Arab Board Anesthesia Part 1 cheat sheet

Adult spinal cord terminates as the conus medullaris at L1-L2 in adults; a dural puncture at L3-L4 or below avoids cord injury.

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

The internal jugular vein lies lateral to the carotid artery within the carotid sheath; the right IJV is preferred because it is larger and has a straighter path to the SVC.

The pleura extends above the medial third of the clavicle, so subclavian vein cannulation carries a risk of pneumothorax.

The brachial plexus emerges between the anterior and middle scalene muscles; the interscalene approach targets the C5-C7 roots/trunks.

The recurrent laryngeal nerve supplies all intrinsic laryngeal muscles except the cricothyroid; it is at risk during thyroid surgery and with subglottic instrumentation.

The angle of Louis (T4-T5) marks the level of the carina and the bifurcation of the trachea.

The femoral nerve lies lateral to the femoral artery, which lies lateral to the femoral vein (NAVY: nerve, artery, vein, ylem).

Functional residual capacity (FRC) = expiratory reserve volume + residual volume; it is the volume remaining after a normal expiration and is the main oxygen reservoir during apnea.

Closing capacity = closing volume + residual volume; when closing capacity exceeds FRC, airway closure occurs during tidal breathing, causing shunt.

Oxygen content = (1.34 × Hb × SaO2) + (0.003 × PaO2); dissolved oxygen contributes little at atmospheric pressure.

Cardiac output = heart rate × stroke volume; stroke volume is determined by preload, afterload, and contractility (Frank-Starling relationship).

Cerebral blood flow is approximately 50 mL/100 g/min and is coupled to metabolism; it is autoregulated between MAP ~50-150 mmHg.

Renal blood flow is ~20% of cardiac output; the kidney autoregulates GFR via the myogenic response and tubuloglomerular feedback.

Alveolar gas equation: PAO2 = FiO2 × (Patm − 47) − (PaCO2 / R), where R is the respiratory quotient (~0.8).

Hypoxic pulmonary vasoconstriction diverts blood from poorly ventilated alveoli; it is inhibited by volatile anesthetics and vasodilators.

Context-sensitive half-time is the time for plasma concentration to fall by half after cessation of an infusion; it increases with infusion duration for drugs like remifentanil (minimally) versus fentanyl (substantially).

Propofol induction dose is ~2-2.5 mg/kg IV; it causes dose-dependent hypotension via vasodilation and myocardial depression.

Succinylcholine is a depolarizing blocker metabolized by plasma pseudocholinesterase; prolonged block occurs in pseudocholinesterase deficiency.

Rocuronium and vecuronium are aminosteroid nondepolarizers; rocuronium has the fastest onset and can be reversed by sugammadex.

Neostigmine inhibits acetylcholinesterase and is co-administered with an antimuscarinic (glycopyrrolate) to block muscarinic effects.

MAC (minimum alveolar concentration) is the alveolar concentration preventing movement to a noxious stimulus in 50% of patients; potency is inversely related to MAC.

Hepatic clearance depends on hepatic blood flow and intrinsic enzyme activity; the first-pass effect reduces oral bioavailability.

Zero-order kinetics (e.g., phenytoin, ethanol at high doses) means a constant amount is eliminated per unit time, so small dose increases can cause large plasma level rises.

The oxygen flush valve delivers 35-75 L/min directly to the breathing circuit, bypassing the vaporizer.

A circle system with CO2 absorber allows low fresh gas flows; the soda lime reaction is exothermic and produces water.

The diameter index safety system (DISS) and pin index safety system (PISS) prevent misconnection of gas cylinders and pipeline outlets.

Oxygen cylinders are color-coded white (US) or black with white shoulders (ISO); medical air is yellow.

A self-inflating bag (Ambu) does not require a gas supply and functions during pipeline failure.

The laryngeal mask airway sits over the laryngeal inlet; it does not protect against aspiration and is not a definitive airway.

A Mapleson A (Magill) circuit is efficient for spontaneous ventilation; Mapleson D (Bain) is efficient for controlled ventilation.

The scavenging system removes waste anesthetic gas; the reservoir bag and adjustable pressure-limiting (APL) valve control circuit pressure.

Pulse oximetry relies on differential light absorption of oxyhemoglobin and deoxyhemoglobin at red (~660 nm) and infrared (~940 nm) wavelengths.

Capnography measures CO2 by infrared absorption; the normal end-tidal CO2 is 35-45 mmHg, and an abrupt fall suggests embolism, hypotension, or circuit disconnection.

Invasive blood pressure measurement requires a transducer leveled at the phlebostatic axis (fourth intercostal space, midaxillary line).

Doppler ultrasound uses the frequency shift of reflected sound to estimate blood flow velocity.

Laminar flow is described by the Hagen-Poiseuille equation (flow ∝ radius^4 × pressure gradient / length × viscosity); turbulent flow follows the Reynolds number.

The gas laws: Boyle's law (PV = constant at constant T), Charles's law (V/T constant at constant P), and Dalton's law (total pressure = sum of partial pressures).

Electrical safety: microshock risk exists for patients with intracardiac catheters; isolation transformers and ground fault circuit interrupters reduce risk.

The bispectral index (BIS) is a processed EEG monitor used to titrate depth of anesthesia; values of 40-60 correspond to surgical anesthesia.

Rapid sequence induction uses a fast-onset induction agent plus succinylcholine or high-dose rocuronium with cricoid pressure to reduce aspiration risk.

Spinal anesthesia typically uses a hyperbaric local anesthetic (e.g., bupivacaine in dextrose) injected at L3-L4 or below; the block level depends on baricity and patient position.

Epidural anesthesia acts on nerve roots in the epidural space; a test dose with epinephrine detects intravascular placement.

The triad of general anesthesia is hypnosis, analgesia, and muscle relaxation, plus amnesia and autonomic stability.

Local anesthetic systemic toxicity (LAST) presents with perioral numbness, tinnitus, seizures, and cardiovascular collapse; treatment is 20% lipid emulsion.

Maximum recommended dose of lidocaine with epinephrine is ~7 mg/kg; without epinephrine ~4.5 mg/kg (approximate adult values).

Supraclavicular and interscalene blocks target the brachial plexus; phrenic nerve palsy is a common complication of interscalene block.

The ASA physical status classification ranges from I (healthy) to VI (brain-dead organ donor).

Sepsis-3 defines sepsis as life-threatening organ dysfunction from infection, identified by a SOFA score increase of ≥2 points.

Septic shock is sepsis with persistent hypotension requiring vasopressors to maintain MAP ≥65 mmHg and lactate >2 mmol/L despite fluid resuscitation.

ARDS is defined by acute onset, bilateral opacities, PaO2/FiO2 ≤300 mmHg, and exclusion of cardiogenic pulmonary edema (Berlin definition).

Lung-protective ventilation in ARDS uses tidal volumes of 4-6 mL/kg predicted body weight and plateau pressure ≤30 cmH2O.

The Surviving Sepsis Campaign recommends 30 mL/kg crystalloid for initial resuscitation and norepinephrine as the first-line vasopressor.

Acute kidney injury is staged by the KDIGO criteria based on serum creatinine rise and urine output.

The anion gap = Na+ − (Cl− + HCO3−); a normal gap is ~8-12 mEq/L, and an elevated gap suggests ketoacidosis, lactic acidosis, or toxic ingestion.

Permissive hypercapnia is tolerated in ARDS to limit ventilator-induced lung injury.

The WHO analgesic ladder: step 1 non-opioid, step 2 weak opioid, step 3 strong opioid, with adjuvants at any step.

Opioid side effects include respiratory depression, constipation, pruritus, and tolerance; naloxone reverses opioid-induced respiratory depression.

Multimodal analgesia combines agents acting at different sites (e.g., paracetamol, NSAIDs, local anesthetics, opioids) to reduce total opioid requirement.

Neuropathic pain responds to gabapentinoids, tricyclic antidepressants, and SNRIs rather than to opioids alone.

Palliative care focuses on symptom relief and quality of life; opioid dosing is titrated to effect and does not have a fixed ceiling for severe pain.

Nociceptive pain arises from tissue injury; neuropathic pain arises from nerve injury and is described as burning, shooting, or electric-shock-like.

Nerve blocks and epidural analgesia provide targeted pain relief and reduce systemic opioid consumption.

Ketamine at subanesthetic doses acts as an NMDA receptor antagonist and is used for refractory pain and opioid tolerance.

In patients with coronary artery disease, maintain diastolic blood pressure and avoid tachycardia to preserve coronary perfusion.

For pheochromocytoma resection, preoperative alpha-blockade (phenoxybenzamine) precedes beta-blockade to avoid unopposed alpha stimulation.

In obstructive sleep apnea, preoperative CPAP and careful postoperative monitoring reduce respiratory complications.

For carotid endarterectomy, maintain blood pressure to support cerebral perfusion; regional or general anesthesia are both acceptable.

In patients with severe aortic stenosis, maintain sinus rhythm, preload, and afterload; avoid tachycardia and hypotension.

Patients with myasthenia gravis have reduced sensitivity to depolarizing blockers and are sensitive to nondepolarizing blockers.

In obese patients, dose induction agents on lean body weight and use lung-protective ventilation.

For one-lung ventilation, hypoxic pulmonary vasoconstriction is impaired by volatile anesthetics, so FiO2 and ventilation to the dependent lung are optimized.

Adult CPR: chest compressions at 100-120/min, depth 5-6 cm, with a compression-to-ventilation ratio of 30:2.

Defibrillation for shockable rhythms (VF/pulseless VT) uses biphasic 120-200 J; adrenaline is given every 3-5 minutes in cardiac arrest.

In trauma, the primary survey follows ABCDE: Airway, Breathing, Circulation, Disability, Exposure.

Permissive hypotension in hemorrhagic shock targets a systolic pressure ~90 mmHg until hemorrhage control.

Massive transfusion protocols give balanced ratios of red cells, plasma, and platelets (~1:1:1).

Tension pneumothorax is treated with immediate needle decompression followed by chest tube insertion.

The Glasgow Coma Scale ranges from 3 to 15 and assesses eye, verbal, and motor responses.

Anaphylaxis is treated with intramuscular adrenaline 0.5 mg (1:1000) into the anterolateral thigh, repeated as needed.

Informed consent requires capacity, disclosure of material risks and alternatives, and voluntary agreement.

The four ethical principles are autonomy, beneficence, non-maleficence, and justice.

A never event is a serious, preventable patient safety incident (e.g., wrong-site surgery, retained foreign body) that should never occur.

The WHO surgical safety checklist reduces morbidity and mortality by standardizing pre-, intra-, and postoperative communication.

Root cause analysis is a structured method to identify system failures behind adverse events rather than blaming individuals.

The duty of candour requires disclosure of harmful errors to patients and families.

Confidentiality may be breached only when required by law or to prevent serious harm to others.

Handover tools such as SBAR (Situation, Background, Assessment, Recommendation) improve communication and patient safety.