This glossary contains commonly used terms you may hear the team using when you visit ICU. If there is a term missing from this list that you feel would be a useful addition, please send your suggestion(s) using the box below.
Admission: bringing a patient into the intensive care unit.
Airway: the passage(s) through which the patient breathes. Naturally this is a patient’s nose and mouth. When patients are sedated and ventilated this can refer to the endotracheal tube or tracheostomy. Occasionally used as a shorthand reference to an oropharyngeal or nasopharyngeal airway – these are smaller plastic tubes that can be inserted into the patient’s nose or mouth to help keep their natural ‘airway’ open. Related topics: The Ventilator, Tracheostomy
Blood gas: commonly used shorthand for ‘blood gas analysis’. Core monitoring tool widely used in intensive care. Small blood samples (1-2mls) are taken regularly from a patient’s arterial line and processed through an analyser on the unit. Measures blood pH and levels (partial pressures) of oxygen and carbon dioxide. Results are used to adjust organ support therapies.
Blood transfusion: usually refers to an infusion of donated red blood cells (RBCs). Whole blood is not routinely transfused, donated blood is split into red blood cells, platelets and/or plasma. Patient’s receive one or more of these individual components as required.
Cardiac arrest: medical term for a heart stoppage. May be due to a problem directly with the heart itself, such as a heart attack – or elsewhere in the body, such as a pulmonary embolism, sepsis, haemorrhage etc. Attempted cardiopulmonary resuscitation may or may not be successful at restarting the heart.
Central: in the context of a central line refers to a line positioned with the tip lying in one of the large veins close to the heart – known as central veins. Their size, higher blood flow and proximity to the heart allow the infusion of irritative medicines and monitoring of central venous pressure.
Cultures: samples of blood, sputum, urine and other body tissues/fluids sent to microbiology for identification of possible infection. Samples are incubated and checked frequently for signs of bacterial growth.
Death: the irreversible loss of the capacity for consciousness combined with the irreversible loss of the capacity to breathe. May be diagnosed on cardiovascular (heart) or neurological (brain) criteria.
Delirium: a usually short-lived state of confusion, disorientation, inattention and memory problems commonly associated with critical illness. Related topics: Delirium
Dialysis: circulating a patient’s blood through a machine outside the body to remove toxins, waste products and excess salts from the blood whilst a patient’s own kidneys are unable to do so. Intensive care units commonly offer a gentler/slower version of standard outpatient-type dialysis that is better tolerated by critically ill patients. May be colloquially be referred to as ‘filtration’, Also ‘renal replacement therapy’ or ‘RRT’. Related topics: The kidney machine
Discharge planning: carefully considering where the patient’s ongoing care needs can be met when the patient leaves intensive care. Most patients in critical care are discharged to a medical, surgical or other specialty ward; occasionally patients may be discharged directly home.
Extra-Corporeal Membrane Oxygenation (ECMO): circulating a patient’s blood to a machine outside the body that adds oxygen to – and removes waste carbon dioxide from – the bloodstream. Specialised service in a handful of centres across the UK. Patient’s often have to travel to a different ICU to receive the therapy.
Extubation: removing a patient’s endotracheal (breathing) tube to see if they can breath without the aid of a ventilator. Often follows a sedation-hold (see below).
Facemasks: used to deliver oxygen therapy and breathing support for the awake patient.
Fluid balance: patients in ICU are often unable to control their own fluid balance. They may be dehydrated from lack of food and drink, vomiting or diarrhoea, bleeding or severe infection. ICU patients frequently require generous fluid replacement early in their admission. Later they may require fluid removal either via diuretic drug therapy or a kidney dialysis machine.
Glasgow coma scale: a scoring system used to describe a patient’s level of consciousness/unconsciousness. Normal score is 15. Lowest score of 3 indicates deep unconsciousness/unresponsive patient.
Haemoglobin: the red coloured pigment in red blood cells that binds avidly to oxygen. Composed of protein and iron. Allows red blood cells to carry oxygen to a patient’s organs & tissues.
Hypoglycaemia: low blood glucose level.
Hypotension: low blood pressure (BP). Related topics: Blood pressure support
Hypoxaemia: low blood oxygen level – one cause of hypoxia (see below).
Hypoxia: abnormally low amounts of oxygen being delivered to the body’s cells. May result in cell damage. Some organs – such as the brain – are particularly sensitive to a drop in oxygen delivery.
Inotropes: often used as a general term for blood pressure support drugs.
Intubation: placing an endotracheal (breathing) tube into a patient’s windpipe – usually via their mouth. Patients are usually sedated for this procedure. Related topics: The Ventilator
Jaundice: yellow/green discolouration of a patient’s skin, eyes and other tissues as a result of a raised bilirubin level. Bilirubin is a waste product of expired red blood cells (red blood cells last around 120 days and then need to be disposed of). Bilirubin is normally processed by the liver before being excreted in faeces and urine. Jaundice may arise from abnormal red blood cell breakdown, liver disease or a blockage of the bile ducts.
Ketoacidosis: abnormally acidic blood due to the accumulation of biological acids called ketone bodies. Most commonly occurs in diabetic patients who stop taking/absorbing their insulin or develop an intercurrent illness. May also arise due to starvation.
Levels of care: used as a descriptor for the dependency of a hospitalised patient. Level 0 refers to standard ward based care. Level 1 refers to ward based care plus additional support e.g. continuous ECG monitoring. Level 2 refers to one invasive organ support therapy excluding invasive ventilation (traditionally called HDU). Level 3 refers to invasive ventilation alone or 2+ other invasive organ support therapies (traditionally called ICU). Related topics: What is the difference between HDU and ICU.
Myocardial Infarction (MI): medical term for ‘heart attack’. A portion of heart muscle is damaged from a shortage of oxygen due to either a decrease in oxygen supply e.g. from an coronary artery blockage – increased demand – or both.
Nasogastric tube: tube passed into the nose, down the back of the throat, down the gullet and into the stomach. May be used to drain stomach contents or to feed a patient that can’t eat/swallow. A nasojejunal tube is longer and passes beyond the stomach into the first part of the bowel. Related topics: Nasogastric tube, Role of the dietician
Oedema: excess fluid in body tissues, commonly in dependant areas such as ankles, legs, buttocks and abdomen. Common in critical illness due to salt/water retention and/or low blood protein levels. May also occur in liver or heart failure.
Pleural effusion: a collection of fluid between the inside of the rib cage and the outer surface of the lung. Small effusions are often asymptomatic but large ones can cause breathing difficulties by squashing the adjacent lung. Effusions have a wide range of causes including infection, heart failure and cancer. May require drainage through a chest drain.
Pneumothorax: a collection of air between the inside of the rib cage and the outer surface of the lung. May occur spontaneously or as a result of trauma, chronic chest disease or as a complication from medical procedures. Similar to pleural effusions, small pneumothoracies may go unnoticed whilst large ones can be life threatening. If air is drawn into the collection with each breath but cannot escape due to a one-way valve effect, the collection of air becomes pressurised and may compress major blood vessels and the heart. This ‘tension pneumothorax’ is a medical emergency.
Prone positioning: positioning a patient on their front. Sometimes undertaken to help improve a ventilated patient’s oxygen levels.
Pulmonary Embolism (PE): clot that becomes lodged in arteries passing through the lungs. Small PEs may be asymptomatic whilst large ones can be fatal. Clot may originate from a Deep Vein Thrombosis (DVT). Risk factors include immobility, dehydration, cancer and previous clots.
Resuscitation: often used as a term for ‘Cardiopulmonary Resuscitation’ or ‘CPR’. Attempting to restart someone’s heart using a combination of heart massage, electrical shocks and drugs.
Sedation-hold: turning down or turning off a patient’s sedation and observing for signs of wakefulness. May lead to extubation (removal of the breathing tube) if appropriate. Related topics: Sedation
Sepsis: an overwhelming, potentially life-threatening bodily response to infection that can lead to tissue damage, organ failure and death.
Source isolation: patients with some infections are routinely cared for ‘in isolation’ to help prevent the spread of infection to other patients. Commonly involves use of physical boundaries by caring for a patient in a side room to the main ward. Staff wear additional personal protective equipment and undertake appropriate hand washing before leaving the area. Side rooms may display alert notices and use directional airflow. Some immunosuppressed patients require ‘reverse isolation’ to protect them from picking up infections from other patients.
Total Parenteral Nutrition (TPN): complete (fat, protein, sugars, salts, trace elements etc) nutritional support given directly into the blood stream via a venous line. Usually reserved for situations when adequate nutrition cannot be provided via the gut. Related topics: Role of the dietician, central lines
Transfer: moving a patient within or between hospitals. Critical care patients commonly require intra-hospital transfer to radiology for a scan or to theatres for an operation. Patients may require inter-hospital transfer because their nearest intensive care bed is in another hospital or to receive a specialist treatment not available in their original centre.
Ultrasound: bedside imaging modality with a variety of uses in the intensive care unit including in insertion of central lines and arterial lines. May also be used to assess the heart (echocardiography or ECHO scan) and lungs.
Ventilator-associated pneumonia (VAP): pneumonia in a ventilated patient. Several aspects of ventilation leave patients vulnerable to infection. The breathing tube bypasses many of the body’s natural defences whilst immobility and the absence of coughing lead to retained secretions. Common complication of critical care therapy.
Weaning: process of gradually trying to get a patient off the ventilator and breathing for themselves. May require a tracheostomy. Related topics: Tracheostomy
‘X-ray’: colloquial term for radiograph – an image taken using X-rays. Radiographs are commonly used in the ICU to assess chest disease, line placement and the position of nasogastric (NG) tubes for feeding.