Allergy, Asthma | March 1, 2016 | Author: The Super Pharmacist
Asthma is a condition in which patients experience breathing difficulties and other adverse symptoms related to lung function. It is associated with the increased presence of immune cells and molecules that promote the release of inflammation1. This adversely affects tissue structure and function over time, and contributes to the production of mucus in the lungs. Another important factor of asthma progression is the increased contraction of the smooth muscle in the tubes leading from the mouth and nose to the lungs2. It has been demonstrated that, in asthma patients, this muscle tissue exhibits many differences in comparison to that of normal healthy individuals2. These may include:
These factors may contribute to the increased airway stiffness seen in asthma2. In addition, patients with asthma may be subject to varying levels of constriction in smooth muscle along different section of the airways, (or bronchi) whereas ideally this musculature should contract and relax in a harmonious, synchronised manner to facilitate breathing2. This is also thought to contribute to asthma attacks2. These major factors as above interact to produce symptoms of asthma such as attacks of bronchial constriction, 'wheezing', coughing and the accumulation of mucus in the airways, which patients may feel compelled to expel by coughing (with varying degrees of success)3. Asthma is linked to decreases in quality of life, and other adverse effects such as the increased probability of depressive disorders4. It may become a chronic condition, which requires consistent or increasing levels of treatment and/or healthcare resources4.
Treatments for asthma include3,5-8:
Some types of asthma may be due to infection by micro-organisms such as bacteria. These may stimulate an immune response which leads to inflammation. In these cases, antibiotics may be administered to destroy them. However, bacteria may become resistant to these antibiotics over time. Therefore, the same antibiotic may not kill the same infection if it returns. Long-term or large-dose administration of antibiotics increases the risk of resistance. Therefore, they are not always suitable for use in chronic conditions.
This is the mainstay of asthma treatment, as it is demonstated to be the most effective at reducing and preventing serious complications of asthmatic attacks. Drugs may be prescribed to treat chronic asthma; these include corticosteroids, which inhibit inflammation, Beta-agonists, in forms which can be inhaled, act to promote the relaxation of bronchial smooth muscle. These medications are associated with rare side-effects such as nausea, vomiting, anxiety, changes in emotional or behavioural states, insomnia and immune system suppression. Drug administration over extended periods of time also increases the risk of tolerance and more serious adverse effects.
These are treatments that act to correct or reduce the various physiological mechanisms by which immune reactions are overactive in many cases of asthma. These may mimic certain proteins that play roles in these processes, or bind to others. They may promote immune reactions that result in the inhibition of those that result in inflammation. Some forms of immunotherapy, such as vaccines, are relatively well-established, whereas novel molecules such as DNA fragments are still in development. As many forms of immunotherapy stimulate immune responses themselves, this increases the risk of hypersensitivity, or allergic reactions, to their administration. These reactions may range from itching or respiratory discomfort to anaphylactic shock, which may be fatal.
Patients with severe, chronic, treatment-resistant asthma may consider surgery to correct airway constriction. One such surgery is bronchial thermoplasty, in which some smooth muscle is removed. Surgery may result in complications such as respiratory infection, tissue damage and treatment failure. It may also entail reliance on drugs such as corticosteroids after the procedure. As outlined above, even though they may be associated with effective treatment of symptoms and improvements in quality of life for many patients, some treatment options, particularly surgery, may also be associated with disadvantages such as the increased risk of hospitalisations and a short-term increase in the rate of the recurrence of intensified symptoms8. Therefore, many patients may prefer to try alternative options that may improve lung and airway function before surgical intervention becomes necessary.
Training in breathing techniques are an example of alternative therapies in asthma management. This involves training and/or education in the improvement of control over breathing. This may confer a better approach to attacks of bronchial constriction. Breathing techniques may also improve various components of lung function, such as lung volume. A review and meta-analysis of 13 studies of breathing techniques for adults with asthma including over 900 participants found a tendency towards demonstrable benefits of this therapy9. However, many of these used outcomes, variables or analysis too different to each other to compare adequately. Six of these studies found significant differences in lung function, whereas five others reported no differences9. A meta-analysis of two studies measuring the same outcome showed a significant improvement in asthma symptoms and life quality when breathing techniques were employed9. This analysis may also have been affected by the different types of breathing technique therapies available. These may include:
These are usually taught by a practitioner such as a physiotherapist, and focus on the control of exhalation, pacing of breathing and patient education. The goal of this treatment includes the improvement of the functional residual (or post-exhalation) capacity of the lungs, which is reduced in conditions such as asthma10. This may result in the effective control of asthma, but observations in support of these techniques may be affected by the often-impressive variability in asthma symptoms10. In other words, improvements attributed to breathing technique training may be in fact due to the remission of asthma symptoms, other interventions such as drug therapy, or an incidental temporary reduction of symptom severity10.
This breathing technique focuses on nasal breathing (breathing through the nose). This, according to the physiologist who developed the method, is linked to decreases in the content of infectious material, environmental irritants and other material (which may result in an attack), taken into the lungs. Nasal breathing may also result in the optimal temperature and humidity of air travelling to the lungs11. However, few clinical trials have found any significant efficacy of the Buteyko method12. Some were not adequately controlled and/or showed only a vague trend toward improvement10. One trial randomised 129 patients to the Buteyko method or standard breathing techniques for six weeks. The group practising the Buteyko method showed improvements in asthma control, from 40% to 79%. However, the control group had a similar change, from 44% at the start of the study to 72% at its completion. The reliance on corticosteroid use was significantly reduced in the Buteyko group10.
Yoga is a traditional Asian practise that trains various aspects of the body and mind with the goal of improved function, flexibility and conditioning. Some sub-types of yoga focus on breathing techniques to elicit optimal lung function and relaxation. One of the more prominent of these is prana-yama. This can be done through training and practice, and can also be replicated using devices such as the Pink City exerciser. A trial randomised 120 patients to prana-yama, the Buteyko technique (3-5 days of training for each method) or conventional drug therapy for three months. The Buteyko method was found to be associated with significant improvements in quality of life assessment scores compared to those of the prana-yama or control groups13. Another trial randomised 69 patients taking corticosteroids to prana-yama, the Buteyko method or a placebo for six months. The Buteyko method reduced median symptom scores and additional inhaler use compared to the other two groups. However, neither intervention had a significant effect on lung function, asthma attacks or corticosteroid use.