What is Chronic Obstructive Pulmonary Disease?
Chronic bronchitis and emphysema in which forced expiratory volume, measured by spirometry is decreased.
In chronic bronchitis or asthma, how is airflow modified? Emphysema?
Airway narrowing and resistance increased; Decreased recoil and diminished pressure.
A patient with a chronic productive cough of 10 years duration presents to your clinic with another respiratory tract infection. What is the underlying Dx of this patient? What is the criteria to make this Dx? What major morphologic changes would you expect to see if a biopsy of this patient's lung was taken? What is the likely cause of this Dx?
Chronic bronchitis; > 50% of time over > 2 years; Increased bronchial mucus-secreting apparatus where mucous cells undergo hyperplasia and hypertrophy and are increased relative to serous cells. SMOKING.
A bronchial biopsy is shown below. The patient is a smoker. What are the significant morphological changes shown below? What is used to quantify the progression of mucous gland enlargement?
Bronchial submucousa is greatly expanded by hyperplastic submucosal glands; Reid index = mucosa glands thickness/bronchial wall thickness (normal RI < .4 CB -> RI > .5)
What bugs are smokers and those with chronic bronchitis predisposed to become infected with in their respiratory tract?
H. influenzae and S. pneumoniae
What conditions is chronic bronchitis generally accompanied by? What is a colloquial name for those with chronic bronchitis?
Productive cough for many years and emphysema; Blue bloater (cyanosis and edema)
What is potential mechanism that involves smoking and Alpha1-Antitrypsin that leads to emphysema?
- Smoking interferes with Alpha1-AT by oxidizing methionine residues
- Unopposed elastolytic proteases lead to destruction of elastic tissue
What diseases will you likely get from an Alpha1-AT deficiency?
Emphysema and cirrhosis of the liver
What gene determines amount and type of Alpha1-AT? What is the most common genotpye? What genotype shows the most serious form Alpha1-AT? What population is this genotype most common? Least common? In most patients under age 40 with emphysema, what is their genotype?
- Pi (protease inhibitor) codominate alleles
- Jews, Blacks, Japanese
A 70 year old patient comes to your office complaining of a long history of exertional dyspnea but a minimal non-productive cough. The patient has lost weight and appear to be straining to breathe. What is the likely Dx? Describe their likely respiratory rate and length of expiratory phase. What are the colloquial terms used to describe a person with this condition?
Emphysema; High RR and prolonged EP; Pink puffers, barrel chested
A smoker expires and their lung is shown at autopsy. The lungs show destruction of the cluster of terminal bronchioles. The lesions were primarily found in the upper lobes and the superior segment of the lower lobes. Dx?
A smoker expires and their lung is shown at autopsy. The alveolar septa are destroyed from the center to the periphery of acini. The structure of the lung can be describe as a lacy network of supporting tissue. The lesions are primarily in the lower zones of the lung. What is the Dx? What is the colloquial term for this disease?
Panacinar emphysema; "Cotton candy lung"
A patient presents in the ED with a pneumothorax and a history of smoking. The patient dies and the lung is shown at autopsy. The lesion was found in the apex of the upperlobe of the right lung, but was the only lesion in both lungs. What is the Dx? What is the large area of destruction called?
Localized emphysema; Bulla
What is Status Asthmaticus?
Severe acute asthma that is refractory to Tx
What is asthma generally contributed to?
Hyperresponsiveness is attributed to inflammatory rxn
Describe the general mechanism leading from inciting event to an asthmatic reaction
- Inciting factor (allergen, drug, cold, exercise)
- Macros, mast cells, eosinophils, basophils secrete cytokines
- Smooth muscle contraction, mucous secretion, increased vascular permeability and edema
In a senstized asthamtic, what role doe TH2 cells and IgE antibody bound to the surface of mast cells play in pathogenensis?
- TH2 release mediators of Type I hypersensitivity - Histamine, Bradykinin, Leukotrienes, Prostaglandins, TXA2, Platelet-Activating Factor, IL-4 and IL-5
What is typical bug that causes viral asthma in children < 2 yo? Older children?
- Rhinovirus, Influenza, Parainfluenza
What are general mechanisms that may be involved with occupational asthma?
- IgE mediated hypersensitivity
- Direct release of mediators of smooth muscle contraction
- Activation of parasympathetic drive
What is the best-known cause of drug-induced asthma?
Below is a biopsy from a patient who died from status asthamaticus. What are the characteristic findings on this biopsy?
- Mucous plugs containing strips of epithelium and eosinophils
- Charcot-Leyden crystals (phospholipids of eosinophil membranes)
- Curschmann spirals (mucoid cast of the airways)
- Creola bodies (clusters of epithelial cells)
- Hyperplasia of bronchial smooth muscle is most characteristic