An abscess is a localized necrotizing infection within lung tissue, whereas an empyema is an accumulation of pus in the pleural space.
What are the 3 main routes by which microbes can access lung tissue tand form abscesses?
1) aspiration 2) preceding lung infx 3) septic embolism (also trauma and invasion from other tissue)
What are some of the risk factors for abscesses?
same as pneumonia: altered mentation, alcoholism, coma, post-anesthesia, debilitation, sinusitis, gingivitis, etc, gastric aspiration
What pneumonia-causing bugs like to stick around and cause pulmonary abscesses?
S. aureus, Klebsiella, type 3 pneumococcus (also fungal and bronchiectasis)
What do you call abscesses that form without any of the factors above to predict them?
primary cryptogenic lung abscesses
Which side do single aspiration abscesses most often form on?
Where in the lung do post-pneumo abscesses usually form?
in the base, and they are multiple and diffuse
What are the signs and symptoms of pulmonary abscesses?
--occasional copious foul-smelling purulent or sanginous sputum
What tests do you order to confirm your diagnosis?
(any of these)
If ABX don't resolve a pulmonary abscess, what next?
What complications can occur from pulmonary abscesses?
--extension of infx into pleural cavity-->empyema from bronchopleural fistula
--massive hemoptysis, hemorrhage
--spontaneous rupture into uninvolved lung segments
What are the major types of obstructive airway disease?
--emphysema (loss of elastic recoil of lung)
--chronic bronchitis (airway narrowing)
What are the two major types of restrictive airway disease?
--chest wall disorders: poliomyelitis, obesity, kyphoscoliosis (lungs are normal)
--interstitial and infiltrative dz of lung: ARDS, pneumoconioses and other interstitial fibrosis
What three conditions all fall within COPD?
sometimes asthma is included but it is unlike the others in that it is reversible
What do smokers have more of in their alveoli than nonsmokers?
neutrophils and macrophages
What do neuts and macrophages secrete into the lungs that causes emphysema?
proteases: they digest the lungs
What normally circulates in the lungs and protects them from proteases?
alpha-1-antitrypsin (A1AT) (inhibited by oxidants and free radicals, also sometimes genetically absent)
Where is A1AT made?
in the liver
What is the definition of chronic bronchitis?
IT IS CLINICALLY DEFINED AS
the presence of a productive cough lasting at least 3 months and occurring annually for at least 2 years
AND THERE IS NO CHARACTERISTIC PATHOLOGIC FINDING
What pathological changes are seen in chronic bronchitis?
--thicker mucous gland layer and more goblet cells in bronchi-->more mucus
--reduced number of ciliated cells-->more cellular debris in secretions-->more cough
--lymphocytic infiltrates in bronchial epithelium
What's the doctor slang for a person with chronic bronchitis?
What's a pink puffer?
someone with emphysema
How much of the pulmonary parenchyma must be damaged before emphysema manifests clinically?
What is the first symptom of emphysema?
(other cc's: wheezing, cough: can be productive or not depending on bronchitis)
What spirometric finding makes a definitive diagnosis of emphysema?
expiratory airflow limitation
How does the emphysema patient present?
--barrel chested (uses accessory muscles to chest breathe)
--prolonged expiratory phase
What's the difference between centriacinar and panacinar emphysema?
--Centriacinar (centrilobular): involves only central or proximal parts of acinia, formed by resp bronchioles, usu more severe in upper lobes esp apices, forms in heavy smokers w/ chronic bronchitis, wall of emphysematous spaces oft w/ black pigment
--Panacinar (panlobular): distal alveoli, most severe at base of lung, often assoc w/ a1-antitrypsin deficiency, acini
--pts may exhibit BOTH
What causes bronchiectasis?
--chronic necrotizing infx-->destrx of muscle and elastic tissues-->permanent dilation of bronchi and brochioles
--bronchial obstruction dt tumor, foreign body or mucus plug (CF)
--also assoc w/ autoimmune incl: RA, SLE
How often does a bronchiectasis pt cough up foul purulent sputum?
What tissue changes occur in bronchioles of asthmatics?
--increased goblet cells & mucus production
--hypertrophy of bronchial smooth muscle
--increased migration of mast cells, WBC's and macrophages
--deposition of subepithelial collagen
What do you call a state of unremitting asthma attacks?
status asthmaticus -- may be fatal unless pt is intubated, epi may not work
What can trigger an asthma attack?
In a child with atopic asthma, what is elevated in the blood and lungs?
What else are you likely to find in a pt who has aspirin sensitive asthma?