Chapter 8 Congestive respiratory disorders
OVERVIEW AND AETIOLOGY
Congestive respiratory disorders are conditions that present with mucus build-up in the upper and/or lower respiratory tract. Rhinitis and sinusitis are the most common upper respiratory expression of congestion. Sinusitis is an inflammatory condition of one or more of the four paired paranasal sinuses.1 The condition may be classified by symptom duration (acute if < 4 weeks, chronic if > 12 weeks) or by aetiology (viral, bacterial, fungal or non-infectious).1,2 Chronic sinusitis is one of the most common long-term illnesses in the United States of America, where it affects approximately 14% of the population.3,4
Sinusitis presents with clinical features including:1,2
Sinusitis is usually bacterial in origin. Common organisms include Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes, other streptococci and Neisseria spp.1,5
Lower respiratory congestion is usually associated with an acute infection, or chronic obstructive process, either reversible (such as asthma) or non-reversible (such as chronic obstructive airways disease (COAD).6
RISK FACTORS
Key factors in the development of sinusitis are sinus obstruction and/or impaired ciliary clearance of secretions. Inflammatory polyps were found to be a cause of chronic frontal sinusitis (requiring frontal sinus surgery) in 53% of sinus surgery cases.5,7 Other local conditions that predispose children to rhinosinusitis include an URTI, swimming and diving, enlarged and infected adenoids, vasomotor disturbance leading to obstruction of drainage and deflection of the nasal septum.8
Chronic sinusitis is often a concomitant presentation with other forms of respiratory atopy, such as allergic rhinitis,9 and suppressive treatment of hay fever is hypothesised to lead to the development of chronic sinus inflammation.
Dietary factors are often suggested to contribute to excess mucus production. Dairy, wheat and corn have been proposed to promote a more globular mucus, disable sinus drainage and promote antigen exposure.10 While certain individuals may be predisposed to inflammatory responses with certain foods, the concept that some foods are universally mucus-promoting is an oversimplification of the process.11 In people who believe this, however, the consumption of such products does dispose them to greater subjective respiratory symptoms,11 demonstrating a potential psychosomatic component. (For risk factors for lower respiratory tract (LRT) congestion, see Chapter 6 on respiratory infections and immune insufficiency and Chapter 7 on asthma.)
CONVENTIONAL TREATMENT
The predominant conventional treatment of sinusitis centres on antibiotics to control infection and corticosteroids to reduce acute inflammation.10,12 Adjunctive treatments include topical and oral decongestants and antihistamines to reduce mucosal blood flow, decrease tissue oedema and perhaps enhance drainage of secretions from the sinus ostia.10,12 In chronic or unresponsive cases, nasal endoscopic surgery may assist in clearance of the sinuses, and restoration of mucociliary activity.13
While antibiotics are frequently prescribed, a Cochrane review of 49 studies concluded that they produced insignificant cure rates, with only a small treatment effect on patients in a primary care setting.14 (For conventional treatment of LRT congestion, see Chapter 6 on respiratory infections and immune insufficiency and Chapter 7 on asthma.)
KEY TREATMENT PROTOCOLS
Acute immune support and reduction of pathogens will also be necessary in the acute infection. If congestion is chronic or repeated, then longer-term immune tonics and adaptogens should be used in order to strengthen the resistance of the individual. In forms of congestion linked to atopy, antiallergic substances and those which modulate hypersensitivity can be useful.
Reduce congestion in the sinuses and airways
Blocked sinuses: steam inhalations, heat therapy and nasal irrigation
With chronic sinusitis it is important to liquefy the congested secretions in an effort to clear the sinus passages. Herbal mucolytics act to thin out mucosal secretions and make them easier to expel.15 Trigonella foenum-graecum16 is particularly useful, especially as a hot infusion, with the heat and steam being an integral part of the process. It is important to warn your patient that they should expect a nasal discharge to result, so they can plan the best time for the intervention. If they know, they are also less likely to take antihistamines, which would suppress the desired effect. Other mucolytic herbs to consider are Foeniculum vulgare, Allium cepa, Armoracia rusticana and Allium sativum.17,18
An additional category of herbs applied in the case of sinus congestion are upper respiratory tract anticatarrhals, such as Euphrasia spp., Plantago lanceolata, Sambucus nigra and Hydrastis canadensis.18 Anticatarrhals differ from mucolytics in that their action involves the reduction of mucus production, rather than simply breaking it down to expel.19 Few well-designed clinical trials were found to substantiate the effectiveness of these interventions, but they have a history of traditional use.18,20 H. canadensis is traditionally contraindicated in acute inflammatory conditions of the mucous membranes but may be used in subacute or chronic conditions.18 A combination of Gentiana lutea, Primula veris, Rumex spp., Sambucus nigra and Verbena officinalis is approved by Commission E to treat sinusitis and seems to exert mucolytic or anticatarrhal, antiviral and anti-inflammatory effects in a number of trials.21,22
Nutritional mucolytics may also be very useful when included in a supplement regimen. N-acetylcysteine (NAC) is perhaps the most researched and broadly used mucolytic.23,24 The sulfhydryl group works to cleave disulphide bonds in mucous glycoproteins, making nasal secretions easier to expel.25 NAC has demonstrated the ability to increase the mucociliary clearance rate by 35%, in comparison to no effect by placebo.26
Proteolytic enzymes, including bromelain, may also be useful. Proteolytic enzymes show an ability to break down the naked peptide region of mucous glycoproteins when applied topically.25 There have been questions surrounding the bioavailability of these agents upon oral ingestion, but studies show that ingestion of the compounds leads to appreciable increases in their serum concentration.28,29,30 In a number of trials
POSSIBLE FENUGREEK ALLERGY
One study has found that fenugreek seed powder may contain a number of potential allergenic proteins. In most cases, this reactivity seems to be due to cross-reactivity with peanut sensitisation.19,2 While true fenugreek allergy is unlikely to be a concern, practitioners should be aware of the potential for cross-reactivity when using this mucolytic agent in patients with peanut allergies.
conducted on patients with chronic sinusitis or allergic rhinitis, the administration of bromelain (in addition to individualised conventional treatment) produced significant improvements in parameters including nasal mucosal inflammation, overall symptoms, breathing difficulties and nasal discomfort.30–32
One of the longer-standing traditional remedies for blocked sinuses and nasal congestion has been the inhalation of steam. Often this is with an additive (see below). Studies are mixed on the use of hot, moist air alone, with some positive trials33,34 and others showing no effect greater than room-temperature air.35,36
The ‘old wives’ tale’ cure of chicken soup may not be such a myth. The inhalation of hot air (from hot water) is known to help clear nasal congestion,35,36 but research has shown that hot chicken soup is more effective than hot water.37 The addition of aromatic spices and culinary herbs will also help to open up the nasal passages and clear secretions.38 As an additional benefit, the liquid component inhibits neutrophil migration, possibly helping reduce symptoms in infection.38
The use of botanicals may improve therapeutic effectiveness of steam inhalation. For example Commission E supports the use of inhalation of Matricaria recutita for inflammation and irritation of the respiratory tract.21 The essential oils of Cinnamomum zeylanicum, Thymus vulgaris, Mentha piperita, Perilla frutescens, Cymbopogon spp. and Eucalyptus spp. have demonstrated antibacterial activity against common respiratory pathogens through vapour contact, and thus may also be of use.39–41 One of the most common inhalants is eucalyptus oil; when administered via inhalation or as a chest rub, it has demonstrated ability to reduce nasal congestion and improve breathing function in those with respiratory infection.40,42 A German product combining cineol, limonene and alpha-pinene also has great efficacy in treating purulent mucosinusitis.43 These are constituents of many essential oils including Mentha piperita, citrus oils, Anethum graveolens, Pinus spp., Piper nigrum, Eucalyptus spp. and Melaleuca cajuputi.44 Other common inhalations include Mentha piperita, Lavandula spp., Pinus sylvestris, Melaleuca alternifolia and Rosmarinus officinalis.45 As an extension of this principle, local application of heat more generally has also been shown to alleviate the symptoms of allergic rhinitis.46,47
Nasal irrigation is another natural method of clearing sinus congestion. The origins of this technique lie in yogic and homoeopathic traditions.48,49 Jala neti is a Hatha yoga technique of pouring water in through one nostril using a neti pot so that it pours out the other. The method is believed to be an essential part of health maintenance, and is recommended three or four times a week.50,51 There are a number of positive trials of nasal irrigation among people with allergic rhinitis or chronic sinusitis.52 A Cochrane review in 2007 reported that nasal irrigation could improve the symptoms of chronic rhinosinusitis in the majority of patients, with few adverse effects.49 Benefits are derived not solely from the initial mechanical clearance of the airways, but also due to the physiological benefits of topical saline (sodium chloride), which has been proposed to improve mucus clearance, enhance ciliary beat activity, remove antigens, biofilm or inflammatory mediators, and to be protective of the mucous membranes.49 Sodium bicarbonate is also mucolytic in nature and may therefore be useful in nasal irrigation.53
One method of nasal irrigation is suggested in Figure 8.1, but there are many slight variations, and it is recommended that the practitioner become comfortable with their chosen technique themselves first before recommending it to others. It should also be noted that bulb syringe irrigators have been found to be a potential source of contamination in rhinosinusitis,54 so attempts should be made to ensure the cleanliness of the equipment and procedure.
Phlegm and cough
With regards to mucus congestion and cough, a number of different treatment strategies may be used. Dry (non-productive) or particularly severe coughs can benefit from suppression with an antitussive agent. Otherwise, although it may be annoying, it is best not to suppress the productive cough reflex, as it helps to clear infectious organisms from the airways.55
Mucolytics and anticatarrhals may also be of use where there is a great deal of phlegm, mucus and/or congestion present. These agents will help to reduce catarrhal congestion of the upper or lower respiratory system. As with mucolytic pharmaceuticals, their mechanism of action is not fully understood, but they may act by altering the mucopolysaccharide structure of mucus, decreasing its elasticity or viscosity.24
Herbal medicines with demulcent action may help to reduce a cough if it is a reflex response to hyperactive or irritated receptors in the oropharynx.55 Treatments used in Western herbal traditions for productive cough include Thymus vulgaris, Glycyrrhiza glabra, Lobelia inflata and Polygala senega.21 Additionally, Verbascum thapsus, Tussilago farfara and Althaea officinalis are marked demulcents and antitussives indicated for dry or unproductive coughs.21 Some herbs, such as Prunus serotina, are primary antitussives; however, caution needs to be applied when prescribing these as they can suppress a cough despite there being mucus to expectorate. This may potentially exacerbate an acute respiratory infection.
Glycyrrhiza glabra is approved by Commission E to treat upper respiratory catarrh and cough.21 In addition to its expectorant and antitussive actions, G. glabra has anti-inflammatory, immune-enhancing and mucoprotective effects, the traditional reason behind its use in respiratory tract infections. The herb has demonstrated antitussive effects in animal studies, most likely due to the component liquiritin and its metabolite, liquiritigenin.58 Thymus vulgaris has been used successfully in a large trial for the treatment of bronchial cough.59 It demonstrates an ability to improve mucociliary clearance in vivo, although the mechanism remains to be elucidated.60 In conjunction with the herbs Sambucus nigra, Primula veris, Rumex acetosa, Verbena officinalis and T.vulgaris Gentiana lutea, the extract demonstrated ability to reduce the frequency of symptomatic coughing fits.61,62 It is also traditionally recommended for use in respiratory tract infections as an extract or gargle due to its antimicrobial and antitussive qualities.21,57,63
In the case of productive cough, Inula helenium is another key herb to use, due to its combined effects as a stimulating expectorant and antibacterial agent.64 Given that it contains a high level of mucilage, it also contributes to soothing the mucous membranes, thus covering a wide range of the required therapeutic actions. It is also a respiratory spasmolytic that is well tolerated in long-term therapy.59 Traditional eclectic texts purport Althaea officinalis to be useful in the case of catarrh or irritated mucous membranes.17,65 The polysaccharide constituent has demonstrated inhibition of coughs caused by laryngopharangeal and tracheobronchial irritation.66 New research indicates a relatively pronounced antibacterial effect (stronger than that of Thymus vulgaris) on various strains of E. coli, exerted via inhibition of microbial metabolism.67 Althaea officinalis is more indicated for an irritating than a congestive cough.21
Adhatoda vasica is mentioned in the Vedas for treatment of a number of respiratory illnesses, and is also listed in the Pharmacopoeia of India.68 Extracts of the aerial parts administered orally exhibit the ability to inhibit both mechanical and chemically induced coughs.68 When this treatment was combined with Echinacea spp. and Eleutherococcus senticosus extracts in clinical trials, it produced additive benefits in treating URTI.69 Patients showed greater improvement in many of the parameters tested, including severity of coughing, frequency of coughing, efficacy of mucus discharge in the respiratory tract, nasal congestion and general feeling of sickness.69
Inhaled preparations containing menthol, such as eucalyptus oil, have shown the ability to significantly increase tracheobronchial clearance of mucus from the lungs70 and help to reduce cough.71
As discussed above, nutritional mucolytic agents such as N-acetylcysteine and proteolytic enzymes may be useful in LRT congestion. Dietary treatment should also be employed. Allium spp. is an antimicrobial, expectorant, mucolytic and anti-inflammatory agent.57 The respiratory system is one of the main systems to benefit from the antimicrobial action of its volatile oil, as it is excreted from the lungs. Culinary herbs such as Pimpinella
CHRONIC OBSTRUCTIVE AIRWAYS DISEASE
Overview
Chronic obstructive airways disease (COAD) or chronic obstructive pulmonary disease (COPD) includes emphysema and chronic bronchitis. Unlike asthma, the airflow obstruction is only partially reversible, and the disease process is progressive and irreversible.72 Airflow obstruction is usually associated with abnormal inflammation of the airways, parenchyma and pulmonary vasculature in response to chronic inhalation of noxious particles or gases.5,72,73
COAD is diagnosed when a patient has spirometry readings of:
CAM interventions
Mucolytics and anticatarrhals: Trigonella foenum-graecum, Plantago lanceolata, Hydrastis canadensis, Foeniculum vulgare, Allium cepa, Armoracia rusticana, Allium sativum, N-acetylcysteine, 80,23,81 bromelain, trypsin, papain and aromatic inhalants.82
Anti-inflammatory: Boswellia serrata, Curcuma longa, Zingiber officinale, omega-3 fatty acids, quercetin, fish, antioxidant foods (fruit and vegetables) 83–8527 and possibly antioxidant nutrients,7,86,87 Camellia sinensis.85
Bronchodilating: Adhatoda vasica, Euphorbia spp., Coleus forskohlii, Grindelia camporum, Glycyrrhiza glabra, magnesium88 (dietary and supplemental).
Mucous membrane trophorestoratives: Hydrastis canadensis, vitamins A and C, zinc, selenium, adequate protein intake.89
anisum, Foeniculum vulgare, Trigonella foenum-graecum and Zingiber officinale are warming expectorants and can be incorporated into treatment, either in food or as hot beverages.57
Reduce microbial colonisation
Herbal antimicrobials (encompassing antivirals, antibacterials and antifungals) differ from some pharmaceutical products in that they usually exert a biocidal or bacteriostatic effect on the pathogen rather than being directly cytotoxic. Biocidal agents act via a number of mechanisms, at a number of different target sites in the cell. The combined overall activity seems to result in the bactericidal death of the microbe.90 According to Maillard, when used at lower doses, biocides exert a bacteriostatic effect, inhibiting the growth and colonisation of a pathogen.90 Although more research is needed in the area, it seems that herbal agents (given at the right doses) exert a bacteriostatic, rather than a cytotoxic or even biocidal, effect.
While there are many individual constituents which have been identified as antimicrobial, whole plant extracts remedies seem to be more efficacious at clearing pathogens due to synergism between components.91 For further information on plant compounds and their antimicrobial efficacy, see Table 8.1.