Fellowship of the Royal College of Anaesthetists (FRCA) Subspecialty Anaesthesia Syllabus

Give the paediatric formula for maximum allowable blood loss (MABL).

$$\text{MABL} = \frac{\text{EBV} \times (Hct_{start} - Hct_{min})}{Hct_{start}}$$ where estimated blood volume (EBV) is approximately 90 mL/kg in neonates, 80 mL/kg in infants and 70 mL/kg in older children.

Describe a caudal epidural block in children: indication, landmark and a common dosing guide.

Used for sub-umbilical surgery analgesia. The needle enters the sacral hiatus through the sacrococcygeal membrane between the sacral cornua. Armitage regimen: 0.5 mL/kg for sacral, 1 mL/kg for lumbar/lower thoracic, and 1.25 mL/kg for upper abdominal spread, using 0.25% (or 0.125%) levobupivacaine.

Outline the anaesthetic priorities for pyloric stenosis repair.

It is a medical, not surgical, emergency: first correct the hypochloraemic, hypokalaemic metabolic alkalosis and dehydration with fluid resuscitation before theatre. Then perform rapid sequence induction (full stomach), empty the stomach via NG tube, and anticipate postoperative apnoea due to CSF alkalosis.

List the components of the Monro-Kellie doctrine and its clinical consequence.

The skull is a fixed volume containing brain (~80%), blood (~10%) and CSF (~10%). An increase in any component, or a mass lesion, must be compensated by a decrease in another; once compensation is exhausted, intracranial pressure rises steeply for small volume increases.

Give the formula for cerebral perfusion pressure and typical target values.

$$CPP = MAP - ICP$$ (use ICP or central venous pressure, whichever is higher). Normal ICP is 5-15 mmHg; CPP is usually targeted at 60-70 mmHg in traumatic brain injury to maintain cerebral perfusion while avoiding ARDS-promoting high pressures.

Describe the relationship between $PaCO_2$ and cerebral blood flow, and its anaesthetic use.

Cerebral blood flow changes roughly linearly with $PaCO_2$ between about 3 and 10 kPa (~$1$-$2$ mL/100 g/min per mmHg). Hyperventilation to lower $PaCO_2$ causes vasoconstriction and reduces ICP acutely, but is used cautiously and short-term because excessive reduction risks ischaemia.

List anaesthetic strategies for cerebral protection and ICP control during craniotomy.

Maintain CPP, head-up tilt and avoid neck obstruction (venous drainage), normocapnia or mild hypocapnia, avoid hypoxia/hyperthermia/hyperglycaemia, smooth haemodynamics avoiding coughing/straining, mannitol or hypertonic saline for osmotherapy, and total intravenous anaesthesia or low-dose volatile to preserve autoregulation.

How do volatile agents and propofol differ in their cerebral effects?

Volatile agents are cerebral vasodilators that increase cerebral blood volume and ICP and impair autoregulation in a dose-dependent way (uncoupling flow and metabolism). Propofol reduces cerebral metabolic rate, cerebral blood flow and ICP while preserving coupling, making TIVA favourable in neuroanaesthesia.

State the immediate physiological targets in traumatic brain injury management (the 'avoid hypoxia and hypotension' rule).

Avoid secondary brain injury: maintain $SpO_2 > 94\%$ / $PaO_2 > 13$ kPa, systolic BP $> 110$ mmHg (avoid hypotension), normocapnia ($PaCO_2$ ~4.5-5.0 kPa), normoglycaemia, normothermia, and CPP 60-70 mmHg. Treat raised ICP with tiered measures.

What are the main anaesthetic risks specific to the sitting/beach-chair position for posterior fossa surgery?

Venous air embolism (subatmospheric pressure in head veins), haemodynamic instability/cerebral hypoperfusion, pneumocephalus, and macroglossia/airway oedema. Monitoring includes precordial Doppler/end-tidal $CO_2$ and a central line to aspirate entrained air.

Outline anaesthetic considerations for prone spinal surgery.

Risks include airway/tube displacement, eye and pressure-point injury (postoperative visual loss from ischaemic optic neuropathy), reduced venous return and major blood loss. Manage with careful positioning, free abdomen, eye protection, blood conservation (cell salvage, tranexamic acid) and possible neuromonitoring requiring TIVA without muscle relaxation.

What is the basic principle of cardiopulmonary bypass (CPB)?

Deoxygenated blood is drained by gravity from the right atrium/venae cavae to a reservoir, pumped through a membrane oxygenator and heat exchanger, then returned to the aorta, while the heart is arrested with cardioplegia. This provides a bloodless, motionless field with the machine taking over heart and lung function.

What is cardioplegia and how does it protect the myocardium?

A high-potassium solution (with the aorta cross-clamped) that depolarises and arrests the heart in diastole, abolishing electromechanical activity to minimise myocardial oxygen demand. It may be cold (hypothermic) and given antegrade and/or retrograde, blood- or crystalloid-based.

State the typical anticoagulation target for CPB and how it is monitored and reversed.

Heparin is given (~300-400 units/kg) to achieve an activated clotting time (ACT) above 400-480 seconds before bypass. It is reversed at the end with protamine (~1 mg per 100 units of heparin), watching for protamine reactions.

List methods of achieving lung isolation for one-lung ventilation and a key advantage of each.

Double-lumen tube: allows independent ventilation/suction of each lung and rapid switching, ideal for most thoracic cases. Bronchial blocker: useful in difficult airways, children, or already-intubated/ICU patients, leaving a single-lumen tube in situ for postoperative ventilation.

How is correct double-lumen tube placement confirmed, and what is the management of hypoxaemia during one-lung ventilation?

Confirm with fibreoptic bronchoscopy (and auscultation). For hypoxaemia: increase $FiO_2$, check tube position, apply CPAP to the non-dependent lung and/or PEEP to the dependent lung, intermittent re-inflation, and ultimately ask the surgeon to clamp the pulmonary artery.

Explain hypoxic pulmonary vasoconstriction and its relevance to thoracic anaesthesia.

Hypoxic pulmonary vasoconstriction diverts blood from poorly ventilated (collapsed) lung regions to better ventilated areas, reducing shunt. During one-lung ventilation it limits hypoxaemia; volatile agents and vasodilators can blunt it, worsening oxygenation.

What are the major anaesthetic concerns during aortic cross-clamping in open vascular surgery?

Application causes an abrupt rise in afterload, hypertension proximal to the clamp and increased myocardial work; release causes 'declamping shock' with hypotension from reactive hyperaemia, vasodilatation and washout of metabolites/acid. Both require anticipatory haemodynamic and metabolic management, plus organ (renal/spinal cord) protection.

What are the standard transoesophageal echocardiography views used to assess left ventricular function and which structures they show?

The mid-oesophageal four-chamber view (all chambers and mitral/tricuspid valves), mid-oesophageal long-axis (LVOT, aortic and mitral valves), and transgastric mid-papillary short-axis (LV walls of all three coronary territories, ideal for assessing filling and regional wall motion).

State the modified Allen's test purpose and the main complication TOE is used to detect intraoperatively.

The modified Allen's test assesses ulnar collateral hand circulation before radial arterial cannulation. TOE intraoperatively detects new regional wall motion abnormalities (ischaemia), valve dysfunction, intracardiac air, hypovolaemia and aortic pathology.

List anaesthetic considerations for the oculocardiac reflex during ophthalmic (squint) surgery.

Traction on extraocular muscles or pressure on the globe triggers a trigeminovagal reflex causing bradycardia/asystole. Management: ask the surgeon to stop traction, ensure adequate ventilation, and give IV antimuscarinic (atropine/glycopyrrolate); it fatigues with repeated stimulation.

What is the key anaesthetic challenge of a shared airway in ENT/laser airway surgery and how is fire risk reduced?

The surgeon and anaesthetist share the airway, limiting access and tube space. Laser fire risk is reduced by using the lowest effective $FiO_2$ (avoid $O_2$ and $N_2O$ enrichment), a laser-resistant tube with saline-filled cuff, saline-soaked swabs, and a fire-drill plan to stop gas and remove the tube if ignition occurs.

List the criteria that make a patient and procedure suitable for day-case surgery.

Stable/controlled comorbidity (ASA 1-3 with optimised disease, not strict BMI/age cut-offs), a procedure with low risk of major bleeding or prolonged specialist care, manageable postoperative pain with oral analgesia, a responsible escort and adequate home support, and ability to return if needed.

What additional safety measures are required when anaesthetising in remote/non-theatre locations (e.g. MRI, cath lab)?

Same standard of monitoring, equipment, assistance and recovery as theatre. MRI demands MRI-conditional/non-ferromagnetic equipment, long breathing/infusion lines from outside the bore, projectile precautions, hearing protection and acoustic awareness, plus a plan to evacuate the patient in an emergency.

List the airway and physiological challenges of the patient with obesity for anaesthesia.

Difficult mask ventilation/intubation and rapid desaturation (reduced FRC), higher aspiration risk, obstructive sleep apnoea, restrictive ventilation, ischaemic heart disease, diabetes, and altered pharmacokinetics. Manage with ramped positioning, preoxygenation/CPAP, regional techniques, and weight-appropriate (lean vs total body) drug dosing.

How should anaesthetic drug doses be scaled in obesity (lean body weight vs total body weight)?

Lipophilic drugs and maintenance use total or adjusted body weight (e.g. propofol infusion, volatile uptake), while induction doses of many drugs and most others (e.g. propofol induction, neuromuscular blockers, opioids like fentanyl) are dosed to lean/ideal body weight to avoid overdose. Succinylcholine is dosed to total body weight.

What anaesthetic considerations apply to the patient with end-stage liver disease?

Coagulopathy (reduced clotting factors, thrombocytopenia), encephalopathy, hyperdynamic circulation with low SVR, hepatorenal syndrome, altered drug handling/protein binding, ascites and aspiration risk. Use drugs with hepatic-independent elimination (e.g. atracurium, cisatracurium) and correct coagulation guided by viscoelastic testing.

Which neuromuscular blocking agents are preferred in renal failure and why?

Atracurium and cisatracurium, because they undergo organ-independent Hofmann elimination and ester hydrolysis, so their duration is unaffected by impaired renal clearance. Drugs with renal excretion of active forms/metabolites (e.g. morphine, pancuronium) accumulate and are avoided.

List the key physiological features of frailty/ageing relevant to anaesthesia.

Reduced physiological reserve in all systems, decreased MAC and increased drug sensitivity, stiff non-compliant vasculature (labile BP), impaired baroreflexes, reduced renal/hepatic clearance, increased risk of postoperative delirium, and impaired thermoregulation. Doses are reduced and titrated carefully.

State the ASA physical status classification levels 1-5.

ASA 1: normal healthy patient; ASA 2: mild systemic disease; ASA 3: severe systemic disease that limits activity but is not incapacitating; ASA 4: severe systemic disease that is a constant threat to life; ASA 5: moribund patient not expected to survive without the operation. 'E' is appended for emergencies; ASA 6 is brain-dead organ donor.

Define the levels of procedural sedation and the key safety principle linking them.

Minimal (anxiolysis, normal response to voice), moderate ('conscious', purposeful response to voice/touch, airway maintained), deep (responds to repeated/painful stimuli, may need airway support), and general anaesthesia. Sedation is a continuum, so the practitioner must be able to rescue a patient from one level deeper than intended.