> ## Content Index > Fetch the complete content index at: https://www.preanaesthesia.com/llms.txt > Use this file to discover other available public pages before exploring further. # Patient Glossary - URL: https://www.preanaesthesia.com/patient-glossary/ - Published: 2026-09-28T20:05:18.000Z - Updated: 2026-09-28T20:05:18.000Z - Description: Plain-language explanations of common anaesthesia terms, including spinal anaesthesia, LMA, ASA grade, sedation and recovery. - Author: preetam satish Anaesthesia involves many words and abbreviations that may be unfamiliar. This glossary explains some of the terms you may hear before, during or after an operation or procedure. The exact meaning or relevance of a term can vary depending on the procedure and your health. Your anaesthesiologist can explain what applies to you. ### Airway The passages through which air travels from the nose or mouth to the lungs. During anaesthesia, your anaesthesiologist may use different techniques or devices to keep the airway open and support breathing. ### Anaesthesia Medicines and techniques used to prevent pain and help you undergo an operation or procedure safely. Anaesthesia may involve general anaesthesia, regional anaesthesia, local anaesthesia, sedation, or a combination of these. ### Anaesthesiologist A doctor trained to provide anaesthesia and to monitor and support important body functions such as breathing, blood pressure and circulation during surgery and other procedures. ### Arterial line A thin tube placed into an artery, usually at the wrist. It allows continuous blood-pressure measurement and can also be used to take blood samples. It is used only when needed. ### ASA grade / ASA Physical Status A classification used by anaesthesiologists to describe a patient's general medical condition before a procedure. The scale runs from **ASA I to ASA VI**. A higher number generally reflects more significant medical illness. The ASA grade is only one part of anaesthetic assessment and does **not, by itself, predict exactly how risky an operation or anaesthetic will be**. ### Aspiration When stomach contents enter the airway or lungs. This is one reason patients are given instructions about fasting before anaesthesia. ### Blood pressure The pressure of blood within the arteries. It is routinely measured before and during anaesthesia and may change because of medicines, surgery, pain, fluids or the patient's underlying health. ### Cannula / IV cannula A small plastic tube placed into a vein, usually in the hand or arm. It allows medicines and fluids to be given directly into the bloodstream. ### Central line A thin tube inserted into a large vein, usually in the neck, chest or groin. It is used when more specialised monitoring or intravenous access is required. ### Consent The process of discussing a proposed treatment or procedure so that you can make an informed decision about whether to proceed. For anaesthesia, this may include discussion of the planned technique, reasonable alternatives, expected benefits and relevant risks. The amount of detail needed depends on your health, the procedure and the anaesthetic being considered. ### Difficult airway A term used when an anaesthesiologist expects, or has previously experienced, difficulty maintaining the airway or placing a breathing device. If you have previously been told that managing your airway was difficult, tell your anaesthesiologist. ### Difficult intubation A situation in which placing a breathing tube into the windpipe is more difficult than usual. Previous difficult intubation is important information for future anaesthetics. If you have ever been told that you were difficult to intubate, let your anaesthesia team know. ### Endotracheal tube / ET tube / Breathing tube A flexible tube placed through the mouth, past the vocal cords and into the windpipe. It can be used during general anaesthesia to keep the airway secure and allow breathing to be supported. ### Epidural A regional anaesthetic technique in which a small tube called a catheter is placed in the back near the nerves that carry pain signals. Local anaesthetic and other medicines can be given through the catheter. Epidurals are commonly used for labour pain and for some operations or postoperative pain relief. ### Fasting Not eating or drinking for a specified period before anaesthesia. Fasting reduces the chance of stomach contents entering the lungs during anaesthesia. Follow the fasting instructions given by your healthcare team. The required fasting period is not the same for all types of food and drink. ### General anaesthesia A controlled state of unconsciousness produced using anaesthetic medicines. You are not aware of the operation while the anaesthetic is being given. Your anaesthesiologist monitors you continuously and manages your breathing, circulation and other body functions as required. ### Intubation Placement of a breathing tube through the mouth, past the vocal cords and into the windpipe. It may be used during general anaesthesia to help maintain the airway and support breathing. ### Laryngeal mask airway / LMA A breathing device placed through the mouth during anaesthesia. Unlike an endotracheal tube, an LMA generally sits **above the opening of the windpipe** rather than passing through the vocal cords. It can be used for many operations, although it is not suitable for every patient or procedure. ### Local anaesthesia Medicine injected or applied to a small area of the body to make that area numb while you remain awake. ### MAC / Monitored anaesthesia care A term sometimes used when an anaesthesia professional provides monitoring and medicines, often including sedation, during a procedure. The amount of sedation can vary considerably. Depending on the procedure and the patient's needs, a person may be lightly sedated or much sleepier. The abbreviation **MAC** can have another technical meaning in anaesthesia as well, so its meaning depends on the context in which it is used. ### Monitoring Equipment used to continuously or repeatedly check important body functions during anaesthesia. Routine monitoring commonly includes heart rate, blood pressure, oxygen levels and breathing. Additional monitoring may be needed for some patients or operations. ### Nerve block An injection of local anaesthetic near a particular nerve or group of nerves to numb a specific part of the body. A nerve block may be used as the main anaesthetic for some procedures or together with general anaesthesia to improve pain relief. ### Oxygen saturation / SpO₂ An estimate of the percentage of haemoglobin in the blood that is carrying oxygen. It is usually measured using a small sensor placed on a finger. Oxygen saturation is routinely monitored during anaesthesia. ### PAC / Pre-anaesthesia assessment An assessment carried out before anaesthesia to understand your medical history, medicines, previous anaesthetic experiences and other factors relevant to your procedure. It helps the anaesthesia team plan your care and identify issues that may need attention before surgery. ### PACU / Recovery room The area where patients are monitored after anaesthesia while they wake up and recover from the immediate effects of the procedure and anaesthetic. ### PONV Short for **postoperative nausea and vomiting**. Some patients are more likely than others to experience nausea or vomiting after surgery. Anaesthesiologists may give medicines to reduce this risk. ### Postoperative pain relief Treatment used to reduce pain after an operation. Pain relief may include tablets, injections, intravenous medicines, nerve blocks, epidurals or a combination of methods. The most appropriate approach depends on the procedure, your health and your individual needs. ### Premedication Medicine given before a procedure or anaesthetic for a specific purpose. Depending on the situation, this might include medicine to reduce anxiety, prevent nausea, reduce stomach acidity, relieve pain or treat another medical need. Premedication is not required for every patient. ### Preoxygenation Breathing oxygen through a mask shortly before general anaesthesia begins. This increases the amount of oxygen stored in the lungs and provides an additional safety margin while the airway is being managed. ### Regional anaesthesia Anaesthesia that numbs a larger region of the body by temporarily blocking nerve signals. Examples include spinal anaesthesia, epidural anaesthesia and peripheral nerve blocks. ### Risk The possibility that an unwanted event or complication could occur. Anaesthetic risk is not the same for everyone. It depends on factors including your general health, medical conditions, the type and urgency of surgery and the anaesthetic technique being considered. Your anaesthesiologist considers these factors together rather than relying on any single score or test. ### Sedation Medicines given to help you feel relaxed, sleepy or less aware during a procedure. Sedation ranges from light sedation, where you remain awake and responsive, to deeper levels of sedation. It is different from general anaesthesia, although the distinction can sometimes vary depending on the depth of sedation required. ### Spinal anaesthesia / Spinal A type of regional anaesthesia in which a small amount of local anaesthetic is injected into the lower back into the fluid surrounding the spinal nerves. It usually produces temporary numbness and weakness in the lower part of the body. You may remain awake or receive sedation as well, depending on the procedure and your preferences. The numbness gradually wears off as the medicine stops working. ### Supraglottic airway A general term for breathing devices that sit above the opening of the windpipe. An LMA is one type of supraglottic airway. ### Ventilation The movement of air into and out of the lungs. During some forms of anaesthesia, your breathing may be partly or completely supported by an anaesthesia machine or ventilator. ### Ventilator A machine that helps move air and oxygen into and out of the lungs. It may be used during general anaesthesia when breathing needs to be supported. ### Vital signs Measurements that give information about basic body functions. These include heart rate, blood pressure, breathing rate, oxygen saturation and temperature. ## A note about medical terminology The same term can sometimes have slightly different meanings depending on the situation. Anaesthetic techniques are also chosen individually according to the operation, your medical condition and the anaesthesiologist's assessment. If you hear a term you do not understand, ask your anaesthesia team to explain it.