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Post-operative chest infection

This leaflet is adapted from the leaflet: Post-operative Chest Infection, provided by the Royal College of Anaesthetists, the professional body responsible for the speciality throughout the UK, ensuring the quality of patient care through the maintenance of standards in anaesthesia, critical care and pain medicine.

A chest infection is an infection that affects the lower large airways (bronchi) and the lungs. Pneumonia and bronchitis are the most common chest infections. After an anaesthetic and an operation there is a risk of developing a chest infection.

The term 'lower respiratory tract infection' is often used to describe a chest infection. An 'upper respiratory tract infection' means an infection affecting the nose and throat.

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What is a chest infection and why can it happen after surgery?

After surgery, phlegm can build up in the lungs and this makes it easier for a bacteria or a virus chest infection to develop. The reasons for the build up of phlegm in the lungs and airways includes:

  • General anaesthetics affect the normal way that phlegm is moved out of the lungs.

  • Pain from the operation can mean that taking a deep breath or coughing is difficult.

What does it feel like?

A post-operative chest infection may make a person:

  • Feel very unwell and tired.

  • Have a high temperature.

  • Have a cough that brings up thick yellow or green sputum (phlegm).

  • Have difficulty with breathing, and breathing may be quite fast.

  • Have chest pain, which can be a sign of a chest infection, but will need to be assessed very thoroughly in case there is a different cause, such as a heart problem.

  • Become confused, especially if elderly. This is usually temporary and is likely to improve as the chest infection gets better.

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How do you know if you have a post-operative chest infection?

  • Doctors and physiotherapists listen to the chest with a stethoscope. They can hear extra crackles and wheezes.

  • An X-ray of the chest may show evidence of a chest infection on the X-ray.

  • Blood tests can also show evidence of an infection.

  • A sample of sputum (phlegm) can be sent to the laboratory to try to identify any specific bacteria that are causing the infection.

  • Sometimes the heart rate becomes faster and the blood pressure can fall. These are signs of a serious chest infection.

Who is most likely to get a post-operative chest infection?

The following factors make a post-operative chest infection more likely:

  • Increased age (over 50).

  • Certain operations are more likely to cause a chest infection, particularly if the operation is on the abdomen or the chest, or when:

    • Having major surgery on the head or neck.

    • Having a long-term medical condition - for example, diabetes, kidney disease, asthma or chronic obstructive pulmonary disease.

    • Being very overweight.

    • Being a smoker.

    • Having a weakened immune system. This makes a person less able to fight off bacteria or virus infections. This includes people who have a long-term disease of the immune system or who are on medications that suppress their immune system, such as steroids.

    • Being immobile after surgery, and unable to get out of bed, either due to the surgery or due to a pre-existing problem with moving about.

There is some evidence that having a regional anaesthetic (eg, spinal anaesthetic or epidural injection), either with or without a general anaesthetic, reduces the risk of a chest infection compared to having a general anaesthetic alone.

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How likely am I to get a post-operative chest infection?

The risk is very variable depending on the risk factors listed above. One example is that around 1 in 5 people having major abdominal surgery are likely to get a chest infection, which may be mild or severe. However, people with none of the risks above are quite unlikely to get an infection.

How serious is a post-operative chest infection?

For those who were previously healthy, full recovery from a post-operative chest infection is very likely. But a post-operative chest infection may be very serious, even for a previously healthy person.

Any person who was not previously healthy or had long-standing lung disease or any other long standing illness, is more likely to have a serious life-threatening post-operative chest infection. However, many people with previous lung disease recover after a post-operative chest infection.

What is the treatment for a post-operative chest infection?


Oxygen is given through a facemask or through small plastic tubes that sit just inside the nostrils (sometimes called nasal prongs, or nasal specs). The flow of oxygen can be quite noisy and can make the mouth and nose dry.

Occasionally, using oxygen under pressure by breathing through a mouth piece (like a snorkel) or through a tight fitting mask which covers the mouth and/or nose is used. This helps to expand the lungs better.

Intravenous (IV) drip

Intravenous fluids (a 'drip' into a vein) may be needed to prevent dehydration. This will also help thin the phlegm in the lungs and make it easier to cough up.

A cannula is inserted into a vein in the hand or arm. This is a thin plastic tube which is inserted using a needle, and the needle is then discarded. The cannula will be replaced every 48 hours or so. It is still very important to drink plenty of fluids, if the recent operation allows this.


Antibiotics can also be given through the cannula into a vein. For mild infections, tablet antibiotics may be given. Antibiotics kill bacteria or slow down their growth.

Pain relief

Pain from the operation, and other pains such as headache, will be treated with pain relief medicines. It is important to tell the doctors and nurses about the pain, so they can help. There are many types of medicines that are used for pain relief.

Ventilation breathing

For severe chest infections, it may be necessary to have help with breathing. This is done in an intensive care unit. With the person sedated, a tube is inserted through the mouth or nose and into the windpipe (trachea).

A ventilator (breathing machine) is used until the condition improves. Admission to an intensive care unit with a post-operative chest infection is very serious and some people do not survive.

What can I do to prevent a post-operative chest infection?

Breathe deeply or normally, and avoid shallow breathing after the operation. Also coughing at regular intervals.

This all helps to prevent a chest infection. It also helps to clear an infection more quickly by getting rid of phlegm. This can be greatly helped by physiotherapy or breathing exercises that will be advised by the hospital team.

Quit smoking

Smokers are more likely to get a chest infection after an operation. Giving up smoking, even a few days or weeks before coming into hospital, will allow the damaged linings of the airways to begin to repair. This reduces the risk of getting an infection. However, the greatest benefit is gained by giving up smoking at least two months before the operation.

See a physiotherapist

Physiotherapy treatment after surgery helps to prevent and treat a chest infection. Physiotherapy will help with breathing, help to cough more effectively, and so help to clear the phlegm from the airways and lungs.

Pain relief

Pain can make breathing and coughing more difficult and so increase the risk of a chest infection. Getting adequate pain relief medicines, if necessary, will help breathing deeply and coughing more easily, which will help prevent or clear any infection.

Opt for local or regional anaesthetic

The anaesthetist will consider whether a certain anaesthetic technique will help prevent a chest infection. For some operations, a local or regional anaesthetic may be considered. These are injections which numb an area of the body, meaning that a full general anaesthetic is not needed, and this reduces the risk of a post-operative chest infection.

Local or regional anaesthetics can sometimes be used together with a general anaesthetic, to give better pain relief after the operation.

Get the flu jab

Anyone who has an increased risk of getting influenza (flu), will benefit from being immunised against the flu virus (having a flu jab).

The risk and severity of a post-operative chest infection is greatly increased if a person is unwell with flu. However, the immunisation should be given well ahead of the operation, but avoided in the two weeks before surgery.

What does getting a post-operative chest infection mean for my recovery?

A post-operative chest infection, will delay discharge from hospital by days or weeks.

Chest infections can have many complications. Fluid can build up in the lungs or infection can spread in the bloodstream to affect other organs in the body.

Specific treatment is given for these on the ward or in the intensive care unit. Anyone who needs to be admitted to the intensive care unit will have a very slow recovery.

However, most people who get a post-operative chest infection go on to make a full recovery without long-term effects.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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