AS3.1-6 | Preoperative Evaluation and Medication — Glossary

The formal written documentation of the pre-anaesthetic assessment, including ASA class, airway assessment, relevant history, medication plan, investigations, proposed anaesthetic technique, and fasting instruction; a medicolegal record.

A four-item PONV risk score: female sex, non-smoking status, prior PONV or motion sickness, and expected postoperative opioids; score 3-4 indicates high risk and warrants multimodal prophylaxis.

A six-class classification system (I-VI, with E for emergency) grading the severity of a patient's systemic disease for anaesthetic risk communication; does not directly grade operative difficulty.

Chemical injury to the lungs caused by inhalation of acidic gastric contents (Mendelson's syndrome); risk is highest with gastric pH below 2.5 and volume above 25 mL; aspiration prophylaxis targets both factors.

The use of a short-acting anticoagulant (typically therapeutic LMWH) during the perioperative period when a patient's long-term anticoagulant (warfarin) is held; used in patients at high thromboembolic risk.

Reduction in myocardial contractility and systemic vascular resistance caused by induction agents such as propofol and thiopentone; a major mechanism of perioperative hypotension.

The specific treatment for malignant hyperthermia; a ryanodine receptor antagonist that inhibits calcium release from the sarcoplasmic reticulum; must be available in every operating theatre where volatile agents are used.

A synthetic corticosteroid with potent antiemetic and anti-inflammatory effects; given 4-8 mg IV at induction for PONV prophylaxis; causes postoperative hyperglycaemia — glucose monitoring required in diabetics.

Adverse effects of dopamine D2 antagonists (metoclopramide, promethazine) on the extrapyramidal motor system — acute dystonia, oculogyric crisis, akathisia; treated with procyclidine or benztropine IV.

A competitive GABA-A receptor antagonist that reverses benzodiazepine-induced sedation; has a shorter half-life than midazolam — re-sedation can occur; not routinely given but must be available when benzodiazepine premedication is used.

The ability of a patient to perform activities of daily living, expressed in METs; a practical predictor of perioperative cardiac reserve more informative than resting cardiac tests alone.

A quaternary anticholinergic that does not cross the blood-brain barrier; used as an antisialogogue (0.2 mg IM) before fibreoptic intubation or paediatric anaesthesia; preferred over atropine to avoid central anticholinergic syndrome.

Suppression of the hypothalamic-pituitary-adrenal axis by exogenous corticosteroids; patients taking prednisolone 5 mg or more daily for more than 3 weeks may not mount an adequate cortisol stress response perioperatively.

Mouth opening measured between the upper and lower incisor teeth; 3 finger breadths or more (approximately 4-5 cm) is adequate for most laryngoscopy; below 3 cm predicts difficulty.

Type I (IgE-mediated) hypersensitivity to natural rubber latex proteins; can cause anaphylaxis perioperatively; requires complete latex-free equipment and environment in the operating room.

A systematic airway assessment framework: Look externally, Evaluate 3-3-2 rule, Mallampati class, Obstruction, Neck mobility; used to predict difficult laryngoscopy and intubation.

A composite endpoint including myocardial infarction, cardiac death, and significant arrhythmia; the primary perioperative cardiac outcome predicted by RCRI and similar risk tools.

A rare pharmacogenetic disorder of skeletal muscle calcium regulation (RYR1 gene) triggered by volatile anaesthetics and suxamethonium, causing hyperthermia, rigidity, rhabdomyolysis, and death if untreated; treated with dantrolene.

A life-threatening pharmacogenetic disorder of skeletal muscle (RYR1 gene) triggered by volatile anaesthetic agents and suxamethonium, causing hyperthermia, muscle rigidity, rhabdomyolysis, and metabolic acidosis; treated with dantrolene.

A four-class (I-IV) grading of the oropharyngeal view with mouth fully open and tongue protruded, used to predict difficulty of laryngoscopy and intubation.

A unit of resting oxygen consumption (3.5 mL O2/kg/min); functional capacity of 4 METs or more (e.g., climbing stairs without stopping) indicates adequate cardiorespiratory reserve for most non-cardiac surgeries.

A dopamine D2 antagonist with prokinetic and central antiemetic properties; used for aspiration risk reduction; contraindicated in Parkinson's disease (worsens dopamine deficiency) and in complete bowel obstruction.

A short-acting water-soluble benzodiazepine that is the most commonly used premedication for anxiolysis; standard adult oral dose 5-7.5 mg, 30-60 minutes before induction; must be dose-reduced in elderly, respiratory disease, and hepatic impairment.

A competitive opioid receptor antagonist that reverses opioid-induced respiratory depression; short acting (30-45 min) — re-narcotisation can occur with long-acting opioids; must be available when opioid premedication is given.

Repetitive upper airway collapse during sleep causing apnoea and oxygen desaturation; increases perioperative risk of difficult airway, respiratory depression from opioids, and postoperative hypoxaemia.

A selective 5-HT3 receptor antagonist; the most widely used antiemetic for PONV prophylaxis; minimal sedation; standard dose 4-8 mg IV at induction or 8 mg orally 1 hour before surgery.

The difference between a patient's resting organ function and maximum functional capacity; determines whether the patient can tolerate the physiological stress of anaesthesia and surgery.

An adverse effect of benzodiazepines — instead of sedation, the patient becomes agitated, combative, and confused; more common in children and the elderly; treated with flumazenil.

A common postoperative complication with risk factors including female sex, non-smoker status, history of PONV or motion sickness, and use of postoperative opioids; assessed by the Apfel score.

Nausea and vomiting occurring within 24 hours of surgery; major risk factors include female sex, non-smoking status, prior PONV or motion sickness, use of volatile agents, and postoperative opioids; assessed by Apfel score.

A structured history, medication review, and clinical examination performed before any anaesthetic procedure; produces the anaesthetic plan, monitoring prescription, fasting instruction, and consent documentation.

Drugs administered before anaesthesia induction to achieve anxiolysis, analgesia, aspiration prevention, PONV prophylaxis, or autonomic modification; must be individually prescribed, not given routinely to all patients.

A structured clinical assessment conducted before any anaesthetic procedure, aiming to identify risk factors, optimise modifiable conditions, and formulate an individualised anaesthetic plan.

A drug that accelerates gastrointestinal motility and gastric emptying; metoclopramide and domperidone are prokinetics used perioperatively to reduce aspiration risk by decreasing gastric volume.

A hereditary deficiency of plasma cholinesterase that markedly prolongs the action of suxamethonium and mivacurium, causing prolonged neuromuscular blockade known as suxamethonium apnoea.

A six-level scale assessing depth of sedation: Level 1 (anxious/agitated) to Level 6 (no response); Level 2 (cooperative, oriented, tranquil) is the target for premedication; Level 3 or above after ward administration requires immediate anaesthetic review.

An anaesthetic induction technique using a pre-oxygenation period, rapid-acting induction agent, and immediate dose of suxamethonium or rocuronium with cricoid pressure, used when aspiration risk is elevated (full stomach, GORD, emergency).

A six-variable scoring system (Lee index) predicting the risk of major adverse cardiac events (MACE) before non-cardiac surgery; each additional point increases predicted risk from approximately 0.4% (RCRI 0) to more than 5% (RCRI 3 or more).

The optimal position for direct laryngoscopy: neck flexed (lower cervical flexion) and head extended at the atlanto-occipital joint, aligning oral, pharyngeal, and laryngeal axes.

A non-particulate antacid (0.3 M, 30 mL orally) given 15-30 minutes before emergency induction to raise gastric pH above 2.5; standard premedication for emergency anaesthesia and obstetric general anaesthesia.

Supplementary hydrocortisone given perioperatively to patients on long-term corticosteroids who have HPA axis suppression, to prevent adrenal crisis during the surgical stress response.

An eight-item questionnaire screening for obstructive sleep apnoea risk (Snoring, Tiredness, Observed apnoea, blood Pressure/hypertension, BMI >35, Age >50, Neck >40 cm, Gender male); score 5 or above indicates high risk.

The neuroendocrine and inflammatory response to surgical trauma, including catecholamine surge, cortisol release, and cytokine activation; in patients with limited reserve, this can precipitate organ failure.

The distance from the chin (mentum) to the thyroid notch with head fully extended; 6.5 cm or more is generally considered favourable for laryngoscopy; below 6 cm suggests potential difficulty.

A technique maintaining general anaesthesia entirely with intravenous agents (typically propofol infusion plus a short-acting opioid), without volatile anaesthetic agents; the technique of choice for MH-susceptible patients.