Literature Review - The Efficacy of Acupuncture and Acupressure in Chronic Respiratory Conditions
Literature Review - The Efficacy of Acupuncture and Acupressure in Chronic Respiratory Conditions
Acupuncture is an ancient form of Chinese medicine that is now becoming more accepted as a treatment modality for a variety of conditions here in the West. Although there is much disparity between eastern and western concepts by which acupuncture is believed to work, it has been found to useful and efficacious in the treatment of a number of conditions (WHO, 2002). Here in England approximately 7% of the adult population has received acupuncture (2) and the British Medical Acupuncture Society has among its members over 2000 doctors who use acupuncture in general hospital or general practice (3). To date much of the research conducted has concentrated on examining the efficacy of acupuncture on pain control and anti-emesis. A comparatively smaller number of studies have investigated the effect of acupuncture on various respiratory conditions, chiefly those of bronchial asthma and COPD.
Acupuncture and Acupressure
The ancient Chinese practice of acupuncture is thought to date back to the Stone Age, as the use of the ‘Bian Shi’ (acupuncture needle) has been recorded in several ancient Chinese manuscripts (4). In contrast, acupuncture has only been practised in the west since the seventeenth century, when it was brought to Europe in 1683 by a Dutch man named William Ten Rhijne (5 However, due to clashes between the empirical science of Eastern Medicine and Western evidence based medicine, it was not until recent decades that acupuncture became accepted in the West (6). Acupuncture is the stimulation of special points on the body, usually by the insertion of fine needles (7), where as acupressure is a non-invasive technique that incorporates the principles of Chinese Medicine acupuncture (8). Acupressure has some practical advantages over acupuncture as it requires no equipment, is more accessible and is easily taught to patients, thereby enabling them to engage in holistic self-treatment (9).
Traditional Chinese Medicine (TCM) theory
According to the conceptual framework underlying Traditional Chinese Medicine, all life is seen as empowered by a life energy or basic force known as ‘Qi’ (10). Qi is thought to circulate between the organs of the body along channels known as meridians (7). There are 12 meridians that correspond to the12 main functions or organs of the body. Acupuncture points are located along these meridians and provide a means of altering the flow of ‘Qi’ (7). Illness and susceptibility to disease is associated with an imbalance of this flow of Qi (10). TCM believes that acupuncture can influence the flow of Qi within the meridians and change the balance of Qi (11), thereby restoring the body’s equilibrium and re-instigating a balance. The Taoist theory of Yin and Yang is central to Chinese philosophy, the Tao or the way is to align ones self with the ebb or flow of life, living in harmony with it (10). Ying and Yang are two aspects of Qi energy whose continual movement revolves in a constant interplay of balance. Although Yin and Yang are opposite forces they are interdependent, so when either Yin or Yang is out of balance, they necessarily affect each other and change their proportion and so achieve a new balance (12). When this internal correction of imbalance cannot take place, illness proceeds. Acupuncture or acupressure can then be used to restore equilibrium by altering the flow of Qi through the indicated meridian.
The sensation of DeQi is felt when an acu-point has been correctly stimulated by acupuncture (7). MacPherson and Asghar (2006) found that there were seven sensations found associated with DeQi: aching, dull, heavy, numb, radiating, spreading, and tingling. It was also highlighted that these sensations should not be confused for the ‘pain’ sensation felt at the needling site itself.
The implementation and rationale of acupuncture treatment in Western Medicine is based on neuron-anatomical principles of acu-point selection (14). From a western stance, acupuncture and acupressure can be thought of as a method to stimulate a variety of physiological functions back towards homeostasis (10).
In contrast to the TCM theory that acu-points correspond to meridians and can alter the flow of Qi, Western theory is founded on the physiologic evidence showing co-localisation of acu-points with peripheral nerves and trigger points. Studies by Melzach et al (1977) have found that the DeQi needle sensation could be stimulated in other areas, different to those specified along the meridians proposed by TCM. Hence Anderson (1993) brought into question the specificity of these points.
Although there are clear difference between TCM and Western theory, there remains considerable overlap (7). Wood (1993) found that while the ‘virtualist principles of TCM may have no direct value in explaining the physiological basis for acupuncture’ it was felt that they may have ‘considerable value in providing a credible model, which is acceptable to the patient’. Thus reinforcing the treatment effect. It was proposed that a shared therapeutic model involving TCM would greatly enhance the patient’s perception of the neuro-physiological effects.
Acupuncture and Lung function
It is thought that autonomic control of the airways can be gained through segmental innervation of the thoracic respiratory muscles (17). Therefore sympathetic activity may be modulated through somatic stimulation of afferents in these muscles. There is no evidence to suggest that the release of endorphins influences airway resistance, however it has been suggested that changes in the central control of the CVS could be paralleled by changes in the autonomic output to the airways (17). It is thought that the CV effects of acupuncture are mediated by central opioid activity through the beta-endorphin system. TCM has claimed the ability to favorably influence the course and symptoms of bronchial asthma; however published data on this subject is controversial (19).
It has been hypothesized that such stimulation can lead to bronchodilation, either by cholinergenic inhibition or adrenergenic stimulation of the beta adenergenic receptors found in the bronchial smooth muscle (Tashkin et al, 1977). Secondly, acupuncture is known to stimulate the release of endogenous opioids. In the past decade opioids have been implicated in the control of ventilation, as endogenous opioids and opioid receptors have been found in areas of the medulla oblongata and brainstem that are associated with respiratory control (Fung et al, 1986).
Yu and Lee (1976) hypothesized that acupuncture relieves the part of bronchoconstriction, which does not arise from the constriction of smooth muscle as a result of chemical mediators. They suggest that the effect of acupuncture is medicated through modulation of the reflex component of broncho-constriction. In comparison to the quality and quantity of research into the analgesic effect of acupuncture, far fewer studies have investigated the efficacy of acupuncture in respiratory conditions. A large proportion of trials conducted have investigated bronchial asthma, although few have met the scientific tests necessary to prove the effectiveness of such a treatment (21).
Taskin et al (1985) conducted a controlled trial of real and simulated acupuncture in the management of chronic asthma. Twenty-six subjects were randomized between TCM acupuncture and placebo. The intervention was administered in a subject and evaluator blind, cross over design, twice weekly for four weeks. Following a rest period of three weeks the groups were crossed over. No significant effect of either intervention was found on patient symptoms, medication use or lung function measurements in both the long and short term. These findings are supported by Malstrom et al (2002) who found no significant effect of TCM acupuncture on the airway status of asthmatic patients, in comparison to placebo.
However, Fung et al (1986) conducted a prospective, randomized study into the effects of real acupuncture (RA) and sham acupuncture (SA) on exercise induced asthma. This trial concluded that RA provided better protection against exercise induced asthma than SA. A study comparing the effects of real and simulated acupuncture and isoproterenol in metacholine induced asthma (25) found real acupuncture to have a greater effect than placebo but less of an effect compared to isoproterenol. Lewith et al (2004) conducted a study of 36 people, 33 of which had COPD, to evaluate the efficacy of standardized acupuncture treatment and was carried out on a domiciliary basis. Mock TENS was used as the placebo intervention. The results showed a clinically significant benefit from both treatments but did not show a specific efficacy of acupuncture in disabling nonmalignant breathlessness. Shapira et al (2002) trialed 26 patients with moderate persistent asthma who had been treated with inhaled beta2-agonists. They were randomized to receive 4 sessions of RA or SA in a blinded manner. The patients were crossed over after a wash-out period of 3 weeks. The results showed no statistical difference in FEV1, daily peak flow, provocative metacholine challenge or patient symptom scores.
In contrast, Maa et al (1997) studied 31 new patients beginning a 12-week pulmonary rehabilitation program (PRP) and randomized them between 2 groups. The first group was taught acupressure and practiced it daily at home for 6 weeks. They then performed sham acupressure for the following 6 weeks. Patients in group 2 performed acupressure and sham acupressure in the reverse order. The outcome measures used were patient dyspnoea, activity tolerance and functional exercise capacity. A visual analogue scale was used to assess dyspnoea. Maa et al (1997) concluded that acupressure was useful for patients with COPD as an adjunct to a PRP in reducing dyspnoea. It was also noted that the study raised awareness of TCM and that patients would accept self-administered acupressure as part of their self-care routine.
These findings are supported by Wu et al’s (2004) study of patients with COPD, which sought to compare the outcomes of acupressure using sham acu-points or true acu-points at different meridians and ganglionic sections. Both acupressure programs extended over 4 weeks with 5 sessions of 16minute treatments per week, giving a total of 20 sessions. Before the commencement of the study and after the 20th session, the Pulmonary Functional Status, Dyspnoea Questionnaire-modified scale and the Spielberger State Anxiety scale were administered. A six-minute walking test was also performed and physiological indicators of oxygen saturation and respiratory rate were measured before and after every session. Wu et al (2004) found statistically significant improvements in the outcome measures above in the real acupressure group in comparison to the sham acupressure group. However, a pilot study by Vickers et al (2005) that randomized 47 patients with lung or breast cancer who presented with dyspnoea, to receive true or sham acupressure in addition to their existing dyspnoea treatments, found no clinically significant difference in dyspnoea scores.
Methodological considerations in acupuncture trials
Many studies of acupuncture are seriously flawed by methodological problems (30). A fundamental problem concerns the difficulty in performing double blind trials as used in standard western scientific trials (31). To achieve a true double blind design would mean using a very inexperienced acupuncturist or someone who has not needled previously. This approach may lead to a poor technique and a large margin of error, therefore it has been suggested that a single-blind design with an independent assessor would be more appropriate. Another problematic area is that of placebo versus sham acupuncture controls. A true placebo is difficult to achieve considering the invasive nature of RA, the placebo needs to be non-invasive whilst also being credible to the patient (32). Sham controls involve invasive but inappropriate needling near to or distal from known acu-points. This prevents the elicitation of specific response whilst controlling for a range of non-specific physiological effects induced by needling.
Individualisation of treatment is a fundamental component of TCM; however design of western scientific trials does not easily accommodate such discrepancies between interventions. Hammerschlag (1998) found that this ‘may seriously under evaluate the efficacy of the treatment being assessed’. Essentially, many of the trials discussed were reduced to testing the insertion of needles at particular points (33).
The literature examined above offers by no means a clear verdict concerning the efficacy of acupuncture/acupressure in the treatment of respiratory conditions. Flaws in methodology have contributed massively to this problem. However with the introduction of the STRICTA recommendations in 2001 came a new era for acupuncture research. These recommendations sought to heighten the standards of research being conducted and ensure that they were reported in a clear, concise and accurate manner. The STRICTA recommendations are meant to be used in conjunction with the CONSORT statement, which addressed the general methodology of all RCT clinical trials (15). It was hoped this would facilitate validation of acupuncture research thus leading to better-informed practice.