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2. Trauma MCQs

Practice Set 504 of 640

This practice set contains high-yield board review questions covering key concepts in 2. Trauma. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 10061

Topic: 2. Trauma

A 42-year-old construction worker presents to the ED after a fall from scaffolding, sustaining multiple fractures including bilateral femur fractures and a comminuted humerus fracture. His BP is 70/30 mmHg, HR 140 bpm, and he is unresponsive. After initial fluid resuscitation, his BP remains low. What is the MOST likely cause of his refractory hypotension?

. Neurogenic shock
. Anaphylactic shock
. Spinal cord injury
. Uncontrolled hemorrhagic shock
. Myocardial contusion

Correct Answer & Explanation

. Uncontrolled hemorrhagic shock

Explanation

In a patient with multiple severe fractures, particularly bilateral femur fractures, massive internal hemorrhage is the most likely cause of profound and refractory hypovolemic shock. Each femur fracture can lead to 1-1.5 liters of blood loss, and multiple fractures compound this. Neurogenic shock typically presents with hypotension and bradycardia, and is less likely with this injury pattern alone to cause such severe, refractory hypotension. Anaphylactic shock would have other features like rash, bronchospasm. While spinal cord injury could cause neurogenic shock, the extensive orthopedic trauma points more strongly to hemorrhage. Myocardial contusion is possible but usually leads to cardiac dysfunction, not typically primary cause of this degree of refractory shock initially.

Question 10062

Topic: 2. Trauma

A 72-year-old female with a recent hip fracture repair presents with a serum sodium of 118 mEq/L, confusion, and mild lethargy. Her serum osmolality is 240 mOsm/kg, and urine osmolality is 600 mOsm/kg. She is euvolemic on physical exam. What is the most appropriate initial management?

. Fluid restriction to 1 L/day and careful monitoring
. Administer 3% hypertonic saline infusion
. Administer 0.9% Normal Saline at 100 mL/hr
. Administer a loop diuretic (e.g., Furosemide)
. Increase oral water intake

Correct Answer & Explanation

. Administer 3% hypertonic saline infusion

Explanation

This patient has severe, symptomatic euvolemic hyponatremia (Na+ 118 mEq/L with confusion/lethargy) with characteristics of SIADH (low serum osmolality, inappropriately concentrated urine). For severe symptomatic hyponatremia, particularly when acute, administration of 3% hypertonic saline is indicated to safely raise the serum sodium by 4-6 mEq/L within the first few hours (no more than 8 mEq/L in 24 hours) to alleviate neurological symptoms. Once symptoms improve, or if hyponatremia is less severe/chronic, fluid restriction is the cornerstone of SIADH management. 0.9% NS would not effectively raise sodium in SIADH due to free water retention. Loop diuretics can be used as an adjunct to hypertonic saline in SIADH but not as a sole initial treatment for severe symptoms. Increasing oral water intake would worsen the hyponatremia.

Question 10063

Topic: 2. Trauma

A 22-year-old male with a history of intravenous drug use undergoes open reduction and internal fixation of a humeral shaft fracture. On post-operative day 3, he develops a fever, is tachycardic (HR 120 bpm), and hypotensive (BP 85/45 mmHg). His white blood cell count is 18,000/uL. What is the most immediate life-saving intervention?

. Order blood cultures and start broad-spectrum antibiotics
. Administer a 30 mL/kg IV crystalloid bolus
. Administer empiric vasopressors (e.g., norepinephrine)
. Perform a CT scan of the chest and abdomen to rule out source of infection
. Consult infectious disease specialist

Correct Answer & Explanation

. Administer a 30 mL/kg IV crystalloid bolus

Explanation

The patient presents with signs of septic shock (fever, tachycardia, hypotension, elevated WBC). According to sepsis guidelines, prompt fluid resuscitation with a 30 mL/kg crystalloid bolus is a critical first step to restore tissue perfusion and improve hemodynamics. While blood cultures and broad-spectrum antibiotics are also essential components of the 'sepsis bundle' and should be initiated rapidly, fluid resuscitation to address the hypoperfusion takes immediate precedence in managing the life-threatening hypotension. Vasopressors are used if hypotension persists after adequate fluid resuscitation. Imaging and specialist consultation are secondary.

Question 10064

Topic: 2. Trauma

An 82-year-old female with a femoral neck fracture is scheduled for hemiarthroplasty. Her baseline systolic blood pressure is typically 150-160 mmHg. On the morning of surgery, it is 190/100 mmHg, and she reports mild headache. What is the most appropriate action?

. Delay surgery until blood pressure is controlled with oral medication for several days
. Administer IV Hydralazine 5 mg and proceed with surgery if BP lowers
. Cancel surgery and send home for blood pressure management
. Proceed with surgery immediately, as a hip fracture is time-sensitive
. Administer oral Clonidine and monitor for 2 hours

Correct Answer & Explanation

. Administer IV Hydralazine 5 mg and proceed with surgery if BP lowers

Explanation

A hip fracture is a time-sensitive orthopedic emergency, and delays in surgery beyond 24-48 hours are associated with increased mortality and morbidity. However, severe hypertension (especially with symptoms like headache) increases perioperative risks (stroke, MI, hemorrhage). The goal is to safely lower BP to a more acceptable range (e.g., <180/110 mmHg) without causing hypotension. IV Hydralazine is a direct vasodilator that can acutely lower blood pressure, allowing the surgery to proceed once the BP is safer. Delaying surgery for days or canceling it is generally not advisable for hip fractures. Proceeding immediately with uncontrolled severe hypertension is risky. Oral Clonidine might take too long to act and can cause rebound hypertension if stopped.

Question 10065

Topic: 2. Trauma

During intraoperative femoral reaming for a long bone fracture, the anesthesiologist notes a sudden, transient increase in end-tidal CO2, followed by a decrease in BP and oxygen saturation. Which immediate intervention should be considered by the surgical team?

. Administer IV fluids rapidly
. Cease reaming immediately
. Prepare for blood transfusion
. Administer a bolus of vasopressors
. Increase oxygen concentration

Correct Answer & Explanation

. Cease reaming immediately

Explanation

The described signs (sudden ETCO2 increase then decrease in BP/SpO2) are classic for a fat embolism, particularly during intramedullary reaming of long bones. The immediate and critical action for the surgical team is to cease reaming immediately to prevent further embolization. Anesthesia will simultaneously manage hemodynamics (fluids, vasopressors) and respiratory support (oxygen, ventilatory adjustments). While blood transfusion might be needed if there is blood loss, it does not address the fat embolism directly. Increasing oxygen concentration is supportive but doesn't resolve the underlying cause.

Question 10066

Topic: 2. Trauma

A 35-year-old male with a traumatic brain injury (TBI) and a pelvic fracture develops polyuria (urine output 400 mL/hr) and hypernatremia (Na+ 155 mEq/L). His urine osmolality is 80 mOsm/kg. What is the most likely diagnosis?

. Syndrome of Inappropriate ADH (SIADH)
. Nephrogenic diabetes insipidus
. Central diabetes insipidus
. Osmotic diuresis
. Primary polydipsia

Correct Answer & Explanation

. Central diabetes insipidus

Explanation

This patient's presentation of hypernatremia, polyuria, and a very dilute urine (urine osmolality <100 mOsm/kg) in the context of a traumatic brain injury is highly suggestive of central diabetes insipidus. TBI can damage the hypothalamus or posterior pituitary, leading to inadequate ADH secretion. Nephrogenic diabetes insipidus involves renal unresponsiveness to ADH but is less likely with TBI as the primary event. SIADH causes hyponatremia, not hypernatremia. Osmotic diuresis would have higher urine osmolality. Primary polydipsia would be unusual in a TBI patient and less likely to cause such profound hypernatremia.

Question 10067

Topic: 2. Trauma

A 62-year-old male with a large retroperitoneal hematoma following pelvic fracture embolization suddenly develops significant swelling in his scrotum and perineum. His blood pressure drops from 120/70 mmHg to 90/50 mmHg. What type of fluid shift is occurring?

. Intravascular to intracellular
. Intracellular to intravascular
. Intravascular to third space
. Interstitial to intravascular
. Intracellular to interstitial

Correct Answer & Explanation

. Intravascular to third space

Explanation

The development of significant swelling (edema) in the scrotum and perineum, combined with a dropping blood pressure, in a patient with a large retroperitoneal hematoma, indicates ongoing 'third-spacing' of fluid. Third-spacing refers to the movement of fluid from the intravascular space into a non-functional space (like a hematoma or edematous tissue) where it is effectively lost from the circulating blood volume. This leads to hypovolemia and hypotension. The fluid is moving from the intravascular compartment into an abnormal interstitial or body cavity space.

Question 10068

Topic: 2. Trauma

A 40-year-old male with a history of intravenous drug use and chronic hepatitis C undergoes an emergency open reduction internal fixation of a forearm fracture. Post-operatively, he develops hypotension, tachycardia, and a temperature of 39.5°C. Which of the following is the most important initial diagnostic step?

. Order a CT scan of the abdomen
. Perform an arterial blood gas
. Obtain blood cultures from two sites
. Request a surgical consultation for wound dehiscence
. Order a brain MRI

Correct Answer & Explanation

. Obtain blood cultures from two sites

Explanation

The patient's presentation with fever, hypotension, and tachycardia in the post-operative setting suggests sepsis. Given his risk factors (IV drug use, chronic hepatitis C, emergency surgery), infection is a high probability. The most important initial diagnostic step is to obtain blood cultures from two separate sites before initiating broad-spectrum antibiotics. This helps identify the causative organism and guides definitive therapy. Other tests may be appropriate later, but identifying the pathogen in sepsis is critical.

Question 10069

Topic: 2. Trauma

A 25-year-old male with a severe open tibia fracture develops rhabdomyolysis. His urine output is low, and his serum creatinine is rising rapidly. What is the primary goal of fluid management in this patient?

. Maintain a positive fluid balance of 2 liters per day
. Achieve urine output of 3-4 mL/kg/hr
. Prevent hypernatremia
. Administer colloid solutions to maintain intravascular volume
. Restrict fluids to prevent fluid overload

Correct Answer & Explanation

. Achieve urine output of 3-4 mL/kg/hr

Explanation

In rhabdomyolysis, aggressive intravenous fluid resuscitation is crucial to flush myoglobin from the renal tubules and prevent acute kidney injury. The primary goal of fluid management is to achieve a high urine output, typically 3-4 mL/kg/hr (or approximately 200-300 mL/hr in an adult), to minimize the risk of renal tubular obstruction. While preventing electrolyte abnormalities is important, the most critical fluid goal is high urine output. Restricting fluids would be detrimental. Colloids are not typically first-line for this purpose.

Question 10070

Topic: 2. Trauma

A 40-year-old male with a history of poorly controlled hypertension is undergoing an emergency fixation of a calcaneal fracture. His intraoperative blood pressure remains consistently elevated at 170/95 mmHg despite light anesthesia. What is the primary concern with allowing this sustained high blood pressure during surgery?

. Increased risk of surgical site infection
. Increased risk of acute kidney injury
. Increased risk of myocardial ischemia and stroke
. Increased risk of post-operative deep vein thrombosis
. Delayed wound healing

Correct Answer & Explanation

. Increased risk of myocardial ischemia and stroke

Explanation

Sustained perioperative hypertension, particularly in patients with pre-existing poorly controlled hypertension, significantly increases the risk of major adverse cardiac events (myocardial ischemia/infarction) and cerebrovascular events (stroke). The elevated afterload increases myocardial oxygen demand, and the high pressure stresses cerebral vasculature. While AKI is a concern, myocardial ischemia and stroke are the most critical immediate risks associated with uncontrolled hypertension during surgery. The other options are less directly related or less immediate concerns.

Question 10071

Topic: 2. Trauma

A 70-year-old male receives 3 units of packed red blood cells (PRBCs) rapidly for massive hemorrhage during a pelvic fracture repair. Shortly after, his serum potassium is 6.5 mEq/L. What is the most likely cause of his hyperkalemia?

. Acute kidney injury
. Metabolic acidosis
. Release of intracellular potassium from damaged cells
. Potassium load from transfused PRBCs
. Over-administration of potassium-containing IV fluids

Correct Answer & Explanation

. Potassium load from transfused PRBCs

Explanation

Stored packed red blood cells undergo changes over time, including the leakage of potassium from within the red blood cells into the extracellular storage medium. Rapid and massive transfusion of PRBCs can deliver a significant potassium load, leading to hyperkalemia. While AKI and metabolic acidosis can also cause hyperkalemia, the acute onset immediately after rapid PRBC transfusion points specifically to the potassium content of the transfused blood. Release of intracellular potassium from damaged cells is relevant for crush injuries, not typically for transfusion-related hyperkalemia. Over-administration of potassium-containing fluids is not indicated in this scenario.

Question 10072

Topic: 2. Trauma

A 60-year-old male with a history of alcohol abuse and pancreatitis is undergoing internal fixation of an intertrochanteric hip fracture. On post-operative day 2, his serum sodium is 120 mEq/L, and his blood glucose is 450 mg/dL. What type of hyponatremia is most likely present?

. Euvolemic hyponatremia (SIADH)
. Hypovolemic hyponatremia
. Hypervolemic hyponatremia
. Pseudohyponatremia due to hyperglycemia
. Factitious hyponatremia

Correct Answer & Explanation

. Pseudohyponatremia due to hyperglycemia

Explanation

This patient has severe hyperglycemia (450 mg/dL) concurrent with hyponatremia. Hyperglycemia causes an osmotic shift of water from the intracellular to the extracellular space, diluting the serum sodium, which is known as pseudohyponatremia or translocational hyponatremia. For every 100 mg/dL increase in glucose above 100 mg/dL, serum sodium is expected to decrease by approximately 1.6 to 2.4 mEq/L. Therefore, his measured sodium of 120 mEq/L is a reflection of this osmotic shift, and his 'true' or corrected sodium would be higher. The other types of hyponatremia are less likely as the primary cause given the prominent hyperglycemia.

Question 10073

Topic: 2. Trauma

A 30-year-old male sustains a traumatic amputation of his forearm. He is hemodynamically unstable (BP 70/40 mmHg, HR 140 bpm) due to massive blood loss. What is the most important component of the massive transfusion protocol to address the risk of coagulopathy?

. Early and continuous administration of crystalloids
. Maintaining a 1:1:1 ratio of PRBCs:FFP:Platelets
. Administering calcium gluconate with every unit of blood
. Avoiding hypothermia
. Frequent monitoring of hemoglobin

Correct Answer & Explanation

. Maintaining a 1:1:1 ratio of PRBCs:FFP:Platelets

Explanation

Massive transfusion protocols are designed to prevent the 'lethal triad' of hypothermia, acidosis, and coagulopathy in severely bleeding trauma patients. The most important component for addressing coagulopathy is transfusing blood products in a balanced ratio, typically 1:1:1 or 1:1:2 (PRBCs:FFP:Platelets), to replace clotting factors and platelets along with red blood cells. Crystalloids are part of initial resuscitation but can worsen coagulopathy if given in excess. Calcium gluconate addresses citrate toxicity, a cause of hypocalcemia that contributes to coagulopathy, but the balanced ratio directly replaces factors. Avoiding hypothermia is crucial for preventing coagulopathy but is not a 'component of massive transfusion protocol' in the same way the ratios are.

Question 10074

Topic: 2. Trauma

A 68-year-old male with a history of chronic alcoholism and liver cirrhosis is undergoing an open reduction and internal fixation of a distal tibia fracture. His INR is 1.8 pre-operatively. What is the most appropriate management of his coagulopathy for surgery?

. Proceed with surgery; INR 1.8 is acceptable
. Administer Factor VIIa to normalize INR
. Administer 10 mg Vitamin K intravenously
. Administer Fresh Frozen Plasma (FFP)
. Cancel surgery and monitor INR

Correct Answer & Explanation

. Administer Fresh Frozen Plasma (FFP)

Explanation

Patients with liver cirrhosis often have impaired synthesis of clotting factors, leading to coagulopathy (elevated INR). For a surgical procedure, an INR of 1.8 is generally considered too high and increases the risk of significant bleeding. Fresh Frozen Plasma (FFP) provides a rapid infusion of clotting factors to temporarily normalize the INR. Factor VIIa is a potent procoagulant, often used for refractory bleeding, but not typically first-line for reversal of general coagulopathy. Vitamin K is useful if there's a vitamin K deficiency (less common with cirrhosis alone). Proceeding with surgery with INR 1.8 is risky. Canceling surgery for a fracture is not ideal if the INR can be corrected.

Question 10075

Topic: 2. Trauma

A 70-year-old female presents with a hip fracture. She has a history of mild cognitive impairment and chronic hyponatremia (Na+ 126 mEq/L), which has been stable for months. She is euvolemic on exam. What is the most appropriate target for her serum sodium correction in the perioperative period?

. Rapid correction to 135-140 mEq/L within 12 hours
. Slow, gradual correction, aiming for an increase of no more than 6-8 mEq/L in the first 24 hours
. No correction is needed as she is asymptomatic and chronic
. Correction to 145 mEq/L over 48 hours
. Increase sodium by 1-2 mEq/L per hour until normal

Correct Answer & Explanation

. Slow, gradual correction, aiming for an increase of no more than 6-8 mEq/L in the first 24 hours

Explanation

For chronic hyponatremia, especially in elderly patients, rapid correction of serum sodium is dangerous and can lead to osmotic demyelination syndrome (ODS). Even if asymptomatic, a mild increase in sodium can improve neurological function and prevent further drops. The recommended guideline is to correct slowly and gradually, aiming for an increase of no more than 6-8 mEq/L in the first 24 hours, and generally not exceeding 10-12 mEq/L over 48 hours. Rapid correction within 12 hours or 1-2 mEq/L per hour is too fast. While some argue against correction for very mild, chronic cases, optimizing a patient for major surgery is prudent.

Question 10076

Topic: 2. Trauma

A 28-year-old male with a traumatic pelvic fracture and suspected intra-abdominal hemorrhage has a BP of 80/40 mmHg and HR 130 bpm. He is being resuscitated with blood products. What is the primary target for his systolic blood pressure during initial resuscitation (permissive hypotension) before definitive hemorrhage control?

. Maintain systolic BP >120 mmHg
. Maintain systolic BP 100-110 mmHg
. Maintain systolic BP 90-100 mmHg
. Maintain systolic BP >140 mmHg
. Maintain mean arterial pressure (MAP) >70 mmHg

Correct Answer & Explanation

. Maintain systolic BP 90-100 mmHg

Explanation

For actively bleeding trauma patients without head injury, the concept of permissive hypotension is often applied. The goal is to maintain a systolic blood pressure (SBP) of 90-100 mmHg (or MAP 60-65 mmHg) until definitive surgical or interventional control of hemorrhage can be achieved. Higher blood pressures can dislodge clots and worsen bleeding, while lower pressures can lead to inadequate organ perfusion. Patients with traumatic brain injury are an exception, where a higher SBP target (>100-110 mmHg) is preferred to maintain cerebral perfusion. Maintaining SBP >120 mmHg or >140 mmHg would be detrimental in active hemorrhage.

Question 10077

Topic: 2. Trauma

A 25-year-old male presents with a high-energy distal femur fracture. He is hemodynamically stable. He is found to have a serum phosphate of 2.0 mg/dL (normal 2.5-4.5 mg/dL). What is the most likely cause of his hypophosphatemia?

. Renal phosphate wasting
. Inadequate dietary intake
. Hungry bone syndrome
. Refeeding syndrome
. Alkalosis

Correct Answer & Explanation

. Refeeding syndrome

Explanation

Refeeding syndrome is a potentially fatal complication that can occur when severely malnourished patients are aggressively refed, especially with carbohydrates. The sudden influx of glucose stimulates insulin release, which drives phosphate, potassium, and magnesium into cells, leading to severe hypophosphatemia (and hypokalemia, hypomagnesemia). While other causes of hypophosphatemia exist, a high-energy trauma patient might be malnourished or be undergoing aggressive nutritional support, making refeeding syndrome a significant consideration. Renal phosphate wasting and inadequate dietary intake are less likely to cause acute, significant hypophosphatemia. Hungry bone syndrome usually follows parathyroidectomy. Alkalosis can shift phosphate intracellularly but is a less likely primary cause in this context.

Question 10078

Topic: 2. Trauma

A 22-year-old male sustains a spiral fracture of the middle third of the humerus after an arm wrestling injury. He presents with wrist drop and sensory deficit over the dorsum of the hand. X-rays confirm the fracture. What is the most appropriate initial management?

. Immediate surgical exploration and nerve repair.
. Closed reduction and functional bracing with close observation of nerve recovery.
. Open reduction and internal fixation with nerve transfer.
. Electromyography (EMG) and nerve conduction studies (NCS) to confirm nerve injury.
. Placement of an external fixator and delayed nerve exploration.

Correct Answer & Explanation

. Closed reduction and functional bracing with close observation of nerve recovery.

Explanation

A spiral fracture of the middle third of the humerus with wrist drop is classic for radial nerve palsy, which is the most commonly injured nerve in humeral shaft fractures. Most radial nerve palsies associated with closed humeral shaft fractures are neuropraxias or axonotmesis in continuity and recover spontaneously (up to 90%). Therefore, the initial management is closed reduction and functional bracing of the fracture, with close observation for neurological recovery. Surgical exploration is generally reserved for open fractures, failure of nerve recovery after 3-6 months, or if the nerve is clearly entrapped. EMG/NCS are useful for prognosticating recovery but are not immediate management steps; they are typically performed at 3-6 weeks or later to assess denervation. Nerve transfer is for irreversible nerve damage, not initial management. External fixator is usually for open or highly comminuted unstable fractures.

Question 10079

Topic: 2. Trauma

A 70-year-old female sustains a comminuted, intra-articular fracture of the distal radius (AO type C3) after falling from standing height. She has severe osteoporosis and multiple comorbidities. What is the most appropriate definitive management strategy to optimize functional outcome?

. Closed reduction and casting.
. External fixation alone.
. Dorsal plating with bone graft.
. Volar locking plate fixation.
. Wrist fusion.

Correct Answer & Explanation

. Volar locking plate fixation.

Explanation

For a comminuted, intra-articular distal radius fracture in an osteoporotic elderly patient, volar locking plate fixation has become the preferred treatment. It allows for rigid internal fixation, early mobilization, and better maintenance of reduction compared to casting or external fixation alone. Closed reduction and casting are often insufficient for maintaining reduction in highly comminuted, unstable fractures, especially in osteoporotic bone. External fixation can provide indirect reduction but may not fully restore articular congruity and has issues with pin-site care and stiffness. Dorsal plating is an option but volar plating is biomechanically superior for distal radius fractures, allowing for easier fixation of volar fragments and better restoration of volar tilt. Wrist fusion is reserved for salvage in failed attempts or severe arthritis, not primary fracture treatment.

Question 10080

Topic: 2. Trauma
A 28-year-old male sustains a Gustilo-Anderson Type IIIB open tibia fracture. After initial irrigation and debridement and external fixation, the soft tissue defect is significant. What is the most appropriate next step for soft tissue coverage?
. Delayed primary closure.
. Secondary intention healing with daily wound care.
. Split-thickness skin graft.
. Local rotational flap.
. Free tissue transfer (free flap).

Correct Answer & Explanation

. Free tissue transfer (free flap).

Explanation

A Gustilo-Anderson Type IIIB open tibia fracture involves extensive soft tissue damage and periosteal stripping, exposing bone and requiring complex soft tissue reconstruction. Delayed primary closure and secondary intention are insufficient for such large, complex defects with exposed bone. A split-thickness skin graft requires a well-vascularized bed, which is typically absent over exposed bone or tendon. Local rotational flaps may be an option for smaller defects but are often inadequate for the significant defects seen in Type IIIB fractures of the tibia. Free tissue transfer (free flap) is often the reconstructive method of choice for Type IIIB open tibia fractures, providing robust, vascularized tissue that can cover exposed bone, achieve primary wound healing, and allow for eventual definitive fracture fixation. This is a critical principle in open fracture management.

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