EDAIC Part 1 2027: prepare for Paper A and Paper B

Why: The great radicular artery (artery of Adamkiewicz) is the major blood supply to the lower two-thirds of the spinal cord and originates between T9 and T12 in approximately 75% of cases.

Why: The anterior spinal artery supplies the anterior two-thirds of the spinal cord, including the motor tracts; the posterior spinal artery supplies the dorsal sensory columns.

Why: Spinal cord perfusion pressure is defined as distal mean aortic pressure minus CSF pressure or central venous pressure, whichever is greatest.

Why: During hypoxia or hypercapnia, autoregulation of spinal cord blood flow is lost, and flow becomes linearly related to perfusion pressure.

Why: CSF pressure often increases with aortic cross-clamping; draining CSF reduces this pressure and improves spinal cord perfusion pressure, lowering ischemic risk.

Why: Peripheral nerves are usually viewed in short axis rather than long axis during ultrasound-guided regional anesthesia.

Why: The honeycomb appearance on sonogram represents the fascicles of a polyfascicular peripheral nerve viewed in short axis.

Why: In the out-of-plane technique, the needle crosses the plane of imaging and appears as an echogenic dot on the sonogram.

Why: Most studies suggest that adequate visualization and correct identification of structures is more important than the specific needle approach for outcomes after regional blocks.

Why: Textured surfaces on echogenic needles are manufactured to improve needle tip detection by generating more recordable echoes compared with smooth conventional needles.

Why: Correct sizing of oropharyngeal airways involves measuring from the corner of the mouth to the angle of the jaw or the earlobe, as described in Miller's Anesthesia.

Why: Nasopharyngeal airways are less stimulating than oropharyngeal airways; oropharyngeal airways can precipitate coughing, retching, or laryngospasm because they contact the base of the tongue and epiglottis.

Why: The nasopharyngeal airway is designed to lift the soft palate off the pharyngeal wall, thereby eliminating this mode of airway obstruction.

Why: Oropharyngeal airways can precipitate coughing, retching, or laryngospasm and are not appropriate for use in conscious patients who have not had local anaesthetic applied to the airway.

Why: Inappropriately sized oropharyngeal airways can actually worsen airway obstruction, making correct size selection critically important.

Why: Huang et al. (2014) conducted a Cochrane systematic review comparing cardiopulmonary resuscitation plus delayed defibrillation versus immediate defibrillation for out-of-hospital cardiac arrest, examining the optimal timing of defibrillation.

Why: Salen et al. (2005) investigated whether the presence or absence of sonographically identified cardiac activity predicts resuscitation outcomes, finding it to be a useful prognostic indicator during cardiac arrest.

Why: Chan et al. found no survival improvement associated with in-hospital AED use; overall survival was lower in the AED group. This was an observational association, not proof of causation, and does not change the need for prompt defibrillation of shockable rhythms. Source: JAMA 2010;304:2129-2136, doi:10.1001/jama.2010.1576.

Why: FALSE — Trap: The Cochrane review by Huang et al. found that the benefit of CPR before defibrillation depends on the time to defibrillation. It is not recommended for all patients regardless of time to rhythm analysis; the benefit is primarily seen when there is a prolonged response time.

Why: Ruygrok et al. (2009) validated three termination of resuscitation criteria for predicting good neurologic survival after out-of-hospital cardiac arrest, providing evidence-based guidance for when resuscitation efforts may be ceased.

Why: Sevoflurane is typically used for inhalational induction due to its low blood-gas partition coefficient and non-irritant properties, allowing smooth induction.

Why: The single-breath technique with high-concentration sevoflurane in a prefilled reservoir bag enables rapid induction in cooperative patients.

Why: FALSE — Trap: Ether has a very high blood-gas partition coefficient (12), making inhalational induction slow and technically challenging; it is not preferred for induction.

Why: FALSE — Trap: Maintenance concentrations of isoflurane are 1%–2%, not 3%–4%, once anaesthesia has been established.

Why: Complications during inhalational induction include problems during stage 2, when pharyngeal or laryngeal stimulation may trigger laryngeal spasm.

Why: Novel oral anticoagulants including these four agents are now commonly used for thromboprophylaxis in AF.

Why: FALSE — Trap: While warfarin was the mainstay in the past, novel oral anticoagulants are now commonly utilized and have largely supplemented warfarin.

Why: The benefit of stroke prevention is counterbalanced by the risk of both intracranial and extracranial bleeding with anticoagulation.

Why: Anticoagulation must be discontinued for AF patients with active bleeding in the ICU.

Why: False. The 2024 ESC atrial fibrillation guideline does not recommend antiplatelet therapy as an alternative to oral anticoagulation for AF-related stroke prevention. Aspirin may have a separate vascular indication, which does not make it adequate AF stroke prevention. Source: European Heart Journal 2024;45:3314-3414, section 6.3, doi:10.1093/eurheartj/ehae176.