ASTHMA
Asthma is commonly encountered in the long case, and a thorough grasp of the principles of asthma management is essential.
Definition
Asthma: reversible, inflammatory airways disease. Inflammation could be mediated by eosinophils or other cells (lymphocytes and neutrophils).
Case vignette
A 28-year-old female patient has been admitted with fever, chills and rigors. She also has a productive cough and pleuritic chest pains. She has been recently diagnosed with asthma.
She smokes 5–10 cigarettes a day. She works in a bakery and describes symptoms of rhinorrhoea and wheezing while at work and after work. She has been prescribed an inhaler by her GP, but has not been compliant. On examination her temperature is 38°C and respiratory rate 20. Her oxygen saturation is 88% on room air. There are diffuse polyphonic wheezes in the lung fields, with bronchial breath sounds in the left mid to lower zone. Her sputum mug shows rusty purulent sputum.
Approach to the patient
History
Symptoms of chronic cough, especially nocturnal cough, wheezing and complaints of chest tightness, can be clues to consider asthma in the list of differential diagnoses in the dyspnoeic patient. In the known asthmatic, there are some questions that should invariably be asked.
Ask about:
• the current asthma management regimen, and frequency of bronchodilator use. Check whether the patient is using a bronchodilator at an unusually high frequency.
• what the known precipitants of asthma attacks are and how often the patient experiences exacerbations
• whether the patient has ever been hospitalised or treated in the intensive care unit for exacerbation of asthma
• whether the patient has a nocturnal cough
• whether the patient monitors their airway function with a peak flow meter at home. If they do monitor the peak flow, ask how often it is performed and the usual and most recent readings.
• the variability of the peak flow meter readings before and after bronchodilator therapy. Persistent variability is indicative of poor disease control.
• seasonal variation of symptoms and association with exercise
• whether an allergist has been consulted or special tests for allergy (skin prick test and radioallergosorbent (RAST) test) have been performed
• corticosteroid use—how often the patient is prescribed oral steroids, the maximum dose and the minimum dose ever, and the side-effect profile the patient has experienced
• how this chronic condition has affected the patient’s day-to-day life and occupational activities.
Examination
The patient who has had poorly managed asthma since childhood may show evidence of stunted growth. Observe for evidence of dyspnoea and tachypnoea. Notice whether the patient is using accessory muscles for breathing. Check whether the patient has the fine tremor induced by beta agonist therapy. Feel for tracheal tug. Look for evidence of cyanosis. Do not forget to look for evidence of chronic systemic steroid use, such as easy bruising, ecchymoses, cushingoid body habitus and cutaneous striae. Listen to the lung fields for polyphonic wheezes. Perform forced expiratory timing.
Management
The candidate should formulate an ideal ‘asthma management plan’ for every poorly controlled or newly diagnosed asthmatic patient. Two of the most common causes of poor asthma control are non-compliance with medications and poor inhaler technique. Therefore it is important to ascertain the patient’s level of drug compliance and to ask about the inhaler devices used. Elements of a good asthma management plan are as follows:
2. If control is very poor, with frequent exacerbations and frequent bronchodilator use (daily or several times a day), a course of oral corticosteroids together with high-dose inhaled steroids should be commenced. Oral steroids should be tapered and stopped as soon as disease control is achieved.
3. When the level of disease control is suboptimal despite maximum inhaled corticosteroid therapy, an inhaled long-acting beta2 adrenergic receptor agonist such as salmeterol or oxymeterol should be commenced. Combined preparations of inhaled steroids and long-acting bronchodilators are becoming increasingly popular due to their convenience of use, thus improving compliance.
4. Short-acting bronchodilators should be used only in paroxysmal exacerbations of the disease.
5. In special situations, when the level of control is still poor, leukotriene inhibitors and theophylline should be considered as possible additions to the regimen. Leukotriene inhibitors have shown particular benefit in exercise-induced asthma and aspirin-sensitive asthma.
The patient should be given a good insight into his/her disease condition and taught the proper techniques for using an inhaler device. Referral to an asthma educator would be a wise step. Particularly in young and relatively young, active patients, it is important to make an assessment of how the disease affects their day-to-day lives as well as occupational, educational and social activities.
6. Provide the patient with an asthma self-management plan (see box). Such plans have shown benefit to the adult patient with asthma. The plan should include instructions to the patient on how to self-adjust medications according to the symptoms.
7. All asthmatics should be immunised against seasonal influenza and pneumococcal pneumonia.
Asthma self-management plan
One objective of the asthma action plan is to educate and empower the patient to assume some control over the management of this chronic condition. The plan should be able to educate the patient on how to recognise worsening of symptoms and signs of impending danger. The plan should be in writing and individualised to the patient. It should carry the following information:
• the patient’s peak flow readings when stable, when symptomatic, during exacerbations and also when there is a danger of very severe exacerbations
• preventer and reliever medication dose requirements during the abovementioned stages
• instructions on self-adjusted dose increments during exacerbations (up to a maximum dose) and dose decrements when feeling better
• clear instructions on seeking urgent medical help when in danger
• contact details of the doctor and the pharmacist in case the patient needs further assistance.
Candidates should be familiar with the different inhaler devices, as some patients know their inhaler device or the medication in it only by its colour and shape (Fig 4.1). Therefore, during the preparation period the candidate should consult the hospital asthma educator or the asthma nurse consultant for further information on the various inhaler devices and become familiar with the proper techniques for use. Candidates should be able to interpret formal lung function study reports quickly and accurately.
Drugs used in asthma
Asthma medications are broadly classified into two categories based on their clinical effects. The first category is the group of medications that improve symptoms (relievers) and the second category prevent exacerbations (preventers).
• Relievers—are short-acting beta2 agonists such as salbutamol, terbutaline, and long-acting beta2 agonists such as efemetorol. Tiotropium and ipratropium bromide are inhaled anticholinergic bronchodilator agents with a slower onset of action. Theophylline, which is capable of relaxing bronchial smooth muscle, is also used to treat severe and acute exacerbations of asthma. However, due to its wide adverse effects profile (nausea, diarrhoea, arrhythmias) it is rarely used these days.
• Preventers—include inhaled corticosteroids such as beclomethasone, budesonide, fluticasone and ciclesonide. Other preventers are leukotriene receptor blockers (montelukast) and cromoglycates (mast cell stabilisers).
– Inhaled corticosteroids have proven benefits in reducing exacerbations, reducing mortality and recurrent hospital admissions. These agents are known to improve overall quality of life in chronic asthmatics. However, long-term high-dose therapy with topical corticosteroids can bring about systemic adverse effects such as cataracts, osteoporosis, glaucoma and cutaneous fragility.
– Cromones such as nedocromil sodium and sodium cromoglycate are capable of preventing early and late bronchoconstrictor reactions to allergen exposure and therefore have particular use in seasonal allergic asthma. They have shown benefit in the prevention of exercise-induced asthma. Nedocromil is useful in the treatment of asthma-associated cough.
Occupational asthma
Occupational asthma is a common occupational morbidity and is quite likely to be encountered in the long case setting. It is a diagnosis in cases of adult-onset asthma.
Approach to the patient
Ask about the patient’s occupation, precise onset of symptoms, diurnal patterns of symptoms and occupational exposure related rhinitis or rhinoconjunctivitis in the past. The patient may report improvement in symptoms outside the workplace. Ask about cigarette smoking, which is known to exacerbate the condition. Most cases of occupational asthma are due to immunoglobulin E (IgE)-mediated immunological response. This form of occupational asthma has a characteristic latency prior to the onset of symptoms after exposure.
Investigations
Occupational asthma is usually investigated by performing serial lung function measurements before and after exposure (at work and away from work on repeated occasions). Serial measurement of peak expiratory flow rate (PEFR) may provide useful information but lack diagnostic accuracy. Referral to an immunologist for blood or skin prick testing for specific IgE may enhance definitive diagnosis.
Management
Early and adequate management of occupational asthma is of prime importance, because failure to control the disease early can lead to a very poor prognosis. The management plan should involve an occupational health physician. Respiratory protective gear, when used properly, helps reduce the risk of occupational asthma but does not prevent its onset. Complete avoidance of allergen exposure is an important first step. Medical management is similar to that of standard asthma management. Remember to discuss the patient’s job and financial issues and also possible worker’s compensation claims (if relevant in the jurisdiction).
Chronic severe asthma
A minority of patients may have recalcitrant disease with hallmark features of frequent severe exacerbations requiring hospitalisation, significant associated morbidity, resistance to commonly used anti-asthma agents and significant steroid dependency. In addition to high mortality rates this patient group suffers from significant drug adverse effects and places a major (disproportionate) burden on the healthcare budget. It is important to ensure that these patients are properly worked up and investigated to exclude non-compliance or missed other diagnoses that could be contributing to the situation.
The management objectives in the patient group are reduction in the number of hospitalisations, steroid weaning and restoration of productivity. Some may respond to very high-dose inhaled steroids such as fluticasone or very high-dose long-acting beta agonists. Other agents that could be used in this setting include cyclosporine, gold and methotrexate. The efficacy of the latter is variable and fraught with significant adverse effects.
CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)
Chronic obstructive pulmonary disease (COPD) or chronic airflow limitation (CAL) is an extremely common long case pathology.
Definition
Chronic obstructive pulmonary disease: irreversible airways disease that incorporates chronic bronchitis, emphysema and chronic asthma with fixed airflow obstruction.
Approach to the patient
History
In the history of patients with known or suspected chronic airflow limitation, enquire about current or previous smoking, occupational exposure to fumes, dust and gases, environmental exposure to such agents and any family history of lung disease. The smoking history (including marijuana) has to be comprehensive and detailed. Also ask about chronic sputum production, wheezing, dyspnoea and the level of effort tolerance. Cardiac disease is common in this patient cohort, and therefore it is important to enquire extensively into this and obtain details.
Examination
Look for tar-stained fingernails, cyanosis, pursed-lip breathing, barrel-shaped chest, subcostal retraction, decreased breath sounds and wheezing on unforced expiration. Particular attention should be focused on excluding a fixed wheeze, which could suggest the presence of a bronchial tumour. Look for evidence of cor pulmonale: elevated JVP, peripheral oedema, parasternal heave and a loud P2.
Smoking-associated comorbidities in patients with smoking-related lung damage (COPD)
• Ischaemic heart disease
• Peripheral vascular disease
• Recurrent respiratory sepsis
• Lung carcinoma
• Carcinoma of head and neck
• Carcinoma of the bladder
• Carcinoma of the oesophagus
• Carcinoma of the colon
• Renal carcinoma
• Peptic ulcer disease
• Sexual dysfunction in men
• Osteoporosis in women
• Secondary polycythaemia
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