1. DIEN VU
Pulmonary Embolism
Definition:PulmonaryEmbolism(PE) is obstruction ofpulmonaryarteryor its branches by material (thrombus, tumor, etc) that originated
elsewhere in body. There are 2 types of PE:
1) Massive PE, or called Hemodynamically Unstable (SBP < 90 mmHg for > 15 minutes OR hypotension/shock requiringvasopressors).
 Note:Not all patients withmassive PE develophypotension.
2) Submassive PE, or called Hemodynamically stable (not meet the definition ofmassive PE)
Pathology:Most thrombi develop at sites of decreased flow inthe lower extremityveins, such as valve cusps or bifurcations. Once thrombus
lodges inthe lung, a series ofpathophysiologic response canoccur:
 PulmonaryInfarction(chest pain, hemoptysis presumedfrom anintense inflammatory)
 Abnormal gas exchange due to blockage maycause hypoxia, hypocapnia, andalkalosis.
 Cardiovascular compromise. Diminishedstroke volume andcardiac output, resultinghypotension.
Clinical presentation: dyspnea, cough, SOB. Manypatients including large PE are asymptomatic or have mild/nonspecific symptoms.
Risk Factors: obesityBMI > 29, heavysmoking > 25 cigarettes per day, hypertension.
Diagnosis/ Laboratory indicators: definitive imaging (CT scan, ventilationperfusionscanning, etc)
Treatment:
Suspected Acute PE, initial therapy:
 Respiratorysupports:
o Supplemental oxygen (target Sat O2 > 90%)
o Intubationor mechanicalventilation (severe hypoxemia, hemodynamic collapse, or respiratoryfailure).
 Hemodynamic supports:500 – 1000 mL IV NS (avoidin RV dysfunction), iffailed NS, use IV Vasopressor (NE, NE + DoBUTamine, Epi)
 Empiric anticoagulation:
o Riskof bleeding assessment
 Low risk = no risk factors for bleeding (age > 65, previous bleeding, cancer, metastatic cancer, renal/liver failure,
thrombocytopenia, previous stroke, diabetes, anemia, antiplatelet therapy, poor anticoagulant control, comorbidity,
reducedfunctional capacity, recent surgery, falls, alcohol abuse), empiric anticoagulation should be considered.
 Moderate risk = one or more riskfactors for bleeding, empiric anticoagulation may be considered.
 Unacceptably high risk = absolute contraindications (recent surgeryhemorrhagic stroke, active bleeding) or high risk
of bleeding (aortic dissection, intracranial, spinalcord tumors), avoidempiric anticoagulation.
 Note:Menstruation, epistaxis, minor hemoptysisare not contraindicatedto anticoagulants, but shouldbe monitored.
Definitive treatment:
o Submassive PE / Hemodynamically stable (without hypotension SBP > 90)
 Recommend against thrombolytic therapy (CHEST guideline 5.6.1.2)
 Parenteral anticoagulation = IV UFH, SQ UFH, LMWH, Fondaparinux (CHEST guideline 5.1)
 Recommend LMWH or Fondaparinux over IV UFH andSCUFH (CHEST guideline 5.4.1)
 Recommend LMWH once dailyover twice dailyadministration (CHEST guideline 5.4.2)
o Note:Same totaldailydose. Discrepancy:Lovenox QD dose is 1.5 mg/kg, BIDdose is 1 mg/kg
 Vitamin K antagonist (warfarin) started on same day as parenteral anticoagulation and continue parenteral
anticoagulation for a minimum of 5 days and until the INR > 2 for at least 24 hours (CHEST guideline 5.3)
 Suggest INR = 2.0 – 3.0 (target INR = 2.5) for all treatment durations (CHEST guideline 6.5)
o Massive PE / Hemodynamicallyunstable (with hypotensionSBP< 90, and not high bleeding risk)
 Recommend thrombolytic and short infusion(2 hours) over long infusion (24 hours) (CHEST guideline 5.6.2.1)
 Embolectomywhen thrombolysisis either contraindicatedor unsuccessful (UpToDate)
 UHF is preferredfor thrombolysis/ embolectomy (UpToDate)
 Avoid Direct thrombin andfactor Xa inhibitors inhemodynamicallyunstable patients (UpToDate)

2. DIEN VU
o Anticoagulationduration for bothtypes of PE:(UpToDate)
 Initialanticoagulation (0 – 10 days):important inprevention ofrecurrence and VTE-relateddeath
 Long-term anticoagulation
 10 days – 3 months: for transient risk factors, or
 6 – 12 months: for persisting riskfactors or unprovoked VTE
 Indefinite anticoagulation: onlyfor unprovokedsymptomatic PE (to reduce recurrence), recurrent unprovokedVTE,
recurrent provokedVTE, provoked VTE withpersistent risk factors, unprovoked asymptomatic PE.
 If PE provokedbysurgery
 Recommend anticoagulation for 3 months over shorter period andover longer period(6 – 12 months) or
extendedtherapy (CHEST guideline 6.0)
 If PE provokedbya non-surgery(estrogen therapy, etc)
 Recommend anticoagulationfor 3 months over shorter period andover longer period(6 – 12 months) or
extendedtherapy (CHEST guideline 6.2)
o Treatment Algorithm for PE:(UpToDate)

3. DIEN VU
CHEST guidelines5.6.1.2
recommendagainst thrombolytic
in hemodynamicallystable PE

4. DIEN VU
Monitoring:
 Therapeutics levelsof anticoagulation (UpToDate)
o UFH = aPTT with target range of 1.5 to 2.5 times upper normal limit
o Warfarin= PT/INR withtarget INR= 2 – 3
o LMWH, Factor Xa inhibitor, Direct thrombininhibitor = no monitoring
 Renal dosing adjustment (Lovenox, Fondaparinux)
 Conditions that affect half-life of anticoagulant (renalfailure, pregnancy, weight gain/loss, drug interactions)
 Earlycomplications of PE (recurrence)
 Late complications of PE (recurrence, chronic thromboembolic pulmonaryhypertension)
 Bleeding, ADR
 Riskof recurrence andbleeding
 Predisposingriskfactors for PE (malignancy, inheritedthrombotic disorder, surgery)

5. DIEN VU
Drug Classesfor Anticoagulationand Lab
Anticoagulant Example Lab
Vitamin K Antagonist (VKA) Warfarin (PO) PT/INR
Unfractionated heparin (UHF) Heparin (IV/SQ) Hgb, HCT, aPTT, ACT, Platelet (onlyif HIT risk >1%)
Low Molecular Weight Heparin
(LMWH)
Enoxaparin (SQ)
Dalteparin (IV/SQ)
Cr, Platelet, Anti Xa (onlyif pregnancy, mechanicalheart valve, weight > 190 kg if test
available)
Factor Xa Inhibitor
Apixaban(PO)
Rivaroxaban (PO)
Fondaparinux (SQ)
Renal/Liver function, weight < 60 kg
Direct Thrombin Inhibitor
Bivalirudin (IV)
Argatroban (IV)
Dabigatran (PO)
Bivalirudin= ACT, aPTT
Argatroban= Hgb, HCT, aPTT ifHIT, ACT if PCI
Dabigatran= Platelet, PT, aPTT, Cr, plasma concentration(suggest)
Antiplatelet
Aspirin Aspirin (PO) Renal/Liver function
Thienopyridine
Clopidogrel (PO)
Prasugrel (PO)
Clopidogrel = Hgb, HCT, Platelet, Renal/Liver function
Prasugrel = Hgb, HCT, Platelet function (optional)
GP 2B/3A Inihibitor
Abciximab (IV)
Eptifibatide (IV)
Tirofiban (IV)
- Abciximab= PT, aPTT, Hgb, HCT, Platelet, Fibrinogen, Fibrinsplit product
- Eptifibatide = Hgb, HCT, Cr, PT, aPTT, ACT if during PCI, platelet (2-4 hrs after initiation
or 24 hours before D/C)
- Tirofiban= Platelet (6 hours after initiationthendaily), Hgb, HCT
Non-thienopyridine Cangrelor (IV) S&S of bleeding
Thrombolytic agents
Alteplase (IV)
Tenecteplase (IV)
Alteplase
- Ischemic stroke = BP, CBC, aPTT, PT/INR, glucose
- PE = BP, HR at least 24 hours after administration
- STEMI = BP, cardiac biomarkers, CBC, PT/INR, aPTT
Tenecteplase = CBC, aPTT, EKG
Dosing reference foracute PE: (LexiComp)
 Warfarin(VKA) = individualizedaccording to INR. Range from 2 – 10 mg once daily
 UFH = 80 U/kg IV push, thenIV infusion 18 U/kg/hr OR 333 U/kg SQ, then 250 U/kg SQ q12
 Enoxaparin (LMWH)= 1 mg/kg SQ q12 OR 1.5 mg/kg SQ qd
 Fondaparinux (Xa inhibitor):
o < 50 kg: 5 mg qd
o 50 – 100 kg: 7.5 mg qd
o > 100 kg: 10 mg qd
 Alteplase (thrombolytic): IV 100 mg over 2 hours OR 10 mg IV bolus followedby90 mg IV over 2 hours.
Reference
1. Tapson, VF. Overviewof the treatment, prognosis, and follow-upof acute pulmonaryembolism in adults. UpToDate Inc.
http://www.uptodate.com/contents/overview-of-the-treatment-prognosis-and-follow-up-of-acute-pulmonary-embolism-in-
adults?source=machineLearning&search=pe&selectedTitle=3%7E150&sectionRank=3&anchor=H21434574#H21434574. Accessed
8/18/2015.
2. Guyatt, GH, Akl, EA, Crowther M, et al. Antithrombotic Therapyfor VTE Disease:Antithrombotic Therapyand Preventionof Thrombosis,
9th ed:AmericanCollege of chest Physicians Evidence-Based Clinical Practice Guidelines. CHEST 2012;141 (2)(Suppl): e419S-e494S
http://journal.publications.chestnet.org/pdfaccess.ashx?ResourceID=6568310&PDFSource=13. Accessed 8/20/15
3. Lexi-Comp, Inc. (Lexi-Drugs). http://online.lexi.com/lco/action/home/switch. Accessed8/19/2015