ADBA Dental Anesth key terms

The alveolar concentration of an inhaled anesthetic at which 50 percent of patients do not move in response to a standardized surgical stimulus. It is used to compare potency and to guide dosing of volatile agents.

The phenomenon in which rapid uptake of a high-volume gas such as nitrous oxide concentrates the remaining alveolar gases, speeding induction with a concurrently administered volatile agent.

The observation that a higher inspired concentration of an inhaled anesthetic raises the alveolar-to-inspired ratio more quickly, producing faster induction because more agent enters the lung per unit of uptake.

A solubility ratio describing how an anesthetic distributes between blood and alveolar gas at equilibrium. Low values mean rapid equilibration and faster induction and emergence; high values mean slower onset.

The pharmacokinetic process by which an inhaled anesthetic moves from alveoli into blood and then into brain and other tissues, governed by solubility, ventilation, blood flow, and concentration gradients.

Noninvasive estimation of arterial oxygen saturation by measuring differential light absorption of oxygenated and deoxygenated hemoglobin across a pulsatile vascular bed. It is a standard monitor during sedation and general anesthesia.

Continuous measurement and display of inhaled and exhaled carbon dioxide concentration over time. The waveform confirms tracheal placement, detects apnea or obstruction, and reflects ventilation and cardiac output.

Administration of high inspired oxygen before induction to replace nitrogen in the functional residual capacity, creating an oxygen reservoir that prolongs safe apnea time.

The volume of gas remaining in the lungs at the end of a normal passive expiration. It acts as the oxygen reservoir during apnea and is reduced by obesity, pregnancy, and restrictive lung disease.

Absence of spontaneous breathing. In anesthesia it may be intentional during controlled ventilation or an unintended complication of opioids, propofol, or airway obstruction requiring immediate support.

A drug class that enhances gamma-aminobutyric acid activity, producing anxiolysis, sedation, amnesia, and anticonvulsant effects. Respiratory depression and paradoxical agitation are important dose-related risks.

A competitive benzodiazepine receptor antagonist used to reverse benzodiazepine-induced sedation and respiratory depression. It can precipitate seizures in benzodiazepine-dependent patients and has a shorter duration than many benzodiazepines.

An opioid receptor antagonist that rapidly reverses opioid-induced respiratory depression, sedation, and analgesia. Repeat dosing or infusion may be needed because its duration is shorter than that of many opioids.

A class of analgesics acting at mu, kappa, or delta receptors that produce analgesia, sedation, and dose-dependent respiratory depression. Common perioperative effects include nausea, pruritus, and constipation.

An intravenous alkylphenol sedative-hypnotic with rapid onset and offset from redistribution. It causes dose-dependent hypotension, apnea, and injection pain, and has no intrinsic analgesic effect.

An N-methyl-D-aspartate receptor antagonist producing dissociative sedation with analgesia and amnesia while preserving spontaneous ventilation and airway reflexes. It can cause hypertension, tachycardia, salivation, and emergence reactions.

A short-acting water-soluble benzodiazepine used for anxiolysis, sedation, and amnesia. It can cause respiratory depression, especially when combined with opioids, and is reversible with flumazenil.

A trance-like state of altered consciousness with analgesia and amnesia produced by agents such as ketamine, in which the patient may maintain airway patency and spontaneous respiration.

A drug-induced depression of consciousness in which patients respond purposefully to verbal or light tactile stimulation and maintain spontaneous ventilation and airway patency. It corresponds to conscious sedation in dental practice.

A drug-induced depression of consciousness in which patients respond purposefully only to repeated or painful stimulation and may lose airway patency or spontaneous ventilation. It requires advanced airway and rescue skills.

Anesthetic delivery using only intravenous agents, typically propofol with or without opioids, without inhaled anesthetics. It avoids nitrous oxide and volatile exposure but requires reliable vascular access and vigilance for apnea.

A pump delivery method that uses pharmacokinetic models to maintain a user-set predicted drug concentration in plasma or at the effect site, adjusting infusion rates automatically.

A dose-related spectrum of adverse effects from local anesthetics, beginning with perioral numbness, tinnitus, and agitation and progressing to seizures, coma, arrhythmias, and cardiovascular collapse.

Intravenous administration of a lipid emulsion as an antidote for severe local anesthetic systemic toxicity, given alongside standard resuscitation and airway support to sequester lipophilic anesthetic molecules.

The weight-based upper limit of local anesthetic that may be administered, usually expressed in milligrams per kilogram, adjusted for epinephrine content, patient factors, and site of injection.

An agent such as epinephrine added to a local anesthetic to constrict local blood vessels, slowing systemic absorption, prolonging anesthesia, and reducing bleeding. It can cause tachycardia and hypertension.

Reflex closure of the vocal cords, often triggered by secretions, blood, or stimulation during light anesthesia. It may cause partial or complete airway obstruction and is managed with suction, positive pressure, and deepening anesthesia or muscle relaxation.

An unexpected response opposite to the intended drug effect, such as agitation or disinhibition after benzodiazepine sedation, especially in children or older adults. Management includes reassurance and avoiding further sedative escalation.

A pharmacogenetic hypermetabolic crisis triggered by volatile anesthetics or succinylcholine, marked by rising temperature, rigidity, hypercarbia, and tachycardia. Immediate dantrolene and supportive care are required.

A muscle relaxant that inhibits calcium release from the sarcoplasmic reticulum and is the specific antidote for malignant hyperthermia. It is given intravenously in repeated doses until the crisis abates.

A halogenated liquid anesthetic vaporized for inhalation, such as sevoflurane or desflurane, that produces dose-dependent unconsciousness and amnesia. Potency is described by MAC and exposure can trigger malignant hyperthermia.

A six-category system ranking preoperative medical health from normal (I) to brain-dead organ donor (VI). It guides risk discussion, monitoring, and anesthesia setting but does not predict procedural difficulty.

Structured assessment of history, medications, allergies, airway, and comorbidities before anesthesia to identify risk, plan monitoring, and select an appropriate setting and technique.

A bedside airway assessment scoring visible oropharyngeal structures with the mouth open and tongue protruded, from class I (soft palate, fauces, uvula, pillars) to class IV (hard palate only). Higher classes suggest difficult visualization.

A clinical situation in which trained personnel experience difficulty with mask ventilation, supraglottic device placement, laryngoscopy, or intubation. It requires a preformed rescue plan and alternative devices.

The process of disclosing a procedure's nature, risks, benefits, and alternatives, then confirming the patient's voluntary authorization. It must precede sedation or anesthesia and be documented.

The required fasting interval before sedation or anesthesia to reduce aspiration risk, commonly two hours for clear liquids and longer for light meals. It is individualized for emergencies and comorbidities.

Entry of gastric contents or oral material into the airway, which can cause chemical pneumonitis, obstruction, or infection. Risk rises with full stomach, obesity, pregnancy, and impaired protective reflexes.

The minimum observation required during sedation or anesthesia, including continuous pulse oximetry, intermittent blood pressure, and for deeper levels, exhaled carbon dioxide and continuous electrocardiography.

Objective benchmarks confirming that a patient has regained airway reflexes, stable vital signs, orientation, and adequate pain control before discharge, usually scored with a validated scale and accompanied by written instructions.