5Alveolar capillary bed Obscure the title of this slide and get the group to guess what this is.Emphasise that this is an intricate and delicate structure that is blown apart by cigarette smoke!
6Asthma“A disease characterised by variable dyspnoea due to widespread narrowing of the peripheral airways, varying in severity over short periods of time, either spontaneously or as a result of treatment.”This is the easy bit!Get the students to volunteer the definition.Look for the key words – variable- reversibleThey will also come up with inflammatory. You can mention that COPD also involves inflammation, but that the processes and cells involved are different in asthma and COPD
8Worsening Asthma Increased symptoms Reliever medication less effective Especially nocturnal symptomsReliever medication less effectiveTend to use more frequentlyExercise restrictionsVery vulnerable to severe “attack”At risk of death: previous admission with asthma or ongoing poorly controlledNew presentation: consider inhaled FB
9Signs of Severe Asthma Difficulty speaking Dyspnoea at rest > 25 breaths per minPossible wheezePossible coughTachycardia at rest > 110 beats per minPulse oximetry < 96% at rest on air(PEFR < 50% of best / predicted)
10Life Threatening Asthma Poor respiratory effort / silent chestMay not appear distressedFatigue / exhaustionAgitation / reduced level of consciousnessConfusionCyanosisPulse oximetry < 92% at rest on air
11Treatment of Acute Asthma High dose bronchodilators2.5mg neb salbutamol or Spacer (up to 10 puffs salb)Oral steroids40 – 50mg for 5 daysOxygenIf O2Sats <92%Aim to raise to at least 95%Call for medical assessment
12Treatment of Acute Asthma Review every 15 minsRepeat bronchodilators if poor response (PEFR 50-75% pred)Salb 5mg & add ipratropium 500mcg (spacer 8 puffs ipratropium)Referral to hospitalConsider if PEFR < 75%, late in the day, previous severe attackGeneral concern or poor response to treatment
13Follow up of patients All should be followed up within 48 hours Ensure patients not admitted have clear instructions about when to call for helpBronchodilator not lasting 4 hours, increased symptoms again, PEFR 50-70%
14COPD“Chronic obstructive pulmonary disease (COPD) is characterised by airflow obstruction. The airflow obstruction is usually progressive, not fully reversible and does not change markedly over several months. The disease is predominantly caused by smoking.”(NICE 2004)Start the session by pointing out the main features:ChronicProgressiveNon-variableNon-reversible
16Alveoli Emphysema: a result of the air sacs being “dissolved away” and also lessSupport for theairwaysAlveoli
17Alveolar capillary bed Obscure the title of this slide and get the group to guess what this is.Emphasise that this is an intricate and delicate structure that is blown apart by cigarette smoke!
18Persistent and progressive Is it asthma or COPD?AsthmaCOPDSmoker or ex-smokerPossibleNearly alwaysSymptoms under 45 yrsOftenRareChronic productive coughUncommonCommonPersistent and progressiveBreathlessnessVariableThis is the table from the NICE guidelinesIt is not exhaustive.Talk aboutFH and PH asthma and atopyMention undiagnosed childhood asthmaOccupationVariability of symptoms – Asthma has ‘good and bad days’, COPD has ‘bad days and worse days’Night time waking with breathlessness and / or wheezeCommonUncommonSignificant diurnal or day to day variation in symptomsCommonUncommon
19Assessment of acute COPD Breathlessness at rest?Rapid deterioration / exhaustion?Cyanosis?Acute confusion?Worsening swollen ankles?Significant comorbidity?Cardiac or diabetesAbility to cope at home?Pulse oximetry (< 90% usually admit)
20Management of COPD exacerbation Salbutamol2.5mg neb (4 – 8 puffs spacer)Oxygen (usually 24% – 28% - 40%)Maintain sats between 90 – 93%Consider prednisolone (30mg 7-14 days)Consider antibiotics (usually amoxycillin)Consider an ECGif suspecting cardiac comorbidityNew home care service next year?
27Oxygen Saturation (SaO2) Oxygen carried in bloodstream bound to haemoglobin (& small amount in plasma)1 Hb can carry 4 O2 = 100% saturatedPulse oximeter measures the average % saturation of haemoglobin in sample
28Pulse Oximetry Measures light absorbed by haemoglobin in blood When oxygenated – red frequencyWhen deoxygenated – blue frequencyNeeds to record pulsatile blood flow to ensure arterial bloodNormal values = or > 97%Hypoxia = or < 96%Significant hypoxia < 92%
29Pulse Oximetry – problems / limitations Poor perfusionVascular disease, vasoconstriction, (cold hands), irregular heart rhythms, severe shock –may give falsely low readingsNail varnish – falsely low readingsCarboxyhaemoglobin – very bright red – SpO2 readings will be falsely higherAnaemia – will give falsely high readingsLess haemoglobin, less O2 carriedSpO2 cannot determine CO2 Levels or actual O2 levels