Glossary of ICU terms

When you are in ICU you will inevitably hear terms or abbreviations that are unfamiliar to you. This is a short list of the most common ones. If there you think additional terms should be included please let us know in person or email .

Blood gas machine

A machine which measures the blood gases.

Blood gases

A blood test to check the level of oxygen, carbon dioxide and acidity which may be done several times a day.

Carbon dioxide

This is the waste gas eliminated by the lungs.


Used to empty a patient's bladder.


Intensive Care Units can be referred to by various names which mean the same thing, for example Critical Care Unit (CCU), Intensive Care Unit (ICU) or Intensive Therapy Unit (ITU). The unit cares patients with acute illness or injury that require specialised procedures and treatments by specialised staff.

Central line

A line is inserted into the patient in order for liquids/drugs to be passed into their veins.

Critical Care Team

A team of health professionals who care for critically ill and injured patients. It includes predominantly a critical care intensivist and a critical care nurse but may also include physiotherapists, pharmacists, technicians, social workers and clergy.

Endotracheal tube

This tube is inserted through either the patient's nose or throat into the windpipe and is sometimes referred to as an ET tube.


A critical care physician whose medical practice is focused entirely on the care of critically ill and injured patients.


Blood oxygen level.

Pulse oximeter

A probe that wraps around a hand or foot, connected to a machine, which measures how much oxygen the blood is carrying.

Speaking valve

This allows a patient with a tracheostomy to use their voice and is only used as the patient's condition improves.


Mechanical removal of mucous from the nose, throat or endotracheal tube with a plastic tube.


A tracheostomy (or 'trachy') is a tube inserted into the windpipe via a hole in the patient's throat. This sounds very daunting and can look strange, but it is much more comfortable for the patient and means they can be awake.


Also known as a breathing machine, this piece of equipment blows air and oxygen in and out of the lungs. The breathing machine can do all the breathing for the patient or it can assist the patient's own breathing.


The process of taking a patient off the ventilator once they are able to breathe on their own.

Visiting times

Max 2 visitors at one time 

Contact information

Chelsea and Westminster
Adult intensive care unit (ICU)
5th Floor, Lift Bank B
T: 020 3315 4331

Leigh Paxton (Matron)
T: 020 3315 4332

West Middlesex
Adult intensive care unit (ICU)
1st Floor, Main Building
T: 020 8321 5833

Amanda Dixon (Matron)
T: 020 8321 6763


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