# Pathways perioperative glossary > A glossary of perioperative and pre-operative assessment terminology — ASA physical status, STOP-Bang, functional capacity in METs, frailty, SGLT2 inhibitors before surgery, day-of-surgery cancellation, pre-admission clinic and clinical decision support. *Source: https://getpathways.ai/glossary* ## ASA physical status The ASA physical status classification is a six-point scale published by the American Society of Anesthesiologists to describe a patient's systemic health before anaesthesia. ASA 1 is a normal healthy patient and ASA 6 is a declared brain-dead organ donor. It describes health, not surgical risk, and an "E" suffix marks emergency procedures. URL: https://getpathways.ai/glossary/asa-physical-status ## Clinical decision support Clinical decision support is software that provides clinicians with patient-specific information and recommendations to inform a clinical decision. The defining constraint is that it assists rather than replaces judgement — it issues no orders and makes no diagnoses, and the treating clinician remains responsible for every decision taken. URL: https://getpathways.ai/glossary/clinical-decision-support ## Day-of-surgery cancellation A day-of-surgery cancellation is a planned operation called off on the day it was scheduled, usually after the patient has arrived fasted. Most are preventable: the common causes are unmanaged medications, unoptimised comorbidity, unscreened risk such as sleep apnoea, and logistical failures — all of which are identifiable weeks earlier. URL: https://getpathways.ai/glossary/day-of-surgery-cancellation ## Enhanced Recovery After Surgery Enhanced Recovery After Surgery is a structured approach that bundles evidence-based steps across the whole surgical pathway to reduce the physiological stress of surgery and speed recovery. A substantial part of it is pre-operative — optimising comorbidity, correcting anaemia, avoiding prolonged fasting and preparing the patient — which makes early assessment a precondition rather than an adjunct. URL: https://getpathways.ai/glossary/enhanced-recovery-after-surgery ## Frailty Frailty is a state of reduced physiological reserve across multiple systems, leaving a patient vulnerable to stressors such as surgery. It independently predicts post-operative complications, longer stays, loss of independence and mortality — over and above age, ASA class or the specific procedure — which is why it is screened separately before elective surgery. URL: https://getpathways.ai/glossary/frailty ## Functional capacity (METs) Functional capacity describes how much physical activity a patient can perform, measured in metabolic equivalents (METs). One MET is resting oxygen consumption. Four METs — climbing a flight of stairs or walking up a hill — is the usual threshold below which perioperative guidelines suggest further cardiac assessment before non-cardiac surgery. URL: https://getpathways.ai/glossary/functional-capacity-mets ## HbA1c HbA1c is glycated haemoglobin, reflecting average blood glucose over roughly the preceding three months. It matters before surgery because poor glycaemic control is associated with higher rates of post-operative complications, particularly infection and impaired wound healing. Unlike a one-off glucose reading it cannot be improved quickly, so it has to be identified with weeks to spare. URL: https://getpathways.ai/glossary/hba1c ## Mallampati score The Mallampati score grades how much of the oropharynx is visible when a seated patient opens their mouth and protrudes the tongue, on a four-class scale. Higher classes suggest a potentially more difficult intubation. It is one input to airway assessment rather than a test in itself, and is always read alongside other airway findings. URL: https://getpathways.ai/glossary/mallampati-score ## Obstructive sleep apnoea Obstructive sleep apnoea is repeated collapse of the upper airway during sleep, causing interrupted breathing and disturbed sleep. It matters before surgery because affected patients are more sensitive to sedatives and opioids and are at higher risk of airway obstruction after anaesthesia. Much of it is undiagnosed at the time of booking, so it is screened rather than asked about. URL: https://getpathways.ai/glossary/obstructive-sleep-apnoea ## Perioperative anticoagulation Perioperative anticoagulation is the plan for a patient's blood-thinning medication around surgery. Most anticoagulants are withheld beforehand to reduce bleeding risk, balanced against the thrombotic risk of stopping them. Because the timing depends on the drug, the procedure and kidney function, the plan has to be made days ahead — which requires knowing the patient is taking one. URL: https://getpathways.ai/glossary/perioperative-anticoagulation ## Pre-admission clinic A pre-admission clinic assesses patients before elective surgery to identify and optimise anaesthetic risk. Its persistent problem is allocation rather than capability — clinics are commonly booked out for weeks with low-risk patients while high-risk patients receive a phone call, because slots are filled in booking order rather than by screened risk. URL: https://getpathways.ai/glossary/pre-admission-clinic ## Pre-operative anaemia Pre-operative anaemia is a low haemoglobin concentration identified before surgery. It is common, frequently due to iron deficiency, and associated with more transfusion, longer stays and worse recovery. Because investigating the cause and treating it takes weeks, it is one of the clearest arguments for assessing patients at booking rather than shortly before their procedure. URL: https://getpathways.ai/glossary/preoperative-anaemia ## Pre-operative fasting Pre-operative fasting is the period without food or drink before anaesthesia, intended to reduce the risk of stomach contents entering the lungs. Modern guidance permits clear fluids much closer to surgery than patients often assume. Misunderstood instructions cause avoidable cancellations and unnecessary discomfort, so confirming the patient understood them is part of assessment. URL: https://getpathways.ai/glossary/preoperative-fasting ## Prehabilitation Prehabilitation is structured preparation before surgery — typically exercise, nutrition and psychological support, alongside smoking and alcohol reduction — aimed at improving a patient's physiological reserve before the stress of an operation. It treats the wait for surgery as an intervention window rather than dead time, which requires identifying who would benefit early enough to act. URL: https://getpathways.ai/glossary/prehabilitation ## Revised Cardiac Risk Index The Revised Cardiac Risk Index estimates the risk of major cardiac complications after non-cardiac surgery. It counts six factors — high-risk surgery, ischaemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, and impaired renal function — each scoring one point. More factors means higher risk, and it is used alongside functional capacity rather than instead of it. URL: https://getpathways.ai/glossary/revised-cardiac-risk-index ## SGLT2 inhibitors (perioperative) SGLT2 inhibitors such as empagliflozin and dapagliflozin must be withheld before surgery because they can cause euglycaemic diabetic ketoacidosis, in which ketoacidosis develops with normal or near-normal blood glucose. Because withholding must begin days before the procedure, the plan has to be made at booking rather than on admission. URL: https://getpathways.ai/glossary/sglt2-inhibitor-perioperative ## STOP-Bang score STOP-Bang is an eight-item screening questionnaire for obstructive sleep apnoea. Each item scores one point — snoring, tiredness, observed apnoeas, high blood pressure, BMI over 35, age over 50, neck circumference over 40cm, and male sex. A score of 5 to 8 indicates high risk of moderate-to-severe OSA. URL: https://getpathways.ai/glossary/stop-bang-score ## Theatre utilisation Theatre utilisation measures how much of the operating time allocated to a list is actually used for surgery. It is a core efficiency measure for both public and private services. Late cancellations damage it disproportionately, because a slot lost on the day usually cannot be refilled — unlike one released with a week's notice. URL: https://getpathways.ai/glossary/theatre-utilisation