Pulmonary Embolism

Front 1

significance of PE

Back 1

-most commonly missed caused of death in elderly institutionalized pts
-10% die within 1st hr

Front 2

Etiology of PE

Back 2

-90% for DVT
-most from deep thigh/pelvic veins
-isolated calf vein thrombosis a sig cause of massive PE
-other

Front 3

Risk factors for DVT/PE

Back 3

1. immobilization
2. surgery within 3 months
3. stroke
4. hx of VTE
5. malignancy
6. preg, obesity, HTN, smoking

Front 4

Virchow's triad

Back 4

1. Venous stasis
2. Vessel wall inflammation
3. Hypercoagulability: congenital or acquired, factor V leyden, def in protein C, S, antithrombin III, estrogens

Front 5

Link b/t DVT and PE

Back 5

-1/2 of pts with DVT can be shown to have suffered PE, most without ANY of the classic symptoms

Front 6

Diagnosis of PE

Back 6

-size, location (usually bilat, RLL), pre-existing symptoms (COPD, heart disease)
-hemodynamic vs. respiratory
-acute vs. chronic

Front 7

SSx of PE

Back 7

-Classic Triad: Hemoptysis, Dyspnea, chest pain
-seen in <20% of pts
-most pts w/these sx have some other cause
-common sx: dyspnea, pleuritic chest pain (hurts w/breathing and localized), cough, hemoptysis

Front 8

symptoms of concern for PE

Back 8

1. new onset chest sx and no other provable dx
2. chest wall tenderness, back, shoulder, abd pain
3. new onset wheezing or arrhythmia
4. seizure, syncope

Front 9

Common signs in PE

Back 9

Initial exam often normal!!
1. Tachypnea (70%)
2. rales (51%)
3. tachycardia (30%)
4. S4 (24%)
5. Accentuated P2 (23%)
6. Fever <102 (14%)

Front 10

Signs in massive PE

Back 10

1. tachypnea
2. rales
3. inc P2
4. tachycardia
5. fever
6. diaphoresis
7. S3/S4 gallop
8. thrombosis
9. LE edema
10. murmur, cyanosis

Front 11

w/u for PE

Back 11

1. H&P
2. Labs: CBC, ESR, LFTs (inc LDH), clotting profile (nml)
3. CXR: infiltrate, pleural effusion, westermarks sign (dec in vascularity), RVH, LVH, nml
4. EKG
5. ABG (arterial blood gas)

Front 12

Hampton's hump

Back 12

-pleural based area of consolidation with a rounded apex pointing towards the hilum

Front 13

EKG in PE

Back 13

-25% w/PE have no change!
-NS ST-T wave changes
-right heart strain: tall, peaked P lead II, RBBB, atrial fib, S1-Q3-T3

Front 14

ABG in PE

Back 14

- 85% of PE pts have p02 <80
-pO2 has a zero (or -) predictive value in most patient populations suspected of PE

Front 15

D dimer

Back 15

-NON-SPECIFIC indicator of plasmin mediated proteolysis
-for the quantitative assays, >500ng/mL is abnml
-most helpful if negative to help R/O PE!!- look at slide!

Front 16

V/Q scan

Back 16

-do if suspect PE with no alternative dx
-hard to interpret
-nml scan: no perfusion defects seen
-replaced by spiral CT!

Front 17

Spiral CT

Back 17

-Specificity ≥ 90% with experienced readers
-Detection of proximal emboli easier than segmental emboli (limited beyond this)
-Evaluate in conjunction with pretest clinical probability!!

Front 18

PIOPED II

Back 18

-The likelihood of PE in patients with a positive CT-PA (positive predictive value)
-The likelihood that PE was absent in patients with a negative CT-PA (negative predictive value)

Front 19

Pulmonary Angiogram

Back 19

-GOLD STANDARD for dx PE
-highly sensitive and specific

Front 20

Dopple U/S

Back 20

-evidence of DVT used to imply PE
-Normal veins compress with transducer, while muscular arteries remain open
-In DVT, veins do not collapse completely
-Single negative US does not R/O DVT

Front 21

Echocardiography

Back 21

-may help identify other conditions

Front 22

Goals of therapy for PE

Back 22

1. stop propagation of thrombi
2. prevent recurrent PE
3. remove existing thromboemboli (not always)
4. prevent chronic pulmonary HTN
5. prevent chronic venous insufficiency

Front 23

Treatment options for PE

Back 23

1. O2
2. IV fluids
3. Heparin
4. Xa inhibitor
5. Coumadin
6. Fibrinolysis
7. Embolectomy
8. Caval filter

Front 24

Heparin

Back 24

-should be started in all pts with confirmed/high clinical suspicion of PE in the absence of C/I
-SC LMWH preferred for stable PE
-(wt based) IV infusion UFH if renal failure, inc risk of bleeding, persistent hypotension, thrombolysis

Front 25

LMH heparin

Back 25

-tinzaparin
-dalteparin
-enoxaparin: prophylaxis and tx of both DVT and PE
-monitor anti-Xa levels if <45 kg women, <57 kg men

Front 26

Fonaparinus (Arixtra)

Back 26

-factor Xa inhibitor
-catalyzes factor Xa inactivation without inhibiting thrombin

Front 27

Coumadin

Back 27

-interferes with hepatic synthesis of vit K dependent coagulation factors
-Must first be fully anticoagulated with heparin/fonaparinux; overlap ≥ 5days (therapeutic INR ≥ 24 hrs.)
-Monitor q 1-2 days, then q 2-4 wks.
-duration: first PE, resovled risk -> 3mo; first unprovoked PE: 3 mo then reases; recurrent PE: indefinite or 6 mo
-careful diet hx!

Front 28

Thrombolytics

Back 28

-accelerate clot lysis and is associated with short-term physiologic benefits, but has not been shown to improve mortality
-Streptokinase
-tPA (Alteplase)

Front 29

Streptokinase

Back 29

-highly antigenic (chills, fever, nausea, rashes)
-C/I in pts with prior exposure in last 4 yrs or recent strep infx
-stop heparin
-infusion 1.5 IU over 2 hrs
-resume heparin

Front 30

Alteplase

Back 30

-commonly used in ED
-may continue heparin or hold and restart aftr therapy or when aPTT <2x nml
-infusion 100mg over 2hrs

Front 31

Other txs for PE

Back 31

1. Surgical embolectomy: used in pts who have failed or cannot tolerate lytic therapy
2. Venal caval filter in pts with: recurrent emboli despite full anticoagulation, C/I to anticoagulation

Front 32

Serious pitfalls with PE

Back 32

1. dismissing unexplained SOB as anxiety or hyperventilation w/out adequate w/u
2.. dismissing unexplained chest pain as musxuloskeletal pain without adequate W/U
3. failure to properly diagnose and treat symptomatic DVT

Front 33

Prevention

Back 33

1. recognize pts at risk
2. LMWH (coumadin)
3. Mobilization/positioning
4. Gradient compression stockings