Pulmonary Circulation Disorders Flashcards
The Pulmonary Circuit of the
cardiovascular system is
responsible for _____
oxygenating blood
Any condition that affects the blood
vessels along the route between the
heart and lungs can:
○ Change pulmonary arterial blood pressure.
○ Change pulmonary venous pressure.
○ Stress the heart and rest of the
cardiovascular system
Pulmonary Embolism
A Pulmonary Embolism (PE) is a mechanical obstruction of the pulmonary vasculature, usually from a blood clot from a Deep Vein Thrombosis (DVT)
Virchow’s Triad
○ Venous stasis
○ Vessel wall injury
○ Hypercoagulable state
PEs are also sometimes referred to as:
■ Pulmonary Thromboembolism
■ Venous Thromboembolism (VTE)
Risk Factors for a pulmonary embolism
○ Prior VTE
○ Thrombophilia
○ Surgery
○ Cancer
○ Pregnancy
○ Oral contraceptives
○ Immobilization
○ Trauma
○ Obesity
○ Central venous access
Inherited risk factors for a pulmonary embolism
Factor V Leiden
Prothrombin G20210A
Antithrombin deficiency
Protein C deficiency
Protein S deficiency
Are community or hospitalized patients at greater risk for a PE?
Hospitalized
____ is by far the most common cause of a PE.
DVT
Less common causes of PE:
○ Septic Embolism
○ Air Embolism
○ Fat Embolism
○ Amniotic Fluid Embolism
○ Intravascular Foreign Bodies
○ Tumor Embolism
25% occlusion by a PE may cause ____
increased pulmonary arterial
pressure and decrease in arterial oxygen tension
35%-40% occlusion with a PE may cause _____
increased right atrial pressure
PE signs and symptoms
○ Symptoms usually have rapid onset, but may occasionally
progress over several weeks.
○ Pay attention to onset
○ Classics presentation:
■ Dyspnea
■ Tachypnea
■ Tachycardia
■ Pleuritic chest pain
■ Cough
■ Fever
Diagnostic Approach for PE if high risk
● Get CT Angio or Transthoracic Echo right away
● If referred to cath lab, consider Pulmonary Angio if acute coronary syndrome is excluded
Diagnostic Approach for PE If hemodynamically stable:
■ Initial evaluation using the PERC Score
■ Then two main options for risk scoring-
● Revised Geneva Scoring System
● Wells Clinical Prediction Rule (more common)
Important Diagnostic Studies Used for PE
○ High-sensitivity D-Dimer
○ CT Pulmonary Angiography
○ Pulmonary Angiography
○ V-Q (Ventilation-Perfusion) Scan
○ Lower Extremity Venous Ultrasound
○ Echocardiogram
○ Chest X-ray- If patient is hypoxic and CXR is
normal then suspect a PE.
○ Electrocardiogram (EKG)
Considered the diagnostic study of choice for PE.
CT Pulmonary Angiogram
CT angio findings that are positive for PE:
● Images will be positive for filling
defects within the vasculature
V-Q Scan
● The Ventilation-Perfusion Scan is a nuclear medicine
imaging study (scintigraphy) that is a less sensitive/specific
test for PE that utilizes radioactive isotopes.
● Much less radiation exposure than CT Pulm Angio.
● Preferred imaging study in:
○ Young patients (esp female)
○ Pregnant patients
○ Patients with contrast allergies
○ Patients with severe renal failure
○ Patient with hyperproteinemia
Use of Lower Extremity Venous Ultrasound in PE diagnostics
○ LE compression ultrasonography may contribute to the
diagnosis of PE, but negative test may not exclude PE.