Pulmonary Embolism

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Pulmonary Embolism

• Dr Felix Woodhead
• Consultant Respiratory Physician

2
Pulmonary Embolism

• Part of VTE
• Potentially fatal
• Can complicate hospital admission
• Preventable
• Tests poor

3
Risk factors

• Surgery
• Abdominal
• Lower limb
• Obstetric
• Malignancy
• Previous VTE

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Clinical Probability

• Wells score
• Geneva criteria
• Is a major risk factor present? 1
• Is there no other explanation? 1
• Score
• 2 High probability
• 1 Intermediate probability
• 0 Low probability

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D-dimer

• Only useful if NEGATIVE
• ? by many things (including pregnancy and
  infection)
• Used only after assessment of clinical
  probability
• Not used if high clinical probability

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Imaging

• CTPA in most places
• V/Q
• only if normal CXR and no cardiopulmonary disease
• Intermediate scan requires follow-up imaging
  (CTPA)
• Doppler USS if DVT (no need for resp imaging)

7
Screening for thrombophilia/cancer

• Thrombophilic abnormality occurs in 25-50 VTE
• Usually interacts with environment (esp
  oestrogens), and risk is multiplicative
• Does not predict risk of recurrence
• Screen for cancer with bloods, clinical picture
  and CXR only

8
Treatment

• Thrombolysis only in massive PE (circ collapse)
• Thrombolysis controversial if RV impairment
• Anticoagulate with LMWH then warfarin for
• 4-6/52 if associated with temporary risk factor
• 3/12 if no risk factor (BTS), US recommend 6/12
• ?unfractionated heparin initial bolus

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Pulmonary Arterial Hypertension

• Dr Felix Woodhead
• Consultant Respiratory Physician

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Findings

• Exertional breathlessness
• Exertional chest pain and presyncope
• Normal radiology if idiopathic
• Normal PFTs if idiopathic
• ? systolic PAP on echo only if TR

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Defined by RHC

• mPAP
• gt 25 mmHg at rest (normal 12-16 mmHg)
• gt 30 mmHg on exertion
• Cardiac Output
• Cardiac Index (CO/height2)
• Pulmonary Vascular Resistance

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Causes

• Left ventricular impairment (PCWP gt 15)
• LVF
• Mitral valve disease
• Increased pulmonary blood flow (L?R shunt) ?
  Eisenmengers syndrome
• Hypoxaemia (cor pulmonale)
• Chronic Thromboembolic (CTEPH)
• HIV
• CTD (SSc etc)
• Idiopathic (IPAH)

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Investigations

• PFTs
• CTPA
• Echo ( bubbles)
• 6 minute walk
• Right Heart Catheter
• (traditional) pulmonary angiogram

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Treatment

• Treatment of associated causes
• LV disease
• O2 for cor pulmonale
• Warfarin (for all)
• Calcium channel blockers little used now
• Endothelin receptor blockers Bosentan,
  sitaxentan
• PDE4 antagonists Sildenafil etc
• Prostaglandins
• Nebulised
• Continuous IV via Hickman line

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Sleep medicine

• Dr Felix Woodhead
• Consultant Respiratory Physician

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Obstructive sleep apnoea/hypopnoea Sx

• Periodic reduction of airflow at night
• Caused by ostruction (cf central apnoea) due to
  reduced muscle tone in a suceptible airway
  (obesity)
• Apnoea no airflow for 10 s
• Hypopnoea 50 airflow in 10 s
• AHI (apnoea/hypopnoea index) no of events/hr
• AHI
• 5-14 mild
• 15-30 moderate
• gt30 severe

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Symptoms

• Sleepiness (daytime hypersomnolence)
• Epworth Sleepiness Score
• Witnessed apnoeas
• Nocturia
• Hypertension
• Reduced concentration
• Reduced libido
• Tendency to cor pulmonale, esp in COPD

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Diagnosis

• Overnight oximetry
• Good screening esp in obese
• Cannot be used to exclude OSAHS
• Limited PSG
• Useful initial test in young, non-obese
• Full PSG

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Treatment

• Only if symptomatic
• AHI gt15, desat index gt10/hr
• Nasal CPAP
• fixed
• Autotitrating device

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Domiciliary NIV

• For ventilatory failure
• Other treatments
• Low flow O2 (with care)
• Treatment of sleep disordered breathing
• Hallmark of ventilatory failure is ?pCO2