RESP - Pulmonary vascular disease

Question 1

(3) Causes of Pulmonary Hypertension

Answer 1

1. Increased left atrial pressure: eg mitral stenosis, LVF, diastolic dysfunction
2. Increased pulmonary blood flow: eg left to right shunts, high flow states, excess central volume
3. Increased pulmonary vascular resistance
   a. Vasoconstriction - low alveolar O2 (including hypoventilation)
   b. Obstruction – embolism, primary pulmonary hypertension
   c. Obliteration - arteritis, emphysema, pulmonary fibrosis

Question 2

How may pulmonary hypertension lead to right ventricular failure?

Answer 2

PULMONARY HYPERTENSION
(mean PA pressure > 25mmHg, PVR > 3 Woods units) -> RIGHT VENTRICULAR DILATATION
& HYPERTROPHY

hence increased systemic venous pressure -> peripheral oedema

And poor cardiac output

Question 3

What might be the symptoms of patients with pulmonary vascular disease?

Answer 3

• Shortness of breath: May be sudden or of gradual onset
• Syncope/collapse
• Lassitude
• Swelling of ankles
• Cough
• Chest pain (often pleuritic)
• Haemoptysis

Question 4

What might be the signs of patients with pulmonary vascular disease?

Answer 4

•Signs of pulmonary hypertension
–Right ventricular heave
–Loud P2, 4th heart sound
–Prominent ‘v’ wave in the JVP

•Signs of right heart failure
–Elevated JVP ± v waves
–Tricuspid regurgitation
–SOA, ascites, pulsatile liver

•Signs of the cause

Question 5

A 26 woman presents with a sudden episode of collapse. At presentation she has a reduced conscious state. She has a HR of 120, BP 70/50, Saturation 90% on room air, RR 35. Her chest sounds are normal (no focal signs). JVP 5cm, heart sounds seem normal (? 3rd heart sound) ECG shows sinus tachycardia & right ventricular strain pattern CXR is clear. ABG’s pH 7.48, PaCO2 30mmHg, PaO2 55mmHg, HCO3 24

DDx?

Answer 5

DDx:

• massive PE
• cardiac tamponade
• constrictive pericarditis

Evidence of severe physiological compromise
–Shock with reduced conscious state
–Right heart strain/failure
–Severe type 1 respiratory failure

Question 6

(4) Sources of PE

Answer 6

• DVT (most common)
• Fat (e.g. post trauma)
• Air (post laparoscopic surgery)
• Amniotic fluid

Question 7

What is the pathogenesis of a thrombosis?

Answer 7

•Stasis
–Inpatient (eg heart failure), after some surgical procedures
–Prolonged immobility

•Hypercoagulable state
–Genetic abnormalities, factor deficiencies
–Malignancy
–Polycythaemia
–Pregnancy, medication

•Abnormal vessels eg post trauma

Question 8

Features of PE

Answer 8

–Collapse and hypoxaemia
–Widened Aa gradient of unclear cause
–Pleuritic chest pain (and no clear cause)
–Unexplained breathlessness
–Evidence of pulmonary hypertension (and no clear cause)

Question 9

Diagnostic tests for PE

Answer 9

• CTPA (test of choice)
• Ventilation/Perfusion (VQ) scan (normal rules out PE)
• ECG (S1Q3T3, RV strain suggestive) but not specific
• Echo: maybe useful in massive PE
• D-dimer: good sensitivity but not specific. (hence normal -> rule out PE)

Question 10

Treatment of PE

Answer 10

•Respiratory support
•Haemodynamic support
•Anticoagulation
–Mortality from PE drops to 2-8%
–As soon as possible (once safe)
–Heparins: LMWH vs unfractionated (risk of bleeding, renal impairement)
–Warfarin (overlap with heparin)

•C.f. Thrombolytic therapy
–Still no evidence of improved mortality but it reduces some of the complications of PE
–Reserved for the most severe cases

•IVC filter
–If there is failure of or a contraindication to anticoagulation or if further PE might be lethal
–No clear mortality benefit

Question 11

A 65yo man with known COPD presents with 2 weeks of worsening SOB and associated ankle swelling.
Examination reveals a saturation of 88% on RA, normal BP and heart rate/rhythm. RR 22 with clear use of accessory muscles. Chest examination shows signs of hyperinflation. JVP 5cm with SOA ++

DDx?

Answer 11

COPD and right heart failure (Cor pulmonale)

Question 12

Ix of COPD and right heart failure (Cor pulmonale)

Answer 12

–Basic bloods (FBE, UEC, LFT)
–Arterial blood gases and 6MWT
–CXR
–Lung function
–?sleep study
–echocardiogram

Question 13

Mx of COPD with evidence of RHF

Answer 13

• Cease smoking (if he hasn’t already)
• Oxygen (to keep at 88-92% sat O2)
• Pulmonary rehab
• Bronchodilator therapy
• Diuretics

Question 14

A 24yo woman presents 3 weeks after the delivery of her first child. She is having episodes of near syncope and is SOB on minimal exertion. She has been feeling SOB for about 6 months. On examination she has, a right ventricular heave, a loud P2, a prominent v wave in her JVP, and has sat’s of 93% on RA. The rest of her examination is normal

DDx?

Answer 14

Pulmonary hypertension (evidenced by enlarged pulmonary arteries & RV grossly enlarged on XR)

Question 15

(5) diagnostic classification of pulmonary arterial hypertension

Answer 15

1. Pulmonary arterial hypertension; idiopathic, familial etc
2. PH with left heart disease
3. PH with chronic lung disease/hypoxemia
4. PH due to chronic thrombotic/embolic disease
5. Miscellaneous; e.g. sarcoidosis

RHF does NOT cause Pulmonary HTN. The other way around is possible

Question 16

Rx of pulmonary arterial hypertension + NYHA Class II/III/IV. What factors determine the treatment?

Answer 16

1. Oral anticoagulants ± diuretics ± oxygen ± digoxin
2. Acute Vasoreactivity Testing

If positive:
Oral CCB (Ca2+ channel blocker).
- If sustained response -> continue CCB.
- If no sustained response -> step 3.

If negative & NYHA II, III:

3. • Endothelin Receptor Antagonists (Bosentan, ambrisentan, macitentan)
   • PDE5 inhibitor (sildenafil, tadalafil)
   • Prostanoid Analogues (Inh. iloprost , SQ treprostinil, beraprost).
   • Try combination therapy if failing

If negative & NYHA IV:
4. Epoprostenol (Bosentan, Treprostinil)

If no improvement or deterioration up till here:
5. Atrioseptostomy ± Lung Transplantation

Rx depends on results of acute vasoreactivity testing & NYHA classes.