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Asthma & COPD. Finals Teaching 2013 Alison Portes FY1. Objectives. Main features of asthma and COPD Focus on clinicals – history, examination, investigations, management 10 minutes on each Quiz and summary of key points A few added extras…. Asthma. Asthma. Definition
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Asthma &COPD Finals Teaching 2013 Alison Portes FY1
Objectives • Main features of asthma and COPD • Focus on clinicals – history, examination, investigations, management • 10 minutes on each • Quiz and summary of key points • A few added extras…
Asthma • Definition • Pathophysiology • History • Examination • Investigations • Management • Acute • Chronic • Medications • Paediatric Asthma
Definition • Obstructive airways disease • Chronic • Inflammatory • Variable • Reversible • Hyperresponsiveness
Pathophysiology • Acute asthma airway changes- • Airway constriction • Mucus hypersecretion • Eosinophils • IgE mediated inflammatory response • degranulation of mast cells • histamine release • inflammatory cell infiltration • Chronic asthmaairway changes– airway remodelling • Smooth muscle hyperplasia / hypertrophy • Goblet cell hyperplasia
History • Full respiratory history plus… • Triggers (exercise, illness, cold, pets…) • Diurnal variation • Disturbed sleep • Atopy/family history of atopy • Occupation • Compliance with meds • GP/A&E/ITU attendances
Examination • Standard respiratory exam • ?Start at the back • Tachypnoea • Widespread polyphonic wheeze • Hyperresonant percussion note • Diminished breath sounds • Hyperinflated chest
Investigations • Bedside • PEF • Bloods • Blood gas – when and why? • Imaging • CXR – when and why? • Special tests • PEF monitoring • Spirometry - Bronchodilator challenge
Management - chronic asthma • BTS guidelines • Step 1: SABA only • Step 2: SABA & ICS 200-800 mcg/day • Step 3: add LABA (combined) • Step 4: ↑ ICS dose (stop LABA if no benefit), monteleukast • Step 5: help! Oral steroids…
Asthma Medications Beclomethasone Salbutamol Salmeterol Salmeterol plus flixotide Mechanism?
Acute severe asthma • PEFR 50-33% • RR ≥ 25 • HR ≥ 110 • Unable to complete sentences • But SpO2 >92% • Worse = life-threatening (silent chest, cyanosis, low SpO2) 33-92-CHEST • Better = moderate asthma
Management - Acute severe asthma • How would you like to manage this patient? • Immediate • A to E • Salbutamol 5mg via oxygen driven nebuliser • Repeat obs (SpO2, HR, RR) and PEF to assess for progression of severity and risk to life • If clinically stable and PEF >75%, can repeat Salbutamol nebs and consider oral prednisolone 40-50mg • Otherwise, add ipratropium nebs, IV hydrocortisone, consider magnesium sulphate IV and call for help!
Respiratory Failure • pO2 < 8 kPa • Type I • Normal/low pCO2 • V/Q mismatch/diffusion limitation • Atelectasis, pulmonary oedema, pneumonia, pneumothorax • Type II • ↑ pCO2 • ↓pH if acute • Ventilatoryfailure • COPD, neuromuscular disorders (GBS, MND), CNS depression (drugs, brainstem injuries) • Needs controlled O2 ± ventilation
Paediatric Asthma • Signs of chronic asthma/growth • Inhaler technique/spacers • Asthma vs. Viral induced wheeze • Differences in the BTS management guidelines • What age can a child do a peak flow? • Don’t let them leave without…
Communication • Please explain to Mr X how to correctly use his inhaler • Check understanding • If you haven’t used it for a while, spray in the air to check it works • Shake it • As you breathe in, simultaneously press down on the inhaler • Continue to breathe deeply • Hold your breath for 10 seconds or as long as you comfortably can, before breathing out slowly. • If you need to take another puff, wait for 30 seconds, shake your inhaler again then repeat • Advise on using a spacer
COPD • Definition • Pathophysiology • History • Examination • Investigations • Management • Chronic • Acute Exacerbation
Definition • Umbrella term – chronic bronchitis and /or emphysema • Airflow obstruction (FEV1/FVC < 0.7) • Usually progressive • Not fully reversible • Doesn’t change markedly over few months • Predominantly caused by cigarette smoking • Differentiation from asthma
Pathophysiology • Chronic bronchitis • Clinical diagnosis - chronic cough and sputum production on most days for at least 3 months per year for 2 years • Airway narrowing due to bronchiole inflammation, mucosal oedema and mucus hypersecretion • Emphysema • Pathological diagnosis - permanent destructive enlargement of distal air spaces • Destruction and enlargement of alveoli that reduces elastic recoil and results in bullae
History • Full respiratory history plus… • Smoking, smoking, smoking!! • Consider your differentials – ILD, bronchiectasis, malignancy, heart failure – and rule them out • Red flag symptoms
Examination • Look and comment! • Tar stains • Accessory muscles • Barrel chest • Crepitations • Wheeze
Investigations • Bedside • Sputum, ECG • Bloods • FBC, U&E, CRP, blood cultures, ABG • Imaging • CXR • Echo • Special tests • Spirometry • α1-antitrypsin levels
Management of Chronic COPD • Long term • Conservative – smoking cessation, pulmonary rehabilitation, flu vaccination • Medical – LTOT (only if not smoking), bronchodilators, antimuscarinics, home nebulisers, steroids (can consider if more than 2 infective exacerbations/year), prophylactic antibiotics • Surgical – Transplant, lobectomy, bullectomy • LTOT criteria • PaO2 <7.3 kPa on air during period of clinical stability • PaO2 7.3-8.0 kPa and signs of secondary polycythaemia, nocturnal hypoxaemia, peripheral oedema or pulmonary hypertension • At least 15 hours a day
Antimuscarinics Long-acting Short-acting Ipratropium Tiotropium Mechanism?
Acute Exacerbation of COPD • Sustained worsening of symptoms from usual state • Beyond daily day-day variation • Acute in onset • Often associated with • ↑ SOB, ↑ cough, ↑ sputum volume, ↑ sputum purulence • Not pneumonia!
Management – exacerbation of COPD • How would you like to manage this patient? • Immediate • A to E • Maintain sats 88-92% (titrate to ABG) – O2 via Venturi mask • Corticosteroids (oral/IV) • Empirical antibiotics if purulent sputum • Salbutamol 5mg and Ipratropium via O2 driven nebulisers • Consider need for NIV – if desaturating/decompensating • Admit, chest physiotherapy
FEV1/FVC • Determines the severity of COPD • Describes the proportion of a person’s vital capacity (maximum air expelled after maximum inhalation) that can be expired in the first second. • Normal ~ 70% • Mild 50-70% • Moderate 30-50% • Severe <30%
Quiz • What is in a brown inhaler? • What are the features of life-threatening asthma? • List 4 classes of drug used to treat Asthma/COPD? • What are the criteria for LTOT? • What is the 2nd step in the BTS asthma ladder? And the 4th? • What level SpO2 should you aim for in COPD patients? • What is Spiriva?
Key Points • History and Examination – concentrate on doing the basics well • Investigations – what differential will it rule out? • Learn the essentials now and keep repeating them… • Acute severe/life-threatening asthma criteria • BTS asthma guidelines – the ladder • T1 vs T2 respiratory failure • LTOT criteria • Practice communication task – PEF, inhalers • Questions?
Reading Chest X-RaysRIP...ABCDE • Adequacy: • Rotation (symmetry of clavicles) • Inspiration (ribs) • Penetration (vertebral bodies) • Mention central lines, NG tubes, pacemakers etc • Airway: is the trachea central? • Boundaries and Both lungs: lung borders, consolidation, hazy etc • Cardiac: Heart size • Diaphragm • Everything else: soft tissue mass, fractures