Respiratory physiology

Welcome to the Respiratory Physiology Department at Harefield Hospital. We help people with sleep disorders, lung and cardiac conditions.

This webpage provides an overview of the services, treatments, investigations, tests and appointments we offer.

The information is mainly aimed at medical professionals such as doctors who want to find out more about what we do. They include GPs who may want to refer patients to us, for example.

If you are a patient, the information below also features useful web links to other webpages.

Our services

The Respiratory Physiology Department at Harefield Hospital provides a range of services including:

respiratory testing
muscle weakness tests
exercise tests
sleep diagnostic studies and treatment for sleep apnoea
periodic limb movement test
obesity hypoventilation and other sleep related breathing disorders

CPAP and NIV

We provide continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV) treatments for our outpatient service. We accept direct GP and other hospital referrals.

Transplantation

We perform:

Lung assessments on people before they have a heart or lung transplantation, or heart and lung transplantation at the hospital.
Regular post-operative lung function tests monitor people’s progress and to help detect, as early as possible, any deterioration in the functional state of the lungs due to infection or rejection.

Types of tests and appointments offered by the department

Spirometry and flow volume loops to show how well you breathe in and out. See spirometry
Relaxed vital capacity – a slow breathing test to measure how much air your lungs can hold. This is also called a slow vital capacity test.
Gas transfer measurements
Lung volume measurements using body plethysmography.
Airways resistance measurements using the body plethysmography.
Supine spirometry is a spirometry test carried out while you lie on your back.
Respiratory muscle (MIPS/MEPS and SNIP)
FeNO (Fractional exhaled nitric oxide)
6-minute walk test
Hyperventilation screening
Bronchodilator reversibility tests
Diagnostic sleep studies, such as simple polysomnography and overnight pulse oximetry (to measure heart rate and oxygen levels).
Continuous positive airway pressure (CPAP) machine set-up and technical support.
CPAP titration studies to set-up the right airflow needed for each person using a CPAP machine.
Remote CPAP monitoring.
Non-invasive ventilation (NIV) machine set-up.
Transcutaneous PCO2 monitoring – a non-invasive test to measure breathing while you are asleep and see how well your lungs get oxygen in and carbon dioxide out.
Actigraphy studies to track your movements and sleep and wake patterns.
Hypoxic challenge test to show if you need extra oxygen when flying in an aeroplane or at any altitude. It is also known as a fitness to fly test.

These tests and appointments take between 10 minutes to 2 hours.

Please note

Any patient who is referred to our department will need to have an appointment booked before their scheduled outpatient appointment date.

We will need a referral letter or a duly completed request form with a person’s clinical history, the tests needed and any other relevant information (such as infectious status). How to refer a patient.

Other information

We treat each patient with care and attention. We carefully explain each procedure and answer any questions they may have.

We measure the height and weight of each patient before starting a test or appointment. We ask patients to remove their shoes and outdoor clothing before taking these measurements.