A 70-year-old woman presents with sudden-onset severe retrosternal chest pain lasting 2 hours. Her ECG shows ST-segment elevation of 3 mm in leads V1-V4. The nearest primary percutaneous coronary intervention (PCI) centre is 90 minutes away by ambulance. She has no contraindications to thrombolysis. What is the most appropriate management strategy?
Q182
A 46-year-old woman with known penicillin allergy is admitted with suspected community-acquired pneumonia and sepsis. Her observations show temperature 38.7°C, heart rate 112 bpm, blood pressure 94/58 mmHg, respiratory rate 28/min, and oxygen saturation 90% on room air. She previously developed an urticarial rash when given penicillin. Which antibiotic regimen is most appropriate for initial empirical treatment?
Q183
A 54-year-old man presents with sudden-onset severe chest pain radiating to his back. He describes it as 'tearing' in nature. He has a history of poorly controlled hypertension. On examination, his blood pressure is 178/96 mmHg in the right arm and 142/78 mmHg in the left arm. Heart rate is 98 bpm and respiratory rate is 22/min. His chest radiograph shows a widened mediastinum. What is the most appropriate immediate investigation to confirm the diagnosis?
Q184
A 65-year-old man presents to the Emergency Department with a 24-hour history of fever and confusion. His wife reports he has been increasingly drowsy. He has a past medical history of type 2 diabetes. On examination, his temperature is 38.9°C, heart rate 118 bpm, blood pressure 88/52 mmHg, respiratory rate 26/min, and oxygen saturation 92% on room air. Blood tests show lactate 3.2 mmol/L. According to the Sepsis Six bundle, which of the following should be administered within the first hour?
Q185
A 71-year-old man is brought to the Emergency Department by ambulance with suspected sepsis. He has been unwell for 48 hours with urinary symptoms. Observations on arrival are: temperature 38.2°C, heart rate 105 bpm, blood pressure 88/54 mmHg, respiratory rate 24 breaths/min, oxygen saturation 94% on air, AVPU = Alert. He has been given 1 litre of intravenous crystalloid in the ambulance. Blood tests show lactate 4.2 mmol/L. According to the UK Sepsis Six bundle, which of the following should be completed within the first hour?
Q186
A 26-year-old woman attends the Emergency Department with a 15-minute history of lip swelling, difficulty swallowing, and a sensation of throat tightness. She started taking ramipril for hypertension 3 weeks ago. She has no rash, wheeze, or respiratory distress. Observations are: heart rate 88 bpm, blood pressure 138/82 mmHg, respiratory rate 16 breaths/min, oxygen saturation 98% on air. Examination shows marked lip and tongue swelling without urticaria. What is the most appropriate initial management?
Q187
A 67-year-old woman with type 2 diabetes and hypertension presents with 6 hours of constant central chest discomfort associated with nausea and sweating. Her ECG shows ST depression of 2mm in leads V2-V5 and T-wave inversion in leads I, aVL, V4-V6. High-sensitivity troponin I at presentation is 45 ng/L (normal <16 ng/L). She has been given aspirin, ticagrelor, and fondaparinux. Her GRACE score is calculated at 142. What is the most appropriate management strategy?
Q188
A 52-year-old man is brought to the Emergency Department with altered consciousness. He was found by his wife approximately 1 hour after she heard a loud cry from his study. On examination, he has a Glasgow Coma Scale score of 10, blood pressure 195/110 mmHg, heart rate 55 bpm, and bilateral extensor plantar responses. There is no rash. CT head shows blood in the subarachnoid space. What is the most appropriate immediate management priority?
Q189
A 41-year-old woman with no significant past medical history is brought to the Emergency Department by ambulance with a 1-hour history of perioral tingling, carpopedal spasm, and feeling light-headed. She appears anxious and is breathing rapidly. Arterial blood gas on air shows: pH 7.52, PaCO₂ 2.8 kPa, PaO₂ 13.2 kPa, HCO₃⁻ 22 mmol/L, base excess -1. What is the most likely cause of her presentation?
Q190
A 59-year-old man with known peripheral vascular disease presents with sudden-onset severe interscapular back pain radiating through to the chest. He appears distressed and sweaty. Blood pressure is 178/95 mmHg in the right arm and 142/88 mmHg in the left arm. Chest X-ray shows a widened mediastinum. What is the most appropriate immediate investigation?
Acute Medical Presentations UK Medical PG Practice Questions and MCQs
Question 181: A 70-year-old woman presents with sudden-onset severe retrosternal chest pain lasting 2 hours. Her ECG shows ST-segment elevation of 3 mm in leads V1-V4. The nearest primary percutaneous coronary intervention (PCI) centre is 90 minutes away by ambulance. She has no contraindications to thrombolysis. What is the most appropriate management strategy?
A. Arrange immediate transfer for primary PCI without thrombolysis (Correct Answer)
B. Administer thrombolysis immediately and then transfer for angiography
C. Give aspirin and clopidogrel only, then transfer for primary PCI
D. Arrange primary PCI only if transfer can occur within 120 minutes of first medical contact
E. Administer thrombolysis only if door-to-balloon time would exceed 90 minutes
Explanation: ***Arrange immediate transfer for primary PCI without thrombolysis***
- **Primary PCI** is the preferred reperfusion strategy for **STEMI** when it can be performed within **120 minutes** of first medical contact.
- With a 90-minute transfer time, the patient can receive definitive reperfusion within this critical window, offering superior outcomes to thrombolysis in terms of mortality and stroke reduction.
*Administer thrombolysis immediately and then transfer for angiography*
- **Thrombolysis** is primarily indicated when **Primary PCI** cannot be performed within the **120-minute** time window (e.g., due to prolonged transfer times).
- While a pharmacoinvasive strategy (thrombolysis followed by PCI) exists, direct PCI is superior when feasible within the recommended timeframes.
*Give aspirin and clopidogrel only, then transfer for primary PCI*
- **Aspirin** and **clopidogrel** are crucial adjunctive therapies in **STEMI** but do not constitute the primary reperfusion strategy.
- Delaying definitive reperfusion with **PCI** by only administering antiplatelets significantly worsens myocardial salvage and patient outcomes.
*Arrange primary PCI only if transfer can occur within 120 minutes of first medical contact*
- This statement outlines the **guideline** for determining the appropriate reperfusion strategy but does not represent the direct, actionable management for this specific patient.
- Given the patient's presentation and the 90-minute transfer time, the appropriate *action* is to proceed with the transfer, as it meets the criterion.
*Administer thrombolysis only if door-to-balloon time would exceed 90 minutes*
- The **90-minute** target for **door-to-balloon time** typically applies to patients presenting directly to **PCI-capable hospitals**.
- For patients requiring transfer, the international guidelines generally recommend **Primary PCI** if **first medical contact to balloon time** is within **120 minutes**, not 90 minutes, for deciding between PCI and thrombolysis.
Question 182: A 46-year-old woman with known penicillin allergy is admitted with suspected community-acquired pneumonia and sepsis. Her observations show temperature 38.7°C, heart rate 112 bpm, blood pressure 94/58 mmHg, respiratory rate 28/min, and oxygen saturation 90% on room air. She previously developed an urticarial rash when given penicillin. Which antibiotic regimen is most appropriate for initial empirical treatment?
A. Intravenous co-amoxiclav and clarithromycin
B. Intravenous levofloxacin and clarithromycin (Correct Answer)
C. Intravenous ceftriaxone and doxycycline
D. Intravenous meropenem monotherapy
E. Intravenous vancomycin and gentamicin
Explanation: ***Intravenous levofloxacin and clarithromycin***
- In patients with a **Type 1 hypersensitivity reaction** (e.g., urticarial rash) to penicillin, respiratory **fluoroquinolones** like levofloxacin are safe and effective alternatives for severe pneumonia.
- This combination provides broad-spectrum coverage for both **typical pathogens** (like S. pneumoniae) and **atypical pathogens** (like Legionella), which is essential for high-severity CURB-65 cases.
*Intravenous co-amoxiclav and clarithromycin*
- **Co-amoxiclav** is strictly contraindicated because it contains **amoxicillin**, a penicillin that would trigger the patient's documented allergy.
- Administering this could lead to life-threatening **anaphylaxis** given her history of urticaria.
*Intravenous ceftriaxone and doxycycline*
- **Ceftriaxone** is a cephalosporin that carries a significant risk of **cross-reactivity** (up to 10%) in patients with known penicillin allergies.
- Guidelines generally recommend avoiding all **beta-lactams** if the patient's previous reaction was an immediate **Type 1 hypersensitivity** (urticaria/angioedema).
*Intravenous meropenem monotherapy*
- **Meropenem** is a carbapenem and, like cephalosporins, carries a risk of **cross-reactivity** in patients with a history of penicillin-induced urticaria.
- It is generally reserved for **multi-drug resistant** organisms or hospital-acquired infections, rather than initial empirical treatment for community-acquired pneumonia.
*Intravenous vancomycin and gentamicin*
- This combination fails to provide adequate coverage for common **community-acquired pneumonia** pathogens such as **Streptococcus pneumoniae** or atypicals.
- **Gentamicin** has poor lung tissue penetration and is more commonly used for **Gram-negative sepsis** or urinary tract infections.
Question 183: A 54-year-old man presents with sudden-onset severe chest pain radiating to his back. He describes it as 'tearing' in nature. He has a history of poorly controlled hypertension. On examination, his blood pressure is 178/96 mmHg in the right arm and 142/78 mmHg in the left arm. Heart rate is 98 bpm and respiratory rate is 22/min. His chest radiograph shows a widened mediastinum. What is the most appropriate immediate investigation to confirm the diagnosis?
A. Transthoracic echocardiography
B. CT pulmonary angiography
C. CT aortography with contrast (Correct Answer)
D. Coronary angiography
E. Ventilation-perfusion scan
Explanation: ***CT aortography with contrast***
- This is the **investigation of choice** for hemodynamically stable patients suspected of **aortic dissection**, offering near 100% sensitivity for identifying the **intimal flap**.
- It quickly delineates the extent of the dissection for **Stanford classification** and helps in planning surgical or medical management.
*Transthoracic echocardiography*
- This modality has **poor sensitivity** for visualizing the entire aorta, especially the descending aorta, and for precisely identifying the **dissection flap**.
- While useful for checking for **pericardial effusion** or aortic root involvement (proximal dissection), it is not definitive enough to confirm a back-radiating dissection (often distal or extensive).
*CT pulmonary angiography*
- This study is specifically protocolled to visualize the **pulmonary arteries** and is the gold standard for diagnosing **pulmonary embolism**.
- While the aorta is visible, it lacks the precise timing and contrast bolus required to accurately evaluate an **aortic dissection**, which needs arterial phase imaging of the aorta.
*Coronary angiography*
- This is an **invasive procedure** used primarily to evaluate **coronary artery disease** and would unnecessarily delay the diagnosis of a life-threatening aortic dissection.
- It carries a significant risk in this setting, as the catheter could potentially enter the **false lumen** or cause further injury to the dissected aorta.
*Ventilation-perfusion scan*
- This is a nuclear medicine test primarily used to assess for **pulmonary embolism** in patients who cannot receive IV contrast or where CTPA is contraindicated.
- It provides no anatomical information regarding the structural integrity of the **aorta** and is completely irrelevant for diagnosing an aortic dissection.
Question 184: A 65-year-old man presents to the Emergency Department with a 24-hour history of fever and confusion. His wife reports he has been increasingly drowsy. He has a past medical history of type 2 diabetes. On examination, his temperature is 38.9°C, heart rate 118 bpm, blood pressure 88/52 mmHg, respiratory rate 26/min, and oxygen saturation 92% on room air. Blood tests show lactate 3.2 mmol/L. According to the Sepsis Six bundle, which of the following should be administered within the first hour?
A. Broad-spectrum antibiotics only after blood cultures are taken
B. Intravenous fluid bolus, oxygen, and broad-spectrum antibiotics (Correct Answer)
C. Vasopressors as the first-line treatment before fluid resuscitation
D. Intravenous fluid bolus only, deferring antibiotics until sensitivities are known
E. Oxygen therapy and monitoring only until senior review
Explanation: ***Intravenous fluid bolus, oxygen, and broad-spectrum antibiotics***
- These represent the three 'Give' components of the **Sepsis Six** bundle that must be initiated within the **first hour** to reduce mortality in patients with suspected sepsis or septic shock.
- Given the patient's **hypotension** (88/52 mmHg) and **elevated lactate** (3.2 mmol/L), rapid **fluid resuscitation** and **oxygen** to maintain saturations are critical immediate steps alongside early antimicrobial therapy.
*Broad-spectrum antibiotics only after blood cultures are taken*
- While obtaining **blood cultures** before antibiotics is ideal, the administration of **broad-spectrum antibiotics** should never be delayed beyond the **one-hour window** if cultures are difficult to obtain.
- This option is incomplete as it ignores the urgent need for **fluid resuscitation** and **oxygen** therapy required by the Sepsis Six protocol.
*Vasopressors as the first-line treatment before fluid resuscitation*
- **Intravenous crystalloids** are the first-line treatment for sepsis-induced hypotension; **vasopressors** are only indicated if the patient remains hypotensive after adequate **fluid resuscitation**.
- Initiating vasopressors before addressing **hypovolemia** can worsen tissue perfusion and does not follow the standard **Surviving Sepsis** guidelines.
*Intravenous fluid bolus only, deferring antibiotics until sensitivities are known*
- Deferring antibiotics until **sensitivities** are known can take 24–48 hours, which significantly increases the risk of mortality in **septic shock**.
- Empirical **broad-spectrum antibiotics** must be started immediately within the first hour to cover the most likely pathogens while awaiting culture results.
*Oxygen therapy and monitoring only until senior review*
- Sepsis is a **medical emergency**; the Sepsis Six bundle should be initiated by the first responding clinician rather than waiting for **senior review**.
- Relying solely on **monitoring** and oxygen ignores the underlying infection and the circulatory collapse indicated by the patient's **tachycardia** and **hypotension**.
Question 185: A 71-year-old man is brought to the Emergency Department by ambulance with suspected sepsis. He has been unwell for 48 hours with urinary symptoms. Observations on arrival are: temperature 38.2°C, heart rate 105 bpm, blood pressure 88/54 mmHg, respiratory rate 24 breaths/min, oxygen saturation 94% on air, AVPU = Alert. He has been given 1 litre of intravenous crystalloid in the ambulance. Blood tests show lactate 4.2 mmol/L. According to the UK Sepsis Six bundle, which of the following should be completed within the first hour?
A. Give high-flow oxygen, take blood cultures, give intravenous antibiotics, give intravenous fluid challenge, measure lactate and hourly urine output, and administer vasopressors if required
B. Give oxygen to maintain saturation >94%, take blood cultures, give intravenous antibiotics, give intravenous fluid resuscitation, measure lactate, and measure hourly urine output (Correct Answer)
C. Give oxygen therapy, obtain imaging to identify source, give intravenous antibiotics, give intravenous fluids, check full blood count, and insert urinary catheter
D. Give broad-spectrum antibiotics, give intravenous fluid bolus, measure serum lactate, take blood cultures, commence inotropes, and perform arterial blood gas
E. Administer antibiotics within 30 minutes, give 30mL/kg crystalloid, measure central venous pressure, commence noradrenaline, take blood cultures, and check procalcitonin
Explanation: ***Give oxygen to maintain saturation >94%, take blood cultures, give intravenous antibiotics, give intravenous fluid resuscitation, measure lactate, and measure hourly urine output***
- The **Sepsis Six bundle** is a set of time-critical interventions designed to be completed within one hour to improve outcomes in patients with sepsis.
- It includes three 'gets' (**oxygen**, **antibiotics**, **fluids**) and three 'takes' (**blood cultures**, **lactate**, **urine output**), which are all present in this option.
*Give high-flow oxygen, take blood cultures, give intravenous antibiotics, give intravenous fluid challenge, measure lactate and hourly urine output, and administer vasopressors if required*
- **Oxygen** should be titrated to maintain a target saturation (typically >94%) rather than simply giving "high-flow" oxygen to all patients regardless of need.
- While **vasopressors** are crucial for persistent hypotension in septic shock, they are initiated if fluids fail, and are not one of the original core six components in the initial one-hour bundle.
*Give oxygen therapy, obtain imaging to identify source, give intravenous antibiotics, give intravenous fluids, check full blood count, and insert urinary catheter*
- **Imaging** for source control and a **full blood count** are important diagnostic steps but are not part of the specific six therapeutic and monitoring interventions of the Sepsis Six bundle.
- This option incorrectly omits the critical step of **measuring lactate**, which is vital for assessing tissue hypoperfusion and guiding resuscitation.
*Give broad-spectrum antibiotics, give intravenous fluid bolus, measure serum lactate, take blood cultures, commence inotropes, and perform arterial blood gas*
- **Inotropes** are generally reserved for myocardial dysfunction in sepsis, whereas **vasopressors** (like noradrenaline) are the primary agents for managing hypotension after fluid resuscitation.
- Performing an **arterial blood gas** (ABG) is useful for comprehensive assessment but is not one of the specific core six interventions mandated by the UK Sepsis Trust bundle within the first hour.
*Administer antibiotics within 30 minutes, give 30mL/kg crystalloid, measure central venous pressure, commence noradrenaline, take blood cultures, and check procalcitonin*
- **Central venous pressure (CVP)** monitoring and **procalcitonin** levels are advanced or adjunctive measures and are not explicitly part of the initial Sepsis Six bundle.
- This option correctly includes antibiotics, fluids, and blood cultures but omits the crucial monitoring of **lactate** and **hourly urine output** which are foundational to the Sepsis Six.
Question 186: A 26-year-old woman attends the Emergency Department with a 15-minute history of lip swelling, difficulty swallowing, and a sensation of throat tightness. She started taking ramipril for hypertension 3 weeks ago. She has no rash, wheeze, or respiratory distress. Observations are: heart rate 88 bpm, blood pressure 138/82 mmHg, respiratory rate 16 breaths/min, oxygen saturation 98% on air. Examination shows marked lip and tongue swelling without urticaria. What is the most appropriate initial management?
A. Stop ramipril and observe for airway compromise; consider administration of C1 esterase inhibitor concentrate (Correct Answer)
B. Administer intramuscular adrenaline 0.5mL of 1:1000 immediately
C. Give intravenous hydrocortisone and chlorphenamine
D. Discharge with oral antihistamines and avoid ramipril in future
E. Perform emergency cricothyroidotomy
Explanation: ***Stop ramipril and observe for airway compromise; consider administration of C1 esterase inhibitor concentrate***- The patient's symptoms of lip and tongue swelling, difficulty swallowing, and throat tightness, occurring after starting **ramipril** (an ACE inhibitor) and notably **without urticaria or wheeze**, are classic for **ACE inhibitor-induced angioedema**.- This condition is **bradykinin-mediated**, meaning standard treatments for allergic reactions (like adrenaline, steroids, and antihistamines) are ineffective. Stopping the offending agent and close airway monitoring are paramount, with **C1 esterase inhibitor concentrate** or **icatibant** being specific treatments for severe cases.*Administer intramuscular adrenaline 0.5mL of 1:1000 immediately*- **Adrenaline** is the first-line treatment for **anaphylaxis**, which typically presents with systemic signs like hypotension, wheezing, or widespread urticaria, none of which are noted here.- **ACE inhibitor-induced angioedema** is not a **Type 1 hypersensitivity** reaction; therefore, adrenaline does not address the underlying **bradykinin** accumulation and will not resolve the swelling.*Give intravenous hydrocortisone and chlorphenamine*- **Hydrocortisone** (corticosteroid) and **chlorphenamine** (antihistamine) target **histamine-mediated** allergic reactions, commonly seen in urticaria or typical allergic angioedema.- These medications are generally **ineffective** in **ACE inhibitor-induced angioedema** because its pathogenesis is primarily due to **bradykinin** accumulation, not histamine release.*Discharge with oral antihistamines and avoid ramipril in future*- Discharging the patient is **unsafe** because **ACE inhibitor-induced angioedema** can progress rapidly and unpredictably to **complete airway obstruction** over hours to days, even after stopping the drug.- **Oral antihistamines** do not alleviate **bradykinin-mediated angioedema** and would not prevent the potential for life-threatening airway compromise.*Perform emergency cricothyroidotomy*- **Emergency cricothyroidotomy** is an invasive, **last-resort procedure** indicated only for **complete or impending airway obstruction** when other definitive airway management attempts (e.g., intubation) have failed.- The patient is currently **stable** with normal oxygen saturation and no respiratory distress, indicating her airway is not yet critically compromised to warrant such an extreme measure.
Question 187: A 67-year-old woman with type 2 diabetes and hypertension presents with 6 hours of constant central chest discomfort associated with nausea and sweating. Her ECG shows ST depression of 2mm in leads V2-V5 and T-wave inversion in leads I, aVL, V4-V6. High-sensitivity troponin I at presentation is 45 ng/L (normal <16 ng/L). She has been given aspirin, ticagrelor, and fondaparinux. Her GRACE score is calculated at 142. What is the most appropriate management strategy?
A. Immediate invasive coronary angiography within 24 hours (Correct Answer)
B. Invasive coronary angiography within 72 hours
C. Conservative management with repeat troponin and ECG
D. Immediate thrombolysis
E. Exercise tolerance test before discharge
Explanation: ***Immediate invasive coronary angiography within 24 hours***- This patient presents with a **non-ST elevation myocardial infarction (NSTEMI)**, indicated by typical chest pain, **elevated high-sensitivity troponin**, and **ischemic ECG changes** (ST depression and T-wave inversion).- Her **GRACE score of 142** classifies her as **high risk**, necessitating an **early invasive strategy** (coronary angiography) within 24 hours to reduce mortality and morbidity, as per current guidelines (e.g., ESC, NICE).
*Invasive coronary angiography within 72 hours*- An invasive strategy within 72 hours is generally recommended for patients with an **intermediate GRACE score** (typically 109-140) or other lower-risk NSTEACS features.- Given this patient's **high GRACE score (142)** and widespread **ST-segment depression**, a more urgent intervention within 24 hours is indicated over a 72-hour window.
*Conservative management with repeat troponin and ECG*- Conservative management is only considered for **low-risk NSTEACS patients** (e.g., GRACE score <109) who are symptom-free and have no recurrent ischemia or dynamic ECG changes.- This patient has clear signs of ongoing **myocardial injury** (elevated troponin) and **active ischemia** on ECG, making conservative management inappropriate and potentially harmful.
*Immediate thrombolysis*- **Thrombolysis** is indicated for **ST-elevation myocardial infarction (STEMI)** when primary percutaneous coronary intervention (PCI) is not available in a timely manner, to achieve reperfusion.- It is **contraindicated** in **NSTEMI** and non-ST elevation acute coronary syndrome (NSTEACS) as it does not improve outcomes and significantly increases the risk of **major bleeding**.
*Exercise tolerance test before discharge*- Performing an **exercise tolerance test** during the acute phase of an **NSTEMI** is extremely dangerous, as it can worsen ischemia, precipitate **arrhythmias**, or lead to cardiac arrest.- Functional stress testing is reserved for **stable patients** with suspected but unconfirmed coronary artery disease, or for **risk stratification post-ACS** once the patient is stable and revascularization status is known.
Question 188: A 52-year-old man is brought to the Emergency Department with altered consciousness. He was found by his wife approximately 1 hour after she heard a loud cry from his study. On examination, he has a Glasgow Coma Scale score of 10, blood pressure 195/110 mmHg, heart rate 55 bpm, and bilateral extensor plantar responses. There is no rash. CT head shows blood in the subarachnoid space. What is the most appropriate immediate management priority?
A. Urgent neurosurgical consultation and arrange CT angiography (Correct Answer)
B. Lumbar puncture to confirm subarachnoid haemorrhage
C. Immediate administration of intravenous labetalol
D. Administer intravenous nimodipine
E. Perform emergency craniotomy
Explanation: ***Urgent neurosurgical consultation and arrange CT angiography***
- Following confirmation of **subarachnoid haemorrhage (SAH)** on CT, the absolute priority is identifying the bleeding source via **CT angiography** to plan for definitive repair (clipping or coiling).
- The patient exhibits signs of **raised intracranial pressure (ICP)**, such as bradycardia and hypertension (**Cushing’s reflex**), requiring urgent specialist neurosurgical intervention to manage potential hydrocephalus or mass effect.
*Lumbar puncture to confirm subarachnoid haemorrhage*
- **Lumbar puncture** is redundant in this case as the diagnosis has already been confirmed by the **non-contrast CT scan**.
- It is strictly **contraindicated** in this patient due to signs of significantly **raised ICP** (extensor plantars, bradycardia), which increases the risk of **brain herniation**.
*Immediate administration of intravenous labetalol*
- Aggressive blood pressure reduction with **IV labetalol** can be dangerous as it may severely compromise **cerebral perfusion pressure (CPP)** in the setting of raised ICP.
- While blood pressure should be managed (typically a **systolic target <160 mmHg**), it is secondary to surgical stabilization and imaging the underlying pathology.
*Administer intravenous nimodipine*
- **Nimodipine** is used to prevent **delayed cerebral ischemia** caused by vasospasm, but it is typically given **orally/enterally**, not intravenously, in standard UK practice.
- It is started after stabilization and is not the most immediate priority compared to securing the **aneurysm** and managing ICP.
*Perform emergency craniotomy*
- **Emergency craniotomy** is a definitive procedure that cannot be performed until the site and nature of the bleed are mapped by **vascular imaging**.
- The decision for surgery is made by a **neurosurgeon** based on the results of the **CT angiogram** and the patient's neurological status.
Question 189: A 41-year-old woman with no significant past medical history is brought to the Emergency Department by ambulance with a 1-hour history of perioral tingling, carpopedal spasm, and feeling light-headed. She appears anxious and is breathing rapidly. Arterial blood gas on air shows: pH 7.52, PaCO₂ 2.8 kPa, PaO₂ 13.2 kPa, HCO₃⁻ 22 mmol/L, base excess -1. What is the most likely cause of her presentation?
A. Hyperventilation syndrome (Correct Answer)
B. Pulmonary embolism
C. Diabetic ketoacidosis
D. Salicylate poisoning
E. Acute asthma exacerbation
Explanation: ***Hyperventilation syndrome***- The patient's presentation with **perioral tingling**, **carpopedal spasm**, and light-headedness, coupled with anxiety and rapid breathing, are classic symptoms of hyperventilation syndrome.- The arterial blood gas (ABG) showing a **pH of 7.52** (alkalosis) and a **low PaCO₂ of 2.8 kPa** with a **normal HCO₃⁻** and **PaO₂** confirms an acute, uncompensated respiratory alkalosis, which directly results from excessive CO₂ exhalation due to hyperventilation.*Pulmonary embolism*- While a pulmonary embolism (PE) can cause tachypnea and respiratory alkalosis, it typically leads to **hypoxia** (low PaO₂) due to ventilation-perfusion mismatch, which is not present in this ABG.- The specific symptoms of **carpopedal spasm** and **perioral tingling** are due to decreased ionized calcium in alkalosis, which is more characteristic of hyperventilation rather than a PE.*Diabetic ketoacidosis*- Diabetic ketoacidosis (DKA) is a **high anion gap metabolic acidosis**, characterized by a **low pH** and **low bicarbonate (HCO₃⁻)**, which directly contradicts the patient's ABG showing alkalosis and normal HCO₃⁻.- Clinical features of DKA include polydipsia, polyuria, abdominal pain, and **Kussmaul breathing** (deep, labored respirations), not the rapid, shallow breathing and neurological symptoms described here.*Salicylate poisoning*- Salicylate poisoning typically causes a **mixed acid-base disorder**, often starting with respiratory alkalosis followed by a **high anion gap metabolic acidosis**.- The patient's ABG shows a pure acute respiratory alkalosis with **normal bicarbonate** and base excess, without the metabolic component usually seen in salicylate toxicity.*Acute asthma exacerbation*- An early, mild asthma exacerbation might cause respiratory alkalosis due to tachypnea, but it would also present with characteristic signs of **airway obstruction** such as wheezing, dyspnea, and use of accessory muscles.- The specific symptoms of **perioral tingling** and **carpopedal spasm** are not direct features of asthma but rather consequences of the severe respiratory alkalosis induced by hyperventilation.
Question 190: A 59-year-old man with known peripheral vascular disease presents with sudden-onset severe interscapular back pain radiating through to the chest. He appears distressed and sweaty. Blood pressure is 178/95 mmHg in the right arm and 142/88 mmHg in the left arm. Chest X-ray shows a widened mediastinum. What is the most appropriate immediate investigation?
A. CT angiography of the chest, abdomen, and pelvis (Correct Answer)
B. Transthoracic echocardiography
C. Coronary angiography
D. Ventilation-perfusion (V/Q) scan
E. Transoesophageal echocardiography
Explanation: ***CT angiography of the chest, abdomen, and pelvis***- This is the **gold standard** for diagnosing **acute aortic dissection**, offering high sensitivity and specificity for identifying the **intimal flap** and the extent of the dissection.- It is the most appropriate immediate step as it rapidly confirms the diagnosis and classifies the dissection (Stanford Type A vs. B) to guide **surgical or medical management**.*Transthoracic echocardiography*- While useful for detecting **pericardial effusion** or **aortic root dilation**, it has poor sensitivity for visualising the **descending aorta**.- It cannot provide the comprehensive detail required to map the full extent of an **aortic dissection** compared to CT imaging.*Coronary angiography*- This is an **invasive procedure** indicated for myocardial infarction and is not appropriate as an initial investigation for suspected **aortic dissection**.- Performing this in the presence of an undiagnosed dissection carries a high risk of **iatrogenic injury** or worsening the dissection flap.*Ventilation-perfusion (V/Q) scan*- This investigation is specifically used to diagnose **pulmonary embolism** and has no role in the diagnosis of an **aorta-related pathology**.- Use of this study would result in a critical delay in treating a life-threatening **aortic catastrophe**.*Transoesophageal echocardiography*- Although highly accurate for the **ascending aorta**, it is semi-invasive, requires **sedation**, and depends on the immediate availability of a trained specialist.- While useful in **haemodynamically unstable** patients or in the operating theatre, CT angiography is generally more accessible and provides a faster whole-aorta assessment.
