Pulmonary Embolism Dr Felix Woodhead Consultant Respiratory Physician

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

Risk factors Surgery –Abdominal –Lower limb Obstetric Malignancy Previous VTE

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

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

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)

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

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

Pulmonary Arterial Hypertension Dr Felix Woodhead Consultant Respiratory Physician

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

Defined by RHC mPAP –> 25 mmHg at rest (normal mmHg) –> 30 mmHg on exertion Cardiac Output Cardiac Index (=CO/height 2 ) Pulmonary Vascular Resistance

Causes Left ventricular impairment (PCWP > 15) –LVF –Mitral valve disease Increased pulmonary blood flow (L→R shunt) → Eisenmenger’s syndrome Hypoxaemia (cor pulmonale) Chronic Thromboembolic (CTEPH) HIV CTD (SSc etc) Idiopathic (IPAH)

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

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

Sleep medicine Dr Felix Woodhead Consultant Respiratory Physician

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 –>30 = severe

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

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

Treatment Only if symptomatic AHI >15, desat index >10/hr Nasal CPAP –fixed –Autotitrating device

Domiciliary NIV For ventilatory failure Other treatments –Low flow O 2 (with care) –Treatment of sleep disordered breathing Hallmark of ventilatory failure is ↑pCO 2