Chapter 42- Pulmonary Thromboembolism

Question 1

Risk factors for PTE in human?

Answer 1

Previous venous thrombosis, immobility, age, obesity, central venous catheterization, congenital or acquired coagulopathies.

Question 2

Disease associated with PTE in dogs and cats: in-hospital risk factors?

Answer 2

Catheterization (central venous, dialysis), Immobility/Recumbency, Surgeries

Question 3

What are potent pulmonary vasoconstrictors related to the development of PTE?

Answer 3

thromboxane A2, serotonin, endothelin-1, prostaglandin F2alpha

Question 4

What are the physiologic consequences of PTE? (lung, heart, system??)

Answer 4

Pulmonary hypertension due to increased pulmonary vascular resistance and increased mean pulmonary arterial pressure.

Myocardial infarction and ischemia due to abrupt development of PH results in elevation of RV afterload, RV dilation and dysfunction- decrease coronary blood flow.

RV dilation- interventricular septal bulding and shifting into the LV (ventricular interdependence): This compromise CO and leads to systemic hypotension and cardiogenic shock

Question 5

T/F: Dogs with relative hypocoagulability are less likely to survive than those with hypercoagulable TEG tracings

Answer 5

True

Question 6

What is the Westermark sign?

Answer 6

Regional hypovolemia or hypovascularity: characterized by areas of hypolucency due to reduced blood flow distsal to the site of vascular occlusion.

Question 7

What happens to V/Q in patient with PTE?

Answer 7

VQ mistmach, high or infinite V/Q due to vascular occlusion or extremely low V/Q values in non-occluded region.

Question 8

What are common findings in ABG in dogs with PTE?

Answer 8

1. hypoxemia, 2. hypocabnia, 3. elevated A-a gradient, 4. decreased P/F ratio

Question 9

T/F: acute response to pressure overload on the RV leads to concentric RV dilation due to the high compliance of the RV.

Answer 9

False: Eccentric hypertrophy (Concentric hypertrophy in chronic cases)

Question 10

What are the findings in echo suggestive of PTE?

Answer 10

1. visualization of thrombi in RA/RV/MPA/Proximal pulmonary artery branches
2. eccentric RV dilation
3. underfilled LA and LV

Question 11

D-dimer is a specific marker of ______ following thrombosis

Answer 11

Fibrinolysis

Question 12

Troponin is as a marker of ____________.

Answer 12

myocardial injury

Question 13

NT-proBNP is secreted due to ____________.

Answer 13

Increased wall tension within the myocardium

Question 14

What type of vasopressors are suggested based on canine experimental studies?

Answer 14

NE may be used in hypotensive dogs due to acute PTE and dobutamine may be used in PTE dogs with evidence of RV dysfunction.