DVT

Question 1

Well’s criteria for DVT

Answer 1

• Active cancer
  
  • Treatment or palliation within 6 months
• Bedridden recently >3 days or major surgery within four weeks
• Calf swelling >3 cm compared to the other leg
  
  • Measured 10cm below tibial tuberosity
• Collateral (nonvaricose) superficial veins present Entire leg swollen
• Localized tenderness along the deep venous system
• Pitting edema, confined to symptomatic leg
• Paralysis, paresis, or recent plaster immobilization of the lower extremity
• Previously documented DVT
• Alternative diagnosis to DVT as likely or more likely

Question 2

Treatment for DVT

Answer 2

Options include:

• low molecular weight heparins (LMWH)
• fondaparinux
• intravenous unfractionated heparin (UFH) infusion (titrated to APTT)
• subcutaneous UFH (weight-based dose regimen)

FIRST LINE

• deltaparin 200 units/kg up to 18 000 units SC, daily (LMWH)
• dalteparin 100 units/kg up to 9000 units SC, twice daily
• enoxaparin 1.5 mg/kg SC, daily (clexane - LMWH)
• enoxaparin 1 mg/kg SC, twice daily

SECOND LINE

• fondaparinux patients less than 50 kg: 5 mg; 50 to 100 kg: 7.5 mg; more than 100 kg: 10 mg) SC,

Question 3

ECG changes for PE

Answer 3

• sinus tachy - most common
• RBBB
• RV strain pattern
• RAD
• dominant R wave V1
• right atrial enlargement (P pulmonale)
• S1, Q3, T3
  
  • deep S wave in lead I, Q wave in III, inverted T wave in III
  • This “classic” finding is neither sensitive nor specific for pulmonary embolism; found in only 20% of patients with PE

Question 4

Management of PE

Answer 4

Anticoagulation with unfractionated heparin (UFH) via an infusion should be started, as the efficacy of low molecular weight heparins (LMWH) in this situation is unknown.

Use:

unfractionated heparin 80 units/kg loading dose IV, followed by 18 units/kg/hour IV infusion, adjusted according to APTT.

Warfarin should be started within 48 hours

for fibrinolytic therapy, use:

alteplase (patients 65 kg or more) 10 mg IV bolus, followed by 90 mg IV infusion over 2 hours.

• activated partial thromboplastin time (APTT) should be checked after 4 to 6 hours and the dose adjusted if APTT is not in the therapeutic range. When the APTT is in the therapeutic range, the dose should be reviewed daily.

Question 5

Investigations for PE

Answer 5

• ECG
• CXR
• ABG
• D-dimer
• CTPA
• VQ scan
• lung scintigraphy

_________________________

• transthoracic echocardiography
• coags - aPPT, INR, PT
• thrombophilia screen
• troponins
• BNP
  *

Question 6

Well’s criteria for PE

Answer 6

1. Clinical signs and symptoms of DVT
2. PE is #1 diagnosis OR equally likely
3. Heart rate > 100
4. Immobilization at least 3 days OR surgery in the previous 4 weeks
5. Previous, objectively diagnosed PE or DVT
6. Hemoptysis
7. Malignancy w/ treatment within 6 months or palliative