Adult Asthma

Asthma is a disease of the tracheobronchial tree, in this disease the airways are hyperresponsive to a stimuli(s) and exposure to this stimuli(s) causes an acute inflammatory response in the tracheobronchial tree which obstructs airflow. Asthmatic airways are also chronically inflammed. this chronic inflammation can cause structural changes to the tracheobronchial tree a proccess called remodelling.



Acute Asthma/ Exacerbation of Asthma (coq. Asthma attack)

Many people with asthma have airways that are hyperresponsive to one or more simuli, stimuli which would have little to no effect in normal lungs. These stimuli can be proteins (from pollen, animals)/ temperatures/ exercise and will differ from asthmatic to asthmatic.

Pathophysiology

If an asthmatic is exposed to a stimuli that their airways are hypersensitive to an inflammatory reaction to the stimuli will be elicited in their airways. This inflammatory response commonly consists of, infiltration into the wall and lumen of the airway with eosinophils and T cells, vasodilation of bronchial blood vessels which become leaky leading to oedema, increased mucus production into the lumen of the airway, bronchospasm. This inflammatory response causes airflow obstruction  This airflow obstruction caused by reduced lumen of the airways causes the airflow to become more turbulent. 

This shows symptomatically as an audible wheeze, audible to ear and to auscultation with a stethoscope. The airflow obstruction also gives the patient a sensation that their chest is tightening. It can also cause dyspnoea (shortness of breath) if it is severe enough to reduce adequate ventilation to the alveoli, and subsequently cause hypoxia. The cough is a product of increased mucus production and the inflammation irritating the sensory nerves around the airways. 

An acute attack of asthma can develop over minutes/hours and even days. Some resolve spontaneously  others will be fatal unless medical attention is sought urgently.



If someone is having an asthma attack they are often advised to 
1. Immediately take one or two puffs of their blue salbutamol (coq. reliever) inhaler
2. Sit up and take slow deep breathes
3. Take two additional puffs of their inhaler if they still feel like they are having an attack and to repeat this every two minutes
4. To call 999 if they feel that their inhaler isn't improving their symptoms or that they are getting worse



Assessment


Initial Assessment is with ABC (Airway/Breathing/Circulation). Below are some specific signs/symptoms and investigations for acute attacks of asthma. Patients can deteriorate rapidly with asthma. 

Assuming the deterioration of the patient is caused by asthma, only one sign/symptom in one of the boxes in the left is required for the patient to have that grade of acute asthma. (e.g. a Patient with PaO2 of <8 but with a Peak Expiratory Flow (PEF) of 40% has 'LIFE THREATENING ASTHMA' and should be treated accordingly)

Chronic Asthma

Asthma can often be treated successfully in the community. 

Initial Assessment


Hx

•  Episodes of Wheeze (often worse in the morning and at night) 
•  Cough/ Shortness of Breathe/ Sensation of chest tightness
•  There may be a suspected trigger of said episodes
•  Atopy (Eczema/ Allergic Rhinitis)
•  Family Hx of asthma and atopy
•  Smoking 
•  Occupation
•  Relationship of 'attacks' to potential allergens/triggers 

Ex

•  Wheeze on auscultation
•  Tachypnoeic
•  May have no signs at all
•  Spirometry FEV1/FVC <70% suggests an obstructive airway disease

A normal spirometry when the patient is asymptomatic doesn't exclude asthma as a diagnosis

After the initial assessment you should use your clinical judgement to decide how likely it is that the patient has asthma. 

If it's highly likely then you can start the patient on step one, or whatever step you deem most appropriate according to the severity of the patients symptoms. Arrange to review the patient in the near future to see if the medication is working and if the diagnosis of asthma is still probable.

If you're not quite sure a patient has asthma further tests may be warrented, this can involve teaching the patient how to use a peak flow meter, and asking them to keep a log book of peak flow readings that they can do themselves at home. Other investigations are listed below

Investigations       

• Peak flow measurements
• Asking the patient to maintain a logbook of peakflow measurements
• Spirometry FEV1/FVC < 70% of predicted suggests obstructive airway disease
• Bronchodilator reversibility testing

Management
         
Management of chronic asthma is based upon the concept of control, that is controlling the symptoms of asthma and preventing exacerbations so that the asthma affects the patients quality of life as little as possible.

A stepwise approach is recommended in treating asthma in the community. The patient is put on a certain step according to the severity of their symptoms on initial assessment. The patient should then be reviewed fairly regularly to assess the level of control. To assess level of control you can ask questions based around the six points listed on the left. If the patient has good control you may want to consider going down a step on the treatment algorithm. This is especially true if the patient is on ICS due to the harmful effects long term use of this class of drugs can illicit. If the patients control is poor it is important to assess the patients compliance with the medication and their inhaler technique. If satisfied with such you may want to consider stepping up on the treatment algorithm.  This algorithm and the six points of good control were developed by SIGN.
         

      

It is also recommended that all asthma patients receive a personal action plan. This play details what the patient should be doing on a day to day basis as well as what they should do if they have an acute exacerbation of their asthma.



Medications of asthma

Occupational Asthma

Is a variant of normal Chronic Asthma in which the trigger for the exacerbations of asthma originate at the persons place of work.

Hx  -  The classic question is 'does your asthma improve when you are on holiday/ away from work', an affirmative answer is suggestive of occupational asthma 

Due to the compelxities of finding the specific antigen and the socio-economic complexities for the patient and employeer requires a referral to a specialist.