DFT - EMREE - 07/10/2025 - EMERGENCY MEDICINE

A 25 Y/O M is brought to the ED after an RTA resulting in a closed left tibial fracture. He c/o severe, escalating pain in his left lower leg, rated 10/10, which is poorly responsive to initial IV paracetamol. O/E, the left calf is extremely tense, swollen, and feels "woody" on palpation. He experiences excruciating pain on passive dorsiflexion of his ankle. Distal pulses are palpable, and capillary refill is normal. What is the most likely Dx?

• Deep Vein Thrombosis (DVT)

• Acute Compartment Syndrome

• Necrotizing Fasciitis

• Arterial Thrombosis

• Complex Regional Pain Syndrome

Answer explanation

The combination of severe pain out of proportion to the injury, a tense ("woody") compartment on palpation, and pain on passive muscle stretching are the hallmark clinical features of Acute Compartment Syndrome. The mechanism is increased pressure within a closed fascial space compromising tissue perfusion.

A 24 Y/O M is brought to the ED after a motorcycle accident resulting in a closed fracture of the R tibia. A cast is applied. 4 hours later, the patient c/o escalating leg pain, unrelieved by IV morphine. O/E: BP 130/80, HR 110, RR 18. The R lower leg is visibly tense and swollen within the cast. Capillary refill is <2s and the dorsalis pedis pulse is palpable. He reports extreme pain when his toes are passively extended by the examiner. Which of the following is the earliest and most reliable sign of acute compartment syndrome?

• Pallor of the foot

• Paresthesia between the first and second toes

• Pain on passive muscle stretching

• Paralysis of the extensor hallucis longus

• Absence of a distal pulse

  
  

Answer explanation

Severe pain out of proportion to the injury, especially when elicited by passive stretching of the muscles in the affected compartment, is the earliest and most sensitive clinical indicator of acute compartment syndrome. This finding reflects muscle ischemia and nerve irritation due to rising intracompartmental pressure.

A 24 Y/O M is brought to the ED after a high-speed motor vehicle collision. He was the unrestrained driver. O/E, he is pale, anxious, and diaphoretic. BP is 90/60 mmHg, HR 125 bpm, RR 24/min. Abdomen is tender and guarded, especially in the LUQ. He c/o sharp pain at the tip of his left shoulder. Chest examination reveals equal breath sounds bilaterally with no crepitus. The patient's left shoulder pain is most likely due to irritation of which nerve?

• Suprascapular nerve

• Axillary nerve

•  Phrenic nerve

• Long thoracic nerve

• Musculocutaneous nerve

Answer explanation

The patient's presentation with LUQ tenderness and hemodynamic instability after trauma is highly suggestive of a splenic rupture. The referred pain to the left shoulder tip is a classic finding known as Kehr's sign. This occurs because blood from the ruptured spleen irritates the undersurface of the diaphragm. The phrenic nerve (C3, C4, C5 nerve roots) provides sensory innervation to the diaphragm. This irritation is referred via the phrenic nerve to the C4 dermatome, which supplies the skin over the shoulder tip.

A 35 Y/O M is brought to the ED post-RTA. He is unresponsive. O/E: GCS 8, trachea deviated to the left, absent breath sounds & hyperresonant percussion over the right hemithorax. Vitals: BP 80/50 mmHg, HR 140/min, RR 35/min. What is the most appropriate immediate intervention?

• STAT chest X-ray

  
  

• Endotracheal intubation and ventilation

• Insertion of a large-bore chest tube

•  Immediate needle thoracostomy

• V bolus of 1L normal saline

Answer explanation

The patient presents with the classic triad of tension pneumothorax (absent breath sounds, hyperresonance, hypotension) with tracheal deviation, which is a life-threatening emergency causing obstructive shock. Immediate needle decompression in the 2nd intercostal space, midclavicular line (or 5th ICS, anterior axillary line) is the fastest life-saving intervention to relieve the pressure before definitive chest tube placement.

Incorrect (A): Waiting for a chest X-ray would be a fatal delay. The diagnosis of tension pneumothorax is clinical, and treatment should not be postponed for imaging in an unstable patient.

An 80 kg, 34 Y/O M is in the ICU 6 hours post-laparotomy for a perforated appendix. He has received 4L of Ringer's lactate. His current vitals are stable: BP 110/70 mmHg, HR 98/min. O/E, his abdomen is soft and his peripheries are warm. Labs show a serum lactate of 2.1 mmol/L (down from 4.5 mmol/L on admission). You are assessing the patient to ensure resuscitation is sufficient to prevent acute kidney injury (AKI). Which of the following is the most reliable indicator that fluid resuscitation has successfully restored adequate renal perfusion?

• Normalization of blood pressure

• Urine output of 0.5 – 1.0 mL/kg/hr

• Central Venous O₂ Saturation (ScvO₂) > 70%

• Serum lactate < 2.0 mmol/L

• Capillary refill time < 2 seconds

Answer explanation

The most reliable, non-invasive indicator of adequate renal perfusion and the success of resuscitation in preventing AKI is sustained, adequate urine output. The standard target is 0.5–1.0 mL/kg/hr. This demonstrates that glomerular filtration is occurring, which requires sufficient renal blood flow and pressure.

A 25 Y/O M is brought to the ED after a motor vehicle accident resulting in a closed fracture of his right tibia. He is given IV morphine, but 4 hours later, his calf pain becomes progressively severe, describing it as a deep, burning pressure. O/E, the R calf is visibly swollen, tense, and firm to palpation. He reports numbness over the dorsum of his foot. Passive stretching of his toes elicits excruciating pain. Distal pulses are palpable. What is the most likely diagnosis?

• Deep Vein Thrombosis (DVT)

• Acute Compartment Syndrome

• Peroneal Nerve Neuropraxia

  
  

• Cellulitis with abscess

• Fat Embolism Syndrome

Answer explanation

The patient presents with the classic signs of acute compartment syndrome following a long bone fracture. Key features are pain out of proportion to the injury (unresponsive to opioids), a tense or "woody" compartment on palpation, paresthesia (numbness on the dorsum of the foot, indicating peroneal nerve involvement), and severe pain on passive stretch. The presence of palpable distal pulses does not rule out this diagnosis, as this is a late and ominous sign.

A 25 Y/O M is brought to the ED following a high-speed motorcycle accident. He is agitated, c/o severe L lower leg pain, which he rates as 10/10. O/E, his L leg is visibly deformed and swollen. He is hemodynamically stable with BP 145/90, HR 115, RR 22, SpO2 98% on RA. He has no other apparent injuries and his GCS is 15. What is the most appropriate initial step in managing this patient's pain?

• Administer IV ketorolac

• Administer oral oxycodone

• Administer IV morphine

• Apply a cold compress and elevate the leg

• Obtain an urgent X-ray of the leg

Answer explanation

Why the correct option is best: The patient presents with severe (10/10) acute traumatic pain, indicated by his self-report and tachycardia. The standard of care for severe acute pain in a trauma setting is the prompt administration of a potent parenteral opioid.IV morphine is a first-line agent that provides rapid and effective analgesia, which is the immediate priority after ensuring hemodynamic stability.

A 45 Y/O M is brought to the ED after a high-speed MVA. He is unconscious. O/E, he has central cyanosis, paradoxical movement of the right chest wall, and labored breathing. Vitals: BP 100/70 mmHg, HR 125/min, RR 32/min, SpO2 85% on room air. His GCS is 8 (E2, V2, M4). Breath sounds are ↓ on the right side. What is the most appropriate immediate step in management?

• High-flow O2 via non-rebreather mask

• Immediate needle thoracostomy in the 2nd ICS

• Endotracheal intubation and mechanical ventilation

• Urgent surgical fixation of rib fractures

• Placement of a right-sided chest tube

Answer explanation

The patient has three clear indications for immediate intubation: 1) inability to protect his airway (GCS ≤ 8), 2) respiratory failure secondary to flail chest (paradoxical motion, cyanosis, tachypnea), and 3) severe hypoxemia (SpO2 85%) unresponsive to initial measures. Mechanical ventilation provides internal pneumatic splinting for the flail segment and secures the airway.

A 34 Y/O M is brought to the ED after a high-speed MVA. He was intubated at the scene for a GCS of 7. Primary survey reveals BP 80/40 mmHg, HR 135/min, RR 20/min (ventilated), and SpO2 98%. O/E, his abdomen is rigid and markedly distended. After receiving 2L of crystalloids and 2 units of packed RBCs, his BP is transiently up to 85/50 mmHg but HR remains >130/min. What is the most appropriate next step in the management of this patient?

• Abdominal CT scan with IV contrast

•  Focused Assessment with Sonography for Trauma (FAST)

• Diagnostic Peritoneal Lavage (DPL)

• Immediate exploratory laparotomy

• Transfuse 2 more units of packed RBCs and reassess

Answer explanation

The patient is in hemorrhagic shock (hypotension, tachycardia) and is a transient responder to fluid resuscitation. This, combined with the rigid, distended abdomen, strongly indicates massive intra-abdominal hemorrhage. In a hemodynamically unstable trauma patient with clear signs of an acute surgical abdomen, immediate exploratory laparotomy is the definitive and life-saving intervention required to control the source of bleeding.

A 26 Y/O F is brought to the ED by her boyfriend for evaluation of recurrent episodes of lightheadedness & fatigue x1 week. He reports she ‘almost fainted’ today at home while getting up from the couch. This has never happened before. She has no significant past medical Hx & attributes her symptoms to work stress. O/E: Appears tired but is alert and oriented. BP 115/75 mmHg, HR 82/min, RR 16/min, SpO2 99% on RA. Cardiopulmonary and neurological exams are unremarkable. What is the most appropriate next step in management?

• Obtain a CT head to rule out intracranial pathology.

• Perform a 12-lead ECG and orthostatic vital signs.

• Order a complete blood count (CBC) and serum ferritin.

• Reassure and discharge with advice for stress management.

• Schedule for a 24-hour Holter monitor.

Answer explanation

The patient is presenting with presyncope (lightheadedness, "almost fainted"). The standard initial evaluation for any patient with suspected syncope or presyncope, regardless of age, is a thorough history, physical exam, orthostatic blood pressure measurement, and a 12-lead ECG. This combination is essential to immediately risk-stratify for dangerous cardiac causes (arrhythmia, ischemia) or orthostatic hypotension, which are critical to identify in the ED.