Bronchitis

 

What is bronchitis?

When air enters the lungs, it travels first down the main breathing tube called the trachea, which then divides and divides further into smaller tubes called bronchi. The bronchi themselves divide a multitude of times into airways called bronchioles and finally into minute sacs called alveoli, where oxygen is transferred into the blood and the waste gas, carbon dioxide, is removed from the blood to be breathed out. Infections in the throat and trachea are called upper respiratory tract infections. Infection in the very small tubes and alveoli of the lungs is called pneumonia, whereas an infection in the bronchi (ie in the middle-sized tubes of the lungs) is called bronchitis.

There are two main categories of bronchitis; acute bronchitis and chronic bronchitis. These are very different from each other and will therefore be dealt with separately.

What is acute bronchitis?

Acute bronchitis is usually a fairly minor illness that causes symptoms for a relatively short period of time, such as a few days. It either resolves on its own or with antibiotic treatment, without leaving any obvious long-term consequences.

What causes acute bronchitis?

Most cases of acute bronchitis are actually caused by viruses, which are germs that float in the air that are then transmitted from person to person by 'droplet spread' (ie coughing and sneezing or human contact). They are the cause of most minor illnesses such as colds and flu. Viruses are not affected by antibiotics, but are nearly always killed by the body's own defense mechanisms. Sometimes other types of germs called bacteria will cause bronchitis. In these cases antibiotics may be given in order to kill the infection.

 

Why does it occur?

This is more difficult to answer but generally speaking the person concerned will pick up the germ from the air. Following this, the infection multiplies in the bronchi of the lungs. People are more susceptible to contracting bronchitis if their lung defences are low, such as in cigarette smokers, the elderly or those people who are unwell for another reason such as chronic illness.

What are the symptoms of acute bronchitis?

Most people with acute bronchitis will have a persistent cough and a fever. If the cough produces green or yellow sputum (phlegm) it may signify that the germ is a bacterium rather than a virus. When the doctor listens to the chest he may hear wheezing or crackling within the lungs.

 

What is the treatment?

If the germ causing the bronchitis is a virus, the only treatment consists of drinking plenty of fluids and taking regular Paracetamol or Aspirin to control the temperature and soothe any aches and pains (Aspirin should not be used under the age of 16). If the illness is particularly bad and involves the production of sputum, then medical advice should be sought. An antibiotic may be prescribed if the doctor thinks the causative germ is a bacterium. It is worth noting that most illnesses referred to as "chest infections", including those in children, are non-serious infections caused by a virus which will be killed easily by the body's own defence mechanisms. Medical advice and antibiotics are only required in bad cases or those not getting better on their own. Studies of the use of antibiotics for acute bronchitis have found that, in general, they shorten the symptoms by an average of half a day only. This almost certainly reflects the fact that most cases of acute bronchitis are caused by a virus and will therefore be unaffected by antibiotics.

What are the consequences?

In most cases there are no long-term consequences following an episode of acute bronchitis. However, each episode causes a certain amount of inflammation of the bronchi. If someone gets repeated episodes of acute bronchitis (especially bacterial bronchitis) and especially if they are a smoker, this inflammation may start to damage the lungs and can eventually lead to chronic bronchitis.

 

What is Chronic bronchitis?

Chronic bronchitis is a condition that involves chronic inflammation of the bronchi in the lungs, resulting in excessive production of mucus. This in turn leads to recurrent infections that eventually cause damage to the walls of the bronchi. They become narrow and therefore cause obstruction to the passage of air through the lungs. A condition called emphysema often occurs at the same time as chronic bronchitis. This is caused by damage (usually from cigarette smoking) to the small sacs (alveoli) at the ends of the tiny lung passages. Since the two illnesses often appear together and because they give similar symptoms, they are usually grouped together and called chronic obstructive pulmonary disease (COPD) which is now the modern term for what used to be called chronic bronchitis.

What causes COPD?

Cigarette smoking is the most common cause of COPD. By causing long-term damage and irritation to the lung passages, cigarette smoking eventually results in a situation of chronic inflammation and narrowing of the airways of the lungs with permanent damage and scarring of the tissues of the lungs. Some people are also born with a tendency to COPD because they lack a particular enzyme in their lungs called 'alpha 1 anti-trypsin', although this is a fairly rare condition. Other factors that contribute to COPD are air pollution and certain occupations such as mining, although with the introduction of more stringent safety measures this is now far less common than it used to be.

 

What are the symptoms of COPD?

The main symptoms of COPD are persistent breathlessness and a cough, usually associated with frequent episodes of chest infections with the production of sputum (phlegm). What makes COPD different from acute bronchitis or asthma is that these symptoms are present most of the time and do not usually disappear even when the individual is at their best. Doctors sometimes refer to this as 'irreversible airways obstruction'. This is because the wheezing and breathlessness of asthma are reversible (often within minutes) with correct treatment, whereas the symptoms of COPD are never completely removed, even following treatment because the underlying lung damage remains. Unfortunately, with time, the breathlessness may get worse so that increasing amounts of treatment are needed to improve the symptoms. In severe cases the individual may be breathless even at rest. However, in mild cases the person may be only slightly affected and treatments exist to relieve the problem to enable the sufferer to lead as active a life as possible.

How is COPD diagnosed?

The doctor usually suspects COPD on the basis of the symptoms and examination of the patient. However, they may also arrange for blood tests, a chest x-ray and some special breathing tests (called spirometry) to be done, or in difficult cases, organize an appointment with a specialist to advise on the diagnosis and further treatment.

Spirometry involves the patient blowing out into a tube for as long and as hard as they can. The tube is attached to a machine that analyses various aspects of the person's lung function. The test is then usually repeated after the administration of certain drugs (via a mask attached to a device called a nebuliser) which are designed to open the airways of the lungs. This can help to identify whether the person is suffering from COPD or asthma and can gauge the severity of the condition.

 

Giving up smoking

The most important thing that the patient can do for themselves is to give up smoking. This can significantly slow down the progress of the condition and may even allow some parts of the lung to heal up. Stopping smoking is one of the few things which has been proven to make a difference to the progress of COPD and its importance for people with this condition cannot be over-emphasized. Many GP surgeries now run smoking cessation clinics that can help in a variety of ways to assist smokers to give up the habit.

Exercise

Individuals with COPD should be encouraged to exercise as much as they can as this prevents the general loss of health associated with lack of exercise. As long as activity levels are sensible, it will help to keep the person physically and mentally in better condition than becoming sedentary. In combination with this approach is the importance of the sufferer maintaining an ideal weight. Any reduction in activity due to the illness can easily lead to obesity, which results in increased strain on the lungs, possibly causing a vicious cycle to develop.

Antibiotics

The occasional use of antibiotics for the episodes of chest infection characteristic of COPD has been found to help the occasional worsening of symptoms associated with these infections. However, it is often difficult to tell when a true chest infection is present and antibiotics have not been shown to affect the general progression of the condition.

Occasionally, sufferers of COPD can contract chronic lung infections that are resistant to all usual antibiotics. In these cases, certain antibiotics are sometimes given directly into the lungs via the nebuliser (a machine which produces a fine mist of medication which is inhaled through a mask attached to the machine).

Inhaled medication

There are a number of types of inhaled medication that can help with the symptoms of COPD. These are administered either in the form of an inhaler (or 'puffer' as it is called by many patients) or via a nebuliser.

Bronchodilators

The first of these inhaled medications are the bronchodilators such as salbutamol or ipratropium that work by dilating the small airways of the lungs. They provide short acting relief of breathlessness and can assist with the severity of the cough of COPD.

Inhaled steroids

The other main group of inhaled medication is the inhaled steroids such as beclomethasone or budesonide. Since these are strong anti-inflammatory drugs, they can reduce the inflammation inside the airways of the lungs and have been shown to reduce the number of exacerbations (sudden episodes of deterioration in symptoms) suffered but, unfortunately, do not prevent the progression of the condition in general.

Long acting beta agonists

Another form of inhaler sometimes used in COPD is the so-called 'long acting beta agonist' such as salmoterol or eformoterol. These are similar to one form of the bronchodilators mentioned above but, as the name suggests, have a longer duration of action. There is evidence that these drugs increase lung function, reduce breathlessness and also reduce the number of acute exacerbations of the illness.

Oral steroids

Steroids given in tablet form are sometimes used in high doses for short periods of time to treat acute exacerbations of the breathlessness of COPD, often in combination with a course of antibiotics if infection is thought to be contributing to the sudden deterioration. The response to this treatment tends to vary from one patient to another.

Oxygen

In cases of severe COPD, long term oxygen therapy can help not only to relieve some of the symptoms, but it has also been found to prolong the lifetime of sufferers. The oxygen is administered through a mask or nasal tubing attached either to an oxygen cylinder kept in the home or from a machine called an oxygen concentrator, which takes room air and concentrates the amount of oxygen in it before blowing it out along the tubing to the patient.

Physiotherapy

This can sometimes be useful to assist the clearing of mucus from the lungs.

Flu and pneumonia vaccinations

It is strongly advised that sufferers of COPD have an annual flu injection each autumn and a one-off pneumonia vaccination. These immunisations will give them extra protection from illnesses that would potentially cause them serious problems in the light of their already reduced lung capacity.

If someone with COPD has a sudden worsening of their condition (which may often be due to a chest infection) they may be admitted to hospital for a few days. They will receive intensive physiotherapy and intravenous antibiotics (given straight into the blood stream) to restore them to a condition where they can go home again. If an individual has difficulty with mobility, an occupational therapist may be asked to assess the need for adaptations to the home, such as stair lifts and handrails.

It cannot be stressed strongly enough how important it is for anyone with COPD to give up smoking and preferably for their family to do the same in order to reduce the damage to the remaining healthy lung tissue.

 

Are there any advances in treatment of COPD?

A newly developed inhaled bronchodilator called tiotropium has been designed specifically for the treatment of COPD. It has the effect of producing a long lasting opening up of the airways. Some studies have shown that this drug has benefits compared with some of the more traditional inhaled drugs mentioned above, but at the time of writing it is too early to say how much of an advance in treatment this is.

Gene therapy, as with many illnesses, is being explored in the treatment and prevention of COPD. Doctors have noticed for many years that not all heavy smokers will develop the condition, so there is likely to be an inherited tendency. If the genetic make-up for this tendency could be identified and modified, then there may be a way of preventing COPD from occurring in the first place.