronchial Asthma: Moxibustion

This protocol presents a curative procedure of moxibustion in treating patients with bronchial asthma.

Bronchial asthma is a chronic inflammatory disease of the airway which can lead to symptoms such as recurrent wheezing, shortness of breath, chest tightness, or cough, as a result of increased airway reactivity. With high diurnal variation, these symptoms often occur or worsen at night or in the morning. By burning and roasting the Chinese medica above human acupoints, moxibustion is a type of treatment that stimulates the activity of the human meridians through drugs and heat stimulation to prevent and treat diseases. According to the principle of syndrome differentiation and treatment of traditional Chinese medicine, acupoints are selected on the corresponding parts, which has a definite effect. It is regarded as a characteristic traditional Chinese medicine therapy for bronchial asthma. This protocol elaborates the methods and steps of patient management, material preparation, selection of acupoints, operation, and postoperative nursing to ensure safe and effective moxibustion treatment to significantly improve the clinical symptoms and quality of life of patients with bronchial asthma.

The protocol presented here demonstrates the operation of moxibustion in treating bronchial asthma in terms of patient management, material preparation, acupoint selection, operation, and postoperative nursing. The purpose of this protocol is to control the symptoms of patients with bronchial asthma and improve lung function by moxibustion.

Acupuncture and moxibustion are important components of traditional Chinese medicine (TCM). Concerning bronchial asthma, acupuncture and moxibustion have accumulated extensive clinical experience in treatments, and moxibustion in particular has shown unique advantages^1,2,3,4. Modern studies show that the effects of the biological mechanism of warming promotion and supplementation of moxibustion are as follows: moxibustion activates the acupoints (local starting), promotes the movement of qi and blood, regulates the neuroendocrine-immune network (regulatory pathway), and regulates the functions of the viscera (response of the effector organ)^5,6,7.

Bronchial asthma is a chronic inflammatory disease of the airway which can lead to symptoms such as recurrent wheezing, shortness of breath, chest tightness, or cough, due to the increased airway reactivity. These symptoms often occur or worsen at night or in the morning⁸. Bronchial asthma is one of the most common chronic lung diseases in the world, affecting people of all ages⁹. In recent years, the prevalence of bronchial asthma in China has been increasing yearly. The latest epidemiological survey showed that the prevalence of asthma in adults over 20 years old is 4.2%¹⁰. The disease will lead to airway remodeling and hyperreactivity, which will seriously affect the pulmonary function of patients in the late stage. Currently, the main clinical treatments for bronchial asthma are anti-inflammatory, antispasmodic, and symptomatic treatments. Nevertheless, the high recurrence rate and intractability outline the main disadvantages, let alone the poor long-term drug efficacy and lack of an ideal therapeutic schedule. Compared with inhaled drugs alone, moxibustion could enhance humoral and cellular immunity, which have a significant immunomodulatory effect during treatment^11,12,13. By burning and roasting the Chinese medica above human acupoints, moxibustion is a type of treatment that works through drugs and heat stimulation. It has effects such as dispelling cold sensations by warming the meridians, promoting qi circulation to remove the meridian obstruction, and eliminating stagnation to activate meridians. It is regarded as a TCM characteristic therapy for bronchial asthma¹⁴.

The clinical trial has been approved by the Approval Committee of the Respiratory Department of the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine (No. KY2022022). In this study, the diagnostic criteria of bronchial asthma refer to the Guidelines for Bronchial Asthma Prevent and Management (2020 edition)⁸ and TCM operations refer to the Criteria of Diagnosis and Therapeutic Effect of Diseases and Syndromes in Traditional Chinese Medicine¹⁵. The typical case was a diagnosed bronchial asthma patient admitted to the Respiratory Department of the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine. The patient's informed consent was obtained. All material sources used in the protocol can be obtained (see Table of Materials).

1. Material preparation

1. Moxa Stick: Please ensure that the items listed below are available:
   -Moxa sticks (made of moxa; their specifications are as follows: 200 mm in length and 18 mm in diameter [Table of Materials]).
   -Ignition device (lighter [Table of Materials])
   -Surgical curved plate (200 mm in length and 125 mm in width [Table of Materials]) with water
   -Gauze (minimum specification: 80 mm x 80 mm-8P [Table of Materials])
   -Forceps (all sterile medical forcipes are acceptable and nonessential. No special requirements [Table of Materials])
   NOTE: The ignition devices include matches, alcohol lamps, and lighters, according to the medical production standards, and any of them can be selected during operation. The ignition devices will extinguish the flame in time according to its manual after use. The surgical curved plate with water is to extinguish the moxa stick fire and clean the ashes after burning.
2. Gather all the materials mentioned in steps 1.1 and put them in a medical cart for use in the procedure room (Figure 1).

2. Patient assessment

1. Inclusion criteria
   1. Include patients diagnosed with bronchial asthma according to diagnostic criteria⁸.
      NOTE: Fully communicate with the patient and inform them of the risks brought by the operation. Have the patient sign the informed consent form. Moxibustion should be applied cautiously to those who are afraid of moxibustion. The skin area to be operated on should be complete.
2. Exclusion criteria
   1. Exclude pregnant women, children, and other special groups who should not be operated on.
   2. Exclude people allergic to argyi, alcohol, and other materials.
      ​NOTE: The purpose of patient assessment is to judge whether the patient is in the appropriate condition for a moxibustion operation.

3. Preoperative preparation

1. Cleaning the skin area
   1. The day before the operation, clean the skin area where the operation site is located two or three times with clean water to ensure that surface contaminants are removed. The radius of the cleaning range should be greater than 10 cm. Keep the skin dry after cleaning.
   2. If conditions permit, bathe and clean the skin. Ensure the water temperature is comfortable for the patient.
2. After selecting the point, use an iodophor cotton swab to disinfect the skin from inside to outside two or three times, with the acupoint as the center. The area of the sterilized skin should not be less than 5 cm x 5 cm.
3. Before the operation, the operator must clean their hands with soapy water, according to the specification of hand hygiene for healthcare workers¹⁶.

4. Operation procedure

1. Body position selection: Select the supine position or prone position for this procedure.
   NOTE: The body position should be correctly selected according to the position of the acupoints to expose the acupoints fully.
2. Acupoint selection
   1. Locate the following acupoints according to Meridians and Acupoints¹⁷ (version 2016, published by China Traditional Chinese Medicine Publishing House): Dingchuan (EX-B1), Feishu (BL13), and Zhongfu (LU1).
   2. Locate EX-B1 at the nape back, on both sides of the midpoint of the lower edge of the spinous process of the seventh cervical vertebra 0.5 F-cun¹⁸ (Figure 2).
   3. Locate BL13 on the back side, on both sides of the midpoint of the lower edge of the spinous process of the third thoracic vertebra 1.5 F-cun (Figure 3).
   4. Locate LU1 on the chest, parallel to the first rib gap, on both sides of the anterior median line 6 F-cun (Figure 4).
      NOTE: Take the width of the interphalangeal joint of the patient's thumb as 1 F-cun (Figure 5).
3. Light the moxa stick
   1. Hold the middle and upper 1/3 of the moxa stick and light with the lighter.
      NOTE: No other inflammable is allowed in the surrounding environment.
4. Selection of moxibustion methods
   1. Mild moxibustion
      1. Hold the middle and upper 1/3 of the moxa stick, aim the lighted end above the acupoint 2-3 cm away from the skin, and keep the distance constant during the operation (Figure 6).
      2. Make the operation position appear warm, local skin flushed, but with no burning pain. Keep moxibustion at each acupoint for 10-15 min; the skin temperature of the acupoint is maintained at 40-45 °C, measured by a portable infrared thermometer.
         NOTE: The degree is chosen such that the patient feels warm and the skin is slightly red.
   2. Sparrow-pecking moxibustion
      1. Hold the middle and upper 1/3 of the moxa stick and aim the lighted end above the acupoint, 2-3 cm away from the skin.
      2. Move the burning end of the moxa stick by moving up and down, perpendicular to the skin above the acupoint (like a bird pecking), and keep the same up and down movement (Figure 7).
      3. Make the operation position appear warm, local skin flushed, but with no burning pain. Keep moxibustion at each acupoint for 10-15 min; the skin temperature of the acupoint is maintained at 40-45 °C, measured by a portable infrared thermometer.
   3. Convoluted moxibustion
      1. Hold the middle and upper 1/3 of the moxa stick and aim the lighted end above the acupoint, 2-3 cm away from the skin.
      2. Apply moxibustion by repeatedly rotating (like drawing a circle); draw a circle with a radius of 2.5 cm centered on the acupoint (Figure 8).
      3. Make the operation position appear warm, local skin flushed, but with no burning pain. Keep moxibustion at each acupoint for 10-15 min; the skin temperature of the acupoint is maintained at 40-45 °C, measured by a portable infrared thermometer.
         1. Sense the temperature during the operation. If the patient feels warm and comfortable, keep the distance unchanged. If the patient has a burning sensation, increase the distance between the moxa stick and the skin.
         2. If the patient's local skin sensation is weakened, separate the index finger and middle finger and place them on both sides of the acupoint to feel the temperature, adjust the time and distance of moxibustion according to the situation, and avoid burns.
5. Extinguish the fire and clean the ashes.
   1. After the operation, put the ignited part of the moxa stick into a curved plate filled with water to extinguish the moxa fire. Use forceps to remove the large ash, then gently wipe the residual stains with gauze.
      NOTE: Small blisters can naturally get absorbed. If the blisters are large, they can be punctured with a syringe or a needle and then an antibiotic ointment applied.
6. Postoperative care
   1. Use forceps to remove large ashes and clean the local skin area. Then, gently wipe the residual stains with gauze.
   2. Do not touch or take cold water within half an hour after the operation. Pay attention to keep the procedure area warm. Seek timely medical advice if the patient is feeling unwell.

5. Statistical analysis

1. Express the continuous variables as mean ± standard deviation (SD). Use a paired t-test to compare the differences between before and after treatment.
   NOTE: No categorical variables were involved in this study variable. All statistical tests were two-sided, and p < 0.05 was considered statistically significant. All analyses were performed using statistical software.

Eight patients with bronchial asthma who met the criteria were treated with moxibustion. All patients had the same diagnostic criteria for bronchial asthma, and the patients' pulmonary function FEV1 ratio, PEF ratio (actual/expected; percentage), and asthma control test (ACT) scores were measured before and after the moxibustion treatment in the same way. After one course of treatment, all patients had improved pulmonary function FEV1 ratio, PEF ratio, and ACT scores. Before treatment, the pulmonary function FEV1 ratio was 68.23% ± 4.35%, the PEF ratio was 65.91% ± 4.34%, and the ACT score was 16.13 ± 2.30 points. After treatment, the pulmonary function FEV1 ratio was 77.33% ± 5.53%, the PEF ratio was 77.69% ± 4.97%, and the ACT score was 22.38 ± 1.60 points. These differences were statistically significant (p < 0.05) (Table 1).

In a typical case, a 71-year-old female came to the clinic with recurrent interglottic croup for 10+ years, and cough and tightness of breath for 1+ months, exacerbated for 2 days. The patient met the diagnostic criteria for bronchial asthma, and after excluding contraindications, the patient was informed of the moxibustion procedure and the purpose of treatment, and she voluntarily participated in this trial. The patient was conscious on admission, with cough and sputum, tightness in the chest, aggravated by activity, nocturnal seated breathing, white smooth tongue coating, and a tight pulse. According to these symptoms, the patient was identified as having cold croup in TCM. The moxibustion protocol described above was applied to the Dingchuan (EX-B1), Feishu (BL13), and Zhongfu (LU1) acupoints for 15 min each time, once a day for 7 days.

Before treatment, the patient complained of coughing with frequent tightness in the chest. The examination showed that the pulmonary function FEV1 ratio was 58.9%, PEF ratio was 56.8%, and ACT score was 13. Computer tomography (CT) of the chest showed obvious lung inflation with thickened and disturbed lung texture (Figure 9). After treatment, the patient complained of occasional cough and sputum, and the tightness of the chest improved significantly. The examination showed that the pulmonary function FEV1 ratio was 69.1%, the PEF ratio was 70.4%, and ACT score was 20. Chest CT showed an improvement in lung inflation and partial reduction in pulmonary texture disorder (Figure 9). After treatment, the patient's clinical symptoms improved significantly, the pulmonary function suggested improvement, and the ACT score increased significantly (Table 2).

Figure 1: Operating materials. (A) Moxa stick. (B) Lighter. (C) Surgical curved plate. (D) Gauze. (E) Forceps. Please click here to view a larger version of this figure.

Figure 2: Dingchuan (EX-B1) acupoint position. At the nape back, on both sides of the midpoint of the lower edge of the spinous process of the seventh cervical vertebra 0.5 F-cun. Please click here to view a larger version of this figure.

Figure 3: Feishu (BL13) acupoint position. On the back side, on both sides of the midpoint of the lower edge of the spinous process of the third thoracic vertebra 1.5 F-cun. Please click here to view a larger version of this figure.

Figure 4: Zhongfu (LU1) acupoint position. On the chest, parallel to the first rib gap, on both sides of the anterior median line 6 F-cun. Please click here to view a larger version of this figure.

Figure 5: Measurement diagram of 1 F-cun. Take the width of the interphalangeal joint of the patient's thumb as 1 F-cun. Please click here to view a larger version of this figure.

Figure 6: Operation diagram of mild moxibustion. Hold the middle and upper thirds of the moxa stick, aim the lighted end above the acupoint, 2-3 cm away from the skin, and keep the distance constant during the operation. Please click here to view a larger version of this figure.

Figure 7: Operation diagram of sparrow-pecking moxibustion. Hold the middle and upper thirds of the moxa stick and aim the lighted end above the acupoint, 2-3 cm away from the skin. Move the burning end of the moxa stick by moving up and down perpendicular to the skin above the acupoint (like a bird pecking), and keep the same up and down movements. Please click here to view a larger version of this figure.

Figure 8: Operation diagram of convoluted moxibustion. Hold the middle and upper thirds of the moxa stick and aim the lighted end above the acupoint, 2-3 cm away from the skin. Apply moxibustion by repeatedly rotating (like drawing a circle), with a radius of 2.5 cm centered on the acupoint. Please click here to view a larger version of this figure.

Figure 9: Chest CT performance before and after treatment. (A) Before treatment. (B) After treatment. Please click here to view a larger version of this figure.

Table 1: The effect of moxibustion on patients' pulmonary function FEV1 ratio, PEF ratio, and ACT score.

Table 2: Results of a typical case.

The airway inflammation caused by bronchial asthma is a cascade immune response involving various immune cells, cytokines, and inflammatory mediators¹⁹. Bronchial biopsies of asthmatic patients show the presence of eosinophils, activated mast cells, and Th2 cell-based T cell infiltration²⁰. Pulmonary function indexes FEV1 and PEF reflect the severity of airway obstruction, and are the most commonly used indexes for objectively judging and evaluating the condition of asthma⁸. Western medicine treatments for bronchial asthma are glucocorticoids, β2 receptor agonists, leukotriene regulators, theophylline, and anticholinergic drugs. Glucocorticoids are the most effective in controlling bronchial asthma airway inflammation²¹. However, their long-term use can induce fungal infections, systemic adverse reactions, such as osteoporosis, and suppression of the hypothalamic-pituitary-adrenal axis⁴.

Bronchial asthma belongs to the category of asthma syndrome in TCM. The pathogenesis could be classified as the interaction and block of phlegm and vital qi, which leads to failure of the lung qi in ascending and descending. The syndrome belongs to a deficiency in origin and an excess in superficiality. The representation is the wind, cold, phlegm, heat, blood stasis, and dampness, and the deficiency of the lung, spleen, and kidney are the foundations²². The methods of treating bronchial asthma in TCM can be divided into internal and external therapies. Moxibustion is a type of external therapy, with fewer side effects, a convenient operation, and definite curative effects. Previous studies have shown that the main mechanisms of moxibustion in treating bronchial asthma are reducing the infiltration of eosinophils in peripheral blood or local lung tissue, local inflammatory response, and airway hyperresponsiveness, as well as relieving bronchial spasm and regulating the body's immune response^{22,23,24,25,26,27}.

Moxibustion is the process of burning the Chinese medica above the acupoints or diseased parts of the human body. The photothermal effect from moxa sticks during the burning process is the key to improving the body's immunity and promoting metabolism. Moxibustion is widely used to prevent and treat diseases of various systems, including the alimentary, respiratory, and cardiovascular systems. Moreover, the therapeutic effect on some diseases even exceeds the effect of acupuncture and medicine²⁸. Currently, many animal experiments, clinical trials, and meta-analyses have verified the effect of moxibustion in treating asthma. It can not only effectively control the symptoms of bronchial asthma patients, but also improve pulmonary function^{29,30,31,32,33,34,35,36,37,38,39,40}. In the process of moxibustion treatment, the risks include scalding, skin allergy, and dizziness. Scalding is the most common adverse reaction; therefore, according to the study, 40-45 °C is recommended as the appropriate temperature range for moxibustion to exert its efficacy and is also the temperature data frequently used in moxibustion research. In this range, it can not only play the role of immune regulation and improving blood circulation, but also prevent pain and side injury⁴¹.

In the process of moxibustion treatment, moxibustion smoke has an impact on the operator, mainly manifested in respiratory symptoms and eye discomfort. Therefore, the therapy time of moxibustion and the control of concentration of moxibustion smoke become the key to avoid adverse reactions. Operators should take measures to prevent scalding and smoke in advance, and control the time of moxibustion and the concentration of moxibustion smoke to ensure the safety of the patient and the operator.

Acupoints are the reaction point of disease acting on the body and the entry point of treatment. Acupoints are closely related to the viscera through meridians, which not only reflect the physiological or pathological functions of the viscera, but also are effective stimulation points for the treatment of diseases of viscera. Asthma is often caused by lung disease, which is caused by external pathogenic factors such as stiff attack, improper diet, emotional stimulation, physical Deficiency, and fatigue. Zhang et al. analyzed the clinical acupoint selection rule of moxibustion of asthma according to the literature⁴². The disease location of asthma is mainly in the lung; its original meridian is the Lung Channel of Hand-Taiyin. The Feishu point is the main treatment, so it can be used for the treatment of asthma. Shu- and Mu- point association for treatment is one of the classic acupoint matching methods. The combination of Shu- And Mu- points can achieve a synergistic effect. In TCM, the disease is located in the lung. The Feishu and Zhongfu acupoints are the Shu- and Mu- points of the lung, respectively, which can regulate viscera and relieve cough and wheezing^43,44,45,46. Moxibustion can significantly improve immune function, inhibit airway inflammation and reduce airway hyperresponsiveness, relieve clinical symptoms, and improve the quality of life of patients through Shu- and Mu- point association^47,48,49. Moreover, the Dingchuan acupoint is also widely used clinically because of its definite curative effect on bronchial asthma. It is an extra acupoint outside the meridian and an empirical acupoint for the treatment of asthma. External treatment at the Dingchuan acupoint can effectively inhibit the infiltration of eosinophils, reduce airway inflammation and hyperresponsiveness, and finally achieve the goal of treating bronchial asthma^50,51,52.

While western medicine effectively controls the onset of bronchial asthma, side effects and adverse reactions also emerge in an endless stream, and the treatments are comparatively limited²¹. Moxibustion, as one of the external therapies of TCM for bronchial asthma, gives full play to the characteristics and advantages of TCM, makes up for the shortcomings of internal therapies, shows great advantages, and provides more effective means for the treatment of bronchial asthma.

Our study is a single center study with a relatively small sample size, so we hope to expand the sample size in future studies to minimize bias.

The authors report no conflicts of interest.

We appreciate the financial support from the Science and Technology Development Fund Project of Hospital of Chengdu University of Traditional Chinese Medicine (No. 20ZL10). The authors would like to thank Mr. Yang Yang for participating in our study as a model.