PE and pulmonary hypertension

Question 1

Is a proximal (ileofemoral) or distal (popliteal) most likely to embolise?

Answer 1

Proximal - also more likely to lead to chronic venous insufficiency and venous leg ulcers

Question 2

what is the first line investigation for DVT?

Answer 2

-ultrasound doppler leg scan (will exclude popliteal cyst or pelvic mass)

Question 3

What are the differences seen clinically between a large/medium/small PE?

Answer 3

Large- cardiovascular shock, low BP, central cyanosis, sudden death
Medium-pleuritic pain, haemoptysis, breathless

Small recurrent- progressive dyspnoea, pulmonary hypertension and right heart failure

Question 4

What are the ten risk factors for DVT and PE?

Answer 4

Thrombophilia- FH,freq,site,age
Contraceptive pill (particularly if smokes),HRT
Pregnancy
Pelvic obstruction-eg uterus,ovary,lymph nodes

Trauma-eg RTA

Surgery- eg pelvic,hip,knee

Immobility-eg bed rest,long haul flights

Malignancy

Pulmonary hypertension/vasculitis

Obesity

Question 5

What are the five clinical features of PE?

Answer 5

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

Question 6

What are 8 clinical signs of PE?

Answer 6

Tachycardia, tachypnoea, cyanosis,fever, Low BP, crackles, rub, pleural effusion

Question 7

What is seen on ABG’s and CXR for PE?

Answer 7

Arterial blood gases (ABGs)
low PaO2 , low SaO2 (Type 1 resp failure:PaCO2 normal or low)

CXR:
Normal early on before infarction
Basal atelectasis, consolidation.
Pleural effusion

Question 8

What is seen on ECG and isotope lung scan for PE? what is the blood test used to help diagnose PE?

Answer 8

ECG: Acute Right heart strain pattern (S1Q3T3; T inversion in V1-3)

Isotope lung scan (Ventilation/Perfusion: V/Q
Sensitive for small peripheral emboli
Perfusion defect before infarction
Perfusion+Ventilation matched defect after infarction

D-dimers usually raised

Question 9

Why are CT pulmonary angiogram and echocardiogram used in the investigation of PE?

Answer 9

CT pulmonary angiogram (CTPA) to image pulmonary artery filling defect
to pick up larger clots in proximal vessels

Echocardiogram to measure pulmonary artery pressure and right ventricular size; acute dilatation of RV in keeping with acute PE

Question 10

if no obvious underlying cause for PE:
How would you investigate for cancer?
What other things would you screen for (2)?

Answer 10

Consider cancer – Clinical exam; CXR, PSA, CA125, CEA, Pelvic USS or CT Abdo/pelvis

Autoantibodies (SLE) – Antinuclear, Anti-Cardiolipin Abs

Thrombophilia screen
Anti-thrombin-III deficiency ,Protein C or S deficiency, Factor V Leiden; increased VIII

Question 11

How are DVT’s prevented(5)?

Answer 11

Early post-op mobilisation
TED compression stockings
Calf muscle exercises
Subcutaneous low dose low mol wt heparin perioperatively (Dalteparin- Fragmin)
Novel Oral Anticoagulant (NOAC) medication
Dabigatran - direct thrombin inhibitor
Rivaroxaban/Apixaban - direct inhibitor of activated factor Xa

Question 12

What treatment is used as standard for PE/DVT?

Answer 12

Anticoagulation prevents clot propagation: tips balance to thrombolysis and body dissolves clot

Rarely IV heparin

SC Low mol wt heparin (LMWH e.g. dalteparin-fragmin) –once daily injection ,no monitoring required
Also start warfarin at same time as heparin

Or instead use oral thrombin inhibitor (dabigatran) or factor X inhibitor (Rivaroxaban) on its own from the start –less hassle and in most cases as effective as heparin/warfarin

Oral warfarin-takes 3 days-antagonises Vit K dependent prothrombin

After 3-5 days stop heparin-when INR>2

Or use NOACs without LMWH

Continue Warfarin for 3-6 months
Monitor Warfarin with INR-Target range 2.5-3.5

Question 13

What treatment is used for large life-threatening PE?

Answer 13

Thrombolysis- tissue plasminogen activator (tPA)
Tenecteplase
Only for large life threatening PE-i.e. low BP and severe hypoxaemia due to main pulmonary artery occlusion

Question 14

In the management of PE, when would an IVC filter be used to prevent embolisation from large ileofemoral/IVC clot?

Answer 14

for recurrent PE’s

Question 15

is the pulmonary vascular system high or low pressure? when is this classed as pulmonary hypertension?

Answer 15

Normally a high flow, low pressure system
Normal mean pulmonary arterial pressure (mPAP) is 12-20 mmHg
mPAP >25 mmHg = pulmonary hypertension

Question 16

what are three causes of pulmonary venous hypertension?

Answer 16

LVSD - ischaemic
Mitral Regurgitation / Stenosis
Cardiomyopathy-e.g. alcohol ,viral

Question 17

What are 7 causes of pulmonary arterial hypertension?

Answer 17

Hypoxic – COPD , OSA , Pulmonary fibrosis

Multiple PE – chronic thromboembolic PH (CTEPH)

Vasculitis –e.g. SLE , PAN ,Systemic Sclerosis

Drugs e.g. appetite suppressants - fenfluramine and derivatives

HIV

Cardiac Left to right shunt – ASD, VSD

Primary pulmonary hypertension

Question 18

What is cor pulmonale?

Answer 18

Right heart disease secondary to lung disease
Fluid retention due to hypoxia +/- right heart failure
E.g secondary to COPD

Question 19

What are 7 clinical signs of pulmonary hypertension and right heart failure?

Answer 19

Central cyanosis if hypoxic

Dependent oedema

Raised JVP with V waves (due to secondary tricuspid regurg)

Right ventricular heave at left parasternal edge

Murmur of tricuspid regurgitation

Load P2

Enlarged liver (pulsatile)

Question 20

How is primary pulmonary hypertension diagnosed? what are the 2 clinical features? what is the prognosis without treatment?

Answer 20

Diagnosis by exclusion of other secondary causes
Progressive SOBOE and signs of right heart failure
Poor prognosis of 3 years without treatment

Question 21

what are the three different ways to treat primary pulmonary hypertension?

Answer 21

Pharmacologic Treatment:

• prophylactic anticoagulation (warfarin)
• O2 if hypoxic

Pulmonary Vasodilators:

• Ca2+ channel blockers (oral nifedipine ,diltiazem)
• Endothelin antagonist (Oral Bosentan,Macitentan)
• PDE5-inhibitor (Oral Sildenafil/Tadalafil)
• Prostanoids (IV Epoprostenol or Inhaled Iloprost )
• Soluble Guanylate Cyclase stimulator (oral Riociguat)

Lung transplant

Question 22

what has to be present for a pulmonary infarct to take place?

Answer 22

Embolus necessary but not sufficient

Bronchial artery supply compromised (eg in cardiac failure)

Question 23

what score is used if P.E is clinically likely?

Answer 23

Two level wells score

Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins) 3
An alternative diagnosis is less likely than PE 3
Heart rate > 100 beats per minute 1.5
Immobilisation for more than 3 days or surgery in the previous 4 weeks 1.5
Previous DVT/PE 1.5
Haemoptysis 1
Malignancy (on treatment, treated in the last 6 months, or palliative) 1

Question 24

If the score is above 4 what is done?

Answer 24

= PE is ‘likely’ (more than 4 points) arrange an immediate computed tomography pulmonary angiogram (CTPA). If there is a delay in getting the CTPA then give low-molecular weight heparin until the scan is performed.

Question 25

If the score is below 4 what is done?

Answer 25

a PE is ‘unlikely’ (4 points or less) arranged a D-dimer test. If this is positive arrange an immediate computed tomography pulmonary angiogram (CTPA). If there is a delay in getting the CTPA then give low-molecular weight heparin until the scan is performed.

Question 26

If the patient has allergy to contrast/renal failure what is done instead of CTPA?

Answer 26

V/Q scan