ABA APPLIED Exam key terms

The alveolar concentration of an inhaled anesthetic at one atmosphere that prevents purposeful movement in 50% of patients exposed to a standard surgical stimulus. It allows potency comparisons between volatile agents.

The ratio of anesthetic concentration in blood to that in gas at equilibrium. A lower value means the agent equilibrates faster, producing quicker induction and emergence.

The time for plasma drug concentration to fall by half after stopping an infusion, measured from the moment it is stopped. It lengthens as infusion duration increases for lipophilic drugs.

The estimated drug concentration at the receptor site producing the clinical effect. It lags behind plasma concentration because of circulation and diffusion delay, so it predicts effect better than plasma levels.

A pump system that uses a pharmacokinetic model to adjust infusion rates so a chosen plasma or effect-site drug concentration is reached and maintained. The anesthesiologist sets a target rather than a rate.

The accelerated rise in alveolar concentration of a primary anesthetic caused by rapid uptake of a concurrently administered high-volume gas such as nitrous oxide, which concentrates remaining gases.

The phenomenon in which a high inspired fraction of an inhaled anesthetic raises its own alveolar concentration faster than expected, because substantial uptake shrinks the remaining gas volume.

Pharmacologic paralysis produced by drugs that interrupt transmission at the motor end plate, either competitively at acetylcholine receptors or by depolarizing the membrane. It is used to facilitate intubation and surgery.

The ratio of the fourth to the first evoked muscle twitch after four supramaximal stimuli are delivered to a motor nerve. A value of 0.9 or higher indicates adequate recovery from neuromuscular blockade.

A modified gamma-cyclodextrin that encapsulates aminosteroid neuromuscular blockers such as rocuronium and vecuronium, rapidly reversing blockade. It can reverse deep blockade that neostigmine cannot.

A pharmacogenetic hypermetabolic crisis triggered by volatile anesthetics or succinylcholine in susceptible patients. It presents with rising temperature, rigidity, hypercarbia, and acidosis and is treated with dantrolene.

Adverse effects from excessive local anesthetic in the bloodstream, including seizures, arrhythmias, and cardiovascular collapse. Treatment centers on airway support and intravenous lipid emulsion rescue.

Injection of local anesthetic into the cerebrospinal fluid in the subarachnoid space, blocking nerve transmission below the injection level. It produces rapid, dense surgical anesthesia with a defined upper sensory level.

Delivery of local anesthetic, often with an opioid, into the epidural space outside the dura mater to block nerve roots. A catheter allows continuous dosing and titration of a sensory block.

A positional headache that worsens upright and improves lying flat, caused by cerebrospinal fluid leak through a dural puncture. It may be treated conservatively or with an epidural blood patch.

A technique for securing the airway quickly in patients at risk of aspiration, using preoxygenation, a fast-acting induction agent, and a neuromuscular blocker with minimal delay before intubation, often with cricoid pressure.

A structured decision pathway guiding management when mask ventilation, supraglottic device placement, or intubation fails. It emphasizes limiting attempts, calling for help, and choosing rescue oxygenation strategies.

A life-threatening emergency in which neither tracheal intubation nor any other method successfully delivers oxygen. It mandates immediate invasive rescue, typically emergency front-of-neck airway access.

Administration of high inspired oxygen before induction of anesthesia to replace nitrogen in the functional residual capacity. It prolongs the safe apnea period before desaturation occurs.

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 supine positioning.

A processed electroencephalographic monitor value scaled from 0 to 100 that estimates depth of hypnosis. Lower values suggest deeper anesthesia, and it is used to titrate agents and reduce awareness risk.

An acute myocardial injury with ischemia occurring around the time of surgery, often within 30 days. It is frequently silent and driven by supply-demand imbalance rather than plaque rupture.

Use of beta-adrenergic blocking drugs before or during surgery to reduce heart rate and myocardial oxygen demand. Continuation of chronic therapy is generally recommended, while new initiation requires caution.

Nausea or vomiting occurring after anesthesia and surgery, driven by anesthetic, surgical, and patient factors. Prophylaxis uses risk scoring and multimodal antiemetics from different drug classes.

Inadequate breathing after surgery, often from opioids, residual anesthetics, or neuromuscular blockade. It causes hypoventilation, hypercarbia, and hypoxemia and may require monitoring, reversal, or ventilatory support.

Systematic evaluation of a patient's comorbidities, functional capacity, and planned procedure to estimate perioperative risk and guide testing, optimization, and monitoring decisions.

A multimodal, evidence-based perioperative care pathway that combines optimized nutrition, opioid-sparing analgesia, early mobilization, and standardized anesthesia to speed recovery and shorten hospital stay.

A patient who has taken opioids regularly and shows reduced responsiveness, requiring higher doses for analgesia and facing greater risk of withdrawal and hyperalgesia if opioids are abruptly reduced.

Combining analgesics with different mechanisms, such as local anesthetics, acetaminophen, NSAIDs, and opioids, to improve pain relief while reducing reliance on any single agent and its side effects.

A programmable pump that lets the patient self-administer small intravenous opioid doses within set limits. It improves satisfaction and avoids delays from staff-administered dosing.

Ventilation of only one lung, usually achieved with a double-lumen tube or bronchial blocker, to isolate and rest the operative lung. It risks hypoxemia from shunt through the nonventilated lung.

Constriction of pulmonary arterioles in poorly ventilated lung regions, diverting blood toward better-ventilated areas. It reduces shunt and helps preserve oxygenation during one-lung ventilation.

Airway pressure maintained above atmospheric at the end of expiration during mechanical ventilation. It recruits collapsed alveoli and improves oxygenation but can reduce venous return and cardiac output.

An extracorporeal circuit that temporarily takes over gas exchange and blood circulation during cardiac surgery. It requires systemic anticoagulation and produces a systemic inflammatory response.

Administration of protamine sulfate to neutralize heparin after cardiopulmonary bypass or vascular procedures. Rapid infusion can cause hypotension, pulmonary hypertension, and rare anaphylactoid reactions.

Near-infrared spectroscopy applied to the forehead to estimate regional cerebral oxygen saturation. It is used during cardiac and major surgery to detect desaturation and guide interventions.

Spinal or epidural blockade used during labor and cesarean delivery to provide analgesia or surgical anesthesia. It requires attention to maternal hypotension, uteroplacental blood flow, and fetal status.

Structural features of the child's airway, including a relatively large head, large tongue, short neck, and funnel-shaped larynx, that make intubation more challenging and increase obstruction risk.

Anesthesia maintained entirely with intravenous agents, typically propofol with an opioid, without inhaled anesthetics. It is useful when inhalation is undesirable, such as for malignant hyperthermia susceptibility.