DR REBECCA THOMAS CONSULTANT RESPIRATORY PHYSICIAN YORK DISTRICT HOSPITAL
Definition Guidelines contact complicated definitions Central to this is Presence of symptoms Variable airflow obstruction
Diagnosis Careful clinical history Characteristic pattern of symptoms Demonstration of variable airflow obstruction Spirometry and reversibility Peak flow variability Bronchial challenge testing Evidence of airway inflammation To support diagnosis
What is Asthma? Smooth muscle dysfunction Airway inflammation Broncho constrictor Bronchial hyper-reactivity Hyperplasia Inflammatory mediator release Inflammatory cell infiltration/activation Mucosal oedema Cellular proliferation Epithelial activation Airway remodelling Symptoms/exacerbations
Peak Flow Monitoring > 20% diurnal variation on 3d in a week for 2 weeks on PEF diary Specificity > Sensitivity 75 vs 43%; Hunter et al, CHEST 2002 Easy to use and read Very operator dependent
Spirometry/Reversibility FEV1 15% (and 200ml) increase after SABA or steroid tablets Technique dependent Sensitivity/specificity 61/60%
Spirometry/Reversibility
Full lung function tests Repeat spirometry
Bronchoprovocation Testing Histamine or Methacholine Challenge Used in difficult cases Airway hyper-responsiveness can be determined by challenge testing The concentration of agent causing a 20% fall in FEV1, from baseline = PCO 2 91% sensitive and 90% specific in a hospital setting Hunter et al, CHEST 2002
Histamine or Methacholine Challenge
Airway Inflammation For patients not responding to standard treatment Sputum eosinophil count Blood eosinophil levels N.B. parasitic infections, Churg-Strauss syndrome, eosinophilic pneumonia Exhaled nitric oxide (not good in smokers/urti) Measures of airway inflammation correlate with steroid therapy, asthma control and exacerbation rate
Why is Asthma Important? Asthma UK reviewed phone survey data drawn from 500 people with severe asthma symptoms from across the UK and 1542 structured telephone interviews with a random sample of people with mild, moderate and severe asthma. The survey found:
Why is Asthma Important? Annual impact of asthma on typical PCO
Why is Asthma Important?
Asthma Deaths: 0-19y: 1979-2011
Asthma Deaths: 20y+: 1979-2011
Asthma Deaths: Medications 56% were prescribed 6+ 39% 12+ SABA in year before death Patients >12 short acting reliever inhalers in last 12m urgent review 5 (3%) patients died on LABA monotherapy
Asthma Deaths: Key Findings 19 (10%) of those who died did so within 28 days of being treated in hospital In 13 (68%) of these patients, there were potentially avoidable factors in relation to both their discharge into the community and follow-up arrangements At least 40 (21%) had attended an emergency department with asthma in the previous year Only 23% of people who died had a personal asthma action plan
Management
Complete Control (BTS/SIGN) No daytime symptoms No night-time awakening due to asthma No need for rescue medicayion No exacerbations No limitations on activity including exercise Normal lung function (in practical terms FEV1 and/ or REF > 80% predicted or best) Minimal side effects from medication Aim is control of the disease
Asthma Symptoms in Past 4 Weeks
Stepwise Approach (BTS/SIGN)
Step 1 Mild asthmatic may use as required ß-2 agonist alone Side effects are dose related
Step 2 Inhaled corticosteroids should be considered for patients with any of the following asthma-related features Asthma attack in the last two years Using inhaled ß 2 agonists three times a week or more Symptomatic 3x/wk or more Waking one night a week
Step 2: Regular Preventer Therapy Inhaled corticosteroids have revolutionised asthma therapy Inhibit the inflammatory process symptoms and improved lung function and exacerbation rate
Dose Response to Beclomethasone Dipropionate Mean Increase in Daily PEFR
High Dose ICS: Risks Vs Benefits High dose ICS aim to reduce the risk of asthma symptoms and exacerbations/attacks The potential risks to asthma patients of high doses of ICS include Osteoporosis Cataract formation and glaucoma Skin thinning Adrenal suppression Diabetes
ICS: Conclusions Risk versus benefit favours steroid use Judicious use can prevent excess requirements Systemic effects can be decreased by using spacer device, DPI or mouth rinsing Different preparations and devices require difference doses
Step 3: Long Acting Beta-2 Agonists FACET trial 852 patients randomised to 4 groups, followed up on year Use of daytime rescue medication was less with LDS + LABA than high dose ICS alone Forced Expiratory Volume in One Second (FEV1) during the Study.
Step 3: Long Acting Beta-2 Agonists Meta-analysis of increased dose of inhaled steroid or addition of salmeterol in symptomatic asthma PEFR and FEV1 low dose steroid + salmeterol compared with high dose inhaled steroids Salmeterol group had higher percentage of days and nights without symptoms or need for rescue therapy No evidence for any increase in exacerbations
Step 4: Increase ICS ± Other Agents Why haven t we achieved control? Alternative diagnosis Adherence issues Technical difficulties What can we do next? More medication Device or drug alternatives Referral
Why Haven t You Achieved Control? Alternative diagnosis Adherence Technical difficulties Consider referral
Adherence Issues
Adherence Issues 30-50% do not take medication as recommended HCP have a duty to help patients make informed decisions about treatment and use appropriately prescribed medicines to best effect Computer repeat-prescribing systems provide a practical index of adherence and should be used in conjunction with a non-judgemental discussion about adherence
Adherence Issues In clinical practice it is generally considered that combination inhalers aid compliance Combination inhalers are recommended to: Guarantee that the LABA is not taken without ICS Improve inhaler adherence
Technical Difficulties
Montelukast Vs BDP
Montelukast
Theophylline 62 patients only Significant improvements with theophylline in PEFR, FEV1 and symptom scores Theophylline levels need regular monitoring
Monitoring in Primary Care Symptomatic asthma control Lung function, assessed by spirometry or by PEF Asthma attacks, oral corticosteroid use and time off work or school since last assessment Inhaler technique Adherence Bronchodilator reliance Possession of and use of a self maangement plan/ personal action plan
Stepping Down Review treatment every 3-6 months Review the use of ICS routinely in patients with asthma A stepwise reduction may be clinically appropriate Recommended that ICS decreased by 25-50% at each step Control is maintained by stepping up treatment as necessary and stepping down when control is good. NICE
Conclusions Asthma has a significant burden of morbidity and mortality We need to aim for total control Management is based on simple steps Steps which can be used up and down If control isn t achieved consider an alternative diagnosis, a technical issue and check adherence