Master Emergency Medicine
for DHA

What the DHA Tests in Emergency Medicine

The DHA Emergency Medicine exam tests the ability to rapidly assess, stabilise, and manage acute presentations across all age groups. Candidates must demonstrate knowledge of life-threatening conditions, evidence-based resuscitation protocols, and decision-making for transfer or discharge. Key areas include trauma triage (ATLS principles), acute coronary syndromes, stroke, sepsis, airway emergencies, poisoning, and environmental emergencies. The exam emphasises recognition of red flags, appropriate use of scoring systems (e.g., CURB-65, GCS, qSOFA), and correct application of guidelines such as the ACLS algorithms, NICE sepsis bundle, and local DHA formulary for antidotes and emergency drugs. Practical knowledge of procedural sedation, rapid sequence intubation (RSI), and fluid resuscitation (e.g., balanced crystalloids vs. colloids) is expected. The focus is on safe, time-critical decisions and avoiding common pitfalls in differential diagnosis.

High-Yield Concepts

• Sepsis Recognition and Management: Use qSOFA (≥2: RR≥22, SBP≤100, altered mentation) for early identification. First-hour bundle: blood cultures, lactate, IV broad-spectrum antibiotics (e.g., piperacillin-tazobactam 4.5g IV), 30ml/kg crystalloid for hypotension or lactate ≥4 mmol/L. Vasopressors (norepinephrine) if MAP <65 mmHg after fluids.
• Acute Coronary Syndrome (ACS) Criteria: STEMI: ST elevation ≥1mm in limb leads or ≥2mm in precordial leads, or new LBBB. Door-to-needle time ≤30 min for thrombolysis (tenecteplase) or door-to-balloon ≤90 min for PCI. High-sensitivity troponin: serial measurements at 0 and 3 hours; rule-out if <99th percentile and GRACE score <140.
• Stroke Thrombolysis Eligibility: IV alteplase (0.9 mg/kg, max 90 mg) within 4.5 hours of symptom onset if NIHSS <25, no major contraindications (e.g., INR >1.7, recent surgery, BP >185/110). CT brain must exclude haemorrhage. For large vessel occlusion, consider mechanical thrombectomy up to 6 hours (or 24 hours with perfusion mismatch).
• Anaphylaxis Protocol: First-line: IM adrenaline 0.5 mg (1:1000) anterolateral thigh, repeat every 5 min if needed. High-flow oxygen, IV fluids (bolus 500-1000ml crystalloid). Second-line: chlorphenamine 10mg IV, hydrocortisone 200mg IV. Observe for biphasic reaction for 6-8 hours.
• Major Trauma: ATLS Primary Survey: ABCDE: Airway with C-spine control, Breathing (tension pneumothorax: needle decompression in 2nd ICS midclavicular line), Circulation (pelvic binder for unstable pelvis, IV access, massive transfusion protocol 1:1:1 PRBC:FFP:platelets), Disability (GCS, pupils), Exposure (log roll, rectal tone).
• Diabetic Ketoacidosis (DKA) Management: Dx: glucose >13.9 mmol/L, pH <7.3, bicarbonate <15, ketonaemia. Fluid: 1L 0.9% saline over 1 hour, then 500ml/hr. Insulin: fixed-rate IV infusion 0.1 units/kg/hr. Monitor K+: if <3.5, hold insulin and replace potassium. Correct bicarbonate not recommended unless pH <6.9.
• Status Epilepticus Treatment: First-line: IV lorazepam 0.1 mg/kg (max 4mg) or IM midazolam 10mg if no IV. Second-line: IV phenytoin 20 mg/kg (max 50mg/min) or levetiracetam 60 mg/kg. Refractory: propofol or thiopental with EEG monitoring. Check glucose; give 50ml 50% dextrose if hypoglycaemic.
• Poisoning: Common Antidotes: Paracetamol overdose: N-acetylcysteine (IV 300mg/kg over 21 hours) if serum level above treatment line on Rumack-Matthew nomogram (4h >150 mg/L). Opioid overdose: naloxone 0.4-2mg IV, repeat as needed. Organophosphates: atropine 2mg IV every 5 min until secretions dry, then pralidoxime 2g IV.

Common Traps in Emergency Medicine Questions

• Giving IV fluids to a patient with suspected heart failure before checking for pulmonary oedema can worsen outcome; use cautious boluses and reassess.
• Confusing anaphylaxis with vasovagal syncope: anaphylaxis has skin, respiratory, and GI features; vasovagal has bradycardia and pallor without urticaria.
• Using a single normal troponin to rule out myocardial infarction without serial measurements misses NSTEMI; always repeat at 3 hours.
• Delaying antibiotics in sepsis while awaiting cultures increases mortality; give within 1 hour of recognition, even if cultures are pending.
• In major trauma, assuming a normal blood pressure means no haemorrhagic shock; compensatory tachycardia and narrowed pulse pressure are early signs.
• Administering insulin in DKA without checking potassium can cause fatal hypokalaemia; always correct K+ first if <3.5 mmol/L.

How to Revise Emergency Medicine for the DHA

Prioritise high-acuity, time-sensitive conditions: sepsis, ACS, stroke, anaphylaxis, major trauma, and DKA. Memorise cut-off values (e.g., qSOFA ≥2, door-to-needle 30 min, lactate ≥4 mmol/L) and first-line drug doses (e.g., adrenaline 0.5mg IM, alteplase 0.9 mg/kg). Questions often present a clinical scenario with a single abnormal vital sign or lab value requiring immediate action—do not get distracted by non-critical details. Practise applying scoring systems (CURB-65, GCS, NIHSS) to determine disposition (ICU vs. ward vs. discharge). Review DHA-specific formulary for antidotes and emergency medications. Focus on ATLS and ACLS algorithms, as these are tested in a stepwise manner. Avoid over-investigating before stabilisation; the exam rewards decisive, guideline-based management.

Practise it: MedLumen has 69 Emergency Medicine questions for the DHA, each with a full explanation and references.