Pulmonary Embolism and Deep Venous Thrombosis Flashcards
Where do most PE’s arise most commonly?
• why has there been an increase upper extremity DVTs?
Most Commonly:
• deep veins of the leg
*Upper extremity DVT’s have increased due to more central lines being placed
What is Virchow’s Triad for predisposition to clot formation?
- Stasis
- Hypercoagulability
- Endothelial Injury
What are 6 reasons that you may have a congenital predisposition to be hypercoagulable?
• Factor V Leiden Mutation
• Prothrombin G20210A mutation
• Protein C and Protein S deficiency
• Antithrombin III Deficiency
• Dysfibrinogenemia
• Homocystinemia
Factor V leiden mutations lead to a lack of control of factor V by protein C.
What are 5 reasons for having aquired hypercoagulability?
1. Estrogen Use
2. Hormonal changes of pregnancy
3. Malignancy - especially adenocarcinomas
4. Heparin Induced Thrombocytopenia
5. Nephrotic SYndrome
What are the 3 major determinants of your outcome after a PE?
- Size of the embolus
- Cardiopulmonary status/reserve - morbities here put you at a much elevated risk
- Neurohormonal Substaces
Describe the physiology leading to dyspnea and a low DLCO in a patient with a PE.
- *Dyspnea:**
1. Increased back pressure in pulmonary arteries
2. Edema and bronchoconstriction
3. J-receptors are tipped off leading to Hyperventilation - *Low DLCO:**
1. Perfusion to an entire part of the lung is lost so the amount of CO that will diffuse into the blood is minimal
What is the major compensatory mechanism for PE?
• how does this improve the patient’s condition?
- *Vasodilation of uninvolved vasculature
(a) Improves nature of V/Q relationship
(b) Decreases Pulmonary Vascular resistance**
**Overall, this leads to an improvement in Oxygenation
Patient may have a normal O2 saturation, but be tachypneic and tachycardic**
What are 5 clinical signs that you need to know for a PE?
• what will this patients vitals and PCO2/PO2 look like?
- *1. Dyspnea
2. Pleuritic Pain
3. Tachypnea
4. Tachycardia** - *5. Loud P2
- Increased RR, Increased HR
- Reduced CO2, Reduced O2**
What is the most common thing to see on the CXR of someone who has experienced a PE?
• Most of the time it will appear completely normal
What causes the abnormality pointed out in this CXR?
- Disc Atelectasis of this underperfused airway
- This is a great compensatory mechanism because you don’t ventilate this part of the lung that’s not being perfused
What is seen here?
Westermark’s Sign: on the left there is an absence of markings, while on the left it appears that the pulmonary vessels are distended
• when you see this you should consider pneumothorax as well, but in pneumothorax you would see the collapsed lung
What EKG findings are indicative of PE?
• how sensitive is this test?
NOT Sensitive at all, only 10% of PEs will have S1Q3T3
• S is enlarged in lead I
• Q is enlarged in lead III
• T is inverted in lead III
Lab Data for PEs:
• PaO2?
• PaCO2?
• A-a gradient?
• WBC?
• D-Dimer?
• BNP?
• Troponin?
• LDH?
• PaO2 - low
• PaCO2 - low
• A-a gradient - widened
• WBC - normal or modest elevation
• D-Dimer - WILL BE HIGH
• BNP - released from stressed ventricles
• Troponin - increased - heart ischemia
• LDH- elevated
How should you interpret information from a V/Q scan?
V/Q scan results should be considered in terms of clinical suspicion. Otherwise results from this aren’t very valuable.
Clot on CT
Clot on CT
Clot on CT
