Pulmonary Embolism Flashcards
1
Q
What is a pulmonary embolism?
A
- thrombus in the pulmonary circuit (in an artery) that arises from an embolus
2
Q
What is the mortality rate of pulmonary embolism?
A
about 1/3 of patients die
3
Q
What causes a PE?
A
- DVT (source of the embolus: iliac, popliteal or femoral veins)
- other emboli: fat (from fracture), air (iatrogenic), amniotic fluid (particulate enters during labour)
4
Q
What is the pathology or a PE?
A
- DVT breaks off, becomes an embolus
- the embolus lodges in the arterial bed and causes impaired perfusion
- V/Q imbalance leads to hypoxemia (problem is perfusion)
- platelets degranulate, the mediators released cause bronchial and pulmonary artery constriction, causes hemodynamic instability
- there is reflexive bronchoconstriction
- there is a decrease in cardiac output
- there is a loss of surfactant (d/t decrease in blood supplying both fluid AND oxygen, damages cells)
- loss of surfactant leads to atelectasis
- right sided heart failure (because the right side is working hard to overcome the obstruction)
5
Q
What are the manifestations of a PE?
A
depends on size and site:
- chest pain (from ischemia)
- dyspnea (from hypoxemia)
- tachypnea (compensatory mechanism)
- tachycardia (compensatory mechanism)
6
Q
How is a pulmonary embolism diagnosed?
A
- history and presentation
- ABGs (will show hypoxemia)
- LDH3
- lung scan with 131 I-HSA
- CT chest
- pulmonary angiogram (invasive)
7
Q
What is LDH3?
A
lactate dehydrogenase, an enzyme found in increasing concentrations in lung tissue, when found in serum indicates lung damage
8
Q
What is 131 I-HSA?
A
human serum albumin marked with iodine 131, it is a radioisotope that will show on a scan and will indicate where the obstruction is
9
Q
How is a pulmonary embolus treated?
A
- stat treatment is important to improve the prognosis
- anticoagulants and antithrombolytics
- maintain cardio-pulmonary function (avoid shock)
- treat DVT if it is the cause
