Case

a) Chest xray should be ordered if the PERC tool is zero (d-dimer not even indicated) and you want to workup the patient’s symptoms of dyspnea.

The PERC (PE rule-out criteria) tool was designed to help guide clinicians in identifying low-risk patients (patients in whom the physician has a genuine concern about PE and whose initial risk stratification identifies them as being low risk). Should decrease the use of d-dimer testing.

	YES	NO
Age< 50	0	1
Initial HR <100 bpm	0	1
Initial O2 sat >94% on RA	0	1
No unilateral leg swelling	0	1
No hemoptysis	0	1
No surgery or trauma within 4 weeks	0	1
No hx of VTE	0	1
No estrogen use	0	1

Pretest probability with score of 0 is <1%

b) D-dimer would be checked if the pre-test probability is intermediate or if the pretest prob is low but the PERC is +. Remember to age adjust the d-dimer (500 + ((age-50) * 10) is cutoff for normal) if the patient is older than 50.

c) CT-PE protocol would be appropriate for our patient (high risk) or intermediate risk with a + d-dimer

i.CTA is very specific for PE (80-97%) but sensitivity can vary (53-100%).

ii.The primary limitation of CTA is that it can miss distal emboli (but clinical significance of peripheral clots is unknown).

iii.Therefore, if CTA is negative or non-diagnostic for PE, think of your pre-test probability.

iv.If PTP is high, get an additional study to rule out VTE such as LE Doppler or a VQ scan

d) LE Doppler would be appropriate if the patient is having signs or sx of a DVT. If this is positive, you will treat with anticoagulation and avoid any additional imaging.

e) VQ scan is appropriate for a high risk or intermediate risk with a + d-dimer who has a contraindication to CT (history of reactions to contrast agents, pregnancy, radioactive iodine treatment for thyroid disease, metformin use, and chronic or acutely worsening renal disease)

f) If pt is too hemodynamically unstable for CTA or if CTA is not available, start anticoagulation and get TTE to look for RV dysfunction or TEE to look for emboli in the main pulmonary arteries.

Clinical symptoms of DVT (leg swelling, pain with palpation)	3.0
Other diagnosis less likely than pulmonary embolism	3.0
Heart rate >100	1.5
Immobilization (>3 days) or surgery in the previous four weeks	1.5
Previous DVT/PE	1.5
Hemoptysis	1.0
Malignancy	1.0

Factor	Preferred Anticoagulant
Cancer	LMWH
Once daily oral therapy preferred	Rivaroxaban; edoxaban; VKA
Liver disease and coagulopathy	LMWH	NOACs contraindicated if INR raised because of liver disease; VKA difficult to control and INR may not reflect antithrombotic effect.
Renal disease and creatinine clearance <30 mL/min	VKA	NOACs and LMWH contraindicated with severe renal impairment. Dosing of NOACs with levels of renal impairment differ with the NOAC and among jurisdictions.
Coronary artery disease	VKA, rivaroxaban, apixaban, edoxaban	Coronary artery events appear to occur more often with dabigatran than with VKA.
Dyspepsia or history of GI bleeding	VKA, apixaban	Dabigatran increased dyspepsia. Dabigatran, rivaroxaban, and edoxaban may be associated with more GI bleeding than VKA.
Poor compliance	VKA	INR monitoring can help to detect problems. However, some patients may be more compliant with a NOAC because it is less complex.
Thrombolytic therapy use	UFH infusion
Reversal agent needed	VKA, UFH
Pregnancy or pregnancy risk	LMWH

	Risk of recurrence after 1 year	Risk of recurrence after 5 years	Recommended duration of anticoagulation
VTE provoked by surgery:	1%	3%	3-6 months
VTE provoked by nonsurgical reversible factor (estrogen, pregnancy, leg injury, flight >8hrs):	5%	15%	3-6 months
Unprovoked VTE	10%	30%	If low/mod bleeding risk, indefinite ** If high bleeding risk: 3 months
Provoked VTE with persistent risk factor (antiphospholipid syndrome or other inherited thrombophilias)			Indefinite
VTE in setting of cancer	15% annual risk		Lifelong
Unprovoked isolated distal DVT			Serial U/S or 3 months of a/c if risk factors for extension of clot

BP 140/85, HR 100, RR, 30, O2 sat 92% on room air, mild respiratory distress. Saddle embolus found on CTA chest.	C
BP 70/45, HR 140, RR 32, O2 sat 90% on NRB. PE noted in subsegmental branch of pulmonary artery on right	A
BP 70/45, HR 140, RR 32, O2 90% on NRB. PE noted in subsegmental branch of pulmonary artery on right. Hx of multiple GI bleeds requiring ICU stay, most recently 2 weeks ago.	B
BP 120/80, HR 90, RR 25, O2 93% on RA. Multiple PEs noted bilaterally on CT. Troponin +, BNP elevated, right heart strain on echo.	C
BP 128/70, HR 95, RR 22, O2 92% on RA on admission. Large PE in R main pulmonary artery. Patient started on lovenox and admitted. On hospital day #2, patient is more hypoxic with BP now 100/70, HR 110, RR 30 and O2 sat 92% on NRB.	A