This practice set contains high-yield board review questions covering key concepts in Infection, Pharmacology & VTE. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 241
Topic: Infection, Pharmacology & VTE
When is it generally considered safe and most efficacious to initiate pharmacologic deep vein thrombosis (DVT) prophylaxis in a patient with a surgically stabilized pelvic ring injury and no associated traumatic brain or solid organ injury?
Correct Answer & Explanation
. 24-48 hours post-injury or post-surgery
Explanation
Current trauma guidelines recommend initiating pharmacologic DVT prophylaxis (e.g., LMWH) 24 to 48 hours after injury or surgery in pelvic trauma patients, provided there are no active bleeding issues or other contraindications.
Question 242
Topic: Infection, Pharmacology & VTE
A 60-year-old diabetic patient undergoes ORIF of a displaced posterior malleolus fracture via a posterolateral approach. Two weeks post-operatively, the patient presents with increasing pain, erythema, and purulent discharge from the surgical incision, as conceptually shown below. Cultures confirm a deep surgical site infection. What is the most appropriate immediate management strategy?
Correct Answer: CA deep surgical site infection, especially in a diabetic patient, is a serious complication requiring aggressive management. The presence of purulent discharge and increasing pain/erythema indicates a deep infection. The most appropriate immediate management involves surgical debridement to remove infected and necrotic tissue, initiation of broad-spectrum intravenous antibiotics (tailored to culture results), and often local wound management techniques such as negative pressure wound therapy (NPWT) or antibiotic beads. Hardware removal is typically considered later, once the fracture has healed, unless the infection is uncontrolled or the hardware is clearly contributing to the infection.Option A (Oral antibiotics and continued observation):Oral antibiotics are generally insufficient for deep surgical site infections, especially with purulent discharge. Observation risks progression of the infection, potentially leading to osteomyelitis or sepsis.Option B (Hardware removal and immediate wound closure):Hardware removal is usually delayed until fracture healing, unless the infection is refractory. Immediate wound closure without adequate debridement and control of the infection would likely lead to recurrence and worsening of the infection.Option D (Topical antibiotic ointment and sterile dressing changes):This is appropriate for superficial wound issues but completely inadequate for a deep surgical site infection with purulent discharge.Option E (Referral to a pain management specialist):While the patient is experiencing pain, the primary issue is an active infection that requires surgical and medical intervention, not just pain management. Addressing the infection is paramount.
Question 243
Topic: Infection, Pharmacology & VTE
The patient has a 15 pack-year smoking history and works as a construction worker. Considering the landmark Buckley trial (JBJS 2002) and the principles highlighted in the case regarding operative management of displaced intra-articular calcaneal fractures, which of the following statements is most accurate?
Correct Answer & Explanation
. Smokers have a significantly increased risk of wound complications and may have outcomes similar to or worse than non-operative management.
Explanation
Correct Answer: CThe case explicitly discusses the impact of smoking: 'His 15 pack-year smoking history is a critical prognostic factor... In the context of calcaneal fractures, smoking significantly increases the risk of devastating postoperative wound complications, including marginal flap necrosis, deep infection, and subsequent osteomyelitis. Studies, notably the landmark trial by Buckley et al., have demonstrated that smokers with displaced intra-articular calcaneal fractures often have poorer outcomes following operative intervention compared to non-smokers, making the decision to proceed with open reduction and internal fixation (ORIF) highly nuanced in this demographic.' The Buckley trial specifically showed that while young, healthy, non-smokers had better outcomes with surgery, smokers had outcomes that were not significantly different from, or were worse than, those managed non-operatively, along with a drastically higher rate of wound complications. Therefore, smoking significantly increases complication risks and can negate the benefits of surgery.
Question 244
Topic: Infection, Pharmacology & VTE
A 68-year-old male with a history of unprovoked left lower extremity DVT 3 years prior, currently managed with aspirin 81mg daily, is scheduled for an elective right total hip arthroplasty (THA). He has a BMI of 32 kg/m2 and well-controlled hypertension. During preoperative assessment, he expresses concern about VTE recurrence. Based on AAOS guidelines and his risk profile, which of the following statements regarding his VTE risk and prophylaxis is most accurate?
Correct Answer & Explanation
. He is considered a high-risk patient for recurrent VTE, necessitating intensified pharmacologic prophylaxis, likely with a DOAC or LMWH, for an extended duration.
Explanation
Correct Answer: CThe correct answer is C. The case explicitly states that a history of prior DVT or PE is a substantial independent risk factor for recurrent VTE, elevating the relative risk by approximately 2-4 times compared to patients without such history. For such high-risk patients, AAOS guidelines suggest extending pharmacologic prophylaxis up to 35 days postoperatively, and the choice of agent often leans towards more potent options like DOACs or LMWH due to their higher efficacy in preventing recurrent VTE compared to aspirin, especially for initial and extended prophylaxis in this group.Option A is incorrectbecause the case states the relative risk increase is 2-4 times, not 1.5 times, and aspirin alone is generally not considered sufficient for primary or secondary prophylaxis in high-risk THA patients with a DVT history, where more potent agents are preferred.Option B is incorrectbecause while age and BMI are risk factors, a history of DVT is explicitly highlighted as the 'most significant risk factor requiring augmented or extended prophylaxis' and 'a potent and independent risk factor for recurrent VTE'.Option D is incorrectbecause mechanical prophylaxis with IPCs is generally recommended for both limbs postoperatively. While caution is advised for acutely thrombosed limbs, a DVT 3 years prior does not contraindicate IPCs on the unaffected limb intraoperatively and both limbs postoperatively, unless there is active DVT or post-thrombotic syndrome that makes it uncomfortable or ill-fitting. The statement implies a universal contraindication, which is false.Option E is incorrectbecause the AAOS does not recommend routine duplex ultrasound screening for asymptomatic DVT following THA. Screening should be reserved for patients with signs or symptoms suggestive of DVT or PE.
Question 245
Topic: Infection, Pharmacology & VTE
A 55-year-old female undergoing elective left THA, with a history of right lower extremity DVT 5 years ago, is positioned in the lateral decubitus position. The surgical team is meticulous about padding and alignment. Which of the following intraoperative biomechanical factors is most directly mitigated by careful patient positioning and contributes significantly to VTE risk reduction?
Correct Answer & Explanation
. Venous stasis from prolonged immobility and direct compression of veins in the dependent limb.
Explanation
Correct Answer: CThe correct answer is C. Careful patient positioning, especially in the lateral decubitus position, is crucial to avoid direct pressure on the dependent leg, which can lead to venous outflow obstruction and significant venous stasis. Prolonged immobility under anesthesia also contributes to stasis. Mitigating these factors directly reduces VTE risk.Option A is incorrectbecause systemic hypercoagulability is a physiological response to surgical trauma and is not directly mitigated by patient positioning. It requires pharmacologic intervention.Option B is incorrectbecause direct endothelial injury from surgical dissection is related to the surgical technique and tissue handling, not primarily patient positioning.Option D is incorrectbecause activation of acute phase reactants is a systemic inflammatory response to surgery, not directly influenced by patient positioning.Option E is incorrectbecause reduced fibrinolysis is part of the systemic hypercoagulable state induced by surgery and is not addressed by patient positioning.
Question 246
Topic: Infection, Pharmacology & VTE
A 72-year-old male with a history of Factor V Leiden mutation and a prior unprovoked PE 2 years ago, now on chronic apixaban, is scheduled for elective right THA. His creatinine clearance is 45 mL/min. Which of the following is an absolute contraindication to continuing his current pharmacologic VTE prophylaxis strategy perioperatively?
Correct Answer & Explanation
. A platelet count of 40,000/µL on preoperative labs.
Explanation
Correct Answer: DThe correct answer is D. Severe thrombocytopenia (platelets < 50,000/µL) is listed as an absolute contraindication to pharmacologic prophylaxis due to the unacceptably high risk of bleeding. A platelet count of 40,000/µL falls into this category.Option A is incorrectbecause advanced age (>60-70 years) is a risk factor for VTE, not a contraindication to prophylaxis. In fact, it often warrants intensified prophylaxis.Option B is incorrectbecause moderate renal impairment (CrCl 45 mL/min) is a relative contraindication or requires dose adjustment for renally cleared anticoagulants like apixaban, but it is not an absolute contraindication to all pharmacologic prophylaxis. Apixaban typically requires dose adjustment for CrCl < 30 mL/min, but 45 mL/min might still allow for a reduced dose or a different agent.Option C is incorrectbecause neuraxial anesthesia is a relative contraindication, requiring careful timing considerations for anticoagulant administration to minimize spinal epidural hematoma risk, but it is not an absolute contraindication to pharmacologic prophylaxis itself.Option E is incorrectbecause a history of Factor V Leiden mutation is a strong indication for VTE prophylaxis, especially in a patient with a prior PE, not a contraindication.
Question 247
Topic: Infection, Pharmacology & VTE
A 62-year-old patient with a history of provoked DVT 4 years ago (due to prolonged immobilization after a tibia fracture) is undergoing elective THA. Preoperative labs are normal, and he is not on chronic anticoagulation. The surgeon plans to use LMWH for VTE prophylaxis. According to AAOS guidelines, what is the recommended minimum duration for pharmacologic prophylaxis in this patient?
Correct Answer & Explanation
. A minimum of 10-14 days postoperatively.
Explanation
Correct Answer: BThe correct answer is B. The AAOS strongly recommends continuing pharmacologic prophylaxis for a minimum of 10-14 days postoperatively for most THA patients. For high-risk patients, including those with a history of DVT, the AAOS suggests extending pharmacologic prophylaxis up to 35 days postoperatively. Therefore, 10-14 days is the minimum recommended duration, with a strong consideration for extension up to 35 days given his DVT history.Option A is incorrectas it is too short. The risk of VTE extends beyond the immediate hospital stay.Option C is incorrectas 6 weeks is not the standard minimum or suggested extended duration by AAOS; 35 days (approximately 5 weeks) is the suggested extended duration.Option D is incorrectas this duration is far too short and would not provide adequate protection against VTE.Option E is incorrectbecause indefinite prophylaxis is typically reserved for patients with recurrent unprovoked VTE or very high-risk thrombophilias, not a single provoked DVT 4 years ago in the context of THA prophylaxis.
Question 248
Topic: Infection, Pharmacology & VTE
A 48-year-old male with a history of unprovoked DVT 1 year prior, currently on warfarin for secondary prevention, is scheduled for elective THA. His target INR is 2.5. The surgical team plans for perioperative bridging. Which of the following is the most appropriate bridging strategy for this patient?
Correct Answer & Explanation
. Discontinue warfarin 5 days preoperatively, initiate LMWH 3 days preoperatively, stop LMWH 12-24 hours preoperatively, resume LMWH postoperatively, then restart warfarin.
Explanation
Correct Answer: BThe correct answer is B. For patients on chronic warfarin requiring surgery, a typical bridging strategy involves discontinuing warfarin approximately 5 days preoperatively to allow the INR to normalize. LMWH is then initiated (e.g., 3 days preoperatively) and stopped 12-24 hours before surgery (depending on the LMWH dose and patient bleeding risk). Postoperatively, LMWH is resumed once hemostasis is achieved and bleeding risk is acceptable, and warfarin is restarted. LMWH is continued until the INR is therapeutic (typically 2-3 days after warfarin restart).Option A is incorrectbecause discontinuing warfarin only 1 day preoperatively is insufficient for INR normalization, and starting LMWH so close to surgery and stopping it 6 hours preoperatively is not a standard, safe bridging protocol.Option C is incorrectbecause continuing warfarin perioperatively significantly increases the risk of major bleeding during and after THA, especially with an INR of 2.5.Option D is incorrectbecause switching to aspirin is insufficient for a patient on chronic warfarin for secondary prevention of unprovoked DVT, especially given his high VTE risk.Option E is incorrectbecause discontinuing warfarin 2 days preoperatively might be too short, and starting DOACs postoperatively without proper bridging (e.g., with LMWH) would leave a significant period of inadequate anticoagulation, especially for a high-risk patient.
Question 249
Topic: Infection, Pharmacology & VTE
During an elective THA on a patient with a history of DVT, the surgeon inadvertently causes a small tear in the profunda femoris vein during acetabular preparation. The tear is successfully repaired with fine sutures. What is the most appropriate immediate postoperative VTE prophylaxis adjustment or consideration for this patient?
Correct Answer & Explanation
. Proceed with standard high-risk VTE prophylaxis (e.g., LMWH/DOAC for 35 days) and consider imaging surveillance of the affected limb.
Explanation
Correct Answer: CThe correct answer is C. Inadvertent venous injury, even if repaired, creates localized endothelial trauma and increases the risk of intraluminal thrombus formation. For a patient already at high risk due to DVT history, this event further elevates localized DVT risk. Therefore, proceeding with robust pharmacologic prophylaxis (LMWH/DOAC for 35 days as per AAOS suggestions for high-risk patients) is appropriate, carefully balancing the bleeding risk from the repair. Additionally, imaging surveillance (e.g., duplex ultrasound) of the affected limb may be warranted to monitor for DVT development at the site of injury.Option A is incorrectbecause discontinuing all prophylaxis would leave a high-risk patient unprotected, especially after a direct venous injury. The bleeding risk from a small, successfully repaired tear needs to be weighed against the VTE risk, but usually, prophylaxis is continued.Option B is incorrectbecause initiatingtherapeuticanticoagulation immediately postoperatively is too aggressive and carries a very high risk of bleeding, especially at the surgical site and the venous repair. Prophylactic dosing is the standard.Option D is incorrectbecause switching to aspirin from a more potent agent like LMWH would be a downgrade in efficacy, which is inappropriate for a patient with heightened VTE risk due to DVT history and intraoperative venous injury.Option E is incorrectbecause a prophylactic IVC filter is not indicated for a successfully repaired venous injury. IVC filters are reserved for patients with acute proximal DVT or PE who have absolute contraindications to anticoagulation or recurrent VTE despite adequate anticoagulation; they are not a primary prophylactic measure.
Question 250
Topic: Infection, Pharmacology & VTE
A 65-year-old female with a history of unprovoked DVT 2 years ago, now on apixaban 5mg BID, is scheduled for elective THA. Her preoperative labs are within normal limits, including a platelet count of 250,000/µL and CrCl of 70 mL/min. She is instructed to hold apixaban for 3 days prior to surgery. Postoperatively, on Day 1, she develops sudden onset dyspnea, pleuritic chest pain, and tachycardia. A CT pulmonary angiography (CTPA) confirms a subsegmental pulmonary embolism. Which of the following is the most appropriate immediate management step?
Correct Answer & Explanation
. Initiate therapeutic anticoagulation with LMWH or unfractionated heparin immediately.
Explanation
Correct Answer: BThe correct answer is B. For a confirmed pulmonary embolism (PE), immediate therapeutic anticoagulation is the cornerstone of management. LMWH or unfractionated heparin is typically initiated promptly, followed by a transition to DOACs or warfarin. This patient is hemodynamically stable (no mention of hypotension or shock), so thrombolysis or embolectomy are not first-line.Option A is incorrectbecause aspirin is not therapeutic for an acute PE and would be insufficient.Option C is incorrectbecause while a DVT is often the source of a PE, the diagnosis of PE is already confirmed by CTPA. The priority is to treat the PE, not to delay by looking for the source, unless there's a specific clinical reason (e.g., considering IVC filter if anticoagulation is contraindicated).Option D is incorrectbecause surgical embolectomy is reserved for massive PE in patients with contraindications to thrombolysis or failed thrombolysis, not for a subsegmental PE in a hemodynamically stable patient.Option E is incorrectbecause systemic thrombolysis is indicated for massive PE with hemodynamic instability (hypotension, shock), which is not described in this stable patient with a subsegmental PE.
Question 251
Topic: Infection, Pharmacology & VTE
A 70-year-old male with a history of recurrent DVT and known Antithrombin III deficiency is undergoing elective THA. He is receiving LMWH for VTE prophylaxis. On postoperative day 5, his platelet count drops from 220,000/µL preoperatively to 80,000/µL, and he develops new ecchymoses at injection sites. His surgical wound is clean. What is the most likely diagnosis and appropriate initial management?
Correct Answer & Explanation
. Heparin-induced thrombocytopenia (HIT); immediately discontinue LMWH and initiate a non-heparin anticoagulant.
Explanation
The clinical picture of a significant drop in platelet count (>50% drop) occurring 5 days after starting LMWH, coupled with new thrombotic manifestations (ecchymoses, which can be a sign of paradoxical thrombosis in HIT), is highly suggestive of Heparin-Induced Thrombocytopenia (HIT). HIT is a severe immune-mediated complication of heparin exposure. The immediate management is to discontinue all heparin products and initiate an alternative non-heparin anticoagulant.
Question 252
Topic: Infection, Pharmacology & VTE
A 58-year-old female with a history of unprovoked DVT 3 years prior, currently not on anticoagulation, is scheduled for elective THA. She has no other significant comorbidities. During preoperative counseling, she expresses a strong preference for aspirin due to a fear of injections and concerns about bleeding with stronger anticoagulants. Based on AAOS guidelines and shared decision-making, which of the following is the most appropriate recommendation?
Correct Answer & Explanation
. Discuss the higher efficacy of LMWH or DOACs for high-risk patients, but acknowledge aspirin as a potential option, ideally combined with mechanical prophylaxis and extended duration.
Explanation
Correct Answer: CThe correct answer is C. The AAOS strongly recommends shared decision-making, which involves discussing individual VTE and bleeding risks, the rationale for specific prophylaxis choices, and potential side effects, allowing patients to make informed choices. While LMWH or DOACs are generally favored for their higher efficacy in high-risk patients with a DVT history, the AAOS guidelinessuggestthat aspirin may be considered for VTE prophylaxis after THA, particularly when combined with mechanical prophylaxis. For a patient with a strong preference and concerns, a thorough discussion acknowledging aspirin as a potential, albeit less potent, option (especially with extended duration and mechanical adjuncts) aligns with shared decision-making principles, provided the patient fully understands the comparative risks and benefits.Option A is incorrectbecause while LMWH/DOACs are preferred, 'insisting' goes against shared decision-making, and aspirin is not absolutely contraindicated by AAOS, though its efficacy in this specific high-risk group is lower.Option B is incorrectbecause while respecting preference, prescribing aspirin as sole prophylaxis for only 10-14 days in a high-risk patient with DVT history might be suboptimal. Extended duration and mechanical prophylaxis would still be important considerations.Option D is incorrectbecause aspirin is not absolutely contraindicated by AAOS guidelines for THA prophylaxis, though its role in high-risk patients is debated and often considered less efficacious than other agents.Option E is incorrectbecause a prophylactic IVC filter is not a primary VTE prophylaxis strategy and is reserved for specific indications (acute VTE with contraindication to anticoagulation or recurrent VTE despite adequate anticoagulation), not to avoid medication risks in a patient without acute VTE.
Question 253
Topic: Infection, Pharmacology & VTE
A 60-year-old male with a history of left lower extremity DVT 10 years ago, now fully resolved and not on chronic anticoagulation, is undergoing elective right THA. He is obese (BMI 35 kg/m2). Which of the following non-pharmacologic strategies is most effective and universally recommended by AAOS for VTE prevention in this patient?
Correct Answer & Explanation
. Early and progressive ambulation, starting on postoperative day 0 or 1.
Explanation
Correct Answer: BThe correct answer is B. Early and progressive ambulation, starting as soon as medically stable (postoperative day 0 or 1), is a cornerstone of mechanical VTE prophylaxis. It reactivates the calf muscle pump, improves venous return, and is universally recommended by AAOS in conjunction with pharmacologic agents or as a primary mechanical strategy.Option A is incorrectbecause while GCS have been used, the AAOS CPGs generally indicate that GCS alone are less effective than other methods and do not typically recommend them as primary VTE prophylaxis for THA. IPCs/SCDs are preferred mechanical methods.Option C is incorrectbecause the AAOS does not recommend routine duplex ultrasound screening for asymptomatic DVT following THA. Screening should be reserved for patients with signs or symptoms suggestive of DVT or PE.Option D is incorrectbecause an IVC filter is not a primary prophylactic measure and is reserved for specific indications (acute VTE with contraindication to anticoagulation or recurrent VTE despite adequate anticoagulation), not for general VTE prevention in a patient without acute VTE.Option E is incorrectbecause avoiding lower extremity exercises would promote venous stasis and increase VTE risk. Ankle pumps, foot circles, and early ambulation are crucial for VTE prevention.
Question 254
Topic: Infection, Pharmacology & VTE
A 45-year-old female with a history of unprovoked DVT 6 months prior, currently on rivaroxaban, is scheduled for elective THA. She has no other significant medical history. During the preoperative assessment, the surgeon discusses the optimal VTE prophylaxis strategy. Which of the following AAOS recommendations is most pertinent to her case regarding the choice and duration of pharmacologic prophylaxis?
Correct Answer & Explanation
. LMWH or a DOAC (like rivaroxaban) for an extended duration of up to 35 days postoperatively is suggested due to her high-risk status.
Explanation
Correct Answer: BThe correct answer is B. The patient has a history of unprovoked DVT, which is a significant risk factor for recurrent VTE. The AAOS guidelines suggest extending pharmacologic prophylaxis up to 35 days postoperatively for high-risk patients. LMWH or DOACs (like rivaroxaban, which she is already on) are generally favored for their efficacy in preventing recurrent VTE in this population.Option A is incorrectbecause aspirin is generally considered less efficacious than LMWH or DOACs for high-risk patients with a DVT history, especially for initial and extended prophylaxis. Her DVT being recent further emphasizes the need for potent prophylaxis.Option C is incorrectbecause discontinuing prophylaxis immediately post-surgery would leave a high-risk patient vulnerable to VTE, which is contrary to AAOS recommendations for THA.Option D is incorrectbecause mechanical prophylaxis is generally usedin conjunctionwith pharmacologic agents, not as the sole method, especially in high-risk patients, unless pharmacologic agents are strictly contraindicated.Option E is incorrectbecause while warfarin is effective, it requires regular INR monitoring, making it less convenient than DOACs for many patients, especially for extended prophylaxis. DOACs are also considered preferred agents.
Question 255
Topic: Infection, Pharmacology & VTE
A 50-year-old male with a history of severe uncontrolled hypertension (BP 210/115 mmHg) and a prior DVT 2 years ago is scheduled for elective THA. His surgical team is reviewing his VTE prophylaxis plan. Which of the following statements accurately reflects the AAOS guidelines regarding his hypertension and VTE prophylaxis?
Correct Answer & Explanation
. His hypertension is a relative contraindication to pharmacologic prophylaxis, requiring careful risk-benefit analysis and potentially mechanical-only prophylaxis initially.
Explanation
Correct Answer: BThe correct answer is B. Severe uncontrolled hypertension (e.g., > 200/110 mmHg) is listed as a relative contraindication to pharmacologic prophylaxis. This means it requires careful risk-benefit analysis, shared decision-making, and potentially mechanical-only prophylaxis initially until the blood pressure is better controlled, due to the increased risk of hemorrhagic complications with anticoagulants.Option A is incorrectbecause it is a relative, not absolute, contraindication. Mechanical prophylaxis would still be indicated.Option C is incorrectbecause while DVT history is a major factor, bleeding risk factors like uncontrolled hypertension must be carefully considered when selecting and initiating pharmacologic prophylaxis.Option D is incorrectbecause initiating pharmacologic prophylaxis with severe uncontrolled hypertension significantly increases the risk of major bleeding, including intracranial hemorrhage. Hypertension should ideally be controlled preoperatively.Option E is incorrectbecause while aspirin might have a lower bleeding risk profile than some stronger anticoagulants, any pharmacologic agent carries increased risk in the setting of severe uncontrolled hypertension. It is not inherently the 'safest' without addressing the underlying hypertension.
Question 256
Topic: Infection, Pharmacology & VTE
A patient undergoing total hip arthroplasty is started on warfarin for VTE prophylaxis due to a documented allergy to low-molecular-weight heparin. Warfarin exerts its anticoagulant effect by inhibiting the gamma-carboxylation of which of the following coagulation factors?
Correct Answer & Explanation
. Factors II, VII, IX, and X
Explanation
Warfarin acts as a Vitamin K antagonist, inhibiting the enzyme vitamin K epoxide reductase. This prevents the gamma-carboxylation and functional activation of Vitamin K-dependent clotting factors II, VII, IX, and X, as well as proteins C and S.
Question 257
Topic: Infection, Pharmacology & VTE
Rivaroxaban is frequently utilized for chemical VTE prophylaxis following total hip arthroplasty. What is the specific mechanism of action of this medication?
Correct Answer & Explanation
. Direct Factor Xa inhibitor
Explanation
Rivaroxaban and Apixaban are direct oral anticoagulants (DOACs) that specifically and reversibly inhibit Factor Xa. This interrupts both the intrinsic and extrinsic coagulation cascades, preventing thrombin generation and subsequent thrombus development.
Question 258
Topic: Infection, Pharmacology & VTE
A 75-year-old male sustains an intertrochanteric hip fracture requiring urgent surgical intervention. He is on chronic warfarin therapy with an admission INR of 3.8. What is the most appropriate and rapid reversal agent to administer to expedite safe surgery?
Correct Answer & Explanation
. Four-factor Prothrombin Complex Concentrate (PCC) and Vitamin K
Explanation
For urgent reversal of warfarin (a vitamin K antagonist) in the setting of trauma or urgent surgery, four-factor Prothrombin Complex Concentrate (PCC) combined with Vitamin K provides the most rapid and reliable correction of INR.
Question 259
Topic: Infection, Pharmacology & VTE
A 60-year-old female is 4 days post-op from a total hip arthroplasty. She complains of sudden onset pleuritic chest pain, dyspnea, and tachycardia. Oxygen saturation is 88% on room air. What is the most appropriate initial diagnostic imaging study to evaluate her symptoms?
The clinical presentation is highly suspicious for a pulmonary embolism (PE). Computed tomography pulmonary angiography (CTPA) is the gold standard and most appropriate initial diagnostic imaging study for confirming a PE in this setting.
Question 260
Topic: Infection, Pharmacology & VTE
A 42-year-old male polytrauma patient sustains an unstable pelvic ring injury including a displaced Zone II sacral fracture. He has no intracranial hemorrhage or solid organ injury. What is the preferred initial pharmacologic VTE prophylaxis in this patient once he is hemodynamically stable?
Correct Answer & Explanation
. Low-molecular-weight heparin (LMWH)
Explanation
In high-risk orthopedic trauma patients with pelvic ring fractures, LMWH is the standard of care for VTE prophylaxis due to its superior efficacy in preventing DVT/PE compared to aspirin or unfractionated heparin.
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