VENOUS THROMBOEMBOLISM Flashcards
MANAGEMENT: PULMONARY EMBOLISM
CLINICAL DECISION MAKING TOOLS
Simplified Well’s Score
YEARS
Pregnancy Adapted YEARS
PERC
PESI
Calculate Pretest Probabiliyt (Well’s)
Low (<20%): Pulmonary Embolism Rule Out Criteria (PERC) or D-Dimer.
Moderate (21%-40%): D-dimer, computed tomography (CT) pulmonary angiography
High (>40%): Empiric heparin, CT pulmonary angiography, and may require additional testing to rule out (D-Dimer, extremity ultrasound).
Treatment: Massive (High Risk) Pulmonary Embolism
(Persistent hypotension (systolic blood pressure <90 mm Hg) lasting >15 min or a baseline systolic pressure decrease of >40 mm Hg.)
Evaluate Contraindications to Thrombolysis
If no absolute contraindications or a relative contraindication:
Start unfractionated heparin if no contraindications:
80 U/kg IV bolus, followed by 16-18 U/kg/h infusion. Titrate to factor Xa inhibition
IV systemic thrombolytics
Alteplase:
>65 kg: 100 mg IV: 10 mg IV push followed by 90 mg over 2 h
<65 kg: adjust to maintain dose at <1.5 mg/kg
If absolute contraindication:
Start fractionated heparin (?) if no contraindications.
Enoxaparin: 1 mg/kg q12h subcutaneous
Call Cardiothoracic Surgery to evaluate for open thrombectomy.
Treatment: High Intermediate Risk Pulmonary Embolism (Normotensive or intermittent hypotension with both radiographic and biomarker findings of heart strain)
Right Heart Strain:
CT Angio
OR
Transthoracic Echo
Biomarkers:
pro BNP >900
Troponin borderline or higher
Consider thrombolysis with evidence of shock (SI > 1, Intermittent Hypotension, Lactate > 2, Sp02 <92% with distress) vs. antiocoagulation
Start unfractionated heparin if no contraindications:
80 U/kg IV bolus, followed by 16-18 U/kg/h infusion. Titrate to factor Xa inhibition
IV systemic thrombolytics
Alteplase:
>65 kg: 100 mg IV: 10 mg IV push followed by 90 mg over 2 h
<65 kg: adjust to maintain dose at <1.5 mg/kg
If absolute contraindication:
Start fractionated heparin (?) if no contraindications.
Enoxaparin: 1 mg/kg q12h subcutaneous
Call Cardiothoracic Surgery to evaluate for open thrombectomy.
Treatment: Low Intermediate Risk Pulmonary Embolism
(Hemodynamically stable with either right ventricular strain on CT pulmonary angiography/echo OR abnormal biomarkers, but not both abnormalities.)
Hospitalize and start anticoagulation
Non-low-risk patients may be started on direct oral anticoagulation or fractionated heparin and admitted to the hospital.
Enoxaparin: 1 mg/kg q12h subcutaneous
80 U/kg IV bolus, followed by 16-18 U/kg/h infusion. Titrate to factor Xa inhibition
Treatment:
Low Risk Pulmonary Embolism Hemodynamically stable with NO right ventricular strain on CT pulmonary angiography or echo with normal biomarkers.
Calculate PESI
Low Risk: DOAC
Follow up 14-30 d
Non-Low Risk:
DOAC
OR
Fractionated Hepatin
Admission
DISPOSITION
Calculate PESI
DVT or Submassive PE WITHOUT Right heart Strain: DOAC or fractionated heparin, discharge home, close follow up
Massive PE and high risk for hemodynamic collapse: admission to ICU
DOCUMENTATION: PULMONARY EMBOLISM
CLINICAL FEATURES
Shortness of breath: 34.7%-80%
Tachycardia: 30.4%
Chest pain: 13%-50%
Leg pain or weakness: 9.6%
Tachycardia: 24-30%
Sp02 < 94%: 74%
RISK FACTORS
Trauma in past 4/52
Surgery in past 4/52
Limb Immobility
Active / Recent CA
PMHx: Inherited thrombophilia, Connective tissue disease, Acquire thrombophilia, Prior DVT / PE
Estrogen
Smoking
HIGH RISK FOR RECURRING DVT / PE
Hospitalized or Reduced Mobility
Active Cancer
No reversible risk factor for PE (e.g. recent surgery)
D-DIMER
Sn (97%) and Sp (39%).
Use an age-adjusted D-dimer cutoff in patients aged >50 y (cutoff of 500 mg/L).
Pregnant: with no clinical evidence of DVT, no hemoptysis, and in which PE is not the most likely diagnosis, use a cut off of 1,000 mg/L
BEDSIDE ECHO
Signs of right heart strain or clot within the right atrium.
Only 40%-63% of pulmonary embolisms exhibit right heart strain on transthoracic echocardiography
Signs of Right Heart Strain:
- Dilatrion of the right ventricle: basal diameter >4.2 cm, a mid-cavity diameter >3.5 cm, and a length exceeding 8.6 cm
right ventricle/ left ventricle end diastolic basal diameter ratio >1
qualitative features include diffuse rounding and loss of the typical triangular to crescentic morphology
- Intraventricular Septal Flattening: D Sign
- Paradoxical Septal Motion
- Right Ventricular Hypokinesia: TAPSE < 1.6 cm, RV FAC <35%
CT ANGIO
sn of 93% and sp of 98%
Signs of Right Heart Strain:
Right ventricle > left ventricle
Reflux of contrast into the inferior vena cava or liver
ECG
1) Sinus Tachycardia (MC, 44%)
2) Right Ventricular Strain Pattern:
T wave inversion anteroseptal leads (V1-V4) +/- inferior leads (II,III,aVF) (34%)
3) Right Axis Deviation (16%)
4) Dominant R wave in V1
5) RIght atrial enlargement (P pulmonale): peaked p wave in lead II >2.5 mm
6) Incomplete or complete RBBB
7) S1, Q3, T3 Pattern:
Large S wave in lead I
Small Q wave in lead III
Inverted T wave in lead III (20%)
Absolute Contraindications for IV Thrombolysis
Prior intracranial hemorrhage
Known intracranial neoplasm, arteriovenous malformation, or aneurysm
Within previous 3 mo:
Ischemic stroke
Gastrointestinal bleed
Active bleeding at a non-compressible site
Known bleeding diathesis
Liver failure with international normalized ratio >1.7
Within previous 21 d:
Surgery or invasive procedure requiring the opening of the chest, peritoneum, skull, or spinal canal
Significant trauma
DVT MANAGEMENT
Calculate Pretest Probability (Well’s)
Low (<10%): D-Dimer
Moderate (11%-49%): Duplex Ultrasound of the affected extremity (3-point adequate)
High (>50%): Whole leg or serial duplex ultrasound of the affected extremity (repeat in 1 week)
TREATMENT
DOAC
Unfractionated Heparin (malignancy)
