Asthma in Day to Day Practice VIJAY.K.VANAM
Financial relationships: Disclosures Employed at Mercy Medical Center, Mason City. Nonfinancial relationships: I receive no financial gain from any pharmaceutical company.
Objectives Diagnosis and Management of Asthma Asthma and COPD Overlap Asthma and Obesity Asthma in Elderly Asthma during Pregnancy.
DIAGNOSIS No GOLD standard test Both Symptoms and airflow limitation should vary in time and intensity. Possible associations with triggers.
How to confirm VARIABILITY BD reversibility test ( >12% and >200 ml) Diurnal PEF variability ( >10%). Exercise Challenge Test ( fall >10% and >200 ml) Bronchial provocation challenge test Variability decreases with treatment or in chronic remodeling.
Phenotypes Asthma is heterogeneous disease Most common Allergic Asthma- well to ICS Non Allergic asthma- less well to ICS Late- Onset Asthma- High doses of ICS Asthma with fixed airflow limitation Asthma and obesity
Other supportive tests Allergy testing- RAST/Skin prick and IgE FeNO levels >50- good short term response to ICS PEF monitoring at and away from work- Occupational or work aggravated Asthma SABA and ICS trial if very nonspecefic.
What next after the Diagnosis Assess Comorbidities Rhinitis, rhinosinusitis, GERD, Obesity, OSA, Depression, anxiety and poor socioeconomic status.
Assess treatment Issues Choice of Drug Delivery system Difference between rescue and maintenance inhaler Inhaler technique and side effects Asthma action plan
Drug delivery mechanism MDI DPI Respimat Nebulizers
MDI Uses propellant ( HFA replaces CFC to protect ozone layer) Advantages of MDIs are as follows: Portability Multidose delivery capability Lower risk of bacterial contamination Disadvantages of MDIs are as follows: Needs correct actuation and inhalation coordination Oropharyngeal drug deposition
DPI Advantages include the following: Breath-actuated Spacer not necessary and portable No need to hold breath for 10 seconds after inhalation No propellant DPI disadvantages include the following: Adequate inspiratory flow required for medication delivery. May result in high pharyngeal deposition Humidity potentially causes powder clumping and reduced dispersal of fine particle mass
Nebulizers Advantages of nebulizers: Provide therapy for patients who cannot use other inhalation modalities (eg, MDI, DPI) Allow administration of large doses of medicine Patient coordination not required No CFC release Disadvantages of nebulizers: Decreased portability Longer set-up and administration time Higher cost May need source of compressed air or oxygen (jet nebulizer)
Management
Add on treatment at Step 4/5/6 Low dose OCS LAMA Anti- IgE Anti- IL 5 BT
Anti IgE Indicated for >6 years of age with moderate to severe persistent asthma with positive skin test or invitro reactivity to perennial aeroallergen and whose symptoms are inadequately controlled with ICS. A total serum IgE level between 30 and 700 (1500 in Europe) international units/ml. Reduces exacerbations. Anti-IgE as novel therapy for the treatment of asthma.aufick RB Jr SOCurr Opin Pulm Med. 1999;5(1):76.
Anti IL-5- Eosinophilic phenotype Available as Sub cut or IV infusion. While the FDA did not set a specific threshold, NICE recommends a threshold of an absolute blood eosinophil 300/microL for one drug and >400/microL for other drug. However, this threshold is less clear in patients on daily systemic glucocorticoids.
SLIT SLIT in adults with HDM sensitive patients with allergic rhinitis who have exacerbations despite ICS, provided FEV1>70% predicted has shown promising results.
Bronchial Thermoplasty Bronchial thermoplasty (BT) refers to a technique of applying heat (via a device that delivers localized controlled radiofrequency waves) to the airways during bronchoscopy, which reduces the increased mass of airway smooth muscle associated with asthma
Procedure typically entails three separate bronchoscopies under moderate sedation about three weeks apart. (AIR2) trial (RISA) trial However, all of the trials excluded subjects with more than three exacerbations per year or an FEV 1 <50 percent of predicted, so the safety and efficacy of BT for these patients is not known.
Step Up or Step Down
Non Pharmacological interventions Cessation of smoking and environmental toxins. Avoidance of occupational sensitizers. Aspirin and NSAIDs Aspirin exacerbated respiratory disease. Weight reduction and vaccinations.
Beta Blockers Beta blockers appear to be safe in patients with COPD and indeed may reduce mortality and exacerbations. Beta-blockers may reduce mortality and risk of exacerbations in patients with chronic obstructive pulmonary disease.aurutten FH, Zuithoff NP, Hak E, Grobbee DE, Hoes AW PMID20498416
The acute clinical effects of beta-1-selective beta blockers and nonselective beta blockers on pulmonary function in patients with asthma were examined in a systematic review and metaanalysis of 32 randomized trials including 1367 patients. Meta-analysis suggests that even beta-1-selective antihypertensive agents should be used with caution in patients with asthma, especially in those with severe obstruction or markedly reduced pulmonary function at baseline.
As for asthma, chronic use of cardioselective beta blockers doesn't seem to precipitate asthma attacks in mild or moderate asthma. Beta blockers are key component of care for people who have had previous heart attacks or who have systolic heart failure.. It seems unlikely that the risks of worsening asthma or COPD outweigh the potential benefits of beta blocker use, in these patients.
Asthma and COPD overlap Its not a single disease entity. Consider in patients who are smokers and elderly. Avoid high dose ICS and combine with LABA. Prefer not to use ICS alone or LABA alone.
Asthma and Obesity
Considered one of the major risk factors for development of Asthma. Tends to be more severe. 3 main reasons for above effects- Mechanical factors, inflammatory mediators and immune responses.
Obesity and Lung function ERV and so FRC decreases. Tidal breaths at low FRC causes increased airway resistance.
Obesity Inflammation &Immune Response State of chronic, low grade inflammation. Obesity increases adipose tissue resident macrophages. Macrophages increases Il-6, TNF alpha and Plasminogen activator inhibitor. Increased leptins (proinflammatory) and decreased Adiponectins (antiinflammatory).
Obese patients with asthma are relatively resistant to ICS but respond in a similar manner to anti leukotrienes as do lean asthmatics.
Asthma in Elderly
2 Categories Asthma in Elderly Persistence or recurrence of childhood Asthma. New symptoms of Asthma as elderly. Differentiate Asthma with COPD and Heart failure. Under diagnosed because of pts paradox of well being and lower health expectations.
Structural changes of aging lung Thickened airway wall and loss of eleastic recoil. Kyphosis and chest wall compliance Sarcopenia.
Overlap with COPD No DPI- needs high flow velocity Using spacer device Using nebulizers in NH patients.
Asthma and pregnancy
1/3 rd rule. Most of the medications are Category C but advantages of actively treating asthma markedly outweigh any potentionial risks. Don t step down the therapy. Monitor for neonatal hypoglycemia if SABA is used in high doses 48 hrs before delivery. If prednisone >7.5 mg for >2 weeks, give hydrocortisone during delivery.