Pathophysiology
These three mechanisms predispose venous thrombosis
Virchow's triad: stasis, endothelial injury, hypercoagulability
Elevated ____ on labs is a cardiac biomarker that identifies RV strain in PE patients
BNP
The term ___ describes RV enlargement and/or failure resulting from primary disorder of the lung or pulmonary vasculature
Cor pulmonale
Primary prophylacitic treatment for PE is ___
Anticoagulation (warfarin, heparin)
The V/Q ratio is a measure of ____
Alveolar ventilation/perfusion
____ is the most common inherited thromophilia, and results in blood clots due to a point mutation leaving clotting factors resistant to breakdown.
Factor V Leiden
This bedside imaging modality assesses lower extremity veins for compressibility and thrombus, used to support diagnosis of PE
Doppler ultrasound
The classic EKG patterns associated with right heart strain from PE are ___
S1Q3T3 pattern, P Pulmonale (peak P waves)
____ therapy is utilized during acute onset PE that is causing hemodynamic instability
Tissue plasminogen activatory therapy
The normal overall V/Q ratio for the lungs at rest is ___
0.8
Most pulmonary emboli originate from thrombi in what location before traveling ot the pulmonary system?
Proximal deep veins of the lower extremities (femoral/iliac veins)
____lab detects ___ degradation products and is used in ruling out PE in low probability patients
D-Dimer test, fibrin
This cardiac arrest rhythm — organized electrical activity on the monitor without a palpable pulse — is a classic presentation of sudden cardiac arrest caused by massive PE.
What is pulseless electrical activity (PEA)?
The anticoagnulant fondaparinux is a synthetic heparin used to inhibit ____, and is contraindicated in patients with ____
Factor Xa, severe renal impairment (CrCl under 30ml/min)
A pathological airway obstruction resulting in perfusion without ventilation and a V/Q = 0 is called ___
a shunt
A ____ is a large PE that gets stuck in the ____ blocking blood flow to the lungs
Saddle embolism, pulmonary arteries
____ is a sensitive form of imaging that is the test of choice for identifiying PE
CT angiogram
____ is the loss of lung volume caused by deflation of alveoli and collapse of part of the lung, occuring in ~20% of PE cases
Atelectasis
The therapeutic INR range for a patient on warfarin is between ___. Increased intake of dietary ____ can destabilize INR control
2.0 - 3; Vitamin K (leafy greens)
___ zone in the lungs with the highest V/Q ratio, and ___ has the lowest ration
apex (highest), base (lowest)
_____ syndrome describes a hypercoagulable state associated with malignancy
Trousseau syndrome, due to tumor-derived tissue factor and cytokine release
This clinical decision scale weighs criteria to assess the probability of PE adn guide the appropriate next steps in testing and imaging
Well's Criteria for PE: signs and symptoms, HR > 100BPM, recent immobilization or surgery, prior DVT, hemoptysis, malignancy, if PE is most likely diagnosis
A patient with a massive PE presents in obstructive shock with hypotension, tachycardia, and jugular venous distension. Explain the underlying right-heart mechanism producing this triad.
What is acute right ventricular strain/failure — the abrupt rise in pulmonary vascular resistance backs up pressure into the systemic veins (JVD) while reducing RV output to the left heart, causing hypotension?
Explain why warfarin is bridged with a fast-acting anticoagulant rather tahn started alone
warfarin first depletes the short half-life vitamin K–dependent anticoagulant proteins C and S before it fully depletes the procoagulant factors II, VII, IX, and X — creating a transient hypercoagulable state (with risk of warfarin-induced skin necrosis)
In acute PE, ventilation of the affected lung segment will have a V/Q approaching ____, with the area called a ____
Infinity, Dead Space