Dx and Rx Flashcards
Describe findings of PFTs between asthma exacerbations
Normal - asthma is a reversible lung disease; PFTs are abnormal only during exacerbations.
What is the best initial test for asthma in an acute exacerbation? Most accurate test?
Best initial: Peak expiratory flow (PEF) or arterial blood gas (ABG). Peak flow can be used by the pt to determine function.
Most accurate: Pulmonary function testing (PFTs). Spirometry will show decreased FEV1:FVC ratio (both decrease, but FEV1 decreases more).
Describe findings of PFTs during acute asthma exacerbations in terms of:
- FEV1:FVC ratio
- Change in FEV1 with albuterol
- Change in FEV1 with methacholine or histamine
- Change in diffusion capacity of carbon monoxide
- Decreased ratio of FEV1:FVC
- Increase in FEV1 > 12% or 200mL w/ albuterol
- Decrease in FEV1 > 20% w/ methacholine or histamine
- Increase in DLCO
How is CXR used in pts with asthma or Sx of asthma?
CXR is often normal in pts with asthma, but may show hyperinflation. It is mainly used to:
- Exclude pneumonia as the cause of asthma exacerbation.
- Exclude other diseases such as pneumothorax (asthma predisposes to pneumothorax) or CHF in cases that are not clear.
What are the findings on CBC, skin testing, and Ig levels in asthma?
- CBC may show increased eosinophil count
- Skin testing is used to identify specific allergens that might provoke bronchoconstriction.
- Increased IgE levels suggest an allergic etiology. It may also help guide therapy such as the use of the anti-IgE medication omalizumab. Increased IgE levels are also seen in allergic bronchopulmonary aspergillosis.
What is the first step in treating asthma? What is the second step?
Step 1: Inhaled short-acting beta agonist (SABA), e.g. albuterol, pirbuterol, or levalbuterol. Always start with this for PRN use.
Step 2: Add a long-term control agent to a SABA. Low-dose inhaled corticosteroids (ICS) are the best initial control agents. Examples are beclomethasone, budesonide, flunisolide, fluticasone, mometasone, and triamcinolone.
What are some examples of long-term control agents for asthma that can be used instead of inhaled corticosteroids?
- Cromolyn and nedocromil inhibit mast cell mediator release and eosinophil recruitment.
- Theophylline
- Leukotriene modifiers: montelukast, zafirleukast, or zileuton
In whom are leukotriene modifiers the best alternate long-term control agent to inhaled corticosteroids?
Leukotriene modifiers are best with atopic pts.
What are the 2 most common adverse effects of inhaled steroids?
Dysphonia and oral candidiasis
What is a serious side effect of zafirleukast? What disease is it associated with?
Zafirleukast is hepatotoxic. It is associated with Churg-Strauss syndrome.
What are steps 3 and 4 in asthma management?
Step 3: Add a long-acting beta agonist (LABA) to the SABA and ICS, OR increase the dose of the ICS. LABA medications are salmeterol or formoterol.
Step 4: Increase the dose of the ICS to maximum in addition to the LABA and SABA.
What are steps 5 and 6 in asthma management?
Step 5: Add omalizumab to the SABA, ICS and LABA in pts with an increased IgE level.
Step 6: Oral corticosteroids such as prednisone are added when all the other therapies are not sufficient to control symptoms.
What vaccines are given to all asthma pts?
Killed influenza vaccine and pneumococcal vaccine
Why are LABAs never used first or alone for asthma?
LABAs are never used first because they are associated with an increased risk of death from asthma. They are never used alone because they aren’t effective for acute exacerbations.
What are some adverse effects of systemic corticosteroids? Do high-dose inhaled steroids have these effects?
Systemic corticosteroids are used as a last resort in asthma management because of very harsh side effects such as:
- Osteoporosis
- Cataracts
- Adrenal suppression and fat redistribution
- Hyperlipidemia, hyperglycemia, acne, and hirsutism (particularly in women)
- Thinning of skin, easy bruising, striae
High-dose inhaled steroids very rarely lead to the adverse effects associated with prednisone, which is why the dose of ICS can be increased as the 3rd and/or 4th step in management of asthma.
How can the severity of an asthma exacerbation be quantified?
- Decreased peak expiratory flow
- ABG with increased A-a gradient
What is peak expiratory flow? What is it based on? How is it used?
PEF is an approximation of the FVC. There is no precise “normal” value. It is based predominantly on the pts height and age (not weight). The PEF is used in acute assessment by seeing how much difference there is from the pt’s usual PEF when they are stable.
What is the best initial therapy for a pt with an acute asthma exacerbation?
Oxygen combined with an inhaled SABA and a bolus of steroids.
*Corticosteroids need 4-6 hours to begin to work, so give them right away.
Why and when are epinephrine injections and magnesium used for acute asthma exacerbation?
Epinephrine injections are no more effective than albuterol and have more adverse systemic effects. Epinephrine is rarely used and only as a last resort.
Magnesium has some modest effect on bronchodilation, but is not as effective as albuterol, ipratropium or steroids. It is only used in severe asthma exacerbation not responsive to several rounds of albuterol while waiting for steroids to take effect.
In whom are cromolyn or nedocromil the best alternate to ICS in pts with asthma?
Cromolyn and nedocromil are best in pts with extrinsic allergies like hay fever.
What do you do for pts with acute asthma exacerbation in the ER if they do not respond to oxygen, albuterol or if they develop respiratory acidosis (increased pCO2)?
These pts may need to undergo endotracheal intubation for mechanical ventilation. They should be admitted to the ICU.
What is the best initial test for COPD? Most accurate test? What are the findings?
Best initial: CXR
- Increased AP diameter
- Air trapping and flattened diaphragms
Most accurate: PFT
- Decreased FEV1:FVC (<70%)
- Increased TLC because of increased residual vol.
- Decreased DLCO (emphysema, not bronchitis)
- Incomplete improvement with albuterol
- Little or no worsening with methacholine
In pts with COPD, describe the usual findings on:
- Plethysmography
- ABG
Plethysmography will show an increase in residual volume
ABG will show increased pCO2 and hypoxia in acute exacerbations. Respiratory acidosis may be present if there is insufficient metabolic compensation; bicarbonate will be elevated. In between exacerbations, not all pts with COPD will retain CO2.
In pts with COPD, describe the usual findings on:
- CBC
- EKG
- Ech
CBC may show an increase in hematocrit from chronic hypoxia.
EKG may show RAH and RVH. A fib and multifocal atrial tachycardia (MAT) are possible.
Echo may show RAH and RVH. It may also show pulmonary HTN.
What 3 methods of COPD management improve mortality and delay progression of the disease?
- Smoking cessation
- Oxygen therapy for those with pO2 < 55 or
O2 sat < 88%; mortality benefit is proportional to the number of hours that oxygen is used. - Influenza and pneumococcal vaccines
What 5 methods of COPD management definitely improve symptoms (but do not decrease disease progression or mortality)?
- SABAs
- Anticholinergic meds (ipratropium, tiotropium)
- Steroids
- LABAs
- Pulmonary rehabilitation
How do the first 2 steps of COPD management differ from that of asthma?
Asthma not controlled with albuterol –> add inhaled steroid
COPD not controlled with albuterol –> add anticholinergic –> add inhaled steroid
How does the last resort of COPD management differ from that of asthma?
Asthma - last resort is systemic steroids
COPD - last resort is lung transplant
Describe the usefulness of theophylline, lung volume reduction surgery, cromolyn, and leukotriene modifiers in COPD.
Theophylline and lung volume reduction surgery can possibly improve symptoms of COPD, whereas cromolyn and leukotriene modifiers have no benefit.
*Cromolyn and leukotriene modifiers have no benefit because COPD is not associated with allergies.
When do you start oxygen in a pt with COPD and no comorbidities? When do you start O2 in a pt with pulmonary HTN, high HCT, or cardiomyopathy? How much O2 do you use?
Begin O2 when pCO2 =/< 55 or O2 sat =/< 88%.
In a pt with pulmonary HTN, high HCT, or cardiomyopathy, begin O2 when pCO2 =/< 60 or
O2 sat =/< 90%.
Only use enough O2 as is necessary to raise the pO2 above 90% saturation.
What is the management for acute exacerbation of chronic bronchitis (AECB)?
Bronchodilator, corticosteroid, and an antibiotic
*basically the same as for acute exacerbation of asthma but with the addition of an abx
What is the most common cause of AECB?
Infection
What bugs should abx used in AECB cover?
Abx should cover Strep pneumo, H. influenzae, and Morexella catarrhalis.
Which abx are used for first-line and second-line therapy for AECB?
First-line agents:
- Macrolides: azithromycin, clarithromycin
- Cephalosporins: cefuroxime, cefixime, cefaclor, ceftibuten
- Amoxicillin/clavulinic acid (augmentin)
- Respiratory quinolones: levofloxacin, moxifloxacin, gemifloxacin
Second-line agents:
- Doxycycline
- TMP/SMX (bactrim)
What are the best initial and most accurate tests for bronchiectasis? What do they show?
Best initial: CXR - shows dilated, thickened bronchi, sometimes with a “tram-tracks” appearance.
Most accurate: High-resolution CT scan - shows widening of the bronchi in multiple areas.
How do you determine the specific bacterial etiology of recurrent episodes of infection in someone with bronchiectasis?
Sputum culture is the only way.
Describe the management/treatment of bronchiectasis
- Chest physiotherapy (“cupping and clapping”) and postural drainage are essential for dislodging plugged-up bronchi.
- Treat each episode of infection as it arises, using the same abx as for COPD, with two differences:
1) inhaled abx have some efficacy; 2) a specific microbiological Dx is preferred because Mycobacterium avium intracellulare (MAI) can be found. - Rotate abx, 1 weekly each month
- Surgical resection of focal lesions may be indicated.
What diagnostic tests can be used for allergic bronchopulmonary aspergillosis?
- Peripheral eosinophilia
- Skin test reactivity to aspergillus antigens
- Precipitating antibodies to aspergillus on blood test
- Elevated serum IgE
- Pulmonary infiltrates on chest x-ray or CT
What is the Rx for ABPA?
- Oral steroids (prednisone) for severe cases*
- Itraconazole orally for recurrent episodes
*Inhaled steroids are not effective for ABPA
What test is used to diagnose cystic fibrosis? How does it work? What does it show?
Increased sweat chlorine test is the most accurate test for CF. Pilocarpine increases acetylcholine levels which increases sweat production. Chloride levels in sweat above 60 meq/L on repeated testing establishes the diagnosis.
What indicates a positive increased chloride sweat test in diagnosing CF?
Chloride levels in sweat above 60 meq/L on repeated testing establishes the diagnosis.
Describe the role of genotyping in diagnosing CF?
Genotyping is not as accurate as increased sweat chloride level. This is because there are so many different types of mutations leading to CF.
What findings may be present on chest x-ray or CT in a pt with CF?
- Bronchiectasis
- Pneumothorax
- Scarring
- Atelectasis
- Hyperinflation
What might an ABG show for a pt with CF? What do PFTs show?
ABG shows hypoxia and, in advance disease, respiratory acidosis.
PFTs show:
- mixed obstructive and restrictive patterns
- decreases in FVC and TLC
- decreased DLCO
What 4 bugs are commonly found in sputum cultures of pts with CF?
- Nontypable H. influenzae
- Pseudomonas aeruginosa
- Staph aureus
- Burkholderia cepacia
What is the Rx for CF?
- Abx - same as bronchiectasis and COPD:
1st line - macrolides, cephalosporins, augmentin, or quinolones
2nd line - doxycycline or bactrim
Also: inhaled aminoglycosides may be used; this is exclusive to CF - Inhaled recombinant human deoxyribonuclease (rhDNase) - breaks up massive amounts of DNA in respiratory mucus plugs.
- Inhaled bronchodilators e.g. albuterol
- Pneumococcal and influenza vaccines
- Lung transplant is the last resort
What is the best initial test for respiratory infections e.g. pneumonia?
Chest x-ray is the best initial test, but it cannot determine the bacterial etiology.
Sputum gram stain and culture are the best ways to first try to determine a specific bacterial etiology; however, no etiology is found in over 50% of cases because Mycoplasma, Chlamydophila, Legionella, Coxiella and viruses are responsible for 30-50% of cases but aren’t visible on Gram stain.
Bilateral interstitial infiltrates are seen with which bugs on CXR?
The bugs that cause atypical pneumonia:
- Mycoplasma
- Chlamydia
- Coxiella
- Pneumocystis
- Viruses
What findings make a sputum Gram stain adequate?
> 25 WBCs and < 10 epithelial cells
When are thoacocentesis and bronchoscopy used in CAP?
Thoracentesis - The analysis of pleural effusion can be used to determine the presence of an empyema if the Dx is unclear. Empyema will improve more rapidly if it is drained with a chest tube.
Bronchoscopy - This is rarely used in CAP. It is used to diagnose pneumocystis pneumonia in which noninvasive testing rarely reveals a diagnosis and precise confirmation of the etiology is critical to guide therapy. It is also used if there is severe disease such as someone needing placement in an ICU when initial testing does not yield an organism and the pt’s condition is worsening despite empiric therapy.
Describe the lab results for empyema
Empyema is an infected pleural effusion.
- LDH > 60% of serum level or protein above 50% of serum level is suggestive of exudate.*
- WBC count above 1000 microliters or pH < 7.2 is suggestive of infection.
*Exudates are caused by infection and cancer.
