10. Diagnosis and treatment of pulmonary embolism

Question 1

What common symptoms do suspected PE patients present with

Answer 1

• Dyspnea [usually sudden onset]
• Cough
• Hemoptysis
• Tachycardia and Tachypnea
• Sudden, sharp chest pain [usually due to occlusion of a major branch]
• Jugular venous distension [in cases of Saddle embolus]
• Syncope [in a severe PE like saddle embolus]
• Pleural effusion [secondary symptoms]
• Kussmaul Sign [Jugular vein doesn’t go down in pressure during inspiration]
• Cardiac collapse or Respiratory collapse

Even though PE is a life threatening condition, patients have normal physical exam signs

Any patient presenting with signs of Dyspnea or Chest pain undergo the ABCDE management, BP and EKG measurement, Pulse oxymeter, arterial blood gas analysis, CBC, D-dimer, troponin, CRP, O2 therapy, IV access

Question 2

What things will you order to diagnose a suspected PE case?

Answer 2

Any patient presenting with signs of Dyspnea and chest pain undergo a general management strategy to quickly rule out conditions. When patient is stable, we do a focused history.

For PE we often use the Well’s score where a score > 4 makes PE highly likely to be the cause of patients symptoms

We also get:
- Chest X-ray
- Labs for D-dimer, CBC, ABG [D-dimer is elevated in many other conditions other than PE]
- EKG [to monitor acute collapse of heart functions and view for right heart strain signs]

As confirmatory we get:
- Chest CT with contrast [gold standard to accurately dx PE]
- V/Q Scintigraphy [when iodine contrast is contraindicated]
- Chest Angiography [being discontinued due to high risk of complications, but still indicated in patients not able get CTPA or V/Q Scintigraphy]

Question 3

Chest X-ray signs we could find in a potential PE case?

Answer 3

• Hampton Hump [wedge shaped opacity in peripheral lung due to infarction]
• Westmark Sign [are of lucency in parenchyma due to oligemia]
• Fleishner Sign [prominent Pulmonary artery due to distension proximal to embolus]
• Non specific sign [pleural effusion, cardiomegaly, atelectasis from smaller embolism]

Question 4

Once we know we have PE, what other imaging becomes useful?

Answer 4

• Lower Leg US [to find DVT or dilations in deep veins of leg as potential source]
• Echocardiography [in suspected cardiac involvement cases like tricuspid regurgitations, Hypokinesia, Increased right atrial pressure, increased pulmonary artery pressure, venous backflow into IVC]

Question 5

Treatment strategies employed to treat PE

Answer 5

• Supportive therapy [IV access to hypotensive patients, O2 therapy to hypoxemic patients]
• Analgesia to manage pain [avoiding NSAIDS]
• Anticoagulation: Initial anticoagulation [IV UFH; LMWH subcutaneous; Factor Xa inhibitors; Direct Thrombin inhibitors] and Maintenance anticoagulation [Oral Vit K antagonists like Warfarin; Oral Factor Xa inhibitors; Oral Direct thrombin inhibitors]
• IVC filters [to catch emboli before it reaches heart]
• Re-perfusion therapy in selected patients [Thrombolysis via tPA; Embolectomy]

Question 6

How do we choose treatment pathway for a patient? What does it depend on?

Answer 6

Choice of treatment pathway is dependent on whether patient is stable or unstable

If patient is Stable:
- Heparin [IV UFH or LMWH]
- No signs of recurrent PE
- Oral anticoagulants life long
- IVC filters with anticoagulation is contraindicated

If patient was stable but shows up with recurrent PE:
- IVC filters

If patient is Unstable:
- Thrombolysis
- Embolectomy [if Thrombolysis is unsuccessful or contraindicated]

Question 7

Absolute Contraindications for Thrombolysis

Answer 7

• Previous history for stroke
• Recent surgery
• Active External or Internal bleeding
• Intracranial injury or tumour