Arab Board Anesthesia Part 1 flashcards

34 cards. Read the term and the definition here. The deck at the top of this page is optional.

Conus medullaris level

In adults the spinal cord ends at L1-L2; dural puncture at L3-L4 or below avoids direct needle injury to the cord.

Cricothyroid membrane

Membrane between thyroid and cricoid cartilages, roughly 1-2 cm below the laryngeal prominence; it is the standard site for emergency front-of-neck airway access.

Recurrent laryngeal nerve

Branch of the vagus nerve supplying all intrinsic laryngeal muscles except the cricothyroid; it is at risk during thyroid surgery and can be injured by subglottic instrumentation.

Functional residual capacity

Expiratory reserve volume plus residual volume; it is the volume remaining after a normal expiration and serves as the main oxygen reservoir during apnea.

Closing capacity

Closing volume plus residual volume; when it exceeds FRC, small airways close during tidal breathing, producing shunt and hypoxemia.

Oxygen content formula

CaO2 = (1.34 × Hb × SaO2) + (0.003 × PaO2); dissolved oxygen contributes only a small fraction at atmospheric pressure.

Alveolar gas equation

PAO2 = FiO2 × (Patm − 47) − (PaCO2 / R); it estimates alveolar oxygen tension and helps calculate the A-a gradient.

Context-sensitive half-time

Time for plasma concentration to fall by half after an infusion stops; it grows with infusion duration for drugs such as fentanyl but minimally for remifentanil.

Minimum alveolar concentration

Alveolar concentration of a volatile anesthetic preventing movement to a noxious stimulus in 50% of patients; potency is inversely related to MAC.

Succinylcholine metabolism

Depolarizing blocker hydrolyzed by plasma pseudocholinesterase; deficiency of this enzyme causes prolonged neuromuscular blockade.

Sugammadex reversal

Modified cyclodextrin that encapsulates rocuronium and vecuronium, rapidly reversing aminosteroid neuromuscular blockade even after high-dose rocuronium.

Zero-order kinetics

Elimination of a constant amount per unit time at high concentrations (e.g., phenytoin, ethanol); small dose increases can cause large plasma level rises.

Oxygen flush valve

Delivers 35-75 L/min directly into the breathing circuit while bypassing the vaporizer; used to rapidly fill the circuit or ventilate manually.

Pin index safety system

Cylinder valve pin configuration that prevents connecting the wrong gas cylinder to the anesthesia machine yoke.

Mapleson A circuit

Magill circuit efficient for spontaneous ventilation; the Mapleson D (Bain) configuration is more efficient for controlled ventilation.

Laryngeal mask airway

Supraglottic device seated over the laryngeal inlet; it does not protect against aspiration and is not a definitive airway.

Pulse oximetry principle

Uses differential absorption of red (~660 nm) and infrared (~940 nm) light by oxyhemoglobin and deoxyhemoglobin to estimate arterial oxygen saturation.

Capnography

Infrared measurement of exhaled CO2; normal end-tidal CO2 is 35-45 mmHg, and an abrupt fall suggests embolism, hypotension, or disconnection.

Phlebostatic axis

Reference point at the fourth intercostal space, midaxillary line, used to level the transducer for accurate invasive blood pressure measurement.

Hagen-Poiseuille equation

Describes laminar flow, which is proportional to the fourth power of radius and the pressure gradient and inversely proportional to length and viscosity.

Rapid sequence induction

Technique using a fast-onset induction agent with succinylcholine or high-dose rocuronium and cricoid pressure to reduce aspiration risk in full-stomach patients.

Lipid emulsion rescue

20% lipid emulsion is the specific treatment for local anesthetic systemic toxicity, given alongside airway and cardiovascular support.

Spinal anesthesia baricity

Hyperbaric local anesthetic (e.g., bupivacaine in dextrose) sinks in CSF, so the block level depends on baricity and patient position.

Sepsis-3 definition

Life-threatening organ dysfunction from infection, identified by a SOFA score increase of at least 2 points.

ARDS Berlin criteria

Acute onset of bilateral opacities with PaO2/FiO2 ≤300 mmHg and no cardiogenic cause; managed with lung-protective ventilation.

Anion gap

Na+ − (Cl− + HCO3−); a normal gap is about 8-12 mEq/L, and elevation suggests ketoacidosis, lactic acidosis, or toxic ingestion.

WHO analgesic ladder

Stepwise approach: step 1 non-opioid, step 2 weak opioid, step 3 strong opioid, with adjuvants added at any step.

Neuropathic pain

Pain arising from nerve injury, described as burning, shooting, or electric-shock-like; treated with gabapentinoids, tricyclics, and SNRIs.

Pheochromocytoma alpha-blockade

Preoperative phenoxybenzamine alpha-blockade must precede beta-blockade to avoid unopposed alpha stimulation and hypertensive crisis during resection.

Aortic stenosis anesthesia

Maintain sinus rhythm, preload, and afterload while avoiding tachycardia and hypotension to preserve coronary perfusion in severe aortic stenosis.

Adult CPR ratio

Chest compressions at 100-120/min and 5-6 cm depth with a compression-to-ventilation ratio of 30:2 for adult cardiac arrest.

Tension pneumothorax

Life-threatening condition treated with immediate needle decompression followed by chest tube insertion; do not delay for imaging.

WHO surgical safety checklist

Standardized pre-, intra-, and postoperative checklist that improves communication and reduces surgical morbidity and mortality.

Duty of candour

Ethical and professional obligation to disclose harmful errors to patients and families openly and promptly.