04a: PE Flashcards
“Virchow’s triad” is a list of (X). What’s included?
X = major risk factors for PE
- Blood stasis
- Hypercoagulable state
- Trauma to vessel wall
State the sources of pulmonary emboli as well as the percent of emboli that come from each source.
- Femoral veins (50%)
- Iliac-pelvic veins (40%)
- Calf veins (under 10%)
- Upper extremity central veins (rare)
Use of indwelling catheters is increasing, causing an increase in (X) from upper extremity (Y) vessels.
X = PE Y = central veins
Patients with which characteristics have highest mortality after PE?
- RV thrombus and dysfunction
2. Hypotensive
Patients with which characteristics have highest mortality after PE?
- RV thrombus and dysfunction
2. Hypotensive
T/F: Most (nearly 99%) of PE patients that survive will completely recover and clot will dissolve.
True
How might Pulmonary HT occur following PE?
Clot doesn’t dissolve, gets lodged and permanently obstructs pulmonary vasculature
T/F: All causes of PE are symptomatic.
False - range from imperceptible (30% no symptoms) to disastrous
Physiological effects of PE depend most importantly on:
Underlying status of CV and resp systems
List the physiological (not clinical) respiratory changes you would expect as effect of PE.
- Increased dead-space, minute, and alveolar ventilation
2. Shunt
List the physiological (not clinical) cardiac changes you would expect as effect of PE.
- Arrhythmia (tachycardia, RBBB)
- Pulmonary HT and systemic hypotension
- Decrease CO
Aside from Resp and cardiac symptoms, which physiological manifestations in patient would make you suspicious of PE?
- Hypothermia
- Cyanosis
- Altered mental status
- Decreased urine output
Which clinical symptoms/signs in high-risk patient would make you suspect PE?
- Dyspnea and cough
- Pleuritic or substernal chest pain
- Apprehension/feel impending doom
- Symptoms at source (leg swelling)
T/F: 50% of patients with PE present with dyspnea.
False - over 80%
If PE results in infarction, what can you say about the clot?
Lodged in area with little collateral blood flow (ex: periphery of lung)
56 y.o. smoker comes in with dyspnea, wheezing, chest pain, and HR of 140. He also has fever of 100. Which parts of history/physical will make you less suspicious of PE?
Wheezing (rare in PE)
T/F: PE is the most frequent cause of in-hospital unexpected death.
True
A PE causes (X), which can then lead to hypoxemia via which ways?
X = dead space
- Atelectasis
- Shunt
(V/Q Mismatch)
Wells Criteria is used to classify patients as low/moderate/high risk of (X). How many points is each category?
X = PE
Low: under 2
Mod: 2-6
High: over 6
List the Wells Criteria and respective points for each risk factor.
- DVT signs (leg swelling/pain with palpation) - 3 pts
- Other diagnosis less likely than PE - 3 pts
- HR over 100 - 1.5 pts
- Immobilization over 3 days or surgery in past month - 1.5 pts
- Previous DVT/PE - 1.5 pts
- Hemoptysis - 1 pt
- Malignancy - 1 pt
T/F: Blood tests and ABGs are very sensitive tests for PE diagnosis.
False - blood tests are of very little value; ABG is very sensitive, though
Your patient may have a PE, so you order an ABG, a very (sensitive/specific) marker. You expect to see (X) results if PE present. (Y) will tell you that PE is very unlikely.
Sensitive (few false neg);
X = hypoxemia and hypocapnia Y = norma A-a gradient
D-dimer test is a very (sensitive/specific) test used for (X) diagnosis. It measures product of (Y). A negative test is (above/below) (Z) value.
Sensitive (95% neg predictive value); X = PE Y = fibrin degradation Below; Z = 500 mg/L
Which test is used in the ED to screen patients with suspected PE?
D-dimer
