Venous thromboembolic events Flashcards
A patient presents to the emergency department with leg pain in the left more than the right. The left calf is warm to touch. Their vital signs are as follows: HR 103, BP 127/86, O2 95% on RA. What is your initial recommendation?
A. Chest CT angiogram
B. Lower extremity ultrasound
C. Lower extremity CT scan
D. Chest radiography
B. Lower extremity ultrasound
Rationale:
The patient’s unilateral leg pain, warmth, and possible swelling, along with tachycardia (HR 103), are concerning for deep vein thrombosis (DVT). The initial diagnostic test of choice for suspected DVT is a lower extremity venous ultrasound with Doppler to assess for venous thrombosis and obstruction.
In a massive pulmonary embolism, which complication leads to rapid hemodynamic collapse?
A. Left atrial dilation
B. Right ventricular failure and shock
C. Chronic mild dyspnea
D. Intermittent palpitations
B. Right ventricular failure and shock
Rationale:
A massive pulmonary embolism (PE) causes acute right ventricular (RV) failure, leading to hemodynamic collapse due to increased pulmonary vascular resistance. The RV cannot effectively pump blood into the lungs, resulting in decreased cardiac output, systemic hypotension, and shock. This can rapidly progress to cardiac arrest if not treated immediately.
Which test is typically elevated in suspected acute VTE, aiding in deciding whether imaging is needed?
A. Hemoglobin
B. D-dimer
C. CK-MB
D. Lipase
B. D-dimer
Rationale:
D-dimer is a fibrin degradation product that is elevated in acute venous thromboembolism (VTE) due to clot breakdown. It is highly sensitive but not specific, meaning that while a normal D-dimer can rule out VTE in low-risk patients, an elevated D-dimer does not confirm VTE and requires further imaging (e.g., venous ultrasound for DVT or CT pulmonary angiography for PE)
- Which condition is most commonly associated with a prothrombotic state leading to VTE?
A. Hyperthyroidism
B. Factor V Leiden mutation
C. Hypotension
D. Iron deficiency anemia
o Answer: B
o Rationale: Inherited thrombophilias such as Factor V Leiden mutation increase the risk of VTE by promoting a hypercoagulable state.
- What is the approximate annual number of deaths related to pulmonary embolism in the United States?
A. 10,000–20,000
B. 30,000–50,000
C. 100,000–180,000
D. Over 300,000
o Answer: C
o Rationale: Pulmonary embolism is responsible for approximately 100,000–180,000 deaths per year in the United States.
- Which of the following is a common modifiable risk factor for VTE?
A. Genetic predisposition
B. Immobilization
C. Gender
D. Age over 80
o Answer: B
o Rationale: Immobilization (e.g., after surgery or during long flights) is a modifiable risk factor that promotes venous stasis.
- Which of the following is a key clinical feature of deep vein thrombosis (DVT) in the lower extremity?
A. Intermittent claudication
B. Calf swelling, tenderness, and redness
C. Chronic leg fatigue without pain
D. Persistent fever with rash
Answer: B
o Rationale: DVT in the leg typically presents with unilateral swelling, tenderness, and erythema.
- Which laboratory test is most sensitive for detecting VTE but lacks specificity?
A. Troponin
B. D-dimer assay
C. C-reactive protein
D. Prothrombin time
o Answer: B
o Rationale: The D-dimer test is very sensitive for fibrin degradation products but is nonspecific, as it can be elevated in many conditions.
- A patient with DVT is at risk for developing which life‐threatening complication?
A. Myocardial infarction
B. Pulmonary embolism
C. Stroke
D. Aortic dissection
o Answer: B
o Rationale: Clot fragments can embolize from the deep veins to the lungs, causing pulmonary embolism—a potentially fatal event.
- In the diagnostic workup of suspected pulmonary embolism (PE), which imaging modality is considered first-line?
A. Ventilation–perfusion (V/Q) scan
B. Chest X-ray
C. CT pulmonary angiography (CTPA)
D. MRI of the chest.
o Answer: C
o Rationale: CT pulmonary angiography is the imaging modality of choice for diagnosing PE in most patients
- A normal D-dimer test in a patient with low clinical probability effectively:
A. Confirms VTE
B. Rules out VTE
C. Indicates a need for immediate anticoagulation
D. Suggests the presence of a thrombus
o Answer: B
o Rationale: In patients with low pretest probability, a normal D-dimer can rule out VTE and avoid further imaging.
- Which clinical decision rule is commonly used to assess the probability of PE?
A. CHADS2 score
B. Wells criteria
C. TIMI score
D. Glasgow Coma Scale
o Answer: B
o Rationale: The Wells criteria are widely used to assess pretest probability for pulmonary embolism.
- Which of the following signs on physical examination is a “red flag” for acute limb ischemia due to DVT complications?
A. Mild calf tenderness
B. Sudden loss of distal pulses
C. Gradual onset of leg cramping
D. Bilateral ankle edema
o Answer: B
o Rationale: Sudden loss of pulses suggests acute arterial occlusion from an embolus, a life-threatening scenario
- In patients with suspected VTE, what does the presence of a patent foramen ovale (PFO) imply?
A. Reduced risk of embolization
B. Potential for paradoxical embolism
C. No clinical significance
D. Increased risk for DVT only
o Answer: B
o Rationale: A PFO can allow a venous thrombus to bypass the pulmonary circulation and cause systemic emboli (paradoxical embolism).
- Which risk factor is common to both VTE and atherosclerotic cardiovascular disease?
A. Hypercoagulability due to Factor V Leiden
B. Inflammation from conditions like rheumatoid arthritis
C. Chronic obstructive pulmonary disease
D. Anemia
o Answer: B
o Rationale: Systemic inflammation contributes to both atherosclerosis and hypercoagulability, increasing the risk of VTE and cardiovascular events.
- Which of the following treatments is considered first-line for acute DVT?
A. Thrombolytic therapy
B. Anticoagulation with low-molecular-weight heparin (LMWH)
C. Immediate surgical thrombectomy
D. High-dose aspirin alone
o Answer: B
o Rationale: Anticoagulation with LMWH is the standard initial treatment for DVT to prevent clot propagation and embolization.
- Massive pulmonary embolism is defined by which of the following features?
A. Minimal symptoms and normal hemodynamics
B. Hemodynamic instability, including systemic hypotension
C. Only imaging findings without clinical signs
D. Mild dyspnea with tachycardia
o Answer: B
o Rationale: Massive PE is characterized by hemodynamic instability, such as hypotension and shock, and is life-threatening.
- A “submassive” pulmonary embolism is characterized by:
A. Normal right ventricular function
B. Right ventricular dysfunction despite normal blood pressure
C. Severe hypotension and cardiogenic shock
D. Complete resolution of symptoms
o Answer: B
o Rationale: Submassive PE involves right ventricular dysfunction without systemic hypotension, but patients remain at risk for deterioration.
- In patients with contraindications to anticoagulation, what prophylactic measure may be used to prevent PE?
A. High-dose statins
B. Inferior vena cava (IVC) filter placement
C. Beta-blocker therapy
D. Compression stockings only
o Answer: B
o Rationale: IVC filters are indicated when anticoagulation is contraindicated to prevent thrombus migration to the pulmonary circulation.
- Which of the following represents an iatrogenic harm (“what will harm your patient”) in VTE management?
A. Appropriate use of anticoagulation
B. Under-dosing of heparin resulting in subtherapeutic anticoagulation
C. Early mobilization
D. Use of compression devices in high-risk patients
o Answer: B
o Rationale: Under-dosing heparin may fail to prevent clot propagation, leading to further embolization and harm.
- What is the main goal of initial management in patients with massive pulmonary embolism?
A. Rapidly reduce blood pressure
B. Restore pulmonary blood flow and support hemodynamics
C. Lower cholesterol levels
D. Increase heart rate
o Answer: B
o Rationale: In massive PE, the priority is to rapidly restore blood flow (often via thrombolysis or embolectomy) and stabilize the patient hemodynamically.
- Which thrombolytic agent is commonly used in the treatment of massive pulmonary embolism?
A. Streptokinase
B. Alteplase
C. Tenecteplase
D. Both B and C
o Answer: D
o Rationale: Both alteplase and tenecteplase are used as thrombolytic agents in massive PE to dissolve clots quickly.
- In the setting of VTE, what does an elevated D-dimer level indicate?
A. Specific localization of a clot
B. Active clot formation and breakdown
C. Normal physiology
D. A false-negative result
o Answer: B
o Rationale: Elevated D-dimer levels indicate fibrinolysis (clot breakdown) but do not specify the clot’s location.
- Which clinical presentation is most common (“what is really common”) in low-risk pulmonary embolism?
A. Sudden collapse and shock
B. Mild dyspnea with chest discomfort
C. Syncope and cyanosis
D. Severe hypotension
o Answer: B
o Rationale: Most PEs (65%–75%) are low risk and present with mild symptoms like dyspnea and chest discomfort.
- What is the typical role of cardiac biomarkers in the evaluation of pulmonary embolism?
A. To diagnose myocardial infarction exclusively
B. To assess right ventricular strain/dysfunction in PE
C. To measure left ventricular ejection fraction
D. To guide anticoagulation dosage
o Answer: B
o Rationale: Elevated cardiac biomarkers (troponin, BNP) in PE suggest right ventricular strain and can help risk stratify patients.
- Which imaging study is considered the gold standard for diagnosing DVT in the extremities?
A. Venous ultrasound
B. CT angiography
C. MRI
D. X-ray
o Answer: A
o Rationale: Venous ultrasound is the first-line, noninvasive diagnostic tool for detecting DVT.
- A patient with suspected PE and high clinical probability should proceed directly to which test?
A. D-dimer assay
B. CT pulmonary angiography
C. V/Q scan
D. Plain chest X-ray
o Answer: B
o Rationale: In patients with high pretest
- Which of the following is a major complication (“what will kill your patient”) of untreated or suboptimally treated PE?
A. Chronic cough
B. Right ventricular failure and cardiogenic shock
C. Mild tachypnea
D. Low-grade fever
Answer: B
o Rationale: Untreated PE can lead to severe right ventricular overload, resulting in shock and death.
- Which patient population is at an increased risk for VTE due to an underlying inflammatory condition?
A. Patients with osteoarthritis
B. Patients with inflammatory bowel disease
C. Patients with seasonal allergies
D. Patients with tension headaches
o Answer: B
o Rationale: Inflammatory bowel disease is associated with increased inflammation and hypercoagulability, raising VTE risk.
- Why is obesity a risk factor for venous thromboembolic events?
A. It directly damages the endothelial lining
B. It promotes venous stasis and systemic inflammation
C. It increases platelet production exclusively
D. It has no impact on VTE risk
o Answer: B
o Rationale: Obesity contributes to venous stasis, systemic inflammation, and hypercoagulability, all of which predispose to VTE.
- In VTE management, which type of anticoagulant is now generally preferred for long-term therapy?
A. Unfractionated heparin
B. Vitamin K antagonists (warfarin)
C. Direct oral anticoagulants (DOACs)
D. Antiplatelet agents alone
o Answer: C
o Rationale: DOACs (e.g., rivaroxaban, apixaban) are often preferred over warfarin due to ease of use, fewer monitoring requirements, and similar efficacy.
- In the acute setting of VTE, which parenteral agent may be used as a bridge to long-term oral anticoagulation?
A. Low-molecular-weight heparin (LMWH)
B. Oral aspirin
C. Clopidogrel
D. Statins
o Answer: A
o Rationale: LMWH is commonly used initially while transitioning patients to long-term oral anticoagulation.
- What is a potential iatrogenic harm (“what will harm your patient”) when managing VTE?
A. Over-anticoagulation leading to bleeding complications
B. Early mobilization
C. Use of compression stockings
D. Routine D-dimer testing
o Answer: A
o Rationale: Excessive anticoagulation increases bleeding risk and can harm the patient if not carefully managed.
- Which of the following clinical signs is common (“what is really common”) in patients with DVT?
A. Bilateral leg edema
B. Unilateral leg swelling and pain
C. Bilateral calf cramps during sleep
D. Cold intolerance in the extremities
o Answer: B
o Rationale: Unilateral leg swelling and pain are classic presentations of DVT.
- What role does an inferior vena cava (IVC) filter play in the management of VTE?
A. It dissolves clots in the deep veins
B. It prevents clots from traveling to the lungs
C. It is used as first-line therapy for DVT
D. It reduces the need for anticoagulation
o Answer: B
o Rationale: IVC filters act as a mechanical barrier to prevent embolization of clots from the lower extremities to the pulmonary circulation.
- Which imaging modality is especially useful in patients with contraindications to CT contrast for diagnosing PE?
A. Ventilation–perfusion (V/Q) scan
B. Chest X-ray
C. PET scan
D. Echocardiogram
o Answer: A
o Rationale: A V/Q scan is an alternative imaging modality for diagnosing PE when contrast CT is contraindicated.
- Which of the following best describes ventilation–perfusion mismatch in the setting of PE?
A. Decreased ventilation and increased perfusion
B. Increased ventilation with decreased perfusion in affected lung segments
C. Uniform ventilation and perfusion throughout the lung
D. Increased perfusion in areas with normal ventilation
o Answer: B
o Rationale: PE causes obstruction of blood flow, resulting in areas with normal ventilation but reduced perfusion, creating a V/Q mismatch.
- Which of the following best describes the mechanism of hypoxemia in pulmonary embolism?
A. Pure ventilation failure
B. Shunting and increased physiologic dead space
C. Primary alveolar hypoventilation
D. Diffusion limitation only
o Answer: B
o Rationale: PE leads to increased dead space and shunting (due to ventilation-perfusion mismatch), resulting in hypoxemia.
- In patients with suspected VTE, which factor would prompt you to skip D-dimer testing and proceed directly to imaging?
A. Low Wells score
B. High clinical probability based on risk factors and symptoms
C. Recent surgery
D. History of asthma
o Answer: B
o Rationale: In patients with a high pretest probability for VTE, imaging is indicated without D-dimer testing.
- What is the significance of an elevated alveolar–arterial (A–a) gradient in the context of PE?
A. It confirms the diagnosis of DVT
B. It indicates impaired gas exchange due to vascular obstruction
C. It is specific for heart failure
D. It rules out pulmonary embolism
o Answer: B
o Rationale: An elevated A–a gradient reflects impaired oxygen exchange, which is common in PE due to ventilation-perfusion mismatch
- Which patient group is at higher risk for VTE due to malignancy?
A. Patients with skin cancer only
B. Patients with active or advanced cancer
C. Patients with benign tumors
D. Patients with no history of cancer
o Answer: B
o Rationale: Active or advanced malignancy is a well-known risk factor for VTE because of tumor-related procoagulant factors.
- What is the most common long-term complication of VTE if not properly managed?
A. Chronic venous insufficiency and post-thrombotic syndrome
B. Immediate myocardial infarction
C. Pulmonary fibrosis
D. Acute renal failure
o Answer: A
o Rationale: Post-thrombotic syndrome and chronic venous insufficiency are common long-term sequelae of untreated or inadequately managed VTE.
- Which of the following statements is true regarding the relationship between VTE and cardiovascular disease?
A. VTE decreases the risk of myocardial infarction
B. Patients with VTE have an increased risk of subsequent cardiovascular events
C. VTE is unrelated to systemic atherosclerosis
D. Only arterial thrombosis is linked with cardiovascular risk
o Answer: B
o Rationale: VTE is associated with an increased risk of cardiovascular events, possibly due to shared inflammatory and prothrombotic pathways.
- Which of the following is a common precipitating factor for VTE in hospitalized patients?
A. Prolonged immobilization
B. Excessive fluid intake
C. High levels of physical activity
D. Routine antibiotic use
o Answer: A
o Rationale: Immobilization is a major precipitant of VTE in hospitalized patients, as it promotes venous stasis.
- What is a key component in the nonpharmacologic prevention of VTE in hospitalized patients?
A. Early ambulation and intermittent pneumatic compression devices
B. Complete bed rest
C. High-dose vitamin C supplementation
D. Prolonged use of sedatives
o Answer: A
o Rationale: Early mobilization and mechanical prophylaxis (compression devices) reduce venous stasis and lower VTE risk.
- When evaluating a patient for PE, which physical finding might indicate right ventricular strain?
A. Clear lung fields on auscultation
B. Elevated jugular venous pressure and a loud P2 component
C. Bradycardia with regular rhythm
D. Normal blood pressure
o Answer: B
o Rationale: Signs of right ventricular strain, such as elevated JVP and a loud P2, suggest increased pulmonary pressures from PE.
- Which of the following best describes a “massive” pulmonary embolism?
A. PE with normal blood pressure and minimal symptoms
B. PE associated with hemodynamic instability, including hypotension and shock
C. PE confined to segmental arteries with no RV dysfunction
D. PE that is asymptomatic on presentation
o Answer: B
o Rationale: Massive PE is defined by hemodynamic instability (e.g., hypotension, shock) and poses an immediate threat to life.
- What is the primary goal of initial therapy in a patient with acute VTE?
A. To reverse the thrombus completely within minutes
B. To prevent clot propagation and embolization
C. To increase the patient’s heart rate
D. To induce hypercoagulability for wound healing
o Answer: B
o Rationale: The immediate therapeutic goal is to prevent further clot extension and embolization through anticoagulation.
- Which of the following complications (“what will harm your patient”) may result from inappropriate anticoagulant dosing?
A. Reduced risk of bleeding
B. Over-anticoagulation causing hemorrhage or under-anticoagulation causing recurrent thrombosis
C. Improved clot stability
D. Enhanced exercise tolerance
o Answer: B
o Rationale: Incorrect dosing can lead to bleeding complications if over-anticoagulated or recurrent VTE if under-anticoagulated.
- In patients with VTE, why might cardiac biomarkers be elevated?
A. Due to direct myocardial infarction
B. Secondary to right ventricular strain from pulmonary embolism
C. Because of systemic infection only
D. They are not typically elevated in VTE
o Answer: B
o Rationale: Cardiac biomarkers (e.g., troponin, BNP) may rise due to right ventricular strain caused by increased pulmonary arterial pressures in PE.
- Which of the following is a common pitfall in the transition of care for patients with VTE?
A. Timely follow-up with outpatient anticoagulation monitoring
B. Inadequate patient education about medication adherence and warning signs
C. Early mobilization in the hospital
D. Routine D-dimer testing after discharge
o Answer: B
o Rationale: Poor patient education and inadequate follow-up can lead to nonadherence, increasing the risk of recurrence and complications.
- Which statement best summarizes the critical management principles for venous thromboembolic events?
A. Rapid diagnosis using clinical probability and imaging, prompt initiation of appropriate anticoagulation (or thrombolysis in massive PE), and aggressive risk factor modification and follow-up
B. Sole reliance on D-dimer testing for diagnosis
C. Immediate surgical intervention for all patients
D. Avoidance of all physical activity indefinitely
.
o Answer: A
o Rationale: Effective VTE management includes timely diagnosis, risk stratification, initiation of anticoagulation (or thrombolysis in high-risk cases), and addressing underlying risk factors with proper follow-up
- Which inherited thrombophilia is most commonly associated with VTE?
A. Protein C deficiency
B. Antithrombin deficiency
C. Factor V Leiden mutation
D. Lupus anticoagulant
o Answer: C
o Rationale: Factor V Leiden is the most common inherited thrombophilia and is frequently associated with VTE.
- In a patient with suspected pulmonary embolism and moderate clinical probability, which step should be taken next?
A. Directly perform a CT pulmonary angiography
B. Order a D-dimer assay and proceed based on the result
C. Immediately start thrombolytic therapy
D. Schedule an echocardiogram
o Answer: B
o Rationale: In moderate-risk patients, a D-dimer test is used to help rule out PE. A negative result can avoid unnecessary imaging.
- What is the main reason for increased VTE risk in patients with cancer?
A. Increased physical activity
B. Tumor cells releasing procoagulant factors
C. Decreased body weight
D. Enhanced immune surveillance
o Answer: B
o Rationale: Cancer cells secrete substances that promote coagulation, significantly increasing the risk of VTE.
- Which clinical feature is most indicative of a submassive PE?
A. Severe hypotension
B. Right ventricular dysfunction on imaging without systemic hypotension
C. Normal cardiac biomarkers
D. Absence of dyspnea
o Answer: B
o Rationale: Submassive PE is characterized by RV dysfunction (e.g., on echocardiogram) without overt hemodynamic collapse.
- What is the most common long-term complication after an episode of DVT?
A. Recurrent myocardial infarction
B. Post-thrombotic syndrome
C. Stroke
D. Aortic aneurysm
o Answer: B
o Rationale: Post-thrombotic syndrome, including chronic leg pain, swelling, and skin changes, is a common sequelae of DVT.
- For patients with VTE, which direct oral anticoagulant (DOAC) is typically initiated without a heparin bridge?
A. Dabigatran
B. Rivaroxaban
C. Edoxaban
D. Warfarin
o Answer: B
o Rationale: Rivaroxaban can generally be started without initial heparin bridging, unlike dabigatran or edoxaban.
- Which of the following best explains the mechanism behind the elevated A–a gradient in pulmonary embolism?
A. Increased ventilation leading to hyperoxia
B. Impaired pulmonary blood flow causing ventilation-perfusion mismatch
C. Enhanced diffusion capacity of the alveoli
D. Reduced oxygen consumption in peripheral tissues.
o Answer: B
o Rationale: PE causes a ventilation-perfusion mismatch, leading to an elevated A–a gradient due to impaired oxygen transfer
- Which of the following is a common pitfall (“what will harm your patient”) in the management of PE?
A. Over-reliance on clinical decision rules without confirming imaging
B. Use of direct oral anticoagulants when contraindicated
C. Routine use of compression stockings
D. Early mobilization in stable patients
o Answer: A
o Rationale: Sole reliance on clinical decision rules without confirmatory imaging can lead to misdiagnosis or missed PE, thereby harming the patient.
- Which risk factor is considered non-modifiable for VTE?
A. Smoking
B. Obesity
C. Age
D. Immobility
o Answer: C
o Rationale: Age is non-modifiable; however, smoking, obesity, and immobility are modifiable risk factors.
- What is the primary therapeutic mechanism of low-molecular-weight heparin (LMWH) in VTE management?
A. Inhibiting vitamin K-dependent clotting factors
B. Activating antithrombin, thereby inhibiting factor Xa
C. Directly dissolving clots
D. Blocking platelet aggregation
o Answer: B
o Rationale: LMWH primarily works by activating antithrombin, which then inhibits factor Xa (and to a lesser extent, thrombin).
- In patients with submassive PE, which additional therapy might be considered if there is evidence of worsening right ventricular function?
A. High-dose aspirin
B. Catheter-directed thrombolysis
C. Routine use of beta-blockers
D. Insertion of an IVC filter
o Answer: B
o Rationale: In submassive PE with worsening RV dysfunction, catheter-directed thrombolysis may be indicated to improve outcomes.
- Which clinical sign is most indicative of right ventricular strain in the setting of PE?
A. Bradycardia
B. Elevated jugular venous pressure
C. Warm extremities
D. Clear lung auscultation.
o Answer: B
o Rationale: Elevated jugular venous pressure suggests increased RV pressures and strain from a PE
- A patient with a history of recent surgery and prolonged immobilization presents with sudden dyspnea and pleuritic chest pain. Which is the most likely diagnosis?
A. Pneumonia
B. Pulmonary embolism
C. Asthma exacerbation
D. Chronic obstructive pulmonary disease
o Answer: B
o Rationale: The history of recent surgery and immobility, along with sudden dyspnea and chest pain, is highly suggestive of a PE.
- What is the role of intermittent pneumatic compression devices in VTE prevention?
A. They dissolve existing clots
B. They reduce venous stasis by enhancing blood flow in the lower extremities
C. They increase coagulation factors
D. They serve as an alternative to thrombolytic therapy
o Answer: B
o Rationale: Pneumatic compression devices help prevent VTE by mechanically promoting venous return and reducing stasis.
- Which of the following best summarizes the importance of early mobilization in hospitalized patients at risk for VTE?
A. It improves muscle strength but has no effect on clot prevention
B. It reduces venous stasis and helps lower the risk of clot formation
C. It is contraindicated in patients with a high risk of bleeding
D. It only benefits patients with chronic venous insufficiency
o Answer: B
o Rationale: Early mobilization is crucial in reducing venous stasis, thereby decreasing the risk of VTE in hospitalized patients.
o Answer: B
o Rationale: Early mobilization is crucial in reducing venous stasis, thereby decreasing the risk of VTE in hospitalized patients.
