Anaphylaxis UK Medical PG Practice Questions and MCQs
Practice UK Medical PG questions for Anaphylaxis. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Anaphylaxis UK Medical PG Question 1: A 55-year-old man presents with acute severe abdominal pain and hypotension. He takes warfarin for atrial fibrillation. CT shows large retroperitoneal hematoma. His INR is 7.5. What is the most appropriate immediate management?
- A. Stop warfarin and observe
- B. Vitamin K 10mg IV
- C. Fresh frozen plasma
- D. Prothrombin complex concentrate (Correct Answer)
- E. Factor VIIa
Anaphylaxis Explanation: ***Prothrombin complex concentrate*** - This patient presents with **acute severe abdominal pain**, **hypotension**, and a **large retroperitoneal hematoma** while on warfarin with a significantly elevated **INR of 7.5**. This indicates a life-threatening bleed requiring rapid and complete reversal of anticoagulation. - **PCC** provides a rapid infusion of vitamin K-dependent clotting factors (II, VII, IX, X), leading to the fastest reversal of warfarin's anticoagulant effect, which is critical in active, severe bleeding with hemodynamic instability. *Stop warfarin and observe* - While stopping warfarin is an initial necessary step, it is wholly insufficient for managing a **life-threatening retroperitoneal hematoma** and **hypotension** caused by excessive anticoagulation. - Observing the patient without active intervention would lead to further blood loss and potentially fatal consequences due to delayed reversal of anticoagulation. *Vitamin K 10mg IV* - Intravenous **Vitamin K** promotes the synthesis of new clotting factors, effectively reversing warfarin's effects. However, its onset of action is **slow**, typically taking several hours (6-24 hours) to achieve a significant reduction in INR. - This option is not suitable for an **immediate life-threatening hemorrhage** where rapid reversal of anticoagulation is required to stabilize the patient. *Fresh frozen plasma* - **FFP** contains all clotting factors and can reverse warfarin's effects. However, it requires **thawing time**, often necessitates infusion of large volumes which can lead to **volume overload**, and carries risks of **transfusion reactions**. - **PCC** is generally preferred over FFP for rapid warfarin reversal in severe bleeding due to its faster onset, smaller volume, and lower associated risks. *Factor VIIa* - Recombinant **Factor VIIa** can promote hemostasis by directly activating Factor X, but it is typically used for specific bleeding disorders or as a last resort in refractory bleeding. - It is not the primary or most appropriate agent for comprehensive **warfarin reversal** as it does not replace the full spectrum of vitamin K-dependent factors (II, IX, X) inhibited by warfarin. PCC offers a more complete and targeted approach.
Anaphylaxis UK Medical PG Question 2: A 67-year-old man presents with sudden onset weakness of his right arm and face. He cannot speak but understands commands. CT head shows no hemorrhage. He presents 3 hours after onset. What is the most appropriate treatment?
- A. Aspirin 300mg
- B. Alteplase (Correct Answer)
- C. Clopidogrel
- D. Heparin
- E. Mechanical thrombectomy
Anaphylaxis Explanation: ***Alteplase*** - The patient's presentation with sudden onset neurological deficits (right arm and face weakness, aphasia) without hemorrhage on CT and within 3 hours of symptom onset is characteristic of an **acute ischemic stroke** within the **thrombolysis window**. - **Alteplase** (rtPA) is the primary intervention for eligible patients with acute ischemic stroke, aiming to dissolve the clot and restore blood flow to the brain within 4.5 hours of symptom onset. *Aspirin 300mg* - While **aspirin** is an antiplatelet medication used in stroke management, it is primarily for **secondary prevention** and initial management if thrombolysis is contraindicated or after thrombolysis. - It is not the most appropriate immediate treatment to dissolve an acute clot in an eligible patient presenting within the thrombolysis window. *Clopidogrel* - **Clopidogrel** is an antiplatelet agent used for **secondary stroke prevention** or in combination with aspirin in certain high-risk TIA/minor stroke cases. - It does not actively lyse an acute **thrombus** and is not the first-line acute treatment for ischemic stroke within the thrombolysis window. *Heparin* - **Heparin** is an anticoagulant that prevents clot formation and extension, but it is generally **not recommended** for routine use in acute ischemic stroke due to an increased risk of **hemorrhagic transformation**. - Its role is limited to specific situations like **cerebral venous sinus thrombosis** or certain cardioembolic strokes, often after careful risk assessment. *Mechanical thrombectomy* - **Mechanical thrombectomy** is indicated for **large vessel occlusion** (LVO) ischemic strokes, typically performed within 6 to 24 hours (or even longer in select cases) of symptom onset. - While highly effective for LVO, **alteplase** remains the first-line pharmacologic treatment if the patient is within the thrombolysis window and has no contraindications, often administered even before thrombectomy if an LVO is present.
Anaphylaxis UK Medical PG Question 3: A 61-year-old man presents with sudden onset severe chest pain radiating to his back. CT angiogram shows Stanford type B aortic dissection without complications. His BP is 180/95 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. Immediate surgery referral
Anaphylaxis Explanation: ***Medical management with beta-blockers***- Uncomplicated **Stanford type B dissection** (distal to the left subclavian artery and without malperfusion or rupture) is primarily managed medically.- The immediate goal is aggressive control of **blood pressure (SBP target < 120 mmHg)** and reduction of the heart rate (HR target < 60 bpm) using IV **beta-blockers** (e.g., labetalol, esmolol) to decrease aortic wall shear stress.*Emergency surgical repair*- This is the standard management for **Stanford type A aortic dissection** (involving the ascending aorta) due to the high risk of catastrophic rupture or cardiac tamponade.- It is reserved for complicated **Type B dissections** (those with rupture, malperfusion syndrome, or refractory pain/hypertension) but not for the uncomplicated case presented.*Endovascular stent graft*- Endovascular repair (**TEVAR**) is typically considered if a Type B dissection becomes complicated or if medical therapy fails, but it is not the *initial* therapy.- This approach is favored over open surgery for many complicated Type B dissections, but initial stabilization always requires **medical therapy**.*Thrombolysis*- **Thrombolysis** is strictly contraindicated if there is suspicion or confirmation of an aortic dissection.- Administering thrombolytics significantly increases the risk of **aortic rupture** and subsequent hemorrhage, particularly when the patient is hypertensive.*Immediate surgery referral*- While a surgical referral is necessary for definitive care planning, the most **immediate and crucial step** in an uncomplicated Type B dissection is aggressive **medical management** to prevent progression and rupture.- Delaying blood pressure control while awaiting a referral or preparing for surgery exponentially increases the risk of mortality.
Anaphylaxis UK Medical PG Question 4: A 46-year-old man presents with acute onset severe abdominal pain and shock. He takes warfarin for atrial fibrillation. His INR is 6.8. CT shows retroperitoneal hematoma. What is the most appropriate immediate management?
- A. Vitamin K 10mg IV
- B. Fresh frozen plasma
- C. Prothrombin complex concentrate (Correct Answer)
- D. Stop warfarin only
- E. Tranexamic acid
Anaphylaxis Explanation: ***Prothrombin complex concentrate***- This patient presents with **major hemorrhage** (retroperitoneal hematoma) and **shock** due to severe **warfarin coagulopathy** (INR 6.8).- **PCC** provides the fastest and most complete reversal of **Vitamin K antagonist** effects by supplying factors II, VII, IX, and X, crucial for immediate **hemostasis** in life-threatening bleeding.*Vitamin K 10mg IV*- While essential for long-term factor replenishment, **intravenous Vitamin K** has a delayed onset of action, typically taking 6 to 12 hours to significantly reduce the INR.- It is always administered alongside a rapid reversal agent (like PCC) in cases of life-threatening bleeding but is insufficient as the *only* immediate management due to its slow effect.*Fresh frozen plasma*- FFP contains all necessary clotting factors but requires large volumes, is slow to infuse, necessitates **ABO compatibility** testing, and carries a significant risk of **transfusion-associated circulatory overload (TACO)**.- Current guidelines reserve FFP mainly for situations where PCC is unavailable or for specific coagulopathies not covered by PCC.*Stop warfarin only*- Stopping the drug is necessary to prevent further anticoagulation, but the half-lives of the affected clotting factors are long; stopping warfarin alone will not acutely correct the life-threatening coagulopathy needed to stop the active **retroperitoneal hemorrhage**.- Immediate administration of factor concentrates (PCC) or plasma products is required for rapid **hemostatic resuscitation**.*Tranexamic acid*- **Tranexamic acid** is an **antifibrinolytic** agent that works by stabilizing clots by inhibiting plasminogen activation.- It is not the appropriate first-line therapy for reversing the underlying severe **deficiency of Vitamin K-dependent clotting factors** caused by warfarin overdose, which is the primary issue here.
Anaphylaxis UK Medical PG Question 5: A 46-year-old man presents with acute severe epigastric pain and vomiting. His amylase (1800 U/L). He has a history of alcohol excess. What is the most important initial assessment?
- A. CT abdomen
- B. ERCP
- C. Severity scoring (Correct Answer)
- D. Nutritional assessment
- E. Psychiatric evaluation
Anaphylaxis Explanation: ***Severity scoring***
- **Initial assessment** in acute pancreatitis focuses on determining severity using tools like the **Ranson criteria**, **APACHE II**, or the **modified Glasgow criteria** to triage care.
- Early identification of patients with predicted **severe disease** is crucial for appropriate resource allocation, aggressive fluid resuscitation, and monitoring (often in the ICU).
*CT abdomen*
- Routine CT is not necessary for the initial diagnosis, which is based on clinical presentation and markedly elevated **amylase/lipase** (Amylase 1800 U/L).
- CT imaging is typically reserved for diagnosing complications (e.g., **necrosis** or fluid collections) or if the patient fails to improve clinically after 48-72 hours.
*ERCP*
- **Endoscopic retrograde cholangiopancreatography (ERCP)** is an intervention, not an initial assessment, primarily indicated for emergent management of acute **biliary obstruction** with concurrent **cholangitis** (infection of bile ducts).
- It carries risks, including worsening pancreatitis, and is only performed urgently in a small subset of patients with biliary etiology.
*Nutritional assessment*
- While important, nutritional assessment is secondary to immediate priorities like **hemodynamic stabilization**, pain control, and severity grading during the first 24-48 hours.
- The decision to initiate nutritional support (preferably enteral feeding) is generally based on the predicted **severity score** and the expected duration of the fasting period.
*Psychiatric evaluation*
- Although the patient has a history of **alcohol excess**, which necessitates later evaluation and counseling, emergent psychiatric evaluation is not the most critical component of the initial medical assessment for acute pancreatitis.
- The immediate priority remains stabilization and management of the acute, life-threatening abdominal crisis.
Anaphylaxis UK Medical PG Question 6: A 71-year-old man presents with sudden onset weakness of his right arm and face, and inability to speak. CT head shows acute infarct. He presents 8 hours after symptom onset. What is the most appropriate treatment?
- A. Aspirin
- B. Alteplase
- C. Mechanical thrombectomy (Correct Answer)
- D. Clopidogrel
- E. Heparin
Anaphylaxis Explanation: ***Mechanical thrombectomy***- The patient presents with severe stroke symptoms (weakness, facial droop, and aphasia) due to an **acute large vessel occlusion (LVO)**, confirmed by CT showing an **acute infarct**.- Although the patient is outside the standard 4.5-hour window for **IV thrombolysis (Alteplase)**, the extended window for **mechanical thrombectomy** is up to 24 hours from symptom onset in select patients with LVOs, making this the most appropriate intervention at 8 hours.*Aspirin*- **Aspirin** is used as an initial treatment for minor strokes or following reperfusion therapy, but it is insufficient as a sole therapy for acute severe stroke due to **large vessel occlusion**.*Alteplase*- **Intravenous thrombolysis (Alteplase)** is generally indicated only within **4.5 hours** of symptom onset for acute ischemic stroke.- This patient is at **8 hours** post-symptom onset, which falls outside the standard therapeutic window for Alteplase.*Clopidogrel*- **Clopidogrel** is primarily used for **secondary stroke prevention**, often as part of dual antiplatelet therapy.- It is not the indicated acute reperfusion intervention for severe strokes caused by **large vessel occlusion**.*Heparin*- **Intravenous anticoagulation (Heparin)** is generally **contraindicated** in acute ischemic stroke due to a significant risk of **hemorrhagic transformation**.- It is only considered in specific situations like **venous sinus thrombosis** or for patients with **atrial fibrillation** not undergoing reperfusion therapy.
Anaphylaxis UK Medical PG Question 7: A 39-year-old man presents with acute onset severe headache during sexual intercourse. CT head is normal. What is the most appropriate next investigation?
- A. MRI brain
- B. Lumbar puncture (Correct Answer)
- C. CT angiogram
- D. Carotid Doppler
- E. EEG
Anaphylaxis Explanation: ***Lumbar puncture***- This presentation with an acute onset severe headache during sexual intercourse (a **thunderclap headache**) is highly suggestive of **subarachnoid hemorrhage (SAH)**, even if the initial **CT head** is normal.- A **lumbar puncture** is the most appropriate next step to look for **xanthochromia** in the CSF, which confirms SAH, especially if performed 6-12 hours after symptom onset.*MRI brain*- While **MRI** with FLAIR sequences can detect subarachnoid blood, it is generally considered less sensitive than a **lumbar puncture** for ruling out SAH after a negative CT scan.- It is often reserved for cases where SAH is strongly suspected but the LP is inconclusive, or for evaluating the cause of SAH once confirmed.*CT angiogram*- **CT angiogram (CTA)** is primarily used to identify the source of bleeding, such as an **aneurysm**, once SAH has been confirmed.- It is not the initial diagnostic test to confirm the presence of **subarachnoid hemorrhage** itself when a non-contrast CT is normal.*Carotid Doppler*- A **Carotid Doppler** ultrasound assesses for **carotid artery stenosis** or dissection in the neck vessels.- This investigation is not relevant for the acute evaluation of a **thunderclap headache**, which indicates an intracranial event like SAH.*EEG*- An **EEG (electroencephalogram)** measures brain electrical activity and is used to diagnose conditions such as **seizures** or certain encephalopathies.- It has no diagnostic value in the acute assessment of a **thunderclap headache** or suspected subarachnoid hemorrhage.
Anaphylaxis UK Medical PG Question 8: A 45-year-old man presents with sudden onset severe abdominal pain and shock. CT shows retroperitoneal hematoma. His INR is 8.2 following warfarin therapy. What is the most appropriate immediate treatment?
- A. Fresh frozen plasma
- B. Vitamin K 10mg IV
- C. Prothrombin complex concentrate (Correct Answer)
- D. Tranexamic acid
- E. Factor VIIa
Anaphylaxis Explanation: ***Prothrombin complex concentrate*** - The patient's severe retroperitoneal hematoma and shock, coupled with an INR of 8.2 from warfarin therapy, indicate a life-threatening hemorrhage requiring **rapid reversal** of anticoagulation. - **Prothrombin complex concentrate (PCC)** contains concentrated vitamin K-dependent clotting factors (II, VII, IX, X) and provides the fastest and most effective reversal of warfarin's anticoagulant effect. *Fresh frozen plasma* - **Fresh frozen plasma (FFP)** contains all clotting factors but acts slower and requires larger volumes compared to PCC, posing a risk of **volume overload**. - The time to administration and achieving adequate factor levels with FFP is longer than with PCC, making it less ideal for immediate, severe bleeding. *Vitamin K 10mg IV* - **Vitamin K** is crucial for synthesizing new clotting factors, but its therapeutic effect is **delayed**, taking several hours to days to normalize INR. - While essential for sustained reversal, it is not the *most appropriate immediate* treatment for a patient in active shock and severe hemorrhage who needs rapid hemostasis. *Tranexamic acid* - **Tranexamic acid** is an **antifibrinolytic agent** that inhibits clot breakdown by blocking plasminogen activation. - It does not directly replace deficient clotting factors or reverse the anticoagulant effect of warfarin, making it ineffective as the primary treatment for warfarin-induced bleeding. *Factor VIIa* - **Recombinant activated Factor VIIa (rFVIIa)** is primarily used for severe bleeding in patients with hemophilia or other specific coagulopathies. - While it can promote coagulation, it is not the first-line agent for warfarin reversal due to its **thrombogenic risk** and because PCC more comprehensively replaces the multiple deficient vitamin K-dependent factors.
Anaphylaxis UK Medical PG Question 9: A 67-year-old man with COPD presents with acute confusion and drowsiness. ABG shows pH 7.25, pCO2 8.5 kPa, pO2 7.2 kPa, HCO3- 28 mmol/L. What is the most appropriate immediate management?
- A. High-flow oxygen
- B. Non-invasive ventilation (Correct Answer)
- C. Intubation and mechanical ventilation
- D. IV bicarbonate
- E. Controlled oxygen therapy
Anaphylaxis Explanation: ***Non-invasive ventilation***- This patient presents with severe acute hypercapnic respiratory failure (pH 7.25, pCO2 8.5 kPa) and altered mental status (confusion, drowsiness), making **Non-invasive ventilation (NIV)** the most appropriate immediate intervention.- NIV (typically BiPAP) is the first-line treatment for acute exacerbations of COPD causing respiratory acidosis, as it effectively reduces **pCO2** and improves **pH** without the invasiveness of intubation.*High-flow oxygen*- High-flow oxygen risks abolishing the **hypoxic drive** in COPD patients, potentially worsening the already severe **hypercapnia** and respiratory acidosis.- It does not address the underlying problem of inadequate ventilation, which is the primary cause of the elevated pCO2.*Intubation and mechanical ventilation*- This aggressive intervention is generally reserved for patients who have failed NIV, are in **cardiac or respiratory arrest**, or have profound **coma** (e.g., GCS < 8).- Prioritizing NIV is crucial as it significantly reduces the morbidity and mortality associated with **invasive mechanical ventilation**.*IV bicarbonate*- Bicarbonate is generally contraindicated in primary **respiratory acidosis** because its metabolism produces CO2, which the patient is unable to adequately excrete.- The appropriate treatment is to improve ventilation to eliminate excess **CO2**, not to directly buffer the acidosis with bicarbonate.*Controlled oxygen therapy*- While controlled oxygen (e.g., 24-28% via Venturi mask) is the initial standard for hypoxemia in stable COPD, it is inadequate for this level of severe **hypercapnia** and altered mental status (**CO2 narcosis**).- Given the severe **acidosis** (pH 7.25) and impaired consciousness, immediate ventilatory support like NIV is mandatory to improve minute ventilation.
Anaphylaxis UK Medical PG Question 10: A 35-year-old woman presents with sudden onset severe chest pain and shortness of breath. She is 3 weeks postpartum and has been immobile due to cesarean section complications. D-dimer is elevated. What is the most appropriate initial investigation?
- A. Chest X-ray
- B. ECG
- C. CT pulmonary angiogram (Correct Answer)
- D. V/Q scan
- E. Echocardiogram
Anaphylaxis Explanation: ***CT pulmonary angiogram***- This is the **most definitive non-invasive initial test** for diagnosing **Pulmonary Embolism (PE)**, allowing direct visualization of emboli in the pulmonary arteries.- Given the high clinical suspicion (postpartum state, immobility, sudden pleuritic chest pain, and elevated D-dimer), immediate confirmation via **CTPA** is required to guide prompt anticoagulation.*Chest X-ray*- While necessary to rule out alternative pulmonary causes (e.g., pneumothorax or pneumonia), a **Chest X-ray (CXR)** is usually normal in PE and is not diagnostic.- It is a screening tool only and should not delay definitive imaging if the clinical suspicion for **PE** is high.*ECG*- The **ECG** is primarily used to exclude acute cardiac causes of chest pain, such as **myocardial infarction**.- It may show non-specific findings or signs of **Right Heart Strain** (e.g., S1Q3T3 pattern), but it cannot confirm the presence of a pulmonary embolus.*V/Q scan*- A **V/Q (Ventilation/Perfusion) scan** is typically reserved for patients with contraindications to CT contrast (e.g., severe renal failure) or, historically, pregnancy.- **CTPA** is generally preferred over V/Q scanning due to its superior resolution and higher diagnostic accuracy, especially when the chest radiograph is abnormal.*Echocardiogram*- An **Echocardiogram** is valuable for evaluating **Right Ventricular (RV) function** and looking for signs of RV strain or elevated pulmonary artery pressures, particularly in unstable patients.- However, it is not the primary imaging modality used to directly visualize the embolus within the pulmonary artery tree.
More Anaphylaxis UK Medical PG questions available in the OnCourse app. Practice MCQs, flashcards, and get detailed explanations.
