Obstructive diseases: Asthma versus COPD Flashcards
What is the definition of asthma
Reactive airway disease where you have abnormal bronchoconstriction but it is REVERSIBLE (distinguish from COPD which is not)
How would a patient with asthma present
Wheezing with acute onset of SOB and chest tightness with increased length of expiratory phase of breathing (because obstructive, takes longer for air to get out)
Hints on the exam: Symptoms more at night, nasal polyps, eczema or atopic dermatitis, use of intercostals
Someone with history of asthma presents with an acute exacerbation. What is the best initial diagnostic study and the most accurate test
Initial study: Arterial blood gases (increased A-a gradient) or peak expiratory flow (PEF) decreased - do if patient experiencing ACUTE exacerbation
Best test: Pulmonary function testing (PFT) - explained in later flash card
CXR: usually normal in asthma and only used if need to exclude other diseases
What is the role of pulmonary function testing in asthma
- ) Decreased FEV1 and FVC and decreased FEV1/FVC ratio due to more decreased FEV1
- ) FEV1 increased 12% with albuterol - useful if symptomatic
- ) FEV1 decreased 20% with methacholine - BEST test if ASYMPTOMATIC
- ) Decrease in carbon monoxide diffuse capacity
What two diseases do you expect to see IgE risen in
- ) Asthma of allergic etiology
2. ) Allergic bronchopulmonary aspergillosis
What are the steps for asthma medications in order of severity
- ) Inhaled short acting beta agonist
- ) Low dose inhaled corticosteroid for long term
- ) Increased corticosteroid dose or add long acting beta agonist
- ) Add omalizumab if increased IgE levels present
- ) Oral corticosteroids (i.e. prednisone) if too severe
What are the side effects of inhaled corticosteroids and oral steroids
Inhaled: Dysphonia and oral candidiasis
Systemic: Osteoporosis, cataracts, acne, and hirsutism, and adrenal suppression: high lipids and glucose, and then thinning of skin and striae (think that these are all symptoms of adrenal suppression I think)
What are alternative long term control agents for asthma control aside from low dose inhaled corticosteroids
- ) Cromylin and nedocromil: Mast cell mediator release inhibitor
- ) Theophyline
- ) Luekotriene modifiers
What is the side effect of one of the leukotriene modifiers used as long term control, zafirleukast
Hepatotoxic and associated with Churg-Strauss syndrome
What is the role of anticholinergics for asthma
Although theoretically should help, role is not clear and this is more for COPD - remember this
What is the best indicator of an acute asthma exacerbation
Respiratory rate
In acute asthma exacerbation, the way to diagnose as seen earlier is a decreased PEF or ABG with increased A-a gradient. What is a PEF
Peak expiratory flow (PEF) that estimates FVC and based on height and age, not on weight, compared to the patient’s normal PEF
This time, do CXR because you can see if infection is leading to exacerbation
What is the treatment for acute asthma exacerbation
Oxygen combined with albuterol and a bolus of steroids (steroids need 4 to 6 hours to work)
Epinephrine and magnesium use is limited, but use magnesium if several rounds of albuterol don’t work and can open up bronchospasm.
Anything else is ineffective
If refractory to all of this, then do endotracheal intubation
What is the definition of COPD
Destruction of lung parenchyma resulting in loss of elastic fibers that are needed for exhalation, resulting in reduced FEV1 and FVC and increased total lung capacity
Results in shortness of breath
Almost always caused by tobacco smoking which destroys elastin
How does someone with COPD present in the clinic
Shortness of breath that is worsened by exertion with intermittent exacerbations with increased cough, sputum, or SOB from infections
Barrel chest from increased air trapping, with muscle wasting
Like asthma, COPD has a best initial and most accurate test. What are they
Best initial test: Chest X-ray - Will show increased anterior-posterior diameter, air trapping, and flattened diaphragm (was not useful for asthma)
Most accurate test: PFT showing decreased FEV1 and FVC (like asthma) with ratio less than 70%, increased TLC, decreased carbon monoxide diffusion, and no changes with albuterol or methacholine
What will ABG show in an acute COPD exacerbation
Increased PCO2 and hypoxia associated with respiratory acidosis
Bicarbonate may rise to do metabolic compensation
What is the response of the heart to COPD
Right atrial and ventricular hypertrophy with possible pulmonary hypertension and multifocal atrial tachycardia
Diagnose with echo or EKG
What is the most effective treatment for COPD
Inhaled anticholinergic agents: Tiotropium, ipratropium (improves symptoms but not decrease disease progression)
Aside from inhaled anticholinergics, what are some other treatments necessary or useful for COPD
- ) Smoking cessation, oxygen therapy, influenza/pneumococcal vaccine all improve mortality and delays disease progression
- ) All medications that can be used in asthma
- ) Pulmonary rehabilitation
If refractory to everything, then refer for transplantation
What is the best treatments for both asthma and COPD
- ) Asthma: Inhaled steroid
2. ) COPD: Anticholinergic (tiotropium, ipratropium)
What is the treatment of acute COPD exacerbations and compare to acute asthma exacerbation
Combination of bronchodilators and steroids (same as asthma) but this time give antibiotics too since infection is usually the cause
What organisms should be covered in acute exacerbation and what antibiotics should be used
Strep pneumo, H influenzae, moxarella catarrhalis
- ) Macrolides: Azithromycin, clarithromycin
- ) Cephalosporins: Cefuroxime, cefixime
- ) Augmentin
- ) Quinolones
What is the role of oxygen therapy in COPD acute exacerbation
Actually lowers mortality and so should always be used if pO2 is below 55, oxygen saturation below 88%
If hermatocrit risen or signs of right sided heart disease, that criteria increased to pO2 less than 60 or oxygen saturation less than 90%
