I85PREP
⌘ K
Arab Board EM Part 1 study materials
Arab Board EM Part 1 study resources

Arab Board EM Part 1 practice questions

One question at a time. Build your Arab Board EM Part 1 understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Resuscitation and Cardiovascular Emergencies

A 58-year-old man collapses in the emergency department waiting room. He is unresponsive, pulseless, and has no spontaneous breathing. Which is the single most important immediate intervention?

  1. Insert an oropharyngeal airway
  2. Obtain a 12-lead ECG
  3. Start high-quality chest compressions Correct answer.
  4. Establish intravenous access

Explanation

For any pulseless patient, high-quality chest compressions are the priority because they maintain coronary and cerebral perfusion. Diagnostic and adjunctive measures such as ECG, IV access, and airway placement must not delay compressions.

Question 2Resuscitation and Cardiovascular Emergencies

In an adult with a shockable rhythm on the monitor, which energy level is recommended for the first biphasic defibrillation attempt?

  1. 360 J monophasic-equivalent for all devices
  2. 50 J
  3. Manufacturer-recommended dose (typically 120–200 J) Correct answer.
  4. 100 J

Explanation

Biphasic defibrillators should be used at the manufacturer's recommended energy setting for the first shock, which is commonly in the 120–200 J range. Subsequent shocks should be at equivalent or higher energy.

Question 3Resuscitation and Cardiovascular Emergencies

A patient in cardiac arrest has a non-shockable rhythm. Which pair of rhythms is non-shockable?

  1. Asystole and pulseless electrical activity Correct answer.
  2. Ventricular fibrillation and pulseless ventricular tachycardia
  3. Ventricular tachycardia and atrial fibrillation
  4. Torsades de pointes and ventricular fibrillation

Explanation

Asystole and pulseless electrical activity are non-shockable rhythms treated with CPR, epinephrine, and correction of reversible causes. Shockable rhythms are ventricular fibrillation and pulseless ventricular tachycardia.

Question 4Resuscitation and Cardiovascular Emergencies

During adult cardiac arrest resuscitation, what is the recommended initial intravenous dose of epinephrine?

  1. 3 mg once, then repeat every 10 minutes
  2. 1 mg every 3–5 minutes Correct answer.
  3. 0.1 mg every 1 minute
  4. 0.5 mg every 3–5 minutes

Explanation

The standard adult arrest dose is 1 mg of epinephrine (1:10,000) given intravenously or intraosseously every 3–5 minutes. This applies to both shockable and non-shockable rhythms after initial defibrillation attempts or immediately in non-shockable rhythms.

Question 5Resuscitation and Cardiovascular Emergencies

Which of the following is the most common reversible cause of pulseless electrical activity that should be sought with bedside ultrasound?

  1. Cardiac tamponade Correct answer.
  2. Hypoglycemia
  3. Hypothermia
  4. Hyperkalemia

Explanation

Cardiac tamponade is a classic and rapidly fatal reversible cause of PEA that can be identified by bedside ultrasound and treated with pericardiocentesis. The other listed causes are also reversible but tamponade is the prototypical structural cause detected sonographically.

Question 6Resuscitation and Cardiovascular Emergencies

A 70-year-old woman with a wide-complex tachycardia is hypotensive and confused. What is the most appropriate immediate management?

  1. Adenosine 6 mg rapid IV push
  2. Synchronized cardioversion Correct answer.
  3. Vagal maneuvers
  4. Oral amiodarone loading

Explanation

Any tachyarrhythmia with hemodynamic instability (hypotension, altered mental status, shock) requires immediate synchronized cardioversion. Pharmacologic rate control and vagal maneuvers are reserved for stable patients.

Question 7Resuscitation and Cardiovascular Emergencies

In synchronized cardioversion of an unstable patient with a regular narrow-complex tachycardia, what is the typical initial energy setting for a biphasic device?

  1. 200 J
  2. 50–100 J Correct answer.
  3. 10 J
  4. 360 J

Explanation

For synchronized cardioversion of atrial flutter or regular narrow-complex SVT, an initial biphasic energy of 50–100 J is typically recommended. Higher energies are used for atrial fibrillation and ventricular rhythms.

Question 8Resuscitation and Cardiovascular Emergencies

A 24-year-old man is in cardiac arrest after a witnessed drowning. What modification to standard resuscitation is most important?

  1. Delay defibrillation until the patient is warmed
  2. Withhold epinephrine entirely
  3. Prioritize rescue breaths and oxygenation early Correct answer.
  4. Give three stacked shocks before compressions

Explanation

In drowning and other hypoxic arrests, hypoxia is the primary cause, so ventilation and oxygenation should be prioritized early alongside compressions. Standard ACLS otherwise applies, including defibrillation when indicated.

Question 9Resuscitation and Cardiovascular Emergencies

A patient with severe hyperkalemia has a widened QRS and peaked T waves. Which intervention most rapidly stabilizes the myocardium?

  1. Intravenous calcium gluconate Correct answer.
  2. Intravenous furosemide
  3. Intravenous insulin with glucose
  4. Oral sodium polystyrene sulfonate

Explanation

Intravenous calcium antagonizes the membrane effects of potassium and rapidly stabilizes the myocardium when ECG changes are present. Insulin-glucose and other measures shift or remove potassium but do not immediately protect the heart.

Question 10Resuscitation and Cardiovascular Emergencies

Which finding on the ECG is most characteristic of hyperkalemia?

  1. Diffuse ST elevation with PR depression
  2. Sawtooth flutter waves
  3. Delta waves with a short PR interval
  4. Peaked T waves with widened QRS Correct answer.

Explanation

Hyperkalemia produces tall peaked T waves, then QRS widening, PR prolongation, and eventually a sine-wave pattern. These changes reflect impaired myocardial conduction.

Question 11Resuscitation and Cardiovascular Emergencies

A 60-year-old man has crushing substernal chest pain. His ECG shows ST elevation in leads II, III, and aVF. Which coronary artery is most likely occluded?

  1. Left anterior descending artery
  2. Left main coronary artery
  3. Left circumflex artery
  4. Right coronary artery Correct answer.

Explanation

ST elevation in the inferior leads (II, III, aVF) localizes to the inferior wall, most commonly supplied by the right coronary artery. The LAD supplies the anterior wall and the circumflex the lateral wall.

Question 12Resuscitation and Cardiovascular Emergencies

In a patient with ST-elevation myocardial infarction, what is the recommended maximum time from first medical contact to primary percutaneous coronary intervention when it can be delivered?

  1. 90 minutes Correct answer.
  2. 4 hours
  3. 12 hours
  4. 30 minutes

Explanation

Primary PCI should be achieved within 90 minutes of first medical contact when a capable center is available. If this cannot be met, fibrinolysis should be considered within 30 minutes of arrival.

Question 13Resuscitation and Cardiovascular Emergencies

A patient with STEMI cannot reach a PCI-capable center within 120 minutes. Which is the most appropriate reperfusion strategy if there are no contraindications?

  1. Administer fibrinolytic therapy Correct answer.
  2. Give aspirin alone and observe
  3. Wait for elective angiography the next day
  4. Start oral anticoagulation

Explanation

When timely primary PCI is not achievable, fibrinolysis within 30 minutes of arrival is the recommended alternative in eligible patients without contraindications. Aspirin alone is inadequate and delayed angiography loses myocardial salvage.

Question 14Resuscitation and Cardiovascular Emergencies

Which of the following is an absolute contraindication to fibrinolytic therapy in STEMI?

  1. Current use of aspirin
  2. Recent ischemic stroke within 3 months Correct answer.
  3. Prior ischemic stroke 5 years ago
  4. Blood pressure of 150/90 mmHg

Explanation

Any prior intracranial hemorrhage and ischemic stroke within 3 months are absolute contraindications to fibrinolysis because of the high bleeding risk. Moderate hypertension and remote stroke are relative or non-contraindications.

Question 15Resuscitation and Cardiovascular Emergencies

A patient with acute decompensated heart failure presents with severe dyspnea, bibasilar crackles, and hypoxia. Which initial therapy is most appropriate for pulmonary edema with adequate blood pressure?

  1. Immediate synchronized cardioversion
  2. Oral beta-blocker loading
  3. Intravenous furosemide with noninvasive positive pressure ventilation Correct answer.
  4. Rapid intravenous fluid bolus

Explanation

Acute cardiogenic pulmonary edema with adequate perfusion is treated with intravenous loop diuretics and noninvasive positive pressure ventilation to reduce preload and improve oxygenation. Fluid boluses and negative inotropes would worsen the congestion.

Question 16Resuscitation and Cardiovascular Emergencies

A 30-year-old woman has sudden-onset pleuritic chest pain, tachycardia, and hypoxia after a long flight. Which is the most appropriate initial diagnostic step?

  1. CT pulmonary angiography Correct answer.
  2. D-dimer in all cases
  3. Coronary angiography
  4. Exercise stress testing

Explanation

In a patient with high pretest probability of pulmonary embolism, CT pulmonary angiography is the diagnostic test of choice. D-dimer is useful only to rule out PE in low-probability patients.

Question 17Resuscitation and Cardiovascular Emergencies

A patient with massive pulmonary embolism is hypotensive and in obstructive shock. Which intervention is most appropriate?

  1. Vigorous fluid loading
  2. Beta-blockade
  3. Oral anticoagulation alone
  4. Systemic thrombolysis Correct answer.

Explanation

Massive PE with hemodynamic instability is treated with reperfusion, typically systemic thrombolysis, or catheter/surgical embolectomy if thrombolysis is contraindicated. Anticoagulation alone is insufficient in obstructive shock.

Question 18Resuscitation and Cardiovascular Emergencies

A 65-year-old man has sudden tearing chest pain radiating to the back with a 20 mmHg blood pressure difference between arms. Which is the most appropriate initial diagnostic study in a stable patient?

  1. D-dimer
  2. CT angiography of the aorta Correct answer.
  3. Troponin level
  4. Chest radiograph

Explanation

The presentation suggests aortic dissection, and CT angiography of the aorta is the diagnostic study of choice in stable patients. It defines the extent and type of dissection for management planning.

Question 19Resuscitation and Cardiovascular Emergencies

In a patient with suspected acute aortic dissection, which medication should be given first to reduce aortic wall stress?

  1. Intravenous thrombolytic
  2. Intravenous vasodilator alone before rate control
  3. Aspirin loading dose
  4. Intravenous beta-blocker to lower heart rate and blood pressure Correct answer.

Explanation

Beta-blockade is initiated first to reduce heart rate and dP/dt, lowering shear stress on the aortic wall. Vasodilators are added after rate control to achieve target blood pressure.

Question 20Resuscitation and Cardiovascular Emergencies

Which rhythm is most characteristic of a patient with a prolonged QT interval who develops a polymorphic ventricular tachycardia?

  1. Torsades de pointes Correct answer.
  2. Atrial flutter
  3. Monomorphic ventricular tachycardia
  4. Junctional rhythm

Explanation

Torsades de pointes is a polymorphic ventricular tachycardia occurring in the setting of QT prolongation. It is treated with magnesium and correction of the underlying cause.

Question 21Resuscitation and Cardiovascular Emergencies

A patient develops torsades de pointes. Which medication is the first-line treatment?

  1. Intravenous atropine
  2. Intravenous adenosine
  3. Oral digoxin
  4. Intravenous magnesium sulfate Correct answer.

Explanation

Intravenous magnesium is the first-line therapy for torsades de pointes, even in patients with normal magnesium levels. Overdrive pacing or isoproterenol may be used if magnesium is ineffective.

Question 22Resuscitation and Cardiovascular Emergencies

A patient presents with symptomatic bradycardia, hypotension, and altered mental status. Which is the most appropriate first-line medication?

  1. Metoprolol 5 mg intravenous
  2. Atropine 1 mg intravenous Correct answer.
  3. Adenosine 6 mg intravenous
  4. Amiodarone 150 mg intravenous

Explanation

Atropine is the first-line drug for symptomatic bradycardia, given as 1 mg IV every 3–5 minutes up to a total of 3 mg. If it is ineffective, transcutaneous pacing or a catecholamine infusion is used.

Question 23Resuscitation and Cardiovascular Emergencies

Which finding suggests that a wide-complex tachycardia is of ventricular origin rather than supraventricular with aberrancy?

  1. Narrow QRS after vagal maneuvers
  2. Response to adenosine
  3. Presence of AV dissociation Correct answer.
  4. Regular rhythm at 150 bpm

Explanation

AV dissociation is a hallmark of ventricular tachycardia and strongly favors a ventricular origin. Regularity alone and adenosine response do not reliably distinguish the two.

Question 24Resuscitation and Cardiovascular Emergencies

A patient with a regular narrow-complex tachycardia at 180 bpm is hemodynamically stable. After failed vagal maneuvers, which is the most appropriate next step?

  1. Adenosine 6 mg rapid intravenous push Correct answer.
  2. Oral digoxin
  3. Intravenous amiodarone infusion
  4. Synchronized cardioversion

Explanation

For stable regular narrow-complex SVT, adenosine is the first-line pharmacologic therapy after vagal maneuvers. It transiently blocks the AV node and often terminates the arrhythmia.

Question 25Resuscitation and Cardiovascular Emergencies

A patient with ventricular fibrillation remains in VF after two shocks, CPR, and epinephrine. Which antiarrhythmic is recommended for refractory VF?

  1. Adenosine
  2. Diltiazem
  3. Atropine
  4. Amiodarone Correct answer.

Explanation

Amiodarone or lidocaine is recommended for VF/pulseless VT that persists after defibrillation and epinephrine. Adenosine, atropine, and calcium channel blockers have no role in VF.

Question 26Resuscitation and Cardiovascular Emergencies

A 58-year-old man collapses in the emergency department waiting room. He is unresponsive, pulseless, and apneic. After CPR is started and the monitor is attached, which rhythm is the only shockable rhythm requiring immediate defibrillation?

  1. Ventricular fibrillation Correct answer.
  2. Pulseless electrical activity
  3. Asystole
  4. Sinus bradycardia

Explanation

Only ventricular fibrillation and pulseless ventricular tachycardia are shockable rhythms in cardiac arrest; all other arrest rhythms are managed with CPR and epinephrine. Immediate defibrillation is the definitive treatment for VF because it depolarizes the myocardium and allows coordinated rhythm to re-establish.

Question 27Resuscitation and Cardiovascular Emergencies

A 62-year-old woman is admitted with dehydration and develops light-headedness. Her ECG shows a regular rhythm at 38 bpm with a narrow QRS, and her blood pressure is 82/50 mmHg. Which intervention is the most appropriate next step?

  1. Diltiazem 20 mg intravenous push
  2. Amiodarone 300 mg intravenous bolus
  3. Adenosine 6 mg rapid intravenous push
  4. Atropine 1 mg intravenously Correct answer.

Explanation

Symptomatic bradycardia with hypotension from a narrow-complex rhythm is treated first with atropine, which blocks vagal tone and increases the sinus rate. If atropine fails, transcutaneous pacing or a catecholamine infusion is the next step.

Question 28Resuscitation and Cardiovascular Emergencies

A 45-year-old man with no prior cardiac history presents with palpitations. His ECG shows a regular narrow-complex tachycardia at 165 bpm, and he is alert with a blood pressure of 118/74 mmHg. Vagal maneuvers and two doses of adenosine have failed to terminate the rhythm. Which medication is most appropriate now?

  1. Intravenous metoprolol Correct answer.
  2. Intravenous digoxin
  3. Intravenous magnesium sulfate
  4. Intravenous procainamide

Explanation

For a stable, regular narrow-complex supraventricular tachycardia that does not respond to vagal maneuvers or adenosine, a short-acting intravenous beta-blocker such as metoprolol is a first-line rate-control option. It slows atrioventricular nodal conduction and can terminate or control the rhythm.

Question 29Resuscitation and Cardiovascular Emergencies

A 68-year-old man with a history of hypertension presents with sudden severe dyspnea. His blood pressure is 210/110 mmHg, and he has bibasilar crackles and hypoxia. Chest radiograph shows pulmonary edema with a normal heart size. Which initial therapy is most appropriate?

  1. Intravenous furosemide alone with high-flow oxygen
  2. Intravenous diltiazem infusion
  3. Rapid bolus of 1 L normal saline
  4. Intravenous nitroglycerin plus noninvasive positive-pressure ventilation Correct answer.

Explanation

Hypertensive acute pulmonary edema is best treated with afterload reduction using intravenous nitroglycerin combined with noninvasive positive-pressure ventilation, which improves oxygenation and reduces work of breathing. This combination addresses both the elevated systemic vascular resistance and the pulmonary congestion.

Question 30Resuscitation and Cardiovascular Emergencies

A 55-year-old woman with a history of alcohol use disorder presents with palpitations and syncope. Her ECG shows a polymorphic ventricular tachycardia with a twisting axis around the isoelectric line and a prolonged QT interval. Which electrolyte abnormality most commonly predisposes to this rhythm?

  1. Hyperkalemia
  2. Hypomagnesemia Correct answer.
  3. Hypercalcemia
  4. Hypernatremia

Explanation

Torsades de pointes is a polymorphic ventricular tachycardia associated with QT prolongation, and hypomagnesemia is a common precipitant. Magnesium deficiency prolongs the QT interval and destabilizes the ventricular myocardium.

Question 31Respiratory and Thoracic Emergencies

A 24-year-old man sustains blunt chest trauma. He becomes acutely breathless and hypotensive. On examination, the trachea is deviated away from the affected side, with absent breath sounds and hyper-resonance over the right hemithorax, and the neck veins are distended. What is the most appropriate immediate management?

  1. Emergent intubation and positive pressure ventilation
  2. Immediate pericardiocentesis
  3. Urgent portable chest radiograph before any intervention
  4. Needle decompression of the pleural space followed by chest drain insertion Correct answer.

Explanation

The findings indicate tension pneumothorax, a clinical diagnosis requiring immediate decompression without waiting for imaging. Needle decompression (or finger thoracostomy) followed by tube thoracostomy relieves the obstructive shock. Positive pressure ventilation before decompression can worsen the tension.

Question 32Respiratory and Thoracic Emergencies

Which finding on arterial blood gas is most characteristic of acute severe asthma?

  1. Respiratory acidosis with a normal PaCO2
  2. Metabolic alkalosis with hypercapnia
  3. Metabolic acidosis with a normal PaO2
  4. Respiratory alkalosis with hypoxaemia Correct answer.

Explanation

In acute severe asthma, increased respiratory drive causes a fall in PaCO2 (respiratory alkalosis) along with hypoxaemia from ventilation-perfusion mismatch. A normal or rising PaCO2 in a tiring asthmatic signals impending respiratory failure.

Question 33Respiratory and Thoracic Emergencies

A 68-year-old woman with a recent hip replacement develops sudden pleuritic chest pain, breathlessness and tachycardia. She is haemodynamically stable with normal blood pressure. Which investigation is the most appropriate next step to confirm the diagnosis of pulmonary embolism?

  1. CT pulmonary angiography Correct answer.
  2. Transthoracic echocardiography
  3. D-dimer assay
  4. Lower limb venous Doppler ultrasound

Explanation

In a haemodynamically stable patient with high clinical probability of pulmonary embolism, CT pulmonary angiography is the confirmatory test of choice. D-dimer is useful only to exclude PE in low-probability patients and is non-specific in this high-risk setting.

Question 34Respiratory and Thoracic Emergencies

A patient presents with sudden-onset sharp chest pain and breathlessness. Chest radiograph shows a visible pleural line with absent lung markings distal to it and no mediastinal shift. He is haemodynamically stable. What is the most appropriate management?

  1. Emergency thoracotomy
  2. Urgent bronchoscopy
  3. Immediate needle decompression
  4. Observation with supplemental oxygen and analgesia Correct answer.

Explanation

This describes a simple (non-tension) primary spontaneous pneumothorax in a stable patient, which may be managed conservatively with oxygen and observation if small, or with aspiration or drainage depending on size and symptoms. Emergent decompression is reserved for tension physiology.

Question 35Respiratory and Thoracic Emergencies

Which of the following best describes the pathophysiological mechanism of flail chest causing respiratory failure?

  1. Increased pulmonary capillary permeability causes non-cardiogenic pulmonary oedema
  2. Bronchospasm causes air trapping and hyperinflation
  3. Paradoxical inward movement of the flail segment during inspiration reduces effective ventilation Correct answer.
  4. Loss of surfactant production leads to diffuse alveolar collapse

Explanation

In flail chest, a segment of chest wall loses bony continuity and moves paradoxically, impairing effective ventilation; the underlying pulmonary contusion also contributes to hypoxia. The paradoxical motion is the defining mechanical feature.

Question 36Respiratory and Thoracic Emergencies

A patient is intubated for an asthma exacerbation. Shortly after intubation, peak airway pressures rise markedly, breath sounds are reduced bilaterally, and the patient becomes hypotensive with distended neck veins. Which complication is most likely?

  1. Pulmonary oedema
  2. Tension pneumothorax Correct answer.
  3. Mucus plugging
  4. Endotracheal tube obstruction

Explanation

Positive pressure ventilation in a patient with hyperinflated lungs can precipitate a tension pneumothorax, producing high airway pressures, bilateral or unilateral reduced breath sounds, hypotension and distended neck veins. Immediate decompression is required.

Question 37Respiratory and Thoracic Emergencies

A 55-year-old man has a large right-sided pleural effusion. Thoracentesis yields turbid, foul-smelling fluid with a pH of 6.9 and low glucose. What is the most appropriate management?

  1. Observation with serial radiographs
  2. Repeat thoracentesis alone
  3. Insertion of a chest drain for empyema Correct answer.
  4. Oral antibiotics as an outpatient

Explanation

Frankly purulent fluid with low pH and low glucose indicates empyema, which requires adequate drainage via chest tube together with antibiotics. Simple aspiration alone is insufficient for established empyema.

Question 38Respiratory and Thoracic Emergencies

Which clinical feature best distinguishes cardiac asthma (acute cardiogenic pulmonary oedema) from an acute exacerbation of bronchial asthma?

  1. Fine basal crackles with a raised JVP Correct answer.
  2. Prolonged expiratory phase with wheeze
  3. History of atopy
  4. Use of accessory muscles of respiration

Explanation

Cardiogenic pulmonary oedema typically produces fine basal crackles, a raised jugular venous pressure and possibly a third heart sound, reflecting left heart failure. Wheeze and atopy favour bronchial asthma, though cardiac asthma can also wheeze.

Question 39Respiratory and Thoracic Emergencies

A patient with a known large bulla develops acute severe breathlessness. Chest radiograph shows a hyperlucent hemithorax with a thin curved wall and compressed surrounding lung, without a pleural line. What is the most important step before any chest drain is inserted?

  1. Give intravenous antibiotics
  2. Proceed immediately with needle decompression
  3. Confirm the diagnosis with CT to avoid misplacing a drain into a bulla Correct answer.
  4. Perform a diagnostic thoracentesis

Explanation

A giant bulla can mimic a pneumothorax; inserting a drain into a bulla risks creating a bronchopleural fistula or pneumothorax. When the diagnosis is uncertain, CT should confirm before drainage unless there is life-threatening tension physiology.

Question 40Respiratory and Thoracic Emergencies

A 30-year-old woman has sudden pleuritic chest pain and breathlessness two days after a long-haul flight. She is tachycardic and hypoxic. Which ECG finding is most suggestive of acute right heart strain from pulmonary embolism?

  1. Prolonged QT interval
  2. S1Q3T3 pattern Correct answer.
  3. Delta wave
  4. ST elevation in leads V2 to V4

Explanation

The S1Q3T3 pattern (deep S in lead I, Q wave and inverted T in lead III) is a classic, though insensitive, sign of acute right ventricular strain in pulmonary embolism. Other features include sinus tachycardia and right bundle branch block.

Question 41Respiratory and Thoracic Emergencies

A 45-year-old man is found unresponsive with a respiratory rate of 6 per minute and pinpoint pupils after a heroin overdose. Which initial intervention is most appropriate?

  1. Perform immediate intubation without ventilation
  2. Give flumazenil
  3. Administer naloxone and provide bag-mask ventilation Correct answer.
  4. Administer high-dose adrenaline

Explanation

Opioid overdose causes respiratory depression with pinpoint pupils; naloxone reverses the opioid effect while bag-mask ventilation supports oxygenation until the patient responds. Airway and breathing take priority.

Question 42Respiratory and Thoracic Emergencies

Which finding indicates that a patient with an acute exacerbation of COPD has developed a life-threatening respiratory acidosis requiring ventilatory support?

  1. PaO2 of 8.5 kPa on air
  2. Presence of a barrel chest
  3. A raised white cell count
  4. Arterial pH below 7.25 with hypercapnia despite optimal medical therapy Correct answer.

Explanation

Acute respiratory acidosis with a pH below about 7.25 that persists despite controlled oxygen and bronchodilators is an indication for non-invasive ventilation. A raised PaCO2 alone without acidosis is less urgent.

Question 43Respiratory and Thoracic Emergencies

A patient with a stab wound to the left chest is hypotensive with distended neck veins, muffled heart sounds and a narrow pulse pressure. Which diagnosis should be suspected?

  1. Cardiac tamponade Correct answer.
  2. Tension pneumothorax
  3. Massive haemothorax
  4. Aortic dissection

Explanation

The triad of hypotension, distended neck veins and muffled heart sounds suggests cardiac tamponade, which in penetrating trauma results from blood in the pericardial sac. Pulsus paradoxus and a narrow pulse pressure support the diagnosis.

Question 44Respiratory and Thoracic Emergencies

Which of the following is the most common cause of massive haemoptysis requiring emergency intervention?

  1. Bronchial carcinoid tumour
  2. Pulmonary infarction from pulmonary embolism
  3. Alveolar haemorrhage from vasculitis
  4. Rupture of a bronchial artery Correct answer.

Explanation

The bronchial arteries are under systemic pressure and account for the majority of massive haemoptysis, often from inflammatory or cavitating lung disease. Bronchial artery embolisation is the mainstay of emergency control.

Question 45Respiratory and Thoracic Emergencies

A 70-year-old man has acute breathlessness, a swollen right leg and hypoxia. He is hypotensive with a systolic pressure of 80 mmHg. Which management strategy is most appropriate?

  1. Observation and repeat vital signs in four hours
  2. CT pulmonary angiography before any treatment
  3. Systemic thrombolysis Correct answer.
  4. Oral anticoagulation with a direct oral anticoagulant

Explanation

High-risk (massive) pulmonary embolism with hypotension is an indication for immediate systemic thrombolysis or embolectomy. Imaging should not delay reperfusion in an unstable patient.

Question 46Respiratory and Thoracic Emergencies

Which arterial blood gas finding is most consistent with an acute exacerbation of COPD with carbon dioxide retention?

  1. Low PaCO2 with a high pH
  2. Raised PaCO2 with a low pH and normal or raised bicarbonate Correct answer.
  3. Low PaCO2 with a normal pH
  4. Normal PaCO2 with a high pH

Explanation

Acute hypercapnic respiratory failure in COPD shows a raised PaCO2 with respiratory acidosis (low pH); bicarbonate is normal or slightly raised in the acute phase. Chronic compensation would show a higher bicarbonate and near-normal pH.

Question 47Respiratory and Thoracic Emergencies

A young man develops rapidly progressive breathlessness and hypoxaemia after inhaling a large amount of vomitus. Chest radiograph shows bilateral infiltrates. Which mechanism best explains his respiratory failure?

  1. Chemical pneumonitis from acid aspiration causing non-cardiogenic pulmonary oedema Correct answer.
  2. Cardiogenic pulmonary oedema from left ventricular failure
  3. Bronchospasm from an allergic reaction
  4. Pulmonary embolism from venous stasis

Explanation

Aspiration of gastric contents causes chemical pneumonitis, with acid and particulate matter injuring the alveolar-capillary membrane and producing non-cardiogenic pulmonary oedema. Hypoxia can develop rapidly and may require ventilatory support.

Question 48Respiratory and Thoracic Emergencies

A patient is found with a tension pneumothorax and cardiac arrest in the emergency department. Which of the following is the most appropriate immediate action?

  1. Awaiting a chest radiograph before decompression
  2. Administration of intravenous fluids only
  3. Bilateral finger thoracostomy followed by chest drains during resuscitation Correct answer.
  4. Defibrillation before any decompression

Explanation

In traumatic cardiac arrest, bilateral thoracostomies are recommended to treat or exclude tension pneumothorax as a reversible cause. Decompression must occur alongside standard resuscitation, not after imaging.

Question 49Respiratory and Thoracic Emergencies

Which statement about the use of controlled oxygen therapy in acute exacerbation of COPD is correct?

  1. High-flow oxygen has no effect on PaCO2 in COPD
  2. Oxygen should be withheld entirely in COPD
  3. Target oxygen saturation of 88-92% to avoid worsening hypercapnia Correct answer.
  4. Target oxygen saturation of 100% at all times

Explanation

In acute exacerbations of COPD, oxygen should be titrated to a target saturation of 88-92% because uncontrolled high-flow oxygen can worsen hypercapnia and respiratory acidosis. Controlled oxygen must still be given to avoid hypoxaemia.

Question 50Respiratory and Thoracic Emergencies

A patient presents with a large unilateral pleural effusion. Which feature on pleural fluid analysis most strongly suggests an exudate rather than a transudate?

  1. Pleural fluid pH greater than 7.4
  2. Pleural fluid glucose greater than 3.3 mmol/L
  3. Pleural fluid white cell count below 100 cells/mm3
  4. Pleural fluid to serum protein ratio greater than 0.5 Correct answer.

Explanation

By Light's criteria, an exudate is suggested by a pleural fluid to serum protein ratio above 0.5, a pleural fluid to serum LDH ratio above 0.6, or a pleural fluid LDH above two-thirds the upper limit of normal serum LDH.