A 61-year-old man presents with sudden onset weakness of his right arm and face, and inability to speak. CT head shows acute infarct in the left middle cerebral artery territory. He presents 5 hours after symptom onset. What is the most appropriate treatment?
Q12
A 26-year-old man presents with acute onset severe chest pain and dyspnea. He is tall and thin with a marfanoid habitus. Chest X-ray shows a large left-sided pneumothorax. What is the most appropriate management?
Q13
A 59-year-old man presents with sudden onset severe "tearing" chest pain radiating to his back. CT angiogram shows Stanford type B aortic dissection. His BP is 165.95 mmHg. What is the most appropriate initial management?
Q14
A 69-year-old man with a history of ischaemic heart disease and previous inferior myocardial infarction 2 years ago presents with 6 hours of central chest pain. His ECG shows ST-segment elevation in leads V1-V4. Coronary angiography reveals complete occlusion of the proximal left anterior descending artery with TIMI flow grade 0. Primary percutaneous coronary intervention is performed successfully with restoration of TIMI 3 flow. Two hours post-procedure, he develops sudden-onset severe dyspnoea, tachycardia, and hypotension. Examination reveals elevated jugular venous pressure, a new pansystolic murmur at the left lower sternal edge, and bilateral lung crackles. What is the most likely mechanical complication?
Q15
A 27-year-old woman with no significant past medical history presents to the Emergency Department with a 3-hour history of severe, constant lower abdominal pain and one episode of syncope. She appears pale and distressed. Her blood pressure is 88/54 mmHg, heart rate 118 bpm, respiratory rate 22 breaths/min, and temperature 36.8°C. Abdominal examination reveals generalised tenderness with guarding and rebound. Her last menstrual period was 7 weeks ago. A urine pregnancy test is positive. What is the most critical immediate diagnostic consideration in this patient?
Q16
A 33-year-old previously healthy man collapses suddenly while playing football. Bystanders immediately commence CPR, and an automated external defibrillator (AED) is applied within 3 minutes. The AED delivers one shock and advises to continue CPR. Paramedics arrive 8 minutes after collapse, confirm ventricular fibrillation on the monitor, and deliver a second shock. After the shock, organised electrical activity is seen but there is no palpable pulse. What is the most appropriate immediate action?
Q17
A 56-year-old woman presents to the Emergency Department with sudden-onset severe central chest pain radiating to both arms, associated with nausea and diaphoresis. Her initial ECG shows widespread ST-segment depression in leads V2-V6, I, II, and aVL, with ST-segment elevation in lead aVR. Her troponin I is elevated at 892 ng/L. Blood pressure is 92/58 mmHg, heart rate 102 bpm. She has no previous cardiac history but has risk factors including hypertension, hyperlipidaemia, and type 2 diabetes. What is the most likely diagnosis?
Q18
A 63-year-old man is brought to the Emergency Department with a 48-hour history of increasing confusion, fever, and oliguria. He has type 2 diabetes and recently completed a course of antibiotics for a urinary tract infection. On examination, he is drowsy but rousable (GCS 13), temperature 39.2°C, heart rate 128 bpm, blood pressure 82/48 mmHg, respiratory rate 32 breaths/min, and oxygen saturation 90% on room air. Blood tests show: white cell count 22.4 × 10⁹/L, lactate 5.8 mmol/L, creatinine 298 μmol/L (baseline 95 μmol/L), and glucose 18.2 mmol/L. His SOFA score is 8. What is the most accurate classification of his condition?
Q19
A 44-year-old woman is brought to the Emergency Department by ambulance following administration of intramuscular adrenaline by paramedics for suspected anaphylaxis. She had sudden-onset facial swelling, throat tightness, and difficulty breathing 15 minutes after eating at a restaurant. On arrival, she is alert but anxious, with blood pressure 105/68 mmHg, heart rate 98 bpm, respiratory rate 22 breaths/min, oxygen saturation 97% on high-flow oxygen, and scattered wheeze on chest auscultation. Her symptoms have improved significantly. What is the minimum observation period required before considering discharge?
Q20
A 39-year-old man presents to the Emergency Department with 90 minutes of severe central chest pain associated with sweating and nausea. His ECG shows ST-segment elevation of 3 mm in leads II, III, and aVF, with ST-segment depression in leads I and aVL. His blood pressure is 88/52 mmHg, heart rate 48 bpm, and oxygen saturation 96% on room air. He appears clammy and has cool peripheries. What is the most likely explanation for his haemodynamic state?
Acute Medical Presentations UK Medical PG Practice Questions and MCQs
Question 11: A 61-year-old man presents with sudden onset weakness of his right arm and face, and inability to speak. CT head shows acute infarct in the left middle cerebral artery territory. He presents 5 hours after symptom onset. What is the most appropriate treatment?
A. Aspirin
B. Alteplase
C. Mechanical thrombectomy (Correct Answer)
D. Clopidogrel
E. Heparin
Explanation: ***Mechanical thrombectomy***- This patient presents 5 hours after symptom onset with severe neurological deficits consistent with a **left Middle Cerebral Artery (MCA)** infarct, strongly suggesting a **Large Vessel Occlusion (LVO)**.- **Mechanical thrombectomy** is the standard-of-care **reperfusion therapy** for patients with confirmed LVO presenting up to 6 hours, and in selected cases, even up to 24 hours, especially when outside the IV thrombolysis window.*Aspirin*- **Aspirin** is an **antiplatelet agent** used for **secondary prevention** in acute ischemic stroke, typically initiated after reperfusion therapies or when not eligible for them.- For an acute **LVO stroke**, antiplatelet therapy alone is insufficient to achieve rapid and effective reperfusion of the occluded vessel.*Alteplase*- **Intravenous thrombolysis (Alteplase)** is typically administered within **4.5 hours** of symptom onset (last known well time) for acute ischemic stroke.- Since this patient presented at 5 hours, he is outside the standard time window for IV thrombolysis, making mechanical thrombectomy the preferred reperfusion strategy for an LVO.*Clopidogrel*- **Clopidogrel** is an antiplatelet medication primarily used for **secondary prevention** of stroke or TIA, sometimes in dual therapy with aspirin.- It is not an acute primary reperfusion intervention for a severe stroke caused by a **proximal arterial occlusion**.*Heparin*- **Intravenous unfractionated heparin** is generally avoided in acute ischemic stroke due to a significant risk of **hemorrhagic transformation**, particularly within the acute phase.- It is typically reserved for specific indications like cerebral venous thrombosis or specific embolic sources, not routine acute arterial ischemic stroke.
Question 12: A 26-year-old man presents with acute onset severe chest pain and dyspnea. He is tall and thin with a marfanoid habitus. Chest X-ray shows a large left-sided pneumothorax. What is the most appropriate management?
A. Observation
B. Needle aspiration
C. Chest drain insertion (Correct Answer)
D. Thoracotomy
E. VATS procedure
Explanation: ***Chest drain insertion***
- This patient presents with a **large pneumothorax** and acute **dyspnea**, necessitating immediate and definitive management to achieve rapid lung re-expansion.
- A **chest tube** is the standard treatment for primary spontaneous pneumothorax when the pneumothorax is large (often defined as > 2 cm rim) or associated with significant symptoms.
*Observation*
- Observation with supplemental oxygen is only appropriate for patients with a **small** (< 1 cm rim), asymptomatic, primary spontaneous pneumothorax.
- Given the patient's **severe symptoms** (dyspnea, severe chest pain) and the size ("large") of the pneumothorax, observation is dangerous and unlikely to resolve the issue quickly enough.
*Needle aspiration*
- Needle aspiration is typically reserved for **primary spontaneous pneumothorax** that is moderate in size and stable, or in cases of immediate **tension pneumothorax** decompression prior to definitive chest drain insertion.
- While less invasive than a chest drain, aspiration often fails to completely evacuate a **large pneumothorax** and leads to a higher recurrence risk compared to chest drain placement.
*Thoracotomy*
- **Thoracotomy** is a major operation required only if chest tube drainage fails or for patients undergoing definitive surgical pleurodesis, often reserved for highly complex or recurrent disease.
- It is far too invasive and not indicated as the initial emergency treatment for an uncomplicated spontaneous pneumothorax, even if large.
*VATS procedure*
- **Video-Assisted Thoracoscopic Surgery (VATS)** is a minimally invasive surgical intervention primarily used to perform pleurodesis or mechanical abrasion to prevent **recurrent pneumothorax**.
- Like thoracotomy, VATS is an elective surgical procedure for definitive management, not the appropriate acute intervention for achieving immediate lung re-expansion in an unstable or severely symptomatic patient.
Question 13: A 59-year-old man presents with sudden onset severe "tearing" chest pain radiating to his back. CT angiogram shows Stanford type B aortic dissection. His BP is 165.95 mmHg. What is the most appropriate initial management?
A. Emergency surgical repair
B. Endovascular stent graft
C. Medical management with beta-blockers (Correct Answer)
D. Thrombolysis
E. Observation only
Explanation: ***Medical management with beta-blockers***- **Stanford type B aortic dissection** involves the descending aorta, distal to the left subclavian artery, and is typically managed **medically** unless complications arise.- Initial management focuses on **blood pressure control** and **heart rate reduction** to decrease aortic wall stress, with **beta-blockers** (e.g., labetalol, esmolol) being the first-line agents.*Emergency surgical repair*- **Emergency surgical repair** is the primary treatment for **Stanford type A aortic dissection** (involving the ascending aorta), which carries a higher risk of rupture and organ malperfusion.- For **uncomplicated Stanford type B dissection**, surgery is generally avoided due to higher mortality and morbidity risks compared to medical management.*Endovascular stent graft*- **Endovascular stent graft** (TEVAR) is an option for **complicated Stanford type B dissections**, such as those with malperfusion, persistent pain despite optimal medical therapy, or rapid aortic expansion.- It is not the **initial management** for an uncomplicated type B dissection, as medical therapy is preferred first-line.*Thrombolysis*- **Thrombolysis** is indicated for conditions involving **thrombus formation**, such as acute myocardial infarction or ischemic stroke, to dissolve clots.- It is **contraindicated** in aortic dissection, as it can worsen bleeding, expand the false lumen, and increase the risk of rupture due to the **intimal tear**.*Observation only*- **Observation only** is insufficient for aortic dissection, a life-threatening condition requiring urgent intervention to prevent progression and complications.- The patient's symptoms and elevated blood pressure mandate immediate active management to stabilize their condition.
Question 14: A 69-year-old man with a history of ischaemic heart disease and previous inferior myocardial infarction 2 years ago presents with 6 hours of central chest pain. His ECG shows ST-segment elevation in leads V1-V4. Coronary angiography reveals complete occlusion of the proximal left anterior descending artery with TIMI flow grade 0. Primary percutaneous coronary intervention is performed successfully with restoration of TIMI 3 flow. Two hours post-procedure, he develops sudden-onset severe dyspnoea, tachycardia, and hypotension. Examination reveals elevated jugular venous pressure, a new pansystolic murmur at the left lower sternal edge, and bilateral lung crackles. What is the most likely mechanical complication?
A. Acute severe mitral regurgitation from papillary muscle rupture
B. Ventricular septal defect from septal rupture (Correct Answer)
C. Free wall rupture with cardiac tamponade
D. Acute right ventricular infarction with tricuspid regurgitation
E. Left ventricular aneurysm formation with mural thrombus
Explanation: ***Ventricular septal defect from septal rupture***- The presence of a **pansystolic murmur** best heard at the **left lower sternal edge** in the setting of an anterior STEMI (LAD occlusion) is a classic presentation of **interventricular septal rupture**.- This complication causes a **left-to-right shunt**, leading to sudden pulmonary edema (bilateral crackles), elevated jugular venous pressure, and **cardiogenic shock** shortly after reperfusion therapy.*Acute severe mitral regurgitation from papillary muscle rupture*- While this also presents with a pansystolic murmur and acute pulmonary edema, the murmur is typically loudest at the **apex** and radiates to the **base or axilla**.- It is more commonly associated with **inferior or posterior MI** (RCA/LCx territory) because the posteromedial papillary muscle has a single blood supply.*Free wall rupture with cardiac tamponade*- This mechanical complication usually presents with sudden **PEA arrest** or cardiovascular collapse due to **cardiac tamponade**.- Clinical signs include **Beck's triad** (hypotension, distended neck veins, muffled heart sounds), but it does not typically produce a new **pansystolic murmur**.*Acute right ventricular infarction with tricuspid regurgitation*- Right ventricular infarction is most commonly associated with **inferior wall MI** (RCA occlusion) rather than an anterior MI affecting the LAD.- While it can cause elevated JVP and hypotension, the lung fields are typically **clear** (absence of crackles), contrasting with this patient's acute pulmonary edema.*Left ventricular aneurysm formation with mural thrombus*- Ventricular aneurysms are a **late complication** of MI, occurring weeks to months after the event, rather than two hours post-PCI.- While they can predispose to **mural thrombus** and embolism, they do not cause sudden-onset severe dyspnea or acute mechanical murmurs in the acute setting.
Question 15: A 27-year-old woman with no significant past medical history presents to the Emergency Department with a 3-hour history of severe, constant lower abdominal pain and one episode of syncope. She appears pale and distressed. Her blood pressure is 88/54 mmHg, heart rate 118 bpm, respiratory rate 22 breaths/min, and temperature 36.8°C. Abdominal examination reveals generalised tenderness with guarding and rebound. Her last menstrual period was 7 weeks ago. A urine pregnancy test is positive. What is the most critical immediate diagnostic consideration in this patient?
A. Acute appendicitis with perforation causing septic shock
B. Ruptured ectopic pregnancy causing haemorrhagic shock (Correct Answer)
C. Ovarian torsion causing obstructive shock
D. Pelvic inflammatory disease causing distributive shock
E. Threatened miscarriage with vasovagal syncope
Explanation: ***Ruptured ectopic pregnancy causing haemorrhagic shock***- The triad of **amenorrhea** (7 weeks), **positive pregnancy test**, and **haemodynamic instability** (hypotension, tachycardia, syncope) is pathognomonic for a **ruptured ectopic pregnancy** until proven otherwise.- Generalized tenderness with **rebound and guarding** indicates **haemoperitoneum**, which leads to **haemorrhagic shock** and requires emergent surgical intervention.*Acute appendicitis with perforation causing septic shock*- While it causes **peritonitis**, it is typically associated with **fever** and does not explain a **positive pregnancy test** or immediate syncopal event.- **Septic shock** usually develops over a longer period following initial abdominal pain, whereas this patient has an acute **haemorrhagic** presentation.*Ovarian torsion causing obstructive shock*- **Ovarian torsion** typically presents with severe, **unilateral pelvic pain** and nausea rather than generalized peritonitis and significant blood loss.- It does not cause a positive pregnancy test and rarely leads to **haemodynamic collapse** unless accompanied by necrosis and subsequent sepsis.*Pelvic inflammatory disease causing distributive shock*- **PID** usually presents with **vaginal discharge**, fever, and cervical motion tenderness rather than sudden **syncope** and severe hypotension.- **Distributive shock** in PID would be secondary to **sepsis**, which is inconsistent with the patient's normal temperature and the 7-week history of amenorrhea.*Threatened miscarriage with vasovagal syncope*- **Threatened miscarriage** is characterized by vaginal bleeding with a **closed cervix** and does not cause **peritoneal signs** or persistent hypotension.- **Vasovagal syncope** is transient and would not explain the sustained **tachycardia**, hypotension, and pale appearance seen in this patient.
Question 16: A 33-year-old previously healthy man collapses suddenly while playing football. Bystanders immediately commence CPR, and an automated external defibrillator (AED) is applied within 3 minutes. The AED delivers one shock and advises to continue CPR. Paramedics arrive 8 minutes after collapse, confirm ventricular fibrillation on the monitor, and deliver a second shock. After the shock, organised electrical activity is seen but there is no palpable pulse. What is the most appropriate immediate action?
A. Deliver immediate third defibrillation attempt
B. Administer 1 mg intravenous adrenaline immediately
C. Resume CPR for 2 minutes then reassess rhythm (Correct Answer)
D. Check for reversible causes (4 Hs and 4 Ts) before continuing CPR
E. Administer 300 mg intravenous amiodarone before next shock
Explanation: ***Resume CPR for 2 minutes then reassess rhythm***- According to **Advanced Life Support (ALS)** guidelines, after any defibrillation attempt, **chest compressions** must be resumed immediately for 2 minutes to minimize interruptions and optimize myocardial perfusion.- The presence of **organized electrical activity** without a palpable pulse indicates **Pulseless Electrical Activity (PEA)**, for which immediate high-quality CPR is crucial before re-assessing for a shockable rhythm or return of spontaneous circulation.*Deliver immediate third defibrillation attempt*- A third shock is only indicated if the rhythm remains **Ventricular Fibrillation (VF)** or **Pulseless Ventricular Tachycardia (pVT)** after a 2-minute cycle of CPR.- The current assessment shows **organized electrical activity** (PEA), not VF/pVT, making a third shock inappropriate at this immediate juncture.*Administer 1 mg intravenous adrenaline immediately*- In the **ALS algorithm** for shockable rhythms (VF/pVT), **adrenaline** is typically administered after the **third shock**, not immediately after the second.- For **PEA**, adrenaline is indicated, but the immediate priority after a shock and before drug administration is to ensure continuous high-quality **CPR** for the full 2-minute cycle.*Check for reversible causes (4 Hs and 4 Ts) before continuing CPR*- While identifying and treating **reversible causes** is a critical component of resuscitation, it should be performed during pauses in **CPR** or concurrently, not as an action that delays or replaces immediate post-shock chest compressions.- The immediate priority after a shock is to ensure adequate **coronary and cerebral perfusion** through continuous **CPR**.*Administer 300 mg intravenous amiodarone before next shock*- **Amiodarone** is an anti-arrhythmic medication used in refractory **VF/pVT**, specifically administered after the **third shock** (or later shocks) if the rhythm persists.- This patient has only received two shocks, and the current rhythm is **PEA**, making amiodarone administration premature and inappropriate for the current rhythm.
Question 17: A 56-year-old woman presents to the Emergency Department with sudden-onset severe central chest pain radiating to both arms, associated with nausea and diaphoresis. Her initial ECG shows widespread ST-segment depression in leads V2-V6, I, II, and aVL, with ST-segment elevation in lead aVR. Her troponin I is elevated at 892 ng/L. Blood pressure is 92/58 mmHg, heart rate 102 bpm. She has no previous cardiac history but has risk factors including hypertension, hyperlipidaemia, and type 2 diabetes. What is the most likely diagnosis?
A. Anterolateral ST-elevation myocardial infarction
B. Non-ST-elevation myocardial infarction with high-risk features
C. Left main stem coronary artery occlusion (Correct Answer)
D. Acute pericarditis with myocardial involvement
E. Takotsubo cardiomyopathy with apical ballooning
Explanation: ***Left main stem coronary artery occlusion***
- The ECG pattern of **ST-elevation in lead aVR** coupled with **widespread ST-depression** (leads V2-V6, I, II, aVL) is highly specific for **left main stem (LMS)** or proximal **left anterior descending (LAD)** artery occlusion.
- This represents a critical reduction in blood flow to the entire left ventricle, leading to **haemodynamic compromise** (hypotension) and a very high risk of cardiogenic shock or sudden death.
*Anterolateral ST-elevation myocardial infarction*
- An anterolateral **STEMI** would typically present with **ST-elevation** in the precordial leads (V2-V6) and lateral leads (I, aVL), not widespread depression.
- While ST-elevation in aVR can occur in STEMI, it is the distribution of **ischaemic ST-segment depression** in other leads that points specifically to global ischemia from LMS occlusion.
*Non-ST-elevation myocardial infarction with high-risk features*
- While technically a form of NSTEMI because classic regional ST-elevation is absent, the specific **aVR elevation** pattern is a "STEMI equivalent" that demands more urgent intervention than standard NSTEMIs.
- Relying on a routine NSTEMI diagnosis might delay the **urgent coronary angiography** and revascularisation required for critical LMS disease.
*Acute pericarditis with myocardial involvement*
- Pericarditis classically presents with **diffuse, concave ST-elevation** and **PR-segment depression**, which are not seen in this patient's ECG.
- The presence of severe hypotension and a very high **troponin I (892 ng/L)** is more consistent with severe myocardial infarction than myopericarditis.
*Takotsubo cardiomyopathy with apical ballooning*
- Takotsubo typically presents following a **massive emotional or physical stressor** and often mimics an anterior STEMI rather than displaying this specific aVR pattern.
- While it can cause **elevated troponins** and hypotension, the ECG would more commonly show T-wave inversions or ST-elevation rather than **widespread ST-depression with aVR elevation**.
Question 18: A 63-year-old man is brought to the Emergency Department with a 48-hour history of increasing confusion, fever, and oliguria. He has type 2 diabetes and recently completed a course of antibiotics for a urinary tract infection. On examination, he is drowsy but rousable (GCS 13), temperature 39.2°C, heart rate 128 bpm, blood pressure 82/48 mmHg, respiratory rate 32 breaths/min, and oxygen saturation 90% on room air. Blood tests show: white cell count 22.4 × 10⁹/L, lactate 5.8 mmol/L, creatinine 298 μmol/L (baseline 95 μmol/L), and glucose 18.2 mmol/L. His SOFA score is 8. What is the most accurate classification of his condition?
A. Sepsis with acute kidney injury
B. Septic shock with multiorgan dysfunction (Correct Answer)
C. Systemic inflammatory response syndrome (SIRS)
D. Severe sepsis with hyperlactataemia
E. Urosepsis with type 2 respiratory failure
Explanation: ***Septic shock with multiorgan dysfunction***
- This patient meets the criteria for **septic shock** based on **persistent hypotension** (82/48 mmHg) requiring vasopressors (implied by the severe hypotension and shock state) and significant **hyperlactataemia** (5.8 mmol/L) despite fluid resuscitation, all in the context of infection.
- The **SOFA score of 8** indicates acute, life-threatening **multiorgan dysfunction**, specifically involving neurological (confusion), renal (AKI), respiratory (tachypnea, hypoxemia), and cardiovascular systems.
*Sepsis with acute kidney injury*
- While the patient does have **sepsis** (infection with organ dysfunction, e.g., AKI, GCS 13) and an elevated creatinine confirming **acute kidney injury** (298 μmol/L from baseline 95 μmol/L), this diagnosis is incomplete.
- It fails to capture the more severe state of **circulatory and metabolic dysfunction** characterized by profound hypotension and hyperlactataemia, which define **septic shock**.
*Systemic inflammatory response syndrome (SIRS)*
- The patient exhibits several **SIRS criteria** (fever, tachycardia, tachypnoea, leukocytosis), but SIRS is a **non-specific response** and an outdated classification for sepsis severity in the Sepsis-3 guidelines.
- This diagnosis does not adequately convey the presence of **life-threatening organ dysfunction** (SOFA score 8) or the progression to **septic shock**.
*Severe sepsis with hyperlactataemia*
- The term **"severe sepsis"** was officially **retired** with the Sepsis-3 definition in 2016 because it was redundant; sepsis inherently implies organ dysfunction.
- Although the patient has **hyperlactataemia**, the more accurate and current classification for his condition, given the hypotension and high lactate, is **septic shock**.
*Urosepsis with type 2 respiratory failure*
- **Urosepsis** is a likely source of infection given the recent UTI and current symptoms, but it is aetiological rather than a classification of severity.
- There is no specific evidence presented (e.g., blood gas results with high pCO2) to confirm **type 2 respiratory failure** (hypercapnic failure); the low oxygen saturation (90%) suggests hypoxemic (type 1) respiratory failure.
Question 19: A 44-year-old woman is brought to the Emergency Department by ambulance following administration of intramuscular adrenaline by paramedics for suspected anaphylaxis. She had sudden-onset facial swelling, throat tightness, and difficulty breathing 15 minutes after eating at a restaurant. On arrival, she is alert but anxious, with blood pressure 105/68 mmHg, heart rate 98 bpm, respiratory rate 22 breaths/min, oxygen saturation 97% on high-flow oxygen, and scattered wheeze on chest auscultation. Her symptoms have improved significantly. What is the minimum observation period required before considering discharge?
A. 2 hours if completely asymptomatic with normal observations
B. 4 hours if symptoms have fully resolved
C. 6-8 hours due to risk of biphasic reaction (Correct Answer)
D. 12 hours in all cases of treated anaphylaxis
E. 24 hours if patient required adrenaline administration
Explanation: ***6-8 hours due to risk of biphasic reaction***- According to **NICE guidelines** and resuscitation council standards, patients who present with **anaphylaxis** and require adrenaline must be observed for at least **6 to 8 hours**.- This observation period is critical to monitor for a **biphasic reaction**, which is a recurrence of symptoms without further exposure to the allergen, occurring in up to 20% of cases.*2 hours if completely asymptomatic with normal observations*- A **2-hour observation** is insufficient as it falls well within the window where many **biphasic reactions** begin to manifest.- This timeframe is only typically considered for mild allergic reactions without **respiratory or cardiovascular compromise** (not anaphylaxis).*4 hours if symptoms have fully resolved*- While some guidelines mention 2-6 hours for very rapid responders, **4 hours** is generally considered inadequate for a patient who presented with **respiratory distress** and required adrenaline.- The risk of a secondary peak in **inflammatory mediators** remains high beyond this period.*12 hours in all cases of treated anaphylaxis*- While **12 hours** of observation may be appropriate for high-risk patients (e.g., those requiring multiple doses of adrenaline), it is not the **minimum** required for all patients.- Routine 12-hour stays for every anaphylaxis case would lead to unnecessary **healthcare resource utilization**.*24 hours if patient required adrenaline administration*- A **24-hour observation** is usually reserved for patients with severe, protracted anaphylaxis or those with high risk factors for **refractory symptoms**.- Requiring adrenaline alone does not mandate a 24-hour stay if the patient responds promptly and remains **hemodynamically stable**.
Question 20: A 39-year-old man presents to the Emergency Department with 90 minutes of severe central chest pain associated with sweating and nausea. His ECG shows ST-segment elevation of 3 mm in leads II, III, and aVF, with ST-segment depression in leads I and aVL. His blood pressure is 88/52 mmHg, heart rate 48 bpm, and oxygen saturation 96% on room air. He appears clammy and has cool peripheries. What is the most likely explanation for his haemodynamic state?
A. Cardiogenic shock due to extensive left ventricular myocardial infarction
B. Right ventricular infarction causing reduced left ventricular preload (Correct Answer)
C. Acute mitral regurgitation from papillary muscle rupture
D. Hypovolaemia secondary to excessive sweating and reduced oral intake
E. Vasovagal response to severe chest pain causing bradycardia and hypotension
Explanation: ***Right ventricular infarction causing reduced left ventricular preload***
- The ECG shows an **inferior ST-elevation myocardial infarction (STEMI)** (ST elevation in II, III, aVF), which is often caused by **Right Coronary Artery (RCA)** occlusion, frequently involving the **right ventricle (RV)**.
- An infarcted RV fails to effectively pump blood to the lungs, leading to **decreased left ventricular preload**, which manifests as systemic **hypotension** (88/52 mmHg) and **bradycardia** (48 bpm) due to potential SA node involvement or increased vagal tone.
*Cardiogenic shock due to extensive left ventricular myocardial infarction*
- While cardiogenic shock causes hypotension, **extensive left ventricular myocardial infarction** typically presents with ST elevation in **anterior/lateral leads** (e.g., V1-V6, I, aVL), not primarily inferior leads.
- The primary mechanism of hemodynamic compromise in **inferior STEMI** is usually **right ventricular dysfunction** causing preload dependence, rather than global left ventricular pump failure.
*Acute mitral regurgitation from papillary muscle rupture*
- This mechanical complication typically occurs **3 to 7 days** after a myocardial infarction, not within the first 90 minutes of symptom onset.
- It usually presents with a **new holosystolic murmur** and often **acute pulmonary edema**, which are not described in this patient.
*Hypovolaemia secondary to excessive sweating and reduced oral intake*
- While diaphoresis is present, it is unlikely to cause such **profound hypotension (88/52 mmHg)** and bradycardia within a mere 90 minutes.
- The patient's specific ECG changes and shock state are best explained by the **acute cardiac pathology** (MI) rather than simple fluid loss.
*Vasovagal response to severe chest pain causing bradycardia and hypotension*
- Although severe pain or inferior MI can trigger a vasovagal response causing bradycardia and hypotension, it would not typically result in the **cool peripheries** and clammy appearance indicative of a low-output shock state associated with myocardial infarction.
- The clinical picture points more critically to an **acute cardiac cause** for the hemodynamic instability rather than a transient vasovagal episode.
