Thirty Flashcards
What are the risk factors for PE?
Hip or leg fracture
Hip or Knee replacement
Malignancy
Previous DVT or PE
What is the cardiac pathophys in PE?
PE increases PVR which results in increased RV wall tension and increased RV dilatation and hypokinesis. RV dilatation and hypokinesis leads to septal deviation and decreased RV CO which leads to decreased preload which leads to systemic hypotension which could lead to decreased Coronary perfusion and can contribute to ischemia. RV wall tension leads to increased O2 demand. It can also lead to decreased coronary perfusion. Both of these contribute to myocardial ischemia and infarction.
What are the cardiovascular effects in the pathophys of PE?
Obstructive Shock
Pulmonary vasculature constriction (5-HT and TXA2)
What is the respiratory pathophys of PE?
Increased dead space, hypoxemia, decreased CO2 (tachypnea), PFO (right to left shunt), pulmonary infarction
What is the spectrum of presentations in PE? What are some signs and symptoms that point to PE? How can these lead to a diagnosis of PE?
The patient could be in shock or could be asymptomatic.
Symptoms: syncope, near syncope, lightheadedness, palpitations, chest pain, hemoptysis, cough, dyspnea, calf or thigh pain,
Signs: Tachypnea, tachycardia, crackles, decr. breath sounds,
The wells score combines signs, symptoms, and risk factors to give an overall likelihood of PE
How are D-dimers used in diagnosis of PE? What is BNP/how is it used in diagnosis of PE? What about troponin? What will blood gases tell you ?
By ELISA, a level of less than 500 ng/mL has a high negative predictive value for PE.
When Brain natriuretic peptide is elvated, it a marker of ventricular stretch
Troponin is a marker of myocyte death which might happen in RV overload.
They can show if the pt. is hypoxemic.
What does the ECG show in PE? How useful is it?
It most often will show sinus tach with non specific ST and T wave changes. It might include an S1, Q3, T3 pattern (Deep S in lead 1, Q wave in lead 3 and inverted T wave in lead 3)
It is neither specific nor sensitive for PE
What findings might be found on a chest radiograph in PE? What will the corresponding findings be on CT?
Westermark sign-Asymmetrical darkening due to lack of perfusion.
Hampton Hump-Pleural based wedge shaped opacity due to infarction.
On CT, you will see filling defects.
What are the pros and cons of CT angiography in diagnosing PE?
It allows you to view the vessels and see if they’re blocked. You can also see any other parenchymal abnormalities. You can see the relative sizes of the ventricles.
However, it requires contrast which can’t be used if a pt. has an allergy or renal dysfunction (elevated creatinine). It also requires more radiation. It can also miss subsegmental PE.
What is a V/Q scan? How is it useful in diagnosing PE?
Ventilation perfusion scan. Normal results are V/Q matching. In PE, there will be a lack of perfusion.
Pts. with a high clinical probability of PE and a high probability V/Q scan have a 95% likelihood of PE
Pts with a low clinical probability of PE and a low prob. V/Q scan had a 4% likelihood of PE
A normal V/Q scan virtually excludes the likelihood of PE
What is CUS? What does it show? When is it used? How is it done?
An ultrasound is used to visualize the deep veins of the leg. They then are compressed. If they are unable to be compressed, they have a thrombus.
This is an important test when CT angiography can’t be performed.
What are the goals of PE management? What are the treatment options?
– ↓ Mortality – Stabilize the patient • Improve gas exchange • Circulatory abnormalities – Prevent extension – Prevent recurrence – Perform risk stratification • Echo, Troponin, BNP
• Anticoagulation – Prevents recurrence (25% VS no therapy) – Anticoagulation decreases mortality (30% to 3-5%) • IVC Filter • Fibrinolytic therapy • Catheter-directed therapy • Surgical embolectomy
What is considered a massive PE? A submassive PE? A Low risk?
– Massive PE
• Acute PE with sustained hypotension
• SBP 1, ↑ BNP, ↑ troponin
– Low Risk
• Normal BP, normal BNP, normal troponin, normal RV:LV ratio
What drugs should be used in the initial treatment of PE? Continued treatment? Long term?
Inititally:
LMWH/UFH Fondaparinux Warfarin Thrombolysis Rivoroxaban
Continued: Warfarin LMWH Dabigatran Rivoroxaban
Further:
Warfarin
Rivoroxaban
Dabigatran
What advantages does LMWH have over UFH?
- LMWH
- 1mg/kg q12º or 1.5 mg/kg once daily
• Advantage over UFH
– Convenient & fixed dosing
– Laboratory monitoring is not necessary
– Less incidence of thrombocytopenia
