醫學筆記匯整 ED Notes

Risk factors

* Hypercoagulable states
     - Protein C, Protein S deficiency
     - Anti-thrombin III deficiency
     - Lupus anticoagulant ( Anti- phospholipid )
* Recent surgery
* Pregnancy
* Prolonged bed rest / Immobility / Travel 
* Malignancy
* Oral contraceptive use, Drug abuse
* Certain venous aneurysms, DVT

Tips for using D-Dimer wisely :

    - Use a high sensitivity assay
    - Test low risk patients
    - Test when you expect it will be negative (to rule out PE)
    - Don't test D-dimer if you plan to order a CT regardless
    - D-dimer should not be used to rule out Pulmonary Embolism in pregnancy

* EKG findings : 

• Sinus tachycardia : 44 %
• Non specific STT changes : 50 %
   
• RV strain pattern (Tinv over V1-4) : 34 %
      flipped T waves in anterior and inferior leads,
      an uncommon finding which has been shown to be highly specific for PE
   
• RAE : 9 %
• Right axis deviation : 16 % 
• Right ventricular dilatation : dominant R in V1
   
• S1Q3T3 pattern : 20 %
• New incomplete RBBB : 18 %

Chest pain + New T inv over V1-3 

 1. Ant wall ischemia, ACS ? 
 2. PE : RV strain pattern

Also :
Massive acute PE can mimicking STEMI 
Acute PE can leads to STE in aVR 



 

* CXR :

- Common findings include :
   Atelectasis or   pulmonary parenchymal  abnormalities   (18 to 69 %)    
 - Pleural effusion (47 %)
 - Cardiomegaly (50 %)
 - Normal (12 to 22 %)
 

• Hampton hump
  Shallow, wedge-shaped opacity in the periphery of the lung,
  with its base against the pleural surface.
   
• Westermark's sign
  A sharp cut-off of pulmonary vessels
  with distal hypoperfusion in a segmental distribution within the lung.
  ( Regional oligaemia )
   
• Fleischner sign :  Enlarged pulmonary artery
• Palla's sign :  Right descending pulmonary artery enlargement
   
• Knuckle sign : Abrupt tapering of an occluded vessel distally
• Ice melting sign

- Ventilation phase : gaseous radionuclide such as xenon ortechnetium DTPA

- Perfusion phase : intravenous injection of radioactive Tc99m-MAA

Ventilation phase ok, Perfusion phase with defect.