Physiology
Movement of blood to and from the lungs
What is pulmonary perfusion?
Plug formation within vasculature caused by a thrombus (blood clot), tumor, air, fat, sepsis, etc.
What are emboli?
Multiple small thrombi, or singular large thrombi, in the pulmonary arteries
What is a pulmonary embolism?
Tachycardia, tachypnea, and hemoptysis
What are common signs and symptoms of PE?
Utilized to stratify patients into low, medium, or high risk, as well as guide appropriate diagnostic testing
What are the PERC (Pulmonary Embolism Rule-Out Criteria) and Wells scores?
Graphical representation depicting the affinity of hemoglobin to bind O2 in relation to the partial pressure of O2 in the blood
What is the oxygen-hemoglobin dissociation curve?
Most common venous thromboembolism (VTE)
What is a deep vein thrombosis (DVT)?
Alveoli get ventilated with fresh air, but are not getting perfused with blood
What is a ventilation perfusion mismatch (V/Q mismatch)?
Unilateral lower extremity edema
What are common signs and symptoms of DVT?
Tested if Wells score < 4. If (-), r/o PE. If elevated, imaging needed
What is D-dimer?
Vena cava → Right atrium → Right ventricle → Pulmonary arteries, which split before entering their respective lung
What is the pulmonary saddle?
Age ≥ 50, Hx PE/DVT, recent surgery or trauma, prolonged inactivity of skeletal muscle pump (long drives/flights), hormone use (eg. birth control)
What are risk factors for developing a PE?
Vasodilation of non-obstructed pulmonary arteries and increased ventilation rate
What are compensatory mechanisms?
Sudden death caused by large embolism at this location, which prohibits blood supply to both lungs
What is the pulmonary saddle?
Gold Standard Test, use if Wells score > 4
What is a CT pulmonary angiogram (chest CT with PE protocol)?
Thin membrane that covers each lung, contains visceral and parietal layers with thin layer of fluid in between
What is pleura?
Nickname used to refer to PEs due to their common misdiagnosis
What is "The Great Masquerader?"
Condition in which the visceral and parietal pleura swell and become inflamed, causing them to rub against each other
What is pleurisy?
Acute onset sharp chest pain that worsens with inhalation, and is exacerbated by deep inhalation and exhalation
What is pleuritic chest pain?
Alternative imaging modality that shows areas that are ventilated, but not perfused
What is a ventilation/perfusion (V/Q) scan?
A large ___ allows the lungs to break down tiny clots and prevent them from traveling elsewhere in the body
What is residual capacity?
Combination of venous stasis, hypercoagulation, or vascular wall endothelial injury that greatly increases risk of developing PE
What is Virchow's Triad?
Small opening between atrium, allows thrombus to move from R to L atrium, bypassing the lungs, and therefore get pumped out the L ventricle
What is an atrial septal defect?
HR ≥ 100 and O2 < 95%
What are the PERC score vital signs?
Most common EKG findings
What are sinus tachycardia and S1Q3T3?