Egyptian Board Anesthesia key terms

The volume of gas remaining in the lungs after a normal tidal exhalation; it equals expiratory reserve volume plus residual volume and acts as the main oxygen reservoir during apnea.

The lung volume at which small airways begin to close during expiration; when it exceeds functional residual capacity, airway closure occurs during tidal breathing, causing shunt and hypoxemia, especially in the elderly and obese.

The alveolar concentration of an inhaled anesthetic at one atmosphere that prevents movement in 50% of patients in response to a standard surgical stimulus; used to compare potency and titrate depth.

The time for plasma concentration of a drug to fall by half after stopping an infusion, measured from the moment of cessation; it lengthens with longer infusion duration for lipophilic drugs such as propofol and remifentanil is largely spared.

The modeled concentration of a drug at its site of action, linked to plasma concentration by a rate constant that accounts for equilibration delay; used in target-controlled infusion to predict clinical effect.

The phenomenon in which rapid uptake of a high-concentration gas such as nitrous oxide accelerates the rise in alveolar concentration of a concurrently administered volatile agent, speeding induction.

A transient fall in alveolar oxygen tension at the end of nitrous oxide anesthesia, caused by nitrous oxide diffusing from blood into alveoli and diluting oxygen; prevented by giving 100% oxygen.

Objective assessment of neuromuscular block using peripheral nerve stimulation and evoked responses such as train-of-four ratio; essential to confirm adequate recovery before extubation and to avoid residual paralysis.

The amplitude of the fourth evoked response divided by the first during train-of-four stimulation; a ratio of 0.9 or greater at the adductor pollicis indicates adequate recovery from nondepolarizing neuromuscular blockade.

A modified gamma-cyclodextrin that encapsulates rocuronium and vecuronium in plasma, rapidly reversing even deep neuromuscular blockade; dosing depends on the depth of block and it can cause anaphylaxis and transient bradycardia.

Administration of high inspired oxygen before induction of anesthesia or airway instrumentation to replace alveolar nitrogen with oxygen, prolonging the safe apnea time and reducing desaturation during laryngoscopy.

A preoperative tool estimating 30-day risk of major cardiac events after noncardiac surgery from six factors: ischemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, renal impairment, and high-risk surgery.

Incremental exercise testing measuring oxygen consumption, anaerobic threshold, and ventilatory efficiency; used to stratify perioperative risk before major surgery, with poor anaerobic threshold predicting complications.

An acute focal neurological deficit of vascular origin occurring during or within 30 days after surgery; most are ischemic and often follow hypotension, atrial fibrillation, or carotid disease in high-risk patients.

An acute fluctuating disturbance of attention and cognition with altered awareness, common after surgery in older adults; identified with tools such as CAM-ICU and prevented through sleep, orientation, analgesia, and early mobilization.

A decline in memory, attention, or executive function detected by neuropsychological testing weeks to months after surgery, distinct from acute delirium; associated with age, preexisting cognitive impairment, and major surgery.

An induction technique using a fast-acting induction agent and neuromuscular blocker with minimal delay after preoxygenation and cricoid pressure, designed to reduce aspiration risk in patients with a full stomach.

A structured, stepwise plan for managing unanticipated difficulty with ventilation, supraglottic rescue, tracheal intubation, or front-of-neck access; emphasizes limiting attempts and calling for help early.

Indirect laryngoscopy using a camera-equipped blade to display the glottis on a screen; improves glottic view in difficult airways and is a first-line device in many difficult airway guidelines.

Collapse of lung tissue with loss of aerated alveoli, commonly occurring after induction of anesthesia and in the dependent lung; contributes to shunt, hypoxemia, and postoperative pulmonary complications.

A transient increase in airway pressure applied during mechanical ventilation to reopen collapsed alveoli, followed by adequate positive end-expiratory pressure to keep them open and improve oxygenation.

The difference between plateau pressure and positive end-expiratory pressure during mechanical ventilation; a marker of lung stress strongly associated with outcome in acute respiratory distress syndrome.

Placing a ventilated patient face down to improve oxygenation and survival in moderate to severe acute respiratory distress syndrome; requires careful team coordination to avoid pressure injuries and airway loss.

An ultrasound-guided injection of local anesthetic around the trunks and divisions of the brachial plexus above the clavicle, providing dense anesthesia of the entire upper limb; risk includes pneumothorax and phrenic nerve palsy.

Injection of local anesthetic between the anterior and middle scalene muscles targeting the C5-C6 roots, ideal for shoulder surgery; it frequently causes ipsilateral phrenic nerve palsy and hoarseness.

Neurological and cardiovascular toxicity from excessive local anesthetic absorption or intravascular injection, presenting with tinnitus, seizures, arrhythmias, and cardiac arrest; treated with lipid emulsion and supportive care.

An ultrasound-guided block of the saphenous nerve in the mid-thigh that provides knee analgesia after total knee arthroplasty with less quadriceps weakness than femoral nerve block.

Delivery of local anesthetic, often with an opioid, into the epidural space via a catheter to provide segmental neuraxial analgesia; used for labor, thoracic and abdominal surgery, but risks hypotension, retention, and hematoma.

Combining analgesics with different mechanisms, such as paracetamol, NSAIDs, opioids, and regional techniques, to improve pain relief while reducing opioid dose and side effects.

A reduced analgesic response to opioids after repeated exposure, requiring higher doses for the same effect; patients on long-term opioids need careful perioperative planning and may need higher or alternative analgesia.

A paradoxical increase in pain sensitivity caused by prolonged or high-dose opioid exposure, distinct from tolerance and withdrawal; managed by reducing opioids and using multimodal and non-opioid strategies.

The difference between mean arterial pressure and intracranial pressure; it determines cerebral blood flow and must be maintained during neuroanesthesia and in patients with raised intracranial pressure.

The pressure within the rigid skull exerted by brain, cerebrospinal fluid, and blood; sustained elevation reduces cerebral perfusion and can cause herniation, requiring controlled ventilation and osmotic therapy.

The ability of cerebral, renal, and coronary circulations to maintain relatively constant blood flow despite changes in perfusion pressure; cerebral autoregulation is impaired by head injury and some anesthetics.

Ventilation of only one lung, usually via a double-lumen tube or bronchial blocker, to allow thoracic surgery; requires lung-protective settings and management of hypoxemia from shunt.

Blood flow from the uterine and umbilical vessels supplying the fetus; it lacks autoregulation and depends on maternal arterial pressure and cardiac output, so maternal hypotension causes fetal compromise.

Manual or wedge displacement of the gravid uterus to the left during cesarean delivery or maternal resuscitation, relieving aortocaval compression and improving maternal cardiac output and fetal perfusion.

Injection of local anesthetic, often with opioid, into the subarachnoid space to provide surgical anesthesia for cesarean delivery; rapid onset and dense block, with risk of hypotension and high block.

Nausea or vomiting occurring within 24 hours after surgery, driven by patient, anesthetic, and surgical factors; prevented with risk-based prophylaxis using antiemetics and opioid-sparing techniques.

Life-threatening organ dysfunction caused by a dysregulated host response to infection; identified by rising SOFA score and managed with early antibiotics, fluids, vasopressors, and source control.

Sepsis with persistent hypotension requiring vasopressors to maintain mean arterial pressure of at least 65 mmHg and a lactate level above 2 mmol/L despite adequate fluid resuscitation.

An abrupt decline in renal function with rising creatinine or reduced urine output; perioperative causes include hypovolemia, hypotension, nephrotoxins, and contrast, and it independently predicts mortality.

A pharmacogenetic hypermetabolic crisis triggered by volatile anesthetics and succinylcholine, causing hyperthermia, rigidity, hypercarbia, and rhabdomyolysis; treated by stopping triggers and giving dantrolene.

A severe, rapidly developing systemic hypersensitivity reaction with airway swelling, bronchospasm, hypotension, and rash; treated immediately with intramuscular adrenaline, fluids, and oxygen.

A coordinated system for delivering blood products in a balanced ratio to patients with major hemorrhage, while minimizing crystalloid and correcting calcium, temperature, and coagulation.

A strategy for severe trauma and hemorrhage using permissive hypotension, early blood products over crystalloid, rapid hemorrhage control, and correction of hypothermia, acidosis, and coagulopathy.

An antifibrinolytic that blocks lysine binding sites on plasminogen, reducing bleeding in trauma, cardiac, and orthopedic surgery; given early in trauma and associated with improved survival.

Structured preoperative team communication tools that confirm patient identity, procedure, allergies, equipment, and contingency plans; they reduce errors and improve safety culture in the operating room.

A systematic method for investigating adverse events to identify underlying system failures rather than blaming individuals; findings guide changes in processes, equipment, and training.

The ethical and legal process of explaining a proposed procedure, its benefits, risks, and alternatives, and confirming the patient's voluntary decision-making capacity before anesthesia or surgery.