Some patients only have very mild illness with PAP and symptoms may even improve over a few months.

When is pulmonary alveolar proteinosis (PAP) treated?

In most cases, the problems are significant or severe and may get gradually worse. Without treatment, these patients will suffer from the effects of very low blood oxygen levels and the condition can become life-threatening. Therefore the majority of patients choose to undergo treatment.

How is PAP treated?

A number of treatment options can be considered including:

  • Physical treatments
    • Physiotherapy and various ‘cough medicines’
    • Partial lung lavage (lung lavage is explained below)
    • Whole lung lavage
  • Treatments targeting your immune system ('immunological treatments') 
    • Injection of a drug called granulocyte-macrophage colony stimulating factor (GMCSF)
    • GMCSF treatment through inhalation of the drug
    • Suppression of your immune response with drugs, for example, Rituximab(which selectively attacks immune cells which produce excess quantities of damaging antibodies)
    • Plasmapheresis, where we remove antibodies (part of your immune system) from your bloodstream
  • Transplantation of the lungs, or heart and lungs

Physical treatments

There is no evidence of the effectiveness of physiotherapy or various cough-promoting/suppressing drugs in patients with PAP.  Partial lung lavage has been used with some success in Japan but it involves a number of long procedures under sedation and does not have any treatment benefits over whole lung lavage.

Whole lung lavage

Since 1963, the main treatment for PAP has been the washing of the lung – most commonly referred to as whole lung lavage or WLL.  The treatment uses sterile saline (salt water) to wash the abnormal build-up of surfactant material from the lung.  

It is carried out on one lung at a time in an operating theatre while the patient is under general anaesthetic.  The anaesthetist inserts a special double-barrelled breathing tube (called a double-lumen-endobronchial tube) through the mouth and into the windpipe so that the left and right lungs can be isolated from each other. This means that one lung can be used for ventilation (controlled breathing) with oxygen while the other lung can be safely treated with WLL. 

In some cases a very large volume of saline (30 to 40 litres) is washed in and out of the lung before the ‘milkyness’ of the PAP material is removed and the saline comes out almost crystal clear.  It may take several hours to reach this stage.  Any remaining saline is then drained out of the lung and both lungs are ventilated with oxygen through a standard single-barrel (endotracheal) breathing tube. 

Normally the patient is kept asleep and on controlled ventilation (breathing) for a further hour or so to allow for recovery from the procedure.  During this time the patient is cared for in the intensive care unit or recovery unit next to the operating theatres. 

After an hour or so the anaesthesia is stopped, the patient wakes up and the breathing tube is removed so the patient can breathe normally again, with the help of oxygen from a face mask.  The patient is carefully monitored during this period and when safe is transferred back to the main ward.  Monitoring continues on the ward; particularly of oxygen levels, using a small probe which is placed on a fingertip. 

After whole lung lavage

At first, patients tend not to feel much better than before the treatment, probably because of the after-effects of anaesthesia and the small amount of saline remaining in the alveoli.  However, patients usually notice that they feel a lot better about 24 hours after the WLL.

Patients may either be discharged (told that they can leave hospital) at this point or, in some cases, they may stay in preparation for treatment of the other lung by WLL.

In many cases, a further admission to Royal Brompton Hospital is planned for the second WLL.  After both lungs have been treated the patient is reassessed for progress and improvements or any negative reactions to the treatment.  In a minority of cases, no further treatment is needed.  In most cases, further treatment with WLL will be needed but it is not possible to predict how many treatments a patient will need.

What is the likely outcome of PAP treated by whole lung lavage?

The great majority of PAP patients follow a similar pattern of improvement after treatment by WLL.  In some cases, patients enter a long phase of ‘remission’ after WLL meaning that they feel much better and experience fewer symptoms. 

Following treatment with PAP, individuals can get back to normal activities.  Some PAP patients may need to have WLL treatments over a longer period of time in order to feel better.  In some very severe cases, several treatments by WLL are needed just to control the PAP and prevent it from getting worse.

What are the risks of whole lung lavage?

There are some risks associated with the general anaesthesia that is needed for this treatment and these include:

  • Damage to the teeth and gums and sore throat from the placement of the large breathing tube – this is identical to risks in all other procedures that need general anaesthesia.
  • Possible allergic reactions to the drugs used during anaesthesia.
  • There is a potential risk that the blood oxygen level will fall during the treatment because while the treated lung is lavaged, only one lung can be used for breathing.

Some patients with PAP are unusually prone to infections, particularly chest infections, and there is a small risk that a chest infection may be ‘stirred up’ or made worse by the WLL treatment

In over 20 years and more than 300 WLL treatments there have been no serious complications directly as a result of or during the WLL treatment.


This has been tried in the past but should be seen as a final option because of the unfortunate tendency for severe lung diseases to develop in the transplanted lungs.  PAP patients have been given transplanted lungs only for PAP to recur in the new lungs.  For this reason and because of the general non-availability of donor organs, transplantation is not normally considered as an option.

Pulmonary alveolar proteinosis (PAP) is a very rare disease in which the air sacs of the lungs (alveoli) do not work properly.

Useful contacts

If you have any queries about the information provided on these pages or would like to know more, please contact Dr Cliff Morgan, Lead Clinician - Critical Care/Consultant Anaesthetist, on 020 7351 8526.