Respiratory Medicine:Asthma and COPD

Dr Rickbir Singh Randhawa

FY1

Definition:Asthma

Chronic inflammatory airway disease characterised by reversible airway obstruction, airway hyper-responsiveness and bronchial inflammation.

Three factors contribute to reversible airway narrowing:1. Bronchial smooth muscle contraction triggered by a

variety of stimuli2. Mucosal swelling/inflammation caused by mast cell

and basophil degranulation- release of inflammatory mediators

3. Increased mucus production

Definition:COPD

Chronic progressive lung disorder characterized by airway obstruction with little or no reversibility. It includes the following:

Emphysema: defined histologically as permanent destructive enlargement of air spaces distal to the terminal bronchioles

Chronic Bronchitis: defined clinically as a chronic cough with sputum production on most days for 3 months per year over 2 successive years.

AetiologyAsthma

Genetic factors-+VE family Hx, atopic (eczema, allergic rhinitis),

linkages to multiple chromosomal locations genetic heterogeneity

Environmental triggers-Allergens (House dust mite, pollen, pets (fur)), cigarette

smoke, viral URTI, occupational allergens (isocyanates-spray paints, epoxy resins-adhesives/fibreglass fabrics)

Aetiology/Risk factorsCOPD

Bronchial and alveolar damage due to environmental toxins- smoking (cigarette smoke)

Indoor air pollution (such as solid fuel used for cooking and heating)

Outdoor air pollutionOccupational dusts and chemicals (vapours, irritants, and

fumes)Frequent lower respiratory infections during childhood.Rare cause is α1-antitrypsin deficiency (<1%) consider in

non smokers or in younger patients

HistoryAsthma

Intermittent wheezeBreathlessness (dyspnoea)Cough (often nocturnal)Occasionally sputumDiurnal variation in symptoms/ peak flow- morning dips

of peak flow recordings

HistoryAsthma: Precipitating factors

Cold airExerciseAllergens (house dust mite, pollen, pets-animal fur)EmotionsSmoking/passive smoking exposureViral URTIHx of atopy (eczema/hayfever-allergic rhinitis)FHxDrugs (Beta blockers, NSAIDS- ask OTC meds)-

OSCE !

HistoryAsthma: things to also ask!

Precipitating factors if presentCompliance with medicationReliever usage (inhaler) – gauge severityOccupational Hx-causeSleep- interference? SeveritySmoking HxEczema/hayfever- atopyDays off school/work – gauge severityRemember CROSSED mnemonic!

HistoryCOPD

Chronic breathlessnessChronic Cough/sputum productionWheezeSmoker!Minimal diurnal variation in symptoms compared to

asthmaAge of onset >35 years (Rare cause is α1-antitrypsin

deficiency (<1%) consider in non smokers or in younger patients)

Clinical signs O/EAsthma COPD

TachypnoeaUse of accessory muscles of

respirationHyper inflated chest (reduced

chest expansion)Hyper resonant percussion noteReduced air entryPolyphonic wheeze

TachypnoeaUse of accessory muscles of

respirationPurse lip breathingHyper inflated chest (reduced chest

expansion)Hyper resonant percussion noteReduced air entry-prolonged

expirationWheeze, crackles if infective

exacerbation cyanosis

Severity of AsthmaModerate exacerbation:Increasing symptomsPEF >50-75% of best or predictedNo features of severe asthmaSevere exacerbation:Unable to complete sentences in one breathPEF 33-50% of best or predictedRR ≥ 25/minHR ≥110/min

Severity of AsthmaLife threatening attack: Any ofPEF <33% of best or predictedSilent chestCyanosisFeeble respiratory effortHypotensionExhaustion/confusion/coma (CO2 retention)ABG: normal or high CO2 (normal PaCO2 4.6-6.0 kPa) PaO2 <8kPa/O2 sats <92%Low pH <7.35 acidosis (CO2 retention)

Severity of COPDSeverity FEV1 (% predicted)

Mild ≥80%But FEV1/FVC <70%

Moderate 50-79%

Severe 30-49%

Very Severe <30%

InvestigationsAsthma

Acute exacerbation:Peak flow- PEF reading to classify the severityBasic Obs include pulse oximetry- classify severityABG-respiratory failureCXR- exclude differentials i.e. pneumothorax, pneumoniaBloods- FBC (raised WCC infective exacerbation),

U+E’s, CRPBlood culture (febrile)Sputum culture

InvestigationsAsthma

Chronic Asthma:PEF monitoring with peak flow diary- diurnal variation >20%

on ≥3days a week for 2 weeks with morning dips in readings.Pulmonary function test- obstructive defect with

improvement of FEV1 usually >15% improvement after a trial of a Beta 2 agonist.

Bloods- eosinophilia, raised IgE levels in atopic asthma. Skin prick tests- help identify any allergensAspergillus antibody titres- for allergic aspergillus lung

disease

InvestigationsCOPD

Acute exacerbation:ABG- respiratory failureBloods- FBC (raised WCC infection),U+Es, CRPBloods cultures if febrileSputum culture CXR –exclude differential i.e. pneumothorax, pneumoniaECG- cor pulmonale right axis deviation (RVH)

InvestigationsCOPD

Chronic COPD:Spirometry/pulmonary function tests- obstructive defect

FEV1/FVC <70% also with FEV1<80% predicted CXR- normal or show lung hyperinflation( >6 anterior ribs seen,

flat hemi-diaphragms), large central pulmonary arteries, decreased peripheral vascular markings

ABG- hypoxia and/or hypercapniaBloods- FBC (increased Hb and PCV due to secondary

polycythaemia secondary to hypoxia).ECG and echocardiogram- cor pulmonale, pulmonary hypertensionα1-antitrypsin levels- in young patients or with minimal smoking

Hx

Obstructive vs Restrictive defectSpirometry/PFTFEV1 FVC FEV1/

FVCObstructive lung

diseaseDecreased (<80%) Decreased Decreased

(<0.7)

Restrictive lung disease

Decreased Decreased (<80%) Normal (>0.7) or increased

ManagementAcute life threatening Asthma

Start Rx before Ix ABCDE!Oxygen 15L NRB- sit patient up, 02 sats 94-98%/intubateSalbutamol- 5mg Nebulised, back to back Nebs Hydrocortisone 100mg IVIpratropium bromide 0.5mg nebulisedTheophylline (aminophylline) IVMagnesium sulphate 2mg IV if no improvementRemember OSHIT! Mnemonic Normal or high CO2 is a very worrying sign- get early

anaesthetic/ITU r/v

Management Chronic AsthmaChronic Asthma

Chronic Asthma ManagementAsthma Management The BTS Stepwise ApproachRx started at the step most appropriate to the severitySTEP 1: SABASTEP 2: Step 1 + ICSSTEP 3: Step 2 + LABA &/or ↑ ICS doseSTEP 4: Step 3 + leukotriene receptor antagonist

(montelukast)/theophyllineSTEP 5: Step 4 + oral steroids- refer to asthma clinicStep down Rx if symptom control is good for >3 monthsEducate on proper inhaler techniques and routine

monitoring of peak flow.Develop an individual Mx plan to avoid triggers

Management Acute exacerbation COPD

ABCDE approach!Controlled oxygen therapy 24-28% Venturi mask vary

according to ABG- target sats 88-92%Nebulized bronchodilators- salbutamol 5mg (back to back

NEBS) and ipratopium bromide 0.5mg (4-6 hourly)Steroids- IV hydrocortisone 200mg or PO prednisolone

40mg (7-14 days)Abx- if evidence of infection see local guidelinesNIV- if severe respiratory acidosis or medical Rx shows

no improvement e.g. BIPAP- type 2 respiratory failure

Management Chronic COPD

Non Pharmacological MxSmoking CessationNutrition- Rx poor nutrition e.g. fortisipsObesity- healthy diet/lifestyle, regular exercisePulmonary Rehabilitation- graded exercise therapy to

increased exercise tolerance

Chronic Management COPD

Chronic Management COPDMucolytics- aid chronic productive coughCBT/Antidepressants- chronic illnessCriteria for LTOT:Only for those stopped smoking- fire risk!PaO2<7.3 kPa clinically stable- this value should be stable on

two occasions >3 weeks apartPaO2 7.3-8.0 kPa with signs of pulmonary hypertension/cor

pulmonaleTerminally ill patientsSurgical Mx- bullectomy (recurrent pneumothoraces), lung

volume reduction surgery

Inhalers-Quick run throughSABA-e.g. salbutamol (ventolin) “blue inhaler”LABA-e.g. salmeterol (serevent)SAMA- e.g. ipratopium bromide (atrovent)LAMA-e.g. tiotropium bromide (spiriva)IC Steroids:Becotide (beclometasone), Pulmicort (budesonide),

Flixotide (fluticasone)Combination ICS:Seretide (fluticastone + salmeterol)Symbicort (budesonide + formoterol)

Inhaler: Explaining how to use it

1. Remove the dust cap from the inhaler device. 2. Shake the device. Remember the canister holds a suspension of drug, and this needs to

be shaken to ensure a uniform distribution of the drug particles. 3. If you have not used the inhaler for a week or more, or it is the first time you have

used the inhaler, spray it into the air before using it to check that it works. 4. Hold the inhaler upright with you forefinger on the top of the canister. 5. Breathe out as far as is comfortable. 6. Place the mouthpiece in your mouth between your teeth, and close your lips around it. 7. Start to breathe in slowly and deeply, and at the same time, activate the inhaler by

pressing down on the canister. When the canister is pushed down, a valve delivers a measured dose of drug in a fine mist.

8. Hold your breath for as long as is comfortable, then breathe out as normal. 9. If you are instructed to take 2 puffs, wait for about 30 seconds and repeat this process. 10. Do not release two puffs at the same time. This will increase the likelihood of

deposition at the back of the throat and reduce the amount of drug reaching the lungs. 11. Finally, replace the cap on the inhaler.

Clinical scenarioA 64 year old gentleman presents to A&E with increasing

SOB over the last 3 days. This is associated with a cough productive of thick, green sputum. He has a past medical history of “asthma”, but he has smoked 50 cigarettes a day for the past 40 years. On examination he is tachypnoeic, tachycardic, O2 sats 85% on air, he is using his accessory muscles to breathe. Auscultation reveals bilateral diffuse coarse crepitations and widespread wheeze

QuestionsWhat are your main differential diagnoses for this gentleman?How would you investigate this gentleman?Initial management in acute setting?Long-term management?Can you tell me about the pathophysiology of COPD? ie.

Clinical and histopathological definitionsCan you tell me some risk factors for COPD? What are the criteria for mild, moderate, severe and very severe

COPD? What are the criteria for use of long term oxygen therapy (home

oxygen)?

THANK YOU FOR LISTENING

ANY QUESTIONS?