Pulmonary Embolism

Question 1

What are the two types of thromboembolic disease?

Answer 1

DVT

PE

Question 2

What is a PE?

Answer 2

A blockage of a pulmonary artery by a blood clot, fat, tumour or air that can cause pulmonary infarction

Question 3

What are the two different types of DVT?

Answer 3

Proximal (ileo-femoral) - most likely to embolise and lead to chronic venous leg ulcers
Distal (polpiteal) - least likely to embolise

Question 4

What is the clinical presentation of a DVT?

Answer 4

Whole leg/calf involvement

Swollen, hot, red, tender calf

Question 5

What is the differential diagnosis of a DVT?

Answer 5

Popliteal synovial rupture (baker’s cyst)
Superficial thrombophlebitis
Calf cellulitis

Question 6

How can a DVT be diagnosed?

Answer 6

Ultrasound doppler legscan - excludes popliteal cyst or pelvic mass
CT scan - ileo-femoral veins, IVC and pelvis

Question 7

What is the clinical presentation of a large pulmonary emboli?

Answer 7

CV shock, low BP, central cyanosis, sudden death

Question 8

What is the clinical presentation of a medium pulmonary emboli?

Answer 8

Pleuritic pain, haemoptysis, breathlessness

Question 9

What is the clinical presentation of a small recurrent pulmonary emboli?

Answer 9

Progressive dyspnoea, pulmonary hypertention, right heart failure

Question 10

What are the risk factors for a DVT and PE?

Answer 10

Thrombophilia 
Contraceptive pill, HRT
Pregnancy
Pelvic obstruction (uterus, ovary, lymph nodes)
Trauma (road traffic accident) 
Surgery (pelvis, hip, knee)
Immobility (bed rest, long haul flights) 
Malignancy 
Obesity
Pulmonary hypertension 
Vassculitis

Question 11

How can a DVT be prevented?

Answer 11

Early post-op mobilisation 
TED compression socks
Calf muscle exercises
Subcutaneous low dose heparin pre-op
Direct oral anticoagulant (dabigatran, apixaban)

Question 12

What will the history of the presenting complaint be with a DVT?

Answer 12

Shortness of breath (acute onset)
Chest pain (pleuritic)
Haemoptysis 
Leg pain/swelling
Collapse/sudden death

Question 13

What are the clinical features of a PE?

Answer 13

Tachycardia, tachupnoea, cyanosis, fever, low BP, crackles, rub, pleural effusion
ABG: Low PaO2, Low SaO2
CXR: Basal atelectasis, consolodation, pleural effusion

Question 14

What are investigations that can be carried out to diagnose a PE?

Answer 14

Pulmonary Embolism Severity Index (PESI)
ECG: Acute right heart strain pattern 
D-dimers raised
Troponin +/- 
V/Q scan - perfusion defect before infarction, perfusion and ventilation matched defect after infarction
CTPA 
Leg and pelvic ultrasound for silent DVT
Echocardiogram

Question 15

What can cause a PE?

Answer 15

Surgery 
Pregnancy
Malignancy 
Immobility 
Autoantibodies - anti-nuclear, anti-cardiolipin 
Thrombophilia screen

Question 16

How is a low risk PE managed?

Answer 16

Low PESI, negative troponin, no oxygen and no co-morbidities
Ambulatory pathway then home

Question 17

How is a high risk PE managed?

Answer 17

If CV compromise then thrombolysis may be needed
Monitor BP
HDU

Question 18

How is a DVT/PE treated?

Answer 18

Anticoagulation prevents clot propagation
Therapeutic dose of heparin
Empirical treatment if high clinical suspicion whilst await conformation with investigations
LMWH once daily injection requires no monitoring
Start warfarin simulatenously
After 3-5 days stop heparin when INR > 2
Use DOACs - dabigatran, abpixaban

Question 19

What is the target ranges of INR?

Answer 19

2,0-3,0 - 1st event

3. 0 or more for recurrent events
4. 5 if recurrent DVT/PE whilst on warfarin

Question 20

What are some more invasive preventions/treatments of DVT/PE?

Answer 20

IVC filter to prevent embolisation from large ileofemoral/IVC clot
Thrombo-embolectomy
Intra-cathater directed thryombolysis

Question 21

What is the duration of treatment of DVT?

Answer 21

Depends on the balance of risk between risk of repeat clot vs bleeding 
Unprovoked 1st PE: 6 months
Provoked PE: 3 months
Unprovoked low-risk distal DVT: 3 months
Recurrent DVT/PE: life-long

Question 22

What is pulmonary hypertension?

Answer 22

Pulmonary circulation is usually high -flow, low pressure system
Normal mean pulmonary arterial pressure (mPAP): 12-20 mmHg
mPAP > 25 = pulmonary hypertension (PH)

Question 23

What can cause pulmonary hypertension?

Answer 23

Pulmonary venous hypertension (left heart disease): left ventricular systolic dysfuction, mitral regurgitation, cardiomyopathy
Primary pulmonary hypertenstion: hypoxia (COPD, OSA, pulmonary fibrosis)
Multiple PE
Vasculitis
Drugs
HIV
Cardiac left to right shunt

Question 24

What is cor pulmonale?

Answer 24

Right heart failure secondary to lung disease
Fluid retention due to hypoxia
Can complicate COPD, fibrotic lung disease, chronic PE, chronic ventilatory failure (obesity, kyphoscoliosis)

Question 25

What are the clinical signs of pulmonary hypertension/ RHF?

Answer 25

Central cyanosis
Dependent oedema
Raised JVP with V waves 
Right ventricular heave at left parasternal edge
Murmur of tricurpid regurgitation 
Load P2
Enlarged liver

Question 26

How is pulmonary hypertension investigated?

Answer 26

ECG - rhythm, axis, right bundle branch block 
CXR - cardiomegaly 
SaO2 and ABG
Pulmonary function with DLCO (diffusion capacity) 
Echo 
Cardiac catheritisation to measure mPAP
D dimer / VQ scan 
CTPA
Cardiac MRI

Question 27

How is chronic thromboembolic pulmonary hypertenstion treated?

Answer 27

Riociguat - pulmonary arterial vasodilator

Pulmonary endarterectomy