Acute bronchitis

Sometimes, acute bronchitis can cause a secondary infection in your lungs. The lungs can be weakened by the original infection and become more vulnerable to secondary infection by bacteria.

If you develop a secondary infection, it can be more serious than acute bronchitis. It can usually be treated with antibiotics. Occasionally, acute bronchitis can lead to pneumonia, particularly if you have other health conditions.

You should visit your doctor if:

• your develop symptoms of a high temperature (fever) of 38C (100.4F) or above, or your existing high temperature suddenly worsens
• you become drowsy, confused, or disorientated
• you develop chest pains
• your breathing suddenly becomes more rapid
• you become short of breath
• your cough lasts more than three weeks
• you have recurring bouts of acute bronchitis

Pneumonia

Pleural effusion

Pleural effusion is a common complication of pneumonia that affects around 1 in 2 people who are admitted to hospital for moderate to severe pneumonia. A pleural effusion is where an excess amount of fluid gathers inside the double-layered membrane (covering) that surrounds the lungs, and is known as the pleura. The fluid can place pressure on the lungs, making breathing difficult. Pleural effusion will usually resolve when pneumonia is treated.

In cases of pleural effusion, it is usually recommended that a fluid sample is taken and checked in order to determine whether the fluid has become infected (see below). If no infection is present, a ‘watch and wait’ strategy is usually recommended because most cases of pleural effusion will resolve once the underlying pneumonia infection has passed.

Empyema

In around 10% of pneumonia cases that are treated in hospital, the fluids that make up a pleural effusion will become infected by bacteria. This is known as empyema. The bacteria can cause a build-up of pus, which can sometimes reach up to around a quarter of a pint (142.5mm)

Symptoms of empyema include:

• chest pain which is made worse when breathing in
• dry cough
• high temperature (fever) of 38C (100.4F) or above
• chills
• excessive sweating, particularly at night
• shortness of breath
• general sense of feeling unwell

Empyema is usually treated using a combination of antibiotics and a procedure that drains the pus out of the pleura. This is usually done by making a small incision (cut) in your chest (under a local anaesthetic), and then inserting a tube into the pleura to drain away the pus and fluid.

The most serious cases of empyema may require surgery in order to remove the pus and repair any underlying damage to your pleura and lungs.

Lung abscess

A lung abscess is a rare complication of pneumonia, which is mostly seen in people who have a serious, pre-existing illness, or in those with a history of severe alcohol misuse. A lung abscess is a pus-filled cavity that develops inside the tissue of the lungs. The symptoms of a lung abscess are the same as those of severe pneumonia. In addition, you may begin to cough up unpleasant smelling phlegm (thick mucus), and experience swelling in your fingers and toes.

Most cases of lung abscesses can be treated using antibiotics. This usually involves an initial course of intravenous antibiotics (directly into a vein through a drip) followed by oral antibiotics (tablets) for between four to six weeks.

Most people who have a lung abscess will experience an improvement in their symptoms within three to four days. It is important to finish your recommended course of antibiotics, even if you feel perfectly healthy, in order to prevent re-infection of your lungs.

Around 10% people will require surgical treatment because they fail to respond to the antibiotics. Surgery usually involves draining the pus out of the abscess or removing the affected section of the lung.

Metastatic infection

Another rare and serious complication of pneumonia is metastatic infection. Metastatic infection means that the infection has spread from the lungs to another part of the body.

The first place that an infection usually spreads to is the blood, which is known as septicaemia.

Symptoms of septicaemia include:

• high temperature (fever) of 38C (100.4F) or above
• fast heart beat (tachycardia)
• fast breathing
• low blood pressure (hypotension) which will cause you to feel dizzy when you stand up
• a change in mental behaviour, such as confusion or disorientation
• diarrhoea
• reduced urine flow
• cold, clammy skin
• pale skin
• loss of consciousness

Once your blood has become infected, it is possible for the infection to spread to other organs in your body such as:

• the outer layers of your brain (meningitis)
• the lining of your abdomen (peritonitis)
• the inner layer of your heart (endocarditis)
• your joints (septic arthritis)

These types of metastatic infections are usually very serious and require aggressive treatment with high-dose intravenous antibiotics.

Related posts:

1. Diagnosing adult chest infection
2. Treating adult chest infection
3. Symptoms and causes of adult chest infection
4. Chest infection in adults
5. Diagnosing and treating bronchitis
6. Bronchiectasis
7. Complications of bronchiolitis
8. Respiratory tract infection — Bronchiolitis