Pulmonary embolism and hypertension

Question 1

Pulmonary embolism

Answer 1

Blockage of a pulmonary artery by blood clot, fat, tumour or air

Question 2

Pulmonary infarction

Answer 2

If blood flow and oxygen to the lung tissues is compromised the lung tissue may die

Question 3

Thromboembolic disease (2)

Answer 3

Pulmonary embolism

Deep venous thrombosis

Question 4

Proximal (ileo-femoral) DVT

Answer 4

Most likely to embolise

Most likely to lead to chronic venous insufficiency and venous leg ulcers

Question 5

Distal (polpiteal) DVT

Answer 5

Least likely to embolise

Question 6

Clinical presentation of DVT

Answer 6

Whole leg or calf

Swollen, hot, red, tender

Question 7

Differential diagnosis of DVT

Answer 7

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

Question 8

Investigation for DVT

Answer 8

Ultrasound-doppler leg scan

CT scan

Question 9

Clinical presentation of large pulmonary emboli

Answer 9

Cardiovascular shock
Low BP
Central cyanosis
Sudden death

Question 10

Clinical presentation of medium pulmonary emboli

Answer 10

Pleuritic pain
Haemoptysis
Breathless

Question 11

Clinical presentation of small recurrent pulmonary emboli

Answer 11

Progressive dyspnoea
Pulmonary hypertension
Right heart failure

Question 12

Risk factors for pulmonary embolism and DVT

Answer 12

Thrombophilia - Family history, age, frequency, site
Contraceptive pill (especially if smokes)
Hormone replacement therapy
Pregnancy
Pelvic obstruction e.g. uterus, ovary, lymph nodes
Trauma- RTA
Surgery- pelvic, hip, knee
Immobility- long haul flight, bed rest
Malignancy
Pulmonary hypertension/ vasculitis
Obesity

Question 13

Clinical features and diagnosis of PE (symptoms)

Answer 13

Tachycardia
Tachypnoea
Cyanosis
Fever
Low BP
Crackles
Rub
Pleural effusion

Question 14

Clinical features and diagnosis of PE (ABGs)

Answer 14

Low PaO2 and low SaO2

PaCo2 normal/ low

Question 15

Clinical features and diagnosis of PE (CXR)

Answer 15

CXR normal early on before infarction
Pleural effusion
Basal atelectasis, consolidation

Question 16

Investigations for PE

Answer 16

ECG: Acute Right heart strain pattern
D-dimers usually raised
V/Q Isotope lung scan: 
 Sensitive for small peripheral emboli
 Perfusion defect before infarction
 Perfusion + ventilation matched defect after infarction
CT Pulmonary angiogram 
Leg and pelvic ultrasound
Echocardiogram: Acute RV dilatation

Question 17

Prevention of DVT

Answer 17

Early post-op mobilisation
Compression stockings
Calf muscle exercises
Subcutaneously low-dose low mol wt heparin perioperatively (Dalteparin)
Novel Oral AntiCoagulant medication
-Dabigatran - direct thrombin inhibitor
- Rivaroxaban/Apixaban- Factor X inhibitor

Question 18

Treatment for PE/DVT

Answer 18

A. Low mol wt low dose Heparin
Start warfarin at same time as heparin
B. OR Oral thrombin inhibitor (dabigatran)/ Factor X inhibitor (Rivaroxaban) on own from start
C. OR NOACs without LMWH
D. Tissue plasminogen activator (tPA)- tenecteplase
For large life threatening PE
E. IVC filter for recurrent PEs
F. Thrombo-electomy

Question 19

Action if over-anticoagulation

Answer 19

Address underlying cause
Stop anticoagulant
Reverse warfarin with vitamin K1
Reverse heparin with protamine
May need cover with prothrombin complex concentrate or fresh frozen plasma

Question 20

Normal mean pulmonary arterial pressure (mPAP)

Answer 20

12-20mmHg

Question 21

mPAP in Pulmonary hypertension

Answer 21

> 25mmHg

Question 22

Pulmonary Venous Hypertension

Answer 22

Left heart disease

Question 23

Pulmonary Arterial Hypertension

Answer 23

Walls of the smaller branches of the pulmonary arteries become thick and stiff

Question 24

Causes of pulmonary venous hypertension

Answer 24

Left Ventricular Systolic Dysfunction - Ischaemic
Mitral regurgitation/ Stenosis
Cardiomyopathy eg alcohol, viral

Question 25

Causes of secondary pulmonary hypertension

Answer 25

Hypoxic - COPD, OSA, Pulmonary fibrosis
Multiple PE- chronic thromboembolic PH
Vasculitis- SLE, systemic sclerosis
Drugs - appetite suppressants
HIV
Cardiac left to right shunt
Primary pulmonary hypertension

Question 26

Cor pulmonale

Answer 26

Right heart disease secondary to lung disease

Fluid retention due to hypoxia +/- right heart failure

Question 27

Clinical signs of pulmonary hypertension and right heart failure

Answer 27

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

Question 28

Investigation of pulmonary hypertension

Answer 28

ECG
CXR
SaO2 and arterial blood gases 
Pulmonary function incl diffusion capacity
Echocardiogram 
Cardiac Catheterisation – measure mPAP
D dimers and VQ scan if PE suspected 
CT Pulmonary Angiogram 
Cardiac MRI 
Auto-antibodies if vasculitis suspected

Question 29

Diagnosis of primary pulmonary hypertension

Answer 29

Diagnosis by exclusion of other secondary causes

Progressive SOBOE and signs of right heart failure

Question 30

Treatment of primary pulmonary hypertension

Answer 30

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 31

Treatment for chronic thromboembolic pulmonary hypertension (CTEPH)

Answer 31

Pulmonary arterial vasodilator - Riociguat
Pulmonary endarterectomy
Balloon angioplasty

Question 32

Risk factors for PE

Answer 32

Factors in vessel wall
Abnormal blood flow
Hypercoaguable blood