Anaesthesia - loss of feeling or sensation in a part or the whole of the body; usually drug induced.

Analgesia - the relief of pain without causing unconsciousness.

Anticholinergic - a drug that inhibits the action of acetylcholine.

Apnoea - cessation of respiration.

Arrythmia - variation from the normal rhythm of the heart.

Ataractic - a tranquilliser.

Auscultation - examination of the internal organs by listening to their sound.

Basal narcosis - a state of unconsciousness produced prior to surgical anaesthesia.

Blood brain barrier - the membranous barrier that separates blood from the brain; it is permeable to water, oxygen, carbon dioxide, glucose, alcohol, general anaesthetics and some drugs.

Bradycardia - abnormally low heart rate.

Bradypnoea - abnormally low respiratory rate.

Cardiac tamponade - impairment of the heart function by haemorrhage or effusion into the pericardium.

Cyanosis - blue-grey mucous membranes; a sign of inadequate oxygenation of the blood.

Defibrillation - the restoration of normal heart rhythm in ventricular or atrial fibrillation.

Defibrillator - an instrument which restores normal heart rhythm by the application of a high voltage electric current.

Diuresis - increased excretion of urine.

Dyspnoea - laboured breathing.

Dysrhythmia - disturbance of a regularly occurring pattern.

Epidural - outside the dura mater. Epidural analgesia is a form of pain relief obtained by the injection of a local analgesic into the epidural space in order to block the spinal nerves.

Hypercapnia/hypercarbia - excess blood carbon dioxide.

Hyperpnoea - hyperventilation.

Hypertension - persistently high blood pressure.

Hypotension - persistently low blood pressure.

Hypoventilation - shallow breathing at a very slow rate which may cause a build up of carbon dioxide in the blood.

Hypoxia - inadequate oxygen in the tissues.

Laryngospasm - a reflex prolonged contraction of the laryngeal muscles; this may be associated with the clumsy passing of endotracheal tubes.

Narcotic - a drug that produces narcosis (unnatural sleep).

Neurolept - a drug which acts upon the nervous system.

Poikilothermic - describes an animal which is unable to control its body temperature such as neonates and reptiles.

Premedicant - drug/s given preoperatively in order to reduce fear and anxiety and to facilitate the induction, maintenance and recovery of anaesthesia.

Pulse deficit - a sign of atrial fibrillation; the pulse rate is slower than the apex beat.

Sedative - a sleep inducing drug; used to lessen excitement and reduce tension.

Soporific - sleep inducing.

Syncope - fainting.

Tachycardia - a higher than normal heart rate.

Tachypnoea - a higher than normal respiratory rate.

Thoracotomy - a surgical incision into the thorax.

Tracheostomy - a permanent or long term surgical opening into the trachea.

Tracheotomy - a temporary opening into the trachea.

Tranquilliser - a drug that allays fear and anxiety without inducing sleep.