VTE

Question 1

Why is hypoxemia in PE unpredictable?

Answer 1

If clot diverts bloodflow away from an area of the lung which normally sees low ventilations (low V/Q ratio), then hypoxemia may occur. If clot diverst bloodflow to areas of the lung that normally have a high ventilation (high V/Q ratio), then high PaO2 values may be observed.

Question 2

Who should get tPA for PE treatment?

Answer 2

Patients with:

cardiac arrest at any point

arterial hypotension fulfilling criteria for massive PE

resp. failure, evidenced by severe hypoxemia (pulse oximetry reading <90%) despite O2, together with evidence of increased WOB

evidence of right heart strain on echo or elevated troponin

Question 3

D-dimer levels in the respective trimesters of pregnancy are:

Answer 3

first trimester, 750 nanograms/mL

second trimester, 1000 nano- grams/mL

third trimester, 1250 nanograms/mL