Arab Board Anesthesia Final Clinical and Oral Exam key terms

The alveolar concentration of an inhaled anesthetic at one atmosphere that prevents purposeful movement in 50% of patients in response to a standard surgical stimulus. It allows comparison of potency between volatile agents and is reduced by age, hypothermia, pregnancy, and co-administered sedatives.

The time required for the plasma concentration of a drug to fall by half after stopping an infusion, determined mainly by how long the infusion ran and how extensively the drug redistributes into peripheral tissues. It explains why prolonged propofol or remifentanil infusions differ markedly in offset of effect.

The estimated drug concentration at the receptor site producing the observed clinical effect, which lags behind plasma concentration because of circulation and diffusion delay. Target-controlled infusion devices use it to predict onset and offset of drugs such as propofol and remifentanil.

The phenomenon in which rapid uptake of a high-concentration gas such as nitrous oxide increases the alveolar concentration of a simultaneously administered volatile agent, accelerating its induction. It results from concentration and volume effects within the alveolus.

Objective assessment of neuromuscular function using peripheral nerve stimulation, typically train-of-four, post-tetanic count, or double-burst stimulation, to guide dosing of muscle relaxants and confirm adequate reversal before extubation. Quantitative acceleromyography is preferred over subjective tactile or visual estimation.

The ratio of the fourth to the first evoked muscle twitch during supramaximal train-of-four stimulation. A ratio of 0.9 or greater at the adductor pollicis indicates adequate recovery from neuromuscular blockade and reduces residual paralysis risk.

A modified gamma-cyclodextrin that encapsulates rocuronium and vecuronium in plasma, rapidly reversing even deep neuromuscular blockade. It is ineffective against benzylisoquinolinium agents such as atracurium and cisatracurium and carries a small risk of anaphylaxis and bradycardia.

A structured, rehearsed sequence of escalating interventions for anticipated or unanticipated failure to ventilate or intubate, progressing from optimized face-mask ventilation through supraglottic devices, videolaryngoscopy, and finally emergency front-of-neck access. It emphasizes limiting attempts, calling for help, and maintaining oxygenation throughout.

A life-threatening emergency in which neither tracheal intubation nor any supraglottic or face-mask technique can maintain oxygenation. It mandates immediate emergency front-of-neck access, usually a scalpel-bougie-tube cricothyrotomy, without further attempts at laryngoscopy.

Delivery of oxygen into the pharynx during apnea, without ventilation, to slow the rate of hemoglobin desaturation by exploiting mass flow and alveolar oxygen uptake. It prolongs the safe apnea time during intubation attempts and is commonly applied with high-flow nasal cannulae.

An induction technique designed to minimize the interval between loss of consciousness and securing the airway, using a rapidly acting induction agent and neuromuscular blocker with minimal or no mask ventilation. It is indicated when aspiration risk is increased, such as in full stomach or bowel obstruction.

Application of backward pressure on the cricoid cartilage to compress the upper esophagus and reduce passive regurgitation during induction of anesthesia. Evidence for benefit is limited, and excessive force can worsen laryngoscopic view and obstruct ventilation.

Chemical injury to the lung from inhalation of gastric contents, producing bronchospasm, hypoxemia, and a permeability pulmonary edema, most often during induction or emergence. Management is supportive, with airway protection, suction, oxygen, and lung-protective ventilation if respiratory failure develops.

Injection of local anesthetic into the subarachnoid space to block spinal nerve roots, producing rapid, dense surgical anesthesia with predictable segmental spread. Hypotension from sympathetic blockade is common, and contraindications include coagulopathy, raised intracranial pressure, and patient refusal.

A postural headache, worse upright and relieved lying flat, caused by cerebrospinal fluid leakage through a dural puncture, typically appearing within days. Conservative treatment, caffeine, and an epidural blood patch are the mainstays when symptoms are disabling.

Injection of the patient's own sterile blood into the epidural space to seal a cerebrospinal fluid leak causing post-dural puncture headache. It relieves symptoms in most patients; transient back pain and, rarely, infection or neurological injury may occur.

A dose-related syndrome of neurological excitation followed by depression and cardiovascular collapse caused by excessive plasma concentrations of local anesthetic. Management includes airway support, benzodiazepines for seizures, and early intravenous lipid emulsion in severe cardiac toxicity.

A rescue therapy for local anesthetic systemic toxicity consisting of a bolus and infusion of 20% lipid emulsion, thought to create an intravascular lipid phase that sequesters the lipophilic drug. It is given alongside standard resuscitation and may require prolonged CPR.

A local anesthetic solution combined with epinephrine to produce vasoconstriction, which slows systemic absorption, prolongs block duration, and reduces peak plasma concentrations. It is avoided in digits and other end-arterial territories by tradition, though evidence of harm is weak.

A multidisciplinary, evidence-based perioperative pathway combining preoperative counseling, opioid-sparing multimodal analgesia, early feeding, and early mobilization to reduce complications and length of stay. Anesthesia practice within it emphasizes short-acting agents and avoidance of unnecessary drains and catheters.

Use of two or more analgesic drugs or techniques with different mechanisms to improve pain relief while reducing opioid dose and opioid-related adverse effects. Typical components include paracetamol, NSAIDs, regional blocks, and adjuncts such as ketamine or dexmedetomidine.

Structured preoperative optimization of physical fitness, nutrition, and psychological state, and correction of anemia or smoking, to improve tolerance of surgery and speed recovery. It is most studied in major abdominal, thoracic, and orthopedic cancer surgery.

A reduced analgesic response to opioids after repeated exposure, requiring higher doses for equivalent effect. Patients on long-term opioids need baseline replacement plus additional analgesia, and may have opioid-induced hyperalgesia and higher postoperative requirements.

Reduction in respiratory rate, tidal volume, and ventilatory response to carbon dioxide caused by opioid action at brainstem receptors. It is the main cause of harm from neuraxial and systemic opioids and is detected by sedation scoring, capnography, or continuous oximetry.

Continuous measurement and display of the carbon dioxide concentration in respired gas, producing a waveform that confirms tracheal tube placement, detects disconnection, and reflects ventilation and cardiac output. It is a mandatory standard during general anesthesia and is increasingly used for sedation safety.

Factors that make oxygen saturation readings unreliable or misleading, including poor perfusion, motion, venous pulsation, nail polish, and abnormal hemoglobins such as carboxyhemoglobin and methemoglobin. Normal readings also do not exclude hyperoxia or inadequate ventilation.

A standardized pre-use inspection of the anesthesia workstation covering gas supply, vaporizers, breathing circuit, scavenging, unidirectional valves, and the presence of a self-inflating bag and suction. It is performed before every case to prevent delivery of hypoxic or misconnected gas mixtures.

A confidential system for recording adverse events and near misses so that causes can be analyzed and systems improved rather than individuals blamed. It underpins safety culture and feeds into root cause analysis and morbidity and mortality review.

The process of giving a patient adequate information about a proposed intervention, its alternatives, and material risks, and obtaining voluntary agreement, with capacity assessed and documented. An anesthetist must discuss anesthetic options and specific risks relevant to that patient.

A written statement made by a person with capacity specifying treatment preferences or appointing a surrogate decision-maker for a future time when they cannot decide. It guides, but does not replace, clinical judgment and must be interpreted in the current clinical context.

The clinical and sometimes ancillary confirmation of irreversible loss of all brainstem and cerebral function, including unresponsiveness, absent brainstem reflexes, and sustained apnea despite adequate hypercapnic challenge. Preconditions such as exclusion of sedatives, hypothermia, and metabolic disturbance must be met.

The pressure within the rigid cranial vault, normally below about 15 mmHg in adults, determined by brain, blood, and cerebrospinal fluid volumes. Sustained elevation reduces cerebral perfusion pressure and risks herniation, so anesthesia for neurosurgery targets normocapnia, normotension, and head elevation.

The difference between mean arterial pressure and intracranial pressure, representing the driving pressure for cerebral blood flow. It is targeted in neurocritical care, typically above 60 mmHg, by manipulating blood pressure, sedation, and cerebrospinal fluid drainage.

A flow-directed catheter passed through the right heart into the pulmonary artery to measure cardiac output, pulmonary artery pressures, and mixed venous oxygen saturation. Its use has declined because trials showed no outcome benefit and it carries risks of arrhythmia, infection, and pulmonary artery rupture.

The percentage change in stroke volume during the respiratory cycle, used as a dynamic index of fluid responsiveness in patients receiving positive-pressure ventilation with a regular rhythm and adequate tidal volume. Values above roughly 13% suggest that volume expansion will increase cardiac output.

Compression of the heart by accumulating pericardial fluid, impairing diastolic filling and reducing cardiac output, with hypotension, raised jugular venous pressure, and muffled heart sounds. Anesthesia induction can precipitate profound collapse, so drainage is often performed before or with careful hemodynamic support.

A pregnancy-specific disorder of new hypertension after 20 weeks with proteinuria or maternal organ dysfunction, caused by abnormal placentation and endothelial dysfunction. Neuraxial anesthesia is preferred for delivery, with careful blood pressure control and attention to thrombocytopenia and pulmonary edema.

Adverse effects of therapeutic magnesium infusion, ranging from flushing and loss of deep tendon reflexes to respiratory depression, heart block, and cardiac arrest at high levels. Monitoring of reflexes, respiration, and urine output guides infusion, and calcium gluconate is the antidote.

Excessive blood loss after delivery, conventionally over 500 mL after vaginal birth or 1000 mL after cesarean, most often from uterine atony. Management follows a structured sequence of uterine massage, uterotonics, tranexamic acid, and escalation to balloon tamponade, embolization, or surgery.

A preplanned, coordinated approach to replacing large blood losses with balanced ratios of red cells, plasma, and platelets, alongside calcium, warming, and correction of fibrinolysis. It aims to prevent the lethal triad of hypothermia, acidosis, and coagulopathy.

Reflex closure of the vocal cords triggered by stimulation of the airway during light anesthesia or by secretions, blood, or vomit, causing partial or complete obstruction. Management includes removing the stimulus, continuous positive airway pressure with oxygen, deepening anesthesia, and, if persistent, small-dose suxamethonium.

Anatomic features of the child's airway including a relatively large head and tongue, a high and anterior larynx, a long floppy epiglottis, and a narrowest point at the cricoid ring in young children. These favor a straight blade and uncuffed or carefully sized tubes and increase obstruction risk.

A supraglottic device with a cuff that seals against the pharyngeal and laryngeal inlet, allowing ventilation without tracheal intubation. It is useful for short procedures and rescue ventilation but does not protect against aspiration and is unsuitable for high airway pressures.