A 41-year-old woman attends the Emergency Department with her third episode of collapse in six months. Each episode occurs after standing for prolonged periods in warm environments. She describes feeling lightheaded, nauseated, and experiencing blurred vision before losing consciousness. Witnesses report she appears pale, falls slowly to the ground, and recovers within 30-60 seconds. She has no past medical history and takes no medications. All previous investigations including ECG, echocardiography, 48-hour Holter monitoring, and tilt-table testing have been normal. What is the most likely diagnosis?
Q32
A 64-year-old man with metastatic lung cancer on palliative chemotherapy presents to the Emergency Department with a 48-hour history of fever, productive cough, and increasing confusion. His observations: temperature 38.7°C, heart rate 112/min, blood pressure 96/62 mmHg, respiratory rate 28/min, oxygen saturation 88% on room air, AVPU = V. Blood tests show white cell count 2.1 × 10⁹/L (neutrophils 0.6 × 10⁹/L), C-reactive protein 245 mg/L, lactate 3.2 mmol/L, creatinine 145 μmol/L. Chest radiograph shows right lower lobe consolidation. What is the most appropriate initial antibiotic regimen?
Q33
A 56-year-old woman presents with a 3-hour history of palpitations and presyncope. She has no significant past medical history. Her ECG shows a regular narrow complex tachycardia at 180/min with no visible P waves. Blood pressure is 102/68 mmHg, respiratory rate 18/min, oxygen saturation 98% on air. She is alert and oriented. Carotid sinus massage is attempted without effect. Which intravenous medication should be administered first?
Q34
A 29-year-old previously healthy woman collapses at a gym. Bystanders begin CPR immediately. When paramedics arrive 8 minutes later, the cardiac monitor shows ventricular fibrillation. She receives defibrillation at 200 J biphasic and CPR is continued. After the second shock, she achieves return of spontaneous circulation. She remains comatose with GCS 3. Blood glucose is 5.8 mmol/L, temperature 36.2°C. She is intubated and ventilated. Blood pressure is 118/72 mmHg on minimal noradrenaline support. What is the most appropriate additional management?
Q35
A 72-year-old man is admitted with community-acquired pneumonia and sepsis. His initial qSOFA score is 3. Blood cultures are taken and he is started on co-amoxiclav 1.2 g intravenously. Four hours after admission, his blood pressure remains 84/52 mmHg despite 3 litres of crystalloid resuscitation, heart rate is 115/min, and lactate is 4.2 mmol/L. Urine output has been 15 mL in the last 2 hours. What is the most appropriate next step in management?
Q36
A 38-year-old man is brought to the Emergency Department within 5 minutes of receiving an intramuscular penicillin injection at his GP surgery for suspected tonsillitis. He rapidly develops stridor, facial swelling, and wheeze. Blood pressure is 78/45 mmHg, heart rate 128/min, respiratory rate 32/min with audible stridor. He is given intramuscular adrenaline 500 micrograms and high-flow oxygen. After 5 minutes, there is minimal improvement in his stridor and blood pressure remains 82/48 mmHg. What is the most appropriate next step in management?
Q37
A 67-year-old woman with a permanent pacemaker presents following a collapse while climbing stairs. She reports brief loss of consciousness with no warning symptoms and rapid recovery. Examination reveals a slow-rising carotid pulse, a harsh ejection systolic murmur radiating to the carotids, and an absent second heart sound. Blood pressure is 108/68 mmHg, heart rate 72/min and regular. Her ECG shows paced rhythm with appropriate capture. Echocardiography demonstrates severe aortic stenosis with a valve area of 0.7 cm² and mean gradient of 52 mmHg. What is the underlying mechanism of her syncope?
Q38
A 32-year-old woman with a history of Wolff-Parkinson-White syndrome collapses at a wedding. When paramedics arrive, she is unresponsive with no palpable pulse. The cardiac monitor shows an irregular broad complex tachycardia at approximately 240/min with varying QRS morphology. CPR is in progress. What is the most appropriate immediate management?
Q39
A 55-year-old man presents to the Emergency Department with sudden-onset severe chest pain radiating to the back between the scapulae. He describes it as a tearing sensation. He has a history of poorly controlled hypertension. On examination, blood pressure is 178/95 mmHg in the right arm and 142/88 mmHg in the left arm. Heart rate is 102/min and regular. A diastolic murmur is audible at the left sternal edge. His ECG shows left ventricular hypertrophy but no acute ischaemic changes. What is the most appropriate initial imaging investigation?
Q40
A 48-year-old man with type 2 diabetes presents to the Emergency Department with a 24-hour history of fever, rigors, and worsening right upper quadrant pain. On examination, his temperature is 38.9°C, heart rate 118/min, blood pressure 92/58 mmHg, respiratory rate 26/min, and oxygen saturation 94% on room air. He is confused with an AVPU score of V. Blood tests show white cell count 18.2 × 10⁹/L, lactate 3.8 mmol/L, and bilirubin 68 μmol/L. What is the appropriate initial fluid resuscitation strategy according to the Surviving Sepsis Campaign guidelines?
Acute Medical Presentations UK Medical PG Practice Questions and MCQs
Question 31: A 41-year-old woman attends the Emergency Department with her third episode of collapse in six months. Each episode occurs after standing for prolonged periods in warm environments. She describes feeling lightheaded, nauseated, and experiencing blurred vision before losing consciousness. Witnesses report she appears pale, falls slowly to the ground, and recovers within 30-60 seconds. She has no past medical history and takes no medications. All previous investigations including ECG, echocardiography, 48-hour Holter monitoring, and tilt-table testing have been normal. What is the most likely diagnosis?
A. Orthostatic hypotension secondary to autonomic dysfunction
B. Epileptic seizures with postictal confusion masquerading as syncope
C. Psychogenic pseudosyncope requiring psychiatric evaluation
D. Postural orthostatic tachycardia syndrome (POTS)
E. Vasovagal syncope with atypical features requiring further cardiac investigation (Correct Answer)
Explanation: ***Vasovagal syncope with atypical features requiring further cardiac investigation***
- The patient's recurrent episodes of collapse, triggered by **prolonged standing** in **warm environments**, preceded by **lightheadedness, nausea**, and **blurred vision**, with subsequent **pallor** and rapid recovery (30-60 seconds), are classic features of **vasovagal (neurocardiogenic) syncope**.
- Despite normal initial investigations including a tilt-table test, recurrent syncope with these features, especially with potential atypical presentations, necessitates consideration of further cardiac evaluation, such as an **implantable loop recorder (ILR)**, to capture rare events.
*Orthostatic hypotension secondary to autonomic dysfunction*
- **Orthostatic hypotension** typically involves a significant **drop in blood pressure** upon standing, often without the prolonged prodromal symptoms of nausea and blurred vision seen in this patient.
- A **normal tilt-table test** makes significant orthostatic hypotension unlikely, and there is no history of conditions predisposing to **autonomic dysfunction** (e.g., diabetes, Parkinson's disease).
*Epileptic seizures with postictal confusion masquerading as syncope*
- The patient's **rapid recovery** within 30-60 seconds and the absence of **postictal confusion**, tonic-clonic movements, tongue biting, or urinary incontinence, differentiate her episodes from **epileptic seizures**.
- The presence of clear **prodromal autonomic symptoms** like pallor, nausea, and lightheadedness before collapse is characteristic of syncope, not a seizure.
*Psychogenic pseudosyncope requiring psychiatric evaluation*
- The presence of objective physiological signs such as **witnessed pallor** strongly argues against **psychogenic pseudosyncope**, which typically lacks such objective autonomic changes.
- **Psychogenic pseudosyncope** often presents with prolonged episodes, often without a clear physiological trigger, and lacks the consistent prodromal symptoms seen in this patient.
*Postural orthostatic tachycardia syndrome (POTS)*
- **POTS** is characterized by a significant and sustained increase in **heart rate** (at least 30 bpm or to >120 bpm) upon standing, in the absence of orthostatic hypotension.
- Given that her **tilt-table testing** and **48-hour Holter monitoring** were normal, it is highly unlikely that POTS, which would manifest with sustained tachycardia in an upright position, would have been missed.
Question 32: A 64-year-old man with metastatic lung cancer on palliative chemotherapy presents to the Emergency Department with a 48-hour history of fever, productive cough, and increasing confusion. His observations: temperature 38.7°C, heart rate 112/min, blood pressure 96/62 mmHg, respiratory rate 28/min, oxygen saturation 88% on room air, AVPU = V. Blood tests show white cell count 2.1 × 10⁹/L (neutrophils 0.6 × 10⁹/L), C-reactive protein 245 mg/L, lactate 3.2 mmol/L, creatinine 145 μmol/L. Chest radiograph shows right lower lobe consolidation. What is the most appropriate initial antibiotic regimen?
A. Co-amoxiclav 1.2 g intravenously three times daily
B. Clarithromycin 500 mg intravenously twice daily and co-amoxiclav 1.2 g intravenously three times daily
C. Piperacillin-tazobactam 4.5 g intravenously three times daily and gentamicin 5-7 mg/kg intravenously once daily (Correct Answer)
D. Meropenem 1 g intravenously three times daily
E. Ceftriaxone 2 g intravenously once daily and clarithromycin 500 mg intravenously twice daily
Explanation: ***Piperacillin-tazobactam 4.5 g intravenously three times daily and gentamicin 5-7 mg/kg intravenously once daily***
- The patient presents with **neutropenic sepsis** (neutrophils 0.6 × 10⁹/L with fever and infection) and **septic shock**, requiring immediate broad-spectrum **anti-pseudomonal** coverage due to high-risk features.
- **Piperacillin-tazobactam** provides excellent broad-spectrum Gram-positive, Gram-negative (including **Pseudomonas aeruginosa**), and anaerobic coverage; **gentamicin** adds potent synergistic Gram-negative and **anti-pseudomonal** activity.
*Co-amoxiclav 1.2 g intravenously three times daily*
- This regimen lacks specific and sufficient **anti-pseudomonal activity**, which is crucial for patients with chemotherapy-induced **neutropenia** and severe sepsis.
- While effective for some community-acquired infections, it is insufficient for the high-risk bacterial profile and severity of illness seen in **oncological emergencies**.
*Clarithromycin 500 mg intravenously twice daily and co-amoxiclav 1.2 g intravenously three times daily*
- This combination is a standard treatment for severe **community-acquired pneumonia**, but it does not adequately cover for **Pseudomonas aeruginosa** or other highly resistant organisms common in **neutropenic sepsis**.
- **Macrolides** like clarithromycin do not provide the necessary broad-spectrum Gram-negative or **anti-pseudomonal** coverage required for a **neutropenic** patient in septic shock.
*Meropenem 1 g intravenously three times daily*
- **Meropenem** is a carbapenem with very broad-spectrum activity, including excellent **anti-pseudomonal** coverage, but is generally reserved for suspected **ESBL-producing organisms** or as a second-line agent.
- While a potent option, it is not typically the *initial* empirical choice unless there is a known history of **multi-drug resistant** colonization or a severe **penicillin allergy** preventing beta-lactam use.
*Ceftriaxone 2 g intravenously once daily and clarithromycin 500 mg intravenously twice daily*
- **Ceftriaxone** (a third-generation cephalosporin) specifically lacks activity against **Pseudomonas aeruginosa**, a critical pathogen in **neutropenic** patients.
- This combination is appropriate for standard severe **community-acquired pneumonia** but is **inadequate** for a patient with severe **neutropenic sepsis** and features of septic shock.
Question 33: A 56-year-old woman presents with a 3-hour history of palpitations and presyncope. She has no significant past medical history. Her ECG shows a regular narrow complex tachycardia at 180/min with no visible P waves. Blood pressure is 102/68 mmHg, respiratory rate 18/min, oxygen saturation 98% on air. She is alert and oriented. Carotid sinus massage is attempted without effect. Which intravenous medication should be administered first?
A. Adenosine 6 mg as rapid bolus followed by 20 mL saline flush (Correct Answer)
B. Verapamil 5 mg over 2 minutes
C. Metoprolol 5 mg over 5 minutes
D. Amiodarone 300 mg over 20 minutes
E. Magnesium sulphate 2 g over 10 minutes
Explanation: ***Adenosine 6 mg as rapid bolus followed by 20 mL saline flush***
- This patient presents with a **stable regular narrow complex tachycardia** (likely SVT) which did not resolve with vagal maneuvers; **adenosine** is the first-line pharmacological treatment in this scenario.
- It works by transiently blocking the **AV node**, interrupting the re-entrant circuit that causes SVT, and allowing for the restoration of **sinus rhythm**.
*Verapamil 5 mg over 2 minutes*
- **Verapamil**, a non-dihydropyridine calcium channel blocker, is a second-line agent for stable narrow complex tachycardia if adenosine is ineffective or contraindicated.
- It should be used with caution in patients with **heart failure** or **hypotension** as it can worsen cardiac function and blood pressure.
*Metoprolol 5 mg over 5 minutes*
- **Beta-blockers** like metoprolol can slow heart rate in SVT but are generally less effective than adenosine for acute termination of the arrhythmia.
- They are more often used for **rate control** in atrial fibrillation or flutter, or for long-term management of SVT rather than acute termination.
*Amiodarone 300 mg over 20 minutes*
- **Amiodarone** is primarily used for **unstable wide complex tachycardias** or for refractory **ventricular arrhythmias**.
- It is not the first-line drug for stable narrow complex tachycardia and has a slower onset of action compared to adenosine.
*Magnesium sulphate 2 g over 10 minutes*
- **Magnesium sulphate** is the treatment of choice for **Torsades de Pointes**, a specific type of polymorphic ventricular tachycardia.
- It has no role in the acute management of **stable regular narrow complex tachycardia**.
Question 34: A 29-year-old previously healthy woman collapses at a gym. Bystanders begin CPR immediately. When paramedics arrive 8 minutes later, the cardiac monitor shows ventricular fibrillation. She receives defibrillation at 200 J biphasic and CPR is continued. After the second shock, she achieves return of spontaneous circulation. She remains comatose with GCS 3. Blood glucose is 5.8 mmol/L, temperature 36.2°C. She is intubated and ventilated. Blood pressure is 118/72 mmHg on minimal noradrenaline support. What is the most appropriate additional management?
A. Urgent coronary angiography regardless of ECG findings given her young age and cardiac arrest
B. Targeted temperature management to 32-36°C for at least 24 hours (Correct Answer)
C. Immediate CT head to exclude intracranial pathology before further intervention
D. Intravenous amiodarone infusion for 24 hours to prevent VF recurrence
E. Maintain normothermia with active warming to 37°C and await neurological assessment
Explanation: ***Targeted temperature management to 32-36°C for at least 24 hours***
- Guidelines recommend **Targeted Temperature Management (TTM)** for adults who remain unresponsive after **Return of Spontaneous Circulation (ROSC)** following cardiac arrest to improve neurological outcomes.
- Maintaining a constant temperature between **32°C and 36°C** for at least 24 hours helps mitigate **reperfusion injury** and cerebral edema.
*Urgent coronary angiography regardless of ECG findings given her young age and cardiac arrest*
- While essential if **ST-elevation myocardial infarction (STEMI)** is present, routine immediate angiography is not universally mandated for survivors without ECG evidence of ischemia.
- The priority in a stable post-ROSC patient with a **shockable rhythm** and no STEMI is neuroprotection and stabilizing metabolic parameters.
*Immediate CT head to exclude intracranial pathology before further intervention*
- A **CT head** is indicated if the cause of arrest is suspected to be intracranial, but it should not delay the initiation of **neuroprotective strategies** like TTM.
- Given the initial rhythm was **ventricular fibrillation**, a primary cardiac or metabolic cause is more likely than a primary neurological event.
*Intravenous amiodarone infusion for 24 hours to prevent VF recurrence*
- **Amiodarone** is used during active resuscitation for refractory VF/pVT, but there is no strong evidence for routine **prophylactic infusion** post-ROSC to improve survival.
- Management should focus on identifying and treating the **underlying cause** of the arrhythmia rather than prolonged semi-elective antiarrhythmic infusions.
*Maintain normothermia with active warming to 37°C and await neurological assessment*
- Active warming to **37°C** is inappropriate as it risks **rebound hyperthermia**, which is detrimental to the recovering brain.
- Modern post-arrest care emphasizes **fever prevention**; allowing the temperature to rise prematurely can worsen the **ischemic brain injury**.
Question 35: A 72-year-old man is admitted with community-acquired pneumonia and sepsis. His initial qSOFA score is 3. Blood cultures are taken and he is started on co-amoxiclav 1.2 g intravenously. Four hours after admission, his blood pressure remains 84/52 mmHg despite 3 litres of crystalloid resuscitation, heart rate is 115/min, and lactate is 4.2 mmol/L. Urine output has been 15 mL in the last 2 hours. What is the most appropriate next step in management?
A. Commence noradrenaline infusion targeting mean arterial pressure ≥65 mmHg (Correct Answer)
B. Administer further 1 litre crystalloid bolus and reassess
C. Change antibiotic to meropenem and add clarithromycin
D. Continue current management and repeat lactate in 2 hours
E. Arrange urgent echocardiography to assess cardiac function
Explanation: ***Commence noradrenaline infusion targeting mean arterial pressure ≥65 mmHg***- The patient meets the diagnostic criteria for **septic shock**, defined by persistent hypotension requiring **vasopressors** to maintain MAP ≥65 mmHg and a **lactate >2 mmol/L** despite adequate fluid resuscitation.- **Noradrenaline** is the first-line vasopressor of choice to restore perfusion pressure and prevent further end-organ damage, such as the **oliguria** seen in this case.*Administer further 1 litre crystalloid bolus and reassess*- The patient has already received **3 litres of crystalloid**, which is approximately 30mL/kg for a standard adult, yet remains hypotensive and **oliguric**.- Continuing fluid boluses alone in fluid-refractory shock can lead to **fluid overload** and pulmonary edema without correcting the underlying **vasodilation**.*Change antibiotic to meropenem and add clarithromycin*- While **source control** is vital, co-amoxiclav is reasonable empirical therapy for pneumonia, and changing antibiotics will not fix the immediate **hemodynamic collapse**.- Standard sepsis protocols emphasize correcting **tissue hypoperfusion** immediately alongside antimicrobial therapy.*Continue current management and repeat lactate in 2 hours*- Passive monitoring is inappropriate as the patient is in **progressive shock** with evidence of acute kidney injury (low urine output).- Delaying the initiation of **vasopressors** in septic shock is associated with increased mortality and prolonged **organ dysfunction**.*Arrange urgent echocardiography to assess cardiac function*- Although an echo can help differentiate between types of shock, it should not delay the life-saving initiation of **vasopressor support**.- The clinical history of pneumonia and high lactate strongly points to **sepsis** as the primary driver of the hypotension.
Question 36: A 38-year-old man is brought to the Emergency Department within 5 minutes of receiving an intramuscular penicillin injection at his GP surgery for suspected tonsillitis. He rapidly develops stridor, facial swelling, and wheeze. Blood pressure is 78/45 mmHg, heart rate 128/min, respiratory rate 32/min with audible stridor. He is given intramuscular adrenaline 500 micrograms and high-flow oxygen. After 5 minutes, there is minimal improvement in his stridor and blood pressure remains 82/48 mmHg. What is the most appropriate next step in management?
A. Repeat intramuscular adrenaline 500 micrograms and commence intravenous fluid bolus (Correct Answer)
B. Administer intravenous hydrocortisone 200 mg and chlorphenamine 10 mg
C. Commence intravenous adrenaline infusion at 0.05-0.1 micrograms/kg/min
D. Prepare for emergency surgical cricothyroidotomy
E. Administer nebulized adrenaline 5 mg with further intravenous fluids
Explanation: ***Repeat intramuscular adrenaline 500 micrograms and commence intravenous fluid bolus***- In accordance with **Resuscitation Council (UK)** guidelines, if there is no clinical improvement after the initial **IM adrenaline**, a second dose should be administered after **5 minutes**.- Concurrent **aggressive fluid resuscitation** (crystalloid bolus) is critical to address the **distributive shock** caused by massive vasodilation and capillary leak in anaphylaxis.*Administer intravenous hydrocortisone 200 mg and chlorphenamine 10 mg*- These are **second-line treatments** that do not provide immediate relief for life-threatening airway obstruction or hypotension.- **Hydrocortisone** takes hours to work and is primarily used to prevent **biphasic reactions**, while **antihistamines** only address skin symptoms and do not treat physiological collapse.*Commence intravenous adrenaline infusion at 0.05-0.1 micrograms/kg/min*- **IV adrenaline infusions** are reserved for refractory cases that have failed at least two (and often three) IM doses and must be managed by **specialists** in high-dependency settings.- Starting an infusion prematurely carries a high risk of **lethal arrhythmias** and dosing errors compared to the safer **intramuscular route**.*Prepare for emergency surgical cricothyroidotomy*- While **stridor** indicates upper airway narrowing, medical management with further **adrenaline** should be exhausted first while simultaneously calling for senior anesthetic help.- This is an extreme intervention reserved for a **'cannot intubate, cannot oxygenate' (CICO)** scenario where medical therapy has completely failed to provide an airway.*Administer nebulized adrenaline 5 mg with further intravenous fluids*- **Nebulized adrenaline** may provide some symptomatic relief for upper airway edema but is not a substitute for the **systemic effects** provided by IM injection.- It does not address the **hypotension** or systemic mediator release, which are the primary drivers of this patient's clinical deterioration.
Question 37: A 67-year-old woman with a permanent pacemaker presents following a collapse while climbing stairs. She reports brief loss of consciousness with no warning symptoms and rapid recovery. Examination reveals a slow-rising carotid pulse, a harsh ejection systolic murmur radiating to the carotids, and an absent second heart sound. Blood pressure is 108/68 mmHg, heart rate 72/min and regular. Her ECG shows paced rhythm with appropriate capture. Echocardiography demonstrates severe aortic stenosis with a valve area of 0.7 cm² and mean gradient of 52 mmHg. What is the underlying mechanism of her syncope?
A. Vasovagal response to physical exertion causing inappropriate peripheral vasodilation
B. Fixed cardiac output unable to meet increased metabolic demands during exertion (Correct Answer)
C. Left ventricular outflow tract obstruction causing ventricular arrhythmia
D. Pacemaker malfunction causing bradycardia and reduced cardiac output
E. Paradoxical embolism through a patent foramen ovale causing transient cerebral ischaemia
Explanation: ***Fixed cardiac output unable to meet increased metabolic demands during exertion***
- In **severe aortic stenosis**, the stenotic valve creates a fixed **left ventricular outflow tract obstruction**, preventing the heart from increasing its **cardiac output** sufficiently during physical activity.
- During exertion, **peripheral vasodilation** occurs to supply muscles, and the inability to augment cardiac output leads to a drop in **cerebral perfusion pressure**, resulting in syncope.
*Vasovagal response to physical exertion causing inappropriate peripheral vasodilation*
- While physical exertion can trigger vasovagal syncope in some individuals, the patient's severe **aortic stenosis** and classic findings of exertional syncope strongly point to a structural cardiac cause rather than a primary **vasovagal reflex**.
- The mechanism of syncope in severe AS is primarily related to mechanical obstruction and fixed cardiac output, not an "inappropriate" neurocardiogenic response.
*Left ventricular outflow tract obstruction causing ventricular arrhythmia*
- Although patients with severe AS are at increased risk for **ventricular arrhythmias**, the description of syncope as being exertion-related with rapid recovery is more characteristic of **hemodynamic collapse** due to fixed cardiac output rather than an isolated arrhythmogenic event.
- Arrhythmic syncope often occurs without a clear trigger or specific metabolic demand, and recovery might not be as universally rapid.
*Pacemaker malfunction causing bradycardia and reduced cardiac output*
- The ECG explicitly states a **paced rhythm with appropriate capture**, confirming that the **pacemaker** is functioning as intended.
- A heart rate of 72/min is within a normal range for a paced rhythm and does not suggest **bradycardia** as the cause of syncope.
*Paradoxical embolism through a patent foramen ovale causing transient cerebral ischaemia*
- There is no clinical indication of a **patent foramen ovale (PFO)** or a source of **venous thromboembolism** in the patient's presentation.
- Syncope in this context is transient and generalized, typically due to global cerebral hypoperfusion, not focal **transient cerebral ischemia** from an embolus.
Question 38: A 32-year-old woman with a history of Wolff-Parkinson-White syndrome collapses at a wedding. When paramedics arrive, she is unresponsive with no palpable pulse. The cardiac monitor shows an irregular broad complex tachycardia at approximately 240/min with varying QRS morphology. CPR is in progress. What is the most appropriate immediate management?
A. Intravenous amiodarone 300 mg bolus
B. Intravenous adenosine 6 mg rapid bolus
C. Intravenous verapamil 5 mg over 2 minutes
D. Synchronized DC cardioversion starting at 120-150 J biphasic
E. Unsynchronized defibrillation at 150-200 J biphasic (Correct Answer)
Explanation: ***Unsynchronized defibrillation at 150-200 J biphasic***
- The patient is in **cardiac arrest** (unresponsive, no palpable pulse) with an **irregular broad complex tachycardia** at a very high rate, indicating a shockable rhythm like ventricular fibrillation or pre-excited atrial fibrillation that has degenerated. Immediate **defibrillation** is critical.
- **Unsynchronized defibrillation** is the appropriate initial management for a pulseless patient with a shockable rhythm, as the cardiac monitor cannot reliably identify an R-wave for synchronization in a chaotic, pulseless rhythm.
*Intravenous amiodarone 300 mg bolus*
- While **amiodarone** is an antiarrhythmic used in cardiac arrest, it is administered after the **third shock** in refractory ventricular fibrillation/pulseless ventricular tachycardia according to ACLS guidelines.
- Pharmacological interventions should never delay the immediate delivery of **defibrillation** in a pulseless shockable rhythm.
*Intravenous adenosine 6 mg rapid bolus*
- **Adenosine** is absolutely **contraindicated** in patients with **Wolff-Parkinson-White (WPW) syndrome** and atrial fibrillation (or pre-excited atrial fibrillation), as it blocks the AV node, potentially forcing all impulses down the **accessory pathway** and precipitating ventricular fibrillation.
- It is primarily used for the termination of regular **narrow-complex supraventricular tachycardias**.
*Intravenous verapamil 5 mg over 2 minutes*
- Like adenosine, **verapamil** (a calcium channel blocker) blocks the AV node and is **contraindicated** in **WPW syndrome** with pre-excited atrial fibrillation due to the risk of accelerating conduction through the **accessory pathway**, leading to ventricular fibrillation or hemodynamic collapse.
- It is typically used for rate control in certain supraventricular tachycardias with a narrow QRS and in the absence of an accessory pathway.
*Synchronized DC cardioversion starting at 120-150 J biphasic*
- **Synchronized cardioversion** is reserved for **unstable patients who still have a pulse** to avoid delivering a shock during the vulnerable T-wave period.
- This patient is **pulseless** and in cardiac arrest, making synchronization inappropriate and potentially delaying the life-saving shock.
Question 39: A 55-year-old man presents to the Emergency Department with sudden-onset severe chest pain radiating to the back between the scapulae. He describes it as a tearing sensation. He has a history of poorly controlled hypertension. On examination, blood pressure is 178/95 mmHg in the right arm and 142/88 mmHg in the left arm. Heart rate is 102/min and regular. A diastolic murmur is audible at the left sternal edge. His ECG shows left ventricular hypertrophy but no acute ischaemic changes. What is the most appropriate initial imaging investigation?
A. Transthoracic echocardiography
B. Chest radiograph
C. CT pulmonary angiography
D. CT aortography with intravenous contrast (Correct Answer)
E. Coronary angiography
Explanation: ***CT aortography with intravenous contrast***
- This is the **gold standard** initial investigation for suspected **aortic dissection** because it is rapid and has a high sensitivity and specificity for identifying the **intimal flap**.
- It allows for the classification of the dissection (Stanford A vs. B) and assessment of involvement of **branch vessels**, which is crucial for surgical planning.
*Transthoracic echocardiography*
- While useful for detecting **aortic regurgitation** or **pericardial effusion**, it has poor sensitivity for imaging the **descending aorta**.
- **Transoesophageal echocardiography (TOE)** is much more accurate for dissection but is often less accessible and more invasive in the acute setting.
*Chest radiograph*
- A chest X-ray may show a **widened mediastinum** or a "calcium sign," but these findings are not present in all cases.
- It is useful as a screening tool but lacks the **diagnostic sensitivity** and detail required to confirm a dissection or guide management.
*CT pulmonary angiography*
- This imaging modality is specifically designed to visualize the pulmonary arteries to diagnose a **pulmonary embolism**.
- It does not use the correct **contrast timing (bolus tracking)** or field of view necessary to evaluate the entire **thoracic and abdominal aorta**.
*Coronary angiography*
- This is an invasive procedure primarily used to diagnose **myocardial infarction** or stable coronary artery disease.
- In the setting of a suspected aortic dissection, it is potentially dangerous as the **catheter** could enter the false lumen and worsen the tear.
Question 40: A 48-year-old man with type 2 diabetes presents to the Emergency Department with a 24-hour history of fever, rigors, and worsening right upper quadrant pain. On examination, his temperature is 38.9°C, heart rate 118/min, blood pressure 92/58 mmHg, respiratory rate 26/min, and oxygen saturation 94% on room air. He is confused with an AVPU score of V. Blood tests show white cell count 18.2 × 10⁹/L, lactate 3.8 mmol/L, and bilirubin 68 μmol/L. What is the appropriate initial fluid resuscitation strategy according to the Surviving Sepsis Campaign guidelines?
A. 500 mL colloid bolus over 15 minutes
B. 250 mL crystalloid bolus over 30 minutes
C. 30 mL/kg crystalloid bolus within the first 3 hours (Correct Answer)
D. 10 mL/kg crystalloid bolus repeated according to response
E. 1000 mL crystalloid bolus over 60 minutes
Explanation: ***30 mL/kg crystalloid bolus within the first 3 hours***- The patient's presentation with hypotension, elevated lactate, confusion, and other signs indicates **sepsis** with **septic shock**, necessitating aggressive fluid resuscitation.- The **Surviving Sepsis Campaign guidelines** recommend initiating at least **30 mL/kg of IV crystalloid** fluid within the first 3 hours for patients with sepsis-induced hypoperfusion or **septic shock** to improve outcomes.*500 mL colloid bolus over 15 minutes*- **Crystalloids** are the recommended first-line fluid for initial resuscitation in sepsis; **colloids** are not superior and can be more expensive or carry risks.- A 500 mL bolus is significantly less than the **30 mL/kg** recommendation for a patient in **septic shock** and would be insufficient to address the hypoperfusion.*250 mL crystalloid bolus over 30 minutes*- This volume is far too small and inadequate for a patient presenting with **septic shock**, which requires substantial fluid replacement to restore **hemodynamic stability**.- Such small boluses are typically reserved for patients with severe **cardiac dysfunction** or **renal failure** where fluid overload is a primary concern, which is not indicated as the main issue here.*10 mL/kg crystalloid bolus repeated according to response*- While fluid resuscitation should be guided by ongoing assessment, the initial recommendation in **septic shock** is a minimum target of **30 mL/kg** within the first 3 hours, not a smaller starting bolus.- Initiating with a lower **10 mL/kg** bolus may delay the rapid and adequate volume repletion crucial for improving **perfusion** and organ function in early sepsis.*1000 mL crystalloid bolus over 60 minutes*- While 1000 mL is a common bolus, it often falls short of the **30 mL/kg** requirement for most adults (e.g., a 70 kg adult needs 2100 mL).- The guidelines emphasize a weight-based target of **30 mL/kg** to ensure sufficient initial fluid replacement to address **hypovolemia** and improve perfusion within the critical early hours.
