A 47-year-old woman collapses while gardening. Her husband witnesses the episode and reports she suddenly became pale, lost consciousness for approximately 20 seconds, and quickly regained full consciousness without confusion. She had no jerking movements or incontinence. She mentions feeling nauseous and experiencing mild abdominal cramping before the collapse. She has no significant past medical history and takes no regular medications. Examination reveals blood pressure 110/70 mmHg lying and standing, heart rate 68 bpm regular, normal cardiovascular and neurological examination, and mild suprapubic tenderness. What is the most likely diagnosis?
Q152
A 55-year-old man presents to the Emergency Department with a 24-hour history of fever, rigors, and confusion. His wife reports he has been complaining of burning on urination for 3 days. His observations are: blood pressure 88/52 mmHg, heart rate 118 bpm, respiratory rate 26/min, oxygen saturation 94% on room air, temperature 39.2°C, GCS 14 (E4 V4 M6). Blood tests show: lactate 3.2 mmol/L, white cell count 18.5 × 10⁹/L, C-reactive protein 245 mg/L, creatinine 165 µmol/L (baseline 85 µmol/L). Which clinical parameter best indicates this patient meets the criteria for septic shock?
Q153
A 38-year-old man is brought to the Emergency Department by ambulance following sudden collapse at work. Colleagues report he complained of feeling hot and dizzy before losing consciousness. He has a history of severe peanut allergy. On examination, he has widespread urticarial rash, lip swelling, blood pressure 75/40 mmHg, heart rate 128 bpm, respiratory rate 28/min with audible wheeze, and oxygen saturation 88% on room air. He has received 500 micrograms of intramuscular adrenaline. After 5 minutes there is minimal improvement. What is the most appropriate next step?
Q154
A 64-year-old woman presents to the Emergency Department with a 12-hour history of central chest discomfort. She describes it as pressure-like and intermittent. Her troponin I at presentation is 15 ng/L (normal <14 ng/L) and her ECG shows T-wave inversion in leads V4-V6. Her observations are: blood pressure 145/85 mmHg, heart rate 78 bpm, respiratory rate 16/min, oxygen saturation 98% on room air, temperature 36.8°C. What is the most appropriate initial antiplatelet therapy?
Q155
A 54-year-old woman presents to the Emergency Department after a bee sting 45 minutes ago. She has generalized urticaria, mild lip swelling, and some difficulty swallowing but no respiratory distress. Her observations are: blood pressure 125/80 mmHg, heart rate 88 bpm, respiratory rate 16 breaths/minute, oxygen saturation 99% on room air. She is given intramuscular adrenaline 500 micrograms, intravenous chlorphenamine 10 mg, and intravenous hydrocortisone 200 mg. Her symptoms improve within 20 minutes. What is the most appropriate minimum observation period before discharge can be considered?
Q156
A 65-year-old man is admitted with severe community-acquired pneumonia and septic shock. He has received appropriate antibiotics and 2000 mL of crystalloid fluid resuscitation. Despite this, his blood pressure remains 85/50 mmHg with a heart rate of 115 bpm. Lactate is 4.8 mmol/L. Central venous access has been obtained. According to the Surviving Sepsis Campaign guidelines, what is the most appropriate vasopressor to commence?
Q157
A 32-year-old woman with no significant past medical history presents to the Emergency Department with a 3-hour history of palpitations, dizziness, and mild chest discomfort. She appears anxious but is alert. Observations: blood pressure 110/70 mmHg, heart rate 180 bpm, oxygen saturation 98% on room air. ECG shows a regular narrow complex tachycardia at 180 bpm with no visible P waves. She has received adenosine 6 mg IV which caused brief asystole but the tachycardia immediately returned. Vagal manoeuvres were unsuccessful. What is the most appropriate next step in management?
Q158
A 43-year-old man presents to the Emergency Department with severe central chest pain radiating to his back that started suddenly 2 hours ago while lifting heavy boxes. The pain is described as tearing in nature and is the worst pain he has ever experienced. He has a history of hypertension but is poorly compliant with medication. On examination, blood pressure is 175/95 mmHg in the right arm and 140/85 mmHg in the left arm. Heart rate is 95 bpm, respiratory rate 20 breaths/minute. ECG shows sinus rhythm with left ventricular hypertrophy but no acute ischaemic changes. What is the most appropriate immediate investigation?
Q159
A 77-year-old woman with atrial fibrillation on warfarin presents with an episode of syncope that occurred while sitting in a chair watching television. She had no warning symptoms and no post-event confusion. Her daughter witnessed the event and reports she went pale, slumped forward, and was unresponsive for about 30 seconds before recovering fully. She has previously had multiple falls. Observations are: blood pressure lying 145/85 mmHg, standing 140/80 mmHg, heart rate 35 bpm and regular. ECG shows complete heart block with ventricular escape rhythm. What is the most appropriate immediate management?
Q160
A 48-year-old woman is brought to the Emergency Department with suspected anaphylaxis after eating at a restaurant 20 minutes ago. She has been given intramuscular adrenaline 500 micrograms by paramedics. On arrival, she has resolved urticaria but remains breathless with audible wheeze. Her blood pressure is 105/70 mmHg, heart rate 100 bpm, oxygen saturation 93% on high-flow oxygen. She has a history of severe asthma and uses inhalers regularly. What additional investigation should be performed to support the diagnosis of anaphylaxis?
Acute Medical Presentations UK Medical PG Practice Questions and MCQs
Question 151: A 47-year-old woman collapses while gardening. Her husband witnesses the episode and reports she suddenly became pale, lost consciousness for approximately 20 seconds, and quickly regained full consciousness without confusion. She had no jerking movements or incontinence. She mentions feeling nauseous and experiencing mild abdominal cramping before the collapse. She has no significant past medical history and takes no regular medications. Examination reveals blood pressure 110/70 mmHg lying and standing, heart rate 68 bpm regular, normal cardiovascular and neurological examination, and mild suprapubic tenderness. What is the most likely diagnosis?
A. Cardiac syncope secondary to arrhythmia
B. Vasovagal syncope (Correct Answer)
C. Postural hypotension
D. Epileptic seizure
E. Vertebrobasilar insufficiency
Explanation: ***Vasovagal syncope***- The patient exhibits classic **prodromal symptoms** such as nausea and abdominal cramping, followed by a **rapid recovery** without post-ictal confusion.- This is a form of **reflex syncope** where an identifiable trigger (likely visceral stimulation from cramping or prolonged standing during gardening) leads to transient **cerebral hypoperfusion**.*Cardiac syncope secondary to arrhythmia*- Cardiac causes typically present with **sudden onset** without a prodrome and are often associated with **palpitations** or exertion.- This patient has a **normal cardiovascular examination** and a regular heart rate, making an underlying arrhythmia less likely.*Postural hypotension*- This diagnosis is excluded by the **orthostatic blood pressure** measurement, which showed no significant drop between lying and standing (110/70 mmHg both).- Postural hypotension typically occurs immediately upon **standing up**, rather than while performing sustained activity such as gardening.*Epileptic seizure*- The **lack of post-ictal confusion**, absence of tongue biting, and the very **short duration** of unconsciousness (20 seconds) strongly argue against a seizure.- The absence of **rhythmic jerking movements** or urinary incontinence further differentiates this syncopal episode from an epileptic event.*Vertebrobasilar insufficiency*- This condition usually presents with additional **neurological deficits** such as vertigo, diplopia, ataxia, or bilateral limb weakness (the "Ds").- The patient's **normal neurological examination** and the presence of a clear autonomic prodrome make this vascular cause highly unlikely.
Question 152: A 55-year-old man presents to the Emergency Department with a 24-hour history of fever, rigors, and confusion. His wife reports he has been complaining of burning on urination for 3 days. His observations are: blood pressure 88/52 mmHg, heart rate 118 bpm, respiratory rate 26/min, oxygen saturation 94% on room air, temperature 39.2°C, GCS 14 (E4 V4 M6). Blood tests show: lactate 3.2 mmol/L, white cell count 18.5 × 10⁹/L, C-reactive protein 245 mg/L, creatinine 165 µmol/L (baseline 85 µmol/L). Which clinical parameter best indicates this patient meets the criteria for septic shock?
A. Heart rate greater than 110 bpm
B. Lactate greater than 2 mmol/L despite adequate fluid resuscitation (Correct Answer)
C. Temperature greater than 38.3°C
D. White cell count greater than 12 × 10⁹/L
E. Systolic blood pressure less than 90 mmHg
Explanation: ***Lactate greater than 2 mmol/L despite adequate fluid resuscitation***
- According to the **Sepsis-3 criteria**, septic shock is defined by requiring **vasopressors** to maintain a mean arterial pressure (MAP) ≥65 mmHg *and* a **serum lactate >2 mmol/L** despite adequate fluid resuscitation.
- An elevated **lactate** level (3.2 mmol/L in this case) indicates **tissue hypoperfusion** and **cellular metabolic dysfunction**, which are critical markers of severe organ damage and poorer prognosis in shock.
*Heart rate greater than 110 bpm*
- **Tachycardia** (118 bpm) is a common compensatory mechanism in sepsis and a component of **Systemic Inflammatory Response Syndrome (SIRS)** criteria.
- However, an elevated heart rate alone does not specifically define **septic shock**, which requires evidence of circulatory failure and cellular abnormalities beyond simple physiological stress.
*Temperature greater than 38.3°C*
- **Fever** (39.2°C) is a general sign of infection and inflammation, contributing to the diagnosis of **sepsis** (SIRS criteria).
- It is not a specific diagnostic criterion for **septic shock**, as patients can also present with **hypothermia**, and temperature does not directly reflect the circulatory failure or tissue hypoperfusion characteristic of shock.
*White cell count greater than 12 × 10⁹/L*
- **Leukocytosis** (18.5 × 10⁹/L) indicates an immune response to infection and is part of the **SIRS** criteria.
- While supportive of an underlying infection, an elevated white cell count is not a defining feature of **septic shock**, which focuses on organ dysfunction and persistent circulatory failure.
*Systolic blood pressure less than 90 mmHg*
- **Hypotension** (88/52 mmHg) is a significant finding in sepsis and a criterion for **qSOFA** and **sepsis with organ dysfunction**.
- For **septic shock**, hypotension specifically needs to be **refractory to adequate fluid resuscitation** and require **vasopressor support**, coupled with other signs of hypoperfusion like **elevated lactate**.
Question 153: A 38-year-old man is brought to the Emergency Department by ambulance following sudden collapse at work. Colleagues report he complained of feeling hot and dizzy before losing consciousness. He has a history of severe peanut allergy. On examination, he has widespread urticarial rash, lip swelling, blood pressure 75/40 mmHg, heart rate 128 bpm, respiratory rate 28/min with audible wheeze, and oxygen saturation 88% on room air. He has received 500 micrograms of intramuscular adrenaline. After 5 minutes there is minimal improvement. What is the most appropriate next step?
A. Administer a second dose of 500 micrograms intramuscular adrenaline (Correct Answer)
B. Commence intravenous adrenaline infusion at 0.5-1 microgram/kg/min
C. Give intravenous hydrocortisone 200 mg
D. Administer nebulized adrenaline 5 mg
E. Give intravenous chlorphenamine 10 mg
Explanation: ***Administer a second dose of 500 micrograms intramuscular adrenaline***
- According to **anaphylaxis guidelines** (e.g., UK Resuscitation Council), if there is no significant improvement after the initial dose of **intramuscular adrenaline**, a second dose should be administered after **5 minutes**.
- **Intramuscular adrenaline** is the **first-line treatment** for anaphylaxis, addressing **cardiovascular collapse** (hypotension) and **bronchospasm** (wheeze) effectively.
*Commence intravenous adrenaline infusion at 0.5-1 microgram/kg/min*
- **Intravenous adrenaline infusions** are typically reserved for **refractory anaphylaxis** that has not responded to at least **two adequate intramuscular doses**.
- This intervention requires **close monitoring** and expertise, usually in an intensive care setting, due to the significant risk of **cardiac arrhythmias**.
*Give intravenous hydrocortisone 200 mg*
- **Hydrocortisone** (corticosteroids) acts as a **second-line adjunct** primarily to prevent **late-phase (biphasic) reactions** and takes time to exert its effect.
- It does not provide immediate relief for the **life-threatening acute symptoms** of hypotension and bronchospasm seen in severe anaphylaxis.
*Administer nebulized adrenaline 5 mg*
- **Nebulized adrenaline** is primarily indicated for **upper airway obstruction** (e.g., stridor, laryngeal edema) and has limited systemic absorption.
- It is ineffective in addressing the **profound hypotension** and widespread **bronchospasm** that characterize severe anaphylaxis as effectively as systemic IM adrenaline.
*Give intravenous chlorphenamine 10 mg*
- **Antihistamines** (like chlorphenamine) help alleviate **cutaneous symptoms** such as urticaria and angioedema, but they are not life-saving.
- They do not address the critical **respiratory or cardiovascular compromise** in anaphylaxis and should never delay the administration of adrenaline.
Question 154: A 64-year-old woman presents to the Emergency Department with a 12-hour history of central chest discomfort. She describes it as pressure-like and intermittent. Her troponin I at presentation is 15 ng/L (normal <14 ng/L) and her ECG shows T-wave inversion in leads V4-V6. Her observations are: blood pressure 145/85 mmHg, heart rate 78 bpm, respiratory rate 16/min, oxygen saturation 98% on room air, temperature 36.8°C. What is the most appropriate initial antiplatelet therapy?
A. Aspirin 300 mg and clopidogrel 300 mg
B. Aspirin 300 mg and prasugrel 60 mg
C. Aspirin 300 mg and ticagrelor 180 mg (Correct Answer)
D. Aspirin 75 mg and clopidogrel 75 mg
E. Aspirin 300 mg alone
Explanation: ***Aspirin 300 mg and ticagrelor 180 mg***- This patient presents with **Non-ST Elevation Myocardial Infarction (NSTEMI)**, indicated by elevated troponin and ischemic ECG changes (T-wave inversion in V4-V6), necessitating immediate **Dual Antiplatelet Therapy (DAPT)**.- **Ticagrelor 180 mg** is the recommended loading dose for a potent P2Y12 inhibitor in patients with NSTEMI, providing rapid and effective platelet inhibition as per current guidelines and evidence from trials like **PLATO**.*Aspirin 300 mg and clopidogrel 300 mg*- While clopidogrel is a P2Y12 inhibitor used in DAPT, it has a **slower onset of action** and less potent platelet inhibition compared to ticagrelor in the acute setting.- **Clopidogrel** is often reserved for patients with a high bleeding risk or contraindications to more potent P2Y12 inhibitors, making it a less optimal initial choice for NSTEMI.*Aspirin 300 mg and prasugrel 60 mg*- **Prasugrel** is a potent P2Y12 inhibitor primarily indicated for patients undergoing **Percutaneous Coronary Intervention (PCI)** for ACS and has specific contraindications (e.g., history of stroke/TIA, age > 75).- Its use in initial medical management of NSTEMI, especially when the revascularization strategy is not yet determined, is less common than ticagrelor.*Aspirin 75 mg and clopidogrel 75 mg*- These doses represent **maintenance therapy** rather than the essential **loading doses** required for rapid and profound platelet inhibition in an acute NSTEMI.- Administering maintenance doses acutely would lead to inadequate antiplatelet effect and delay the therapeutic benefit, increasing the risk of adverse cardiovascular events.*Aspirin 300 mg alone*- **Single antiplatelet therapy (SAPT)** with aspirin alone is insufficient for the management of NSTEMI, which requires more aggressive platelet inhibition.- **Dual Antiplatelet Therapy (DAPT)**, combining aspirin with a P2Y12 inhibitor, is crucial to significantly reduce the risk of recurrent ischemic events, including myocardial infarction and stent thrombosis.
Question 155: A 54-year-old woman presents to the Emergency Department after a bee sting 45 minutes ago. She has generalized urticaria, mild lip swelling, and some difficulty swallowing but no respiratory distress. Her observations are: blood pressure 125/80 mmHg, heart rate 88 bpm, respiratory rate 16 breaths/minute, oxygen saturation 99% on room air. She is given intramuscular adrenaline 500 micrograms, intravenous chlorphenamine 10 mg, and intravenous hydrocortisone 200 mg. Her symptoms improve within 20 minutes. What is the most appropriate minimum observation period before discharge can be considered?
A. 2 hours from initial presentation
B. 4 hours from symptom resolution
C. 6 hours from initial presentation (Correct Answer)
D. 12 hours from symptom resolution
E. 24 hours from initial presentation
Explanation: ***6 hours from initial presentation***- According to **NICE** and **Resuscitation Council UK** guidelines, patients who respond rapidly to treatment for anaphylaxis should be observed for a minimum of **6 hours** from the onset of symptoms.- This observation period is critical to monitor for **biphasic reactions**, which are recurrences of symptoms without further exposure to the allergen, occurring in up to 20% of cases.*2 hours from initial presentation*- A **2-hour** window is insufficient to safely exclude the risk of a **late-phase (biphasic)** response, which typically peaks several hours after the initial event.- This duration is only considered for very mild allergic reactions that do not meet the criteria for **anaphylaxis** (respiratory or cardiovascular compromise).*4 hours from symptom resolution*- Guidelines specify the observation timeframe from the **time of initial presentation** or symptom onset rather than from the point of resolution.- While monitoring after resolution is important, **4 hours** does not meet the evidence-based standard required for safe discharge following adrenaline administration.*12 hours from symptom resolution*- A **12-hour** observation (up to 24 hours) is generally reserved for high-risk patients, such as those requiring **multiple doses of adrenaline** or those with a history of severe asthma.- While safer, it is not the **minimum** required period for a patient who responded promptly to a single dose and remains hemodynamically stable.*24 hours from initial presentation*- **24-hour admission** is indicated only for the most severe cases, such as those experiencing **refractory anaphylaxis** or severe respiratory distress requiring ICU input.- For a patient with rapid symptom improvement and stable observations like this one, a 24-hour stay is not the standard **minimum observation** requirement.
Question 156: A 65-year-old man is admitted with severe community-acquired pneumonia and septic shock. He has received appropriate antibiotics and 2000 mL of crystalloid fluid resuscitation. Despite this, his blood pressure remains 85/50 mmHg with a heart rate of 115 bpm. Lactate is 4.8 mmol/L. Central venous access has been obtained. According to the Surviving Sepsis Campaign guidelines, what is the most appropriate vasopressor to commence?
A. Noradrenaline infusion titrated to MAP ≥65 mmHg (Correct Answer)
B. Adrenaline infusion titrated to MAP ≥65 mmHg
C. Dopamine infusion starting at 5 mcg/kg/min
D. Vasopressin infusion at 0.03 units/min
E. Dobutamine infusion starting at 5 mcg/kg/min
Explanation: ***Noradrenaline infusion titrated to MAP ≥65 mmHg***
- **Noradrenaline** (norepinephrine) is the **first-line vasopressor** recommended by the **Surviving Sepsis Campaign** for patients with fluid-refractory septic shock.
- It acts as a potent **alpha-1 agonist**, causing vasoconstriction to improve **mean arterial pressure (MAP)**, while its minor beta-adrenergic effects provide mild inotropic support.
*Adrenaline infusion titrated to MAP ≥65 mmHg*
- **Adrenaline** (epinephrine) is considered a **second-line agent** or an add-on when noradrenaline is insufficient to reach hemodynamic targets.
- It is not first-line because it is associated with an increase in **serum lactate levels** and a higher risk of **tachyarrhythmias**.
*Dopamine infusion starting at 5 mcg/kg/min*
- **Dopamine** is no longer recommended as first-line therapy because it carries a significantly higher risk of **arrhythmias** compared to noradrenaline.
- It is only considered in highly selected patients with **low risk of tachyarrhythmias** and absolute or relative **bradycardia**.
*Vasopressin infusion at 0.03 units/min*
- **Vasopressin** is recommended as an **adjunct** to noradrenaline to either raise the MAP to target or to **decrease the noradrenaline dosage**.
- Guidelines emphasize that it should not be used as the **initial monotherapy** or as a primary vasopressor in septic shock management.
*Dobutamine infusion starting at 5 mcg/kg/min*
- **Dobutamine** is an **inotrope**, not a primary vasopressor, and is indicated only when there is evidence of **refractory hypoperfusion** despite adequate MAP and fluid status.
- It is typically utilized when **myocardial dysfunction** (low cardiac output) is suspected or confirmed in the setting of sepsis.
Question 157: A 32-year-old woman with no significant past medical history presents to the Emergency Department with a 3-hour history of palpitations, dizziness, and mild chest discomfort. She appears anxious but is alert. Observations: blood pressure 110/70 mmHg, heart rate 180 bpm, oxygen saturation 98% on room air. ECG shows a regular narrow complex tachycardia at 180 bpm with no visible P waves. She has received adenosine 6 mg IV which caused brief asystole but the tachycardia immediately returned. Vagal manoeuvres were unsuccessful. What is the most appropriate next step in management?
A. Adenosine 12 mg IV (Correct Answer)
B. Verapamil 5 mg IV
C. Amiodarone 300 mg IV over 20 minutes
D. Synchronised DC cardioversion
E. Metoprolol 5 mg IV
Explanation: ***Adenosine 12 mg IV*** - Initial management of stable **narrow complex tachycardia** (SVT) involves vagal maneuvers followed by a sequence of **adenosine** doses (6mg, then 12mg, then a final 12mg). - In this patient, the transient **asystole** response to the 6mg dose proves the drug reached the heart and affected the **AV node**, but a higher 12mg dose is needed to sustain termination of the circuit.*Verapamil 5 mg IV* - This is considered a second-line therapy for SVT and is only used if **adenosine** is contraindicated or if the full escalation protocol of adenosine fails. - It should be used with caution in patients who have recently received **beta-blockers** due to the risk of severe hypotension or asystole.*Amiodarone 300 mg IV over 20 minutes* - **Amiodarone** is generally reserved for **broad complex tachycardias** or stable irregular rhythms like atrial fibrillation, not for acute SVT termination. - It is not the preferred second-line agent for regular narrow complex tachycardias due to its slower onset of action compared to adenosine or calcium channel blockers.*Synchronised DC cardioversion* - This is the first-line treatment for **unstable** patients exhibiting "adverse features" such as shock, syncope, or myocardial ischemia. - As this patient is **hemodynamically stable** (BP 110/70 mmHg, alert), pharmacological management should be exhausted first.*Metoprolol 5 mg IV* - **Beta-blockers** are used for rate control in tachyarrhythmias but are not the primary choice for the acute termination of paroxysmal **SVT**. - Using them with or after calcium channel blockers like verapamil carries a significant risk of **cardiac depression**.
Question 158: A 43-year-old man presents to the Emergency Department with severe central chest pain radiating to his back that started suddenly 2 hours ago while lifting heavy boxes. The pain is described as tearing in nature and is the worst pain he has ever experienced. He has a history of hypertension but is poorly compliant with medication. On examination, blood pressure is 175/95 mmHg in the right arm and 140/85 mmHg in the left arm. Heart rate is 95 bpm, respiratory rate 20 breaths/minute. ECG shows sinus rhythm with left ventricular hypertrophy but no acute ischaemic changes. What is the most appropriate immediate investigation?
A. Transthoracic echocardiogram
B. CT aorta with contrast (Correct Answer)
C. Chest X-ray
D. High-sensitivity troponin
E. D-dimer
Explanation: ***CT aorta with contrast*** - This is the **gold-standard** investigation for suspected **aortic dissection**, providing high sensitivity and specificity for identifying the **intimal flap** and extent of the dissection. - It is the most appropriate immediate step for a hemodynamically stable patient presenting with **tearing chest pain**, a **blood pressure differential**, and a history of **hypertension**. *Transthoracic echocardiogram* - While it can assess for **pericardial effusion**, **aortic regurgitation**, or proximal aortic pathology, its sensitivity for diagnosing **aortic dissection**, particularly in the descending aorta, is limited. - A **transesophageal echocardiogram (TEE)** offers better visualization for dissection but is typically reserved for cases where CT is contraindicated or unavailable, or for unstable patients. *Chest X-ray* - Although it may show a **widened mediastinum**, this finding is neither sensitive nor specific enough to confirm or rule out **aortic dissection**. - It should not delay definitive imaging such as **CT angiography** when clinical suspicion for dissection is high, as an urgent and accurate diagnosis is critical. *High-sensitivity troponin* - This test is primarily used to evaluate for **myocardial infarction**, which is a differential for chest pain, but it does not diagnose **aortic dissection**. - While troponin can be elevated if the dissection extends to and compromises the **coronary ostia**, relying solely on it can lead to misdiagnosis and delayed appropriate treatment for the dissection. *D-dimer* - A negative D-dimer can help rule out dissection in **low-risk** patients with a low pre-test probability, but it is not useful in this high-risk scenario where clinical suspicion is strong. - It is **nonspecific** and can be elevated in various conditions, including pulmonary embolism, infection, or malignancy, making definitive imaging necessary regardless of the D-dimer result in this context.
Question 159: A 77-year-old woman with atrial fibrillation on warfarin presents with an episode of syncope that occurred while sitting in a chair watching television. She had no warning symptoms and no post-event confusion. Her daughter witnessed the event and reports she went pale, slumped forward, and was unresponsive for about 30 seconds before recovering fully. She has previously had multiple falls. Observations are: blood pressure lying 145/85 mmHg, standing 140/80 mmHg, heart rate 35 bpm and regular. ECG shows complete heart block with ventricular escape rhythm. What is the most appropriate immediate management?
A. Intravenous atropine 500 micrograms
B. Transcutaneous pacing (Correct Answer)
C. Arrange permanent pacemaker insertion within 24 hours
D. Intravenous isoprenaline infusion
E. Observe with continuous cardiac monitoring
Explanation: ***Transcutaneous pacing***- This patient presents with **symptomatic complete heart block** (syncope, HR 35 bpm), indicating **hemodynamic instability** and a high risk of **asystole**.- **Transcutaneous pacing** is the most appropriate immediate management to provide rapid electrical stimulation and restore an adequate heart rate, stabilizing the patient until a more definitive solution can be implemented.*Intravenous atropine 500 micrograms*- **Atropine** primarily acts on the **SA node** and proximal **AV node**; it is often ineffective in **complete heart block** with a ventricular escape rhythm, as the block is typically infra-nodal.- While a first-line agent for some bradycardias, it should not delay immediate electrical treatments like pacing in a patient presenting with **syncope** due to high-degree AV block.*Arrange permanent pacemaker insertion within 24 hours*- A **permanent pacemaker** is indeed the definitive long-term treatment for complete heart block, but it does not address the **immediate life-threatening risk** in the acute setting.- The patient requires **emergency stabilization** via temporary pacing to prevent further syncopal episodes or **cardiac arrest** before a permanent device can be implanted.*Intravenous isoprenaline infusion*- **Isoprenaline** is a beta-adrenergic agonist that can increase heart rate, but it is a **second-line pharmacological option** and carries a risk of inducing **ventricular arrhythmias**, especially in an elderly patient with underlying cardiac conditions.- It is less reliable and generally reserved as a bridge to pacing or when pacing is unavailable, making **transcutaneous pacing** a safer and more effective immediate choice.*Observe with continuous cardiac monitoring*- Simple observation is entirely inappropriate for a patient experiencing **complete heart block with syncope** (a Stokes-Adams attack) due to the significant risk of sudden **cardiac arrest**.- This patient requires active and immediate intervention to maintain **cardiac output** and prevent further life-threatening events.
Question 160: A 48-year-old woman is brought to the Emergency Department with suspected anaphylaxis after eating at a restaurant 20 minutes ago. She has been given intramuscular adrenaline 500 micrograms by paramedics. On arrival, she has resolved urticaria but remains breathless with audible wheeze. Her blood pressure is 105/70 mmHg, heart rate 100 bpm, oxygen saturation 93% on high-flow oxygen. She has a history of severe asthma and uses inhalers regularly. What additional investigation should be performed to support the diagnosis of anaphylaxis?
A. Serum IgE levels immediately
B. Skin prick testing within 24 hours
C. Serum mast cell tryptase at 1-2 hours after symptom onset (Correct Answer)
D. Serum histamine levels immediately
E. Component resolved diagnostics within 48 hours
Explanation: ***Serum mast cell tryptase at 1-2 hours after symptom onset***
- **Mast cell tryptase** is a protease released during degranulation; its levels peak 1–2 hours after onset and remain elevated for several hours, making this the optimal window for detection.
- Guidelines recommend a series of three samples: one as soon as possible, one at **1–2 hours**, and a baseline sample at **24 hours** to confirm an acute rise.
*Serum IgE levels immediately*
- Measuring **total IgE** is not useful in the acute setting because levels do not fluctuate rapidly enough to reflect an acute anaphylactic event.
- **Specific IgE** testing may be indicated later during follow-up to identify the allergen but is not an emergency diagnostic tool.
*Skin prick testing within 24 hours*
- **Skin prick testing** should be avoided in the acute phase (at least 4–6 weeks post-event) because mast cell depletion can lead to **false-negative** results.
- Immediate testing also carries a theoretical risk of re-triggering a systemic allergic reaction while the patient is still recovering.
*Serum histamine levels immediately*
- **Histamine** has a very short half-life (minutes) and levels return to baseline rapidly, making it clinically impractical as a diagnostic marker in the ED.
- Unlike tryptase, histamine measurement is technically difficult and not routinely available in standard hospital laboratories.
*Component resolved diagnostics within 48 hours*
- **Component resolved diagnostics** are advanced specialized molecular tests used to identify specific protein triggers in an outpatient **allergy clinic** setting.
- These tests are used for long-term risk assessment and management, not for confirming the diagnosis of an **acute anaphylactic episode**.
