9.1 - 9.4: Respiratory Flashcards
What is the most common infectious cause of rhinitis?
Adenovirus
What is allergic rhinitis? What type of hypersensitivity rxn is it?
Type I hypersensitivity reaction
What are the histological characteristics of allergic rhinitis?
inflammatory infiltrate with eosinophils
What other diseases is allergic rhinitis associated with?
Asthma and eczema
Patient who have repeated bouts of rhinitis are susceptible to what pathologic finding? What are these?
Nasal polyps–Protrusion of edematous, inflamed nasal mucosa
Besides chronic rhinitis, in what other conditions do nasal polyps occur? (2)
Cystic fibrosis and ASA-intolerant asthma
Child with a nasal polyp = ?
Cystic fibrosis
What is aspirin intolerant asthma?
Adult disease characterized by ASA induced bronchospasm, and nasal polyp formation
What are angiofibromas? How do they usually present?
Benign tumors of nasal mucosa composed of large blood vessels and fibrous tissues
-Profuse epistaxis in an adolescent male
In whom are angiofibromas seen?
Adolescent males–very very rarely seen in females
What is nasopharyngeal carcinoma? What is it usually caused by?
Malignant tumor of the nasopharyngeal epithelium, associated with EBV
In whom is nasopharyngeal carcinoma usually seen?
African children and chinese adults
What is the histological findings of nasopharyngeal carcinoma?
Pleomorphic, keratin-positive epithelial cells in a background of lymphocytes
What is the most common cause of epiglottitis?
H. influenzae type b
True or false: H. Influenzae is the most common cause of epiglottitis in both immunized and unimmunized children
True
What are the ssx of epiglottitis?
- Fever
- sore throat
- drooling with dysphagia
- inspiratory stridor
What is the major complication of acute epiglottitis?
Acute airway obstruction
What is laryngotracheobronchitis?
Croup–inflammation of the upper airway
What is the most common cause of laryngotracheobronchitis (croup)? What is the enveloped and genetic material in this?
Parainfluenza virus
-enveloped, -ssRNA
What are the ssx of laryngotracheobronchitis (croup)?
Barking cough and inspiratory stridor
What usually causes vocal cord nodules? What type of material are these composed of?
Excessive use, leading to myxomatous degeneration
True or false: vocal cord nodules are usually unilateral lesions
False–usually bilateral since it’s due to a wear and tear related issue
What are the ssx of vocal cord nodules?
Hoarseness that resolves with rest
What is a laryngeal papilloma? What strains usually causes this?
Benign papillary tumor of the vocal cord caused by HPV 6 and 11
What is the major difference in laryngeal papillomas between children and adults?
Single in adults, multiple in children
What is the major symptoms of a laryngeal papilloma?
Hoarseness
What are the two infectious agents that usually cause laryngeal papillomas?
HPV 6 and 11
What is laryngeal carcinoma?
Squamous cell carcinoma arising from the epithelial lining of the vocal cords
What are the two major risk factors for developing laryngeal carcinoma?
EtOH and tobacco use
What are the ssx of laryngeal carcinomas?
hoarseness, cough, stridor
—-True or false: laryngeal papillomas never progress to carcinomas—-
—False–rare, but does happen—
What is the definition of pneumonia?
Infection of the lung parenchyma that occurs when normal defenses are impaired
How do viral infections predispose patients to pneumonia?
Damage to the mucociliary escalator
How does mucus plugging cause pneumonia?
Bacterial build up behind the block
What causes the fever and chills with pneumonia?
bacteria leak out into the blood, causing systemic effects
What are the s/sx of pneumonia?
- Fever
- Purulent cough
- Tachypnea with pleuritic chest pain
What are the PE findings with pneumonia?
Decreased breath sounds with dullness to percussion
What causes the pleuritic chest pain with pneumonia? (and pain in general)?
Bradykinin and PGE2 release
What causes the pleuritic chest pain with pneumonia?
Stretching an irritated pleura
What are the three patterns of pneumonia on CXR?
- Lobar
- Bronchopneumonia
- Interstitial pneumonia
What is lobar pneumonia?
When an entire lobe is consolidated 2/2 bacterial infection
What is a bronchopneumonia?
Pneumonia limited to the bronchi
How does interstitial pneumonia appear on CXR?
Increased markings of bronchi
Which types of pneumonia are usually bacterial? Which are usually viral?
Lobar and bronchopneumonia usually bacterial
Interstitial = viral
What are the two most common causes of lobar pneumonia?
- Strep pneumoniae
2. Klebsiella pneumoniae
What is the most common cause of community acquired pneumonia?
Strep pneumoniae
Who is usually affected with pneumonia with klebsiella? Why?
Patients with increased risk for aspiration, since it is a normal flora of the GI tract
What causes the currant jelly sputum with klebsiella pneumonia?
Coughing up of the mucoid capsule
Klebsiella pneumonia is often complicated by what?
Abscess
What are the four classic phases of lobar pneumonia?
- Congestion
- Red hepatization
- Grey hepatization
- Resolution
What is the congestion phase of lobar pneumonia?
Congestion of blood vessels, causing edema
What is the red hepatization phase of lobar pneumonia?
Red exudate forms from PMNs and blood, causing a sponge-like alveoli to form (like a hepatocyte)
What is the grey hepatization phase of lobar pneumonia?
Denaturation of the red exudate
What is the resolution phase of lobar pneumonia?
Type II pneumocytes regenerate the lining of the lung
What is the cell type that helps to regenerate the lining of the lung?
Type II pneumocyte
What are the usual bacteria that causes bronchopulmonary pneumonia? (5)
- Staph Aureus
- H. influ
- Pseudomonas
- Moraxella cat
- Legionella
What is the most common cause of secondary pneumonia (after viral infection)?
Staph aureus
What is an empyema?
collection of pus in the pleural space
What are the usual complications of staph aureus pneumonia?
Abscess or empyemas
What bacterial usually afflicts CF pts?
Pseudomonas
What bacterial infections are COPD pts more likely to get? (3)
- H. influ
- Moraxella catarrhalis
- Legionella
What are the sources of legionella?
Water sources
What is unique about Legionella? What stain is needed to see it?
- Intracellular bacteria
- Silver stain
What are the s/sx of interstitial pneumonia?
Same as other forms of pneumonia, but usually less severe. More URI like
What is atypical pneumonia also known as?
Interstitial pneumonia
What are the histological findings of interstitial pneumonia?
PMN infiltration into the walls of the alveoli
What is the usual cause of atypical pneumonia? Who usually gets it?
- Mycoplasma pneumoniae
- Young military recruits or college students
What are the major causes of atypical pneumonia?
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- CMV
- Influenza
- Coxiella burnetii
What is the major diagnostic test that can be performs with mycoplasma pneumoniae infection?
Autoimmune hemolytic anemia from IgM
Why is mycoplasma pneumoniae hard to identify?
Lacks a cell wall
What is the most common cause of atypical pneumonia in infants?
RSV
What is the most common cause of atypical pneumonia in patients on posttransplant immunosuppressive therapy?
CMV
What is the most common cause of atypical pneumonia in the elderly or preexisting lung disease? How can this lead to death?
Influenza
(orthomyxoviridae, enveloped, linear, segmented, -ssRNA)
-Impair mucociliary escalator, and lead to typical pneumonia
What is the cause of Q fever? Who is it classically seen in? Why?
- Coxiella burnetii
- Farmers and vets, since the spores are present in cattle placentas and ticks
What is the gram stain and treatment for Coxiella Burnetii? Does it form spores?
- Gram negative intracellular, spore forming
- Doxycycline and hydroxychloroquine
Coxiella burnetii is a rickettsial organism, but is markedly different. Why? (3)
- Causes pneumonia
- Does not require an arthropod
- Does not produce a skin rash
What are the three bacteria that cause aspiration pneumonia?
- Bacteroides
- Fusobacterium
- Peptococcus
What is the classical location of aspiration pneumonia? Why?
- RLL abscess
- Right bronchus is more vertical
What is primary TB?
Initial exposure that results in focal caseating necrosis in the lower lobe. These undergo calcification to produce a Ghon complex
What is the type of necrosis seen with TB? Where?
Caseating necrosis in the lower lobe of the lung, and hilar lymph nodes
What is a Ghon complex, and where is it usually found in the lung?
- Caseous necrosis from TB undergoing calcification
- Subpleural
What is the usual presentation of primary TB?
Asymptomatic, but having a positive PPD
What is secondary TB? What causes this usually? Where in the lung does it occur?
- Reactivation TB
- AIDS
- Apex of lung
What are the s/sx of secondary TB?
classic TB ssx (fevers, night sweats, weight loss, etc.)
What is the stain that is used to differentiate TB from fungi?
AFB, showing red bacilli
True or false: TB is not limited in its spread of the human body
True
Where does TB usually spread in the brain?
Meninges at the base of the brain
Which lymph nodes does TB usually spread to?
Cervical
What are the s/sx of kidney infection with TB?
Sterile pyuria
—What is Pott’s disease?—
—TB infection of the vertebra, causing a Gibbus deformity—
What happens to the following in COPD:
- FVC
- FEV1
- FEV1:FVC
- TLC
All decreased except for TLC, which goes up
Why does the FEV1:FVC ratio decrease markedly with COPD?
Obstruction lowers the FEV1 much more markedly than the FVC
Why does TLC increase with COPD?
Air trapping
What is the clinical definition of chronic of bronchitis (hint: recall the duration)? What is the hallmark symptom?
- Chronic productive cough lasting at least 3 months over a minimum of 2 years
- Excessive sputum production
What history is highly associated with chronic bronchitis?
Smoking
What is the normal respiratory epithelium?
pseudostratified ciliated
What are the layers of the respiratory wall?
- Epithelium
- Lamina propria
- Submucosa
What is the purpose of having the capillaries of the bronchioles close to the lumen?
Warm the inspired air
What are the two glands that are in the submucosa in the respiratory wall? What is the function of each of these?
- Serous glands humidify air
- Mucinous glands secrete mucus
What is the normal fraction of space that the glands take up in the respiratory wall? What happens with chronic bronchitis?
Less than 40%
Hypertrophy, causing increased mucus production
What is the Reid index? Above what value suggests chronic bronchitis?
The fraction of the mucinous glands relative to the entire thickness of the respiratory wall
More than 50%
What causes the obstructive part of chronic bronchitis?
Plugging of the airways from mucus secretion
What are the two major complications that can occur with chronic bronchitis?
Cor pulmonale
Infx
What are the ssx of chronic bronchitis? What happens to PaCO2 and PaO2?
- Productive cough
- Cyanosis (PaCO2 increased, PaO2 decreased)
What is PAO2 and PaO2? What happens when PACO2 increases?
PAO2 = alveolar oxygen partial pressure
PaO2 = same but in capillaries
PACO2 directly decreases PAO2
What causes the cor pulmonale with chronic bronchitis?
Chronic vasoconstriction d/t lower ventilation. This causes pulmonary pHTN.
What is emphysema? What causes the air trapping that is characteristic of this disease?
Destruction of alveolar air sacs, causing a loss of elastic recoil, and a collapse of small airways. This leads to airway trapping.
What causes the “obstructive” part of emphysema? (2)
Alveoli are “obstructed” from getting air out d/t loss of elastic recoil
No elastic recoil means nothing to stop small bronchioles from collapsing with expiration
What is the major reason for the cartilage in the larger airways?
Keep the airways patent during expiration
What is the main process that occurs to cause emphysema?
Proteases from macrophages are overproduced d/t increased inflammation from chronic insult (e.g. smoking), causing an imbalance in the protease/anti-protease ratio.
What is the ratio that is disturbed to cause emphysema?
Protease:antiprotease
What is the disease that causes a decrease in antiproteases that leads to emphysema?
Alpha-1-antitrypsin deficiency
What is the most common cause and type of emphysema? What lobe(s) of the lung is this usually found in?
centriacinar emphysema caused by smoking
most commonly found in the upper lobes of the lungs
What is centriacinar emphysema? What causes this?
- Destruction of the central part of the acinus
- Smoking
What type of emphysema is caused by alpha-1-antitrypsin deficiency? Which lobes is this more common in?
- Panacinar
- more common in the lower lobes
What causes liver cirrhosis with alpha-1-antitrypsin deficiency? What part of the cell is affected?
Buildup of misfolded antitrypsin in the ER of hepatocytes
What is the stain that highlights alpha-1-antitrypsin?
PAS positive
What is the gene change with alpha-1-antitrypsin deficiency?
PiM (normal) goes to PiZ
What is the clinical significance of patients with PiZM homozygotes?
Panacinar emphysema and cirrhosis without smoking
What is the clinical significance of patients with PiZM heterozygotes?
Asymptomatic, but there is a significant risk for emphysema with cigarette smoking
Why does pursing the lips aid with the SOB seen in emphysema?
Will increase back pressure into alveoli, helping them to keep the bronchioles open, (which normally would have been held open by the elastic recoil of the alveoli)
“Pink-puffer” patients = ?
emphysema patients
What are the s/sx of emphysema? (4)
- Dyspnea
- Cough with minimal sputum
- Weight loss
- Increased AP diameter
What causes the increase in AP chest diameter in emphysema? (hint: what changes physiologically from the normal state)
Normally, the chest wall want to expand lung out, but elastic recoil of lung wants to collapse in.
Loss of recoil causes the chest wall to “win” against the recoil of the lungs
What is the balance point of chest wall expansion vs elastic recoil inward? What happens to this point with emphysema?
- Functional residual capacity
- Increases
What does fibrosis of the lung cause?
Increases the elastic recoil of the lung, causing the chest wall to be pulled inward more
What are the two major late complications of emphysema? Why?
- Hypoxemia (loss of capillaries)
- Cor Pulmonale (constant capillary constriction)
What is asthma?
Reversible airway bronchoconstriction
What is the usual cause of asthma?
Most often due to allergic stimuli (type I hypersensitivity rxn)
What are the three common features of the medical history of patients with asthma?
- Allergic rhinitis
- Eczema
- Family h/o atopy
What is the lymphocyte that is stimulated with atopic asthma? What are the 3 cytokines released from this?
Th2
IL-4, IL-5, and IL-10
What is the role of IL-4 in asthma?
Allows plasma cells to class switch to IgE
What is the role of IL-5 in asthma?
Recruits eosinophils
What is the role of IL-10 in asthma?
Inhibits Th1 cells, and encourages Th2 cell formation
What activates masts cells in an allergic reaction/asthma?
Crosslinking of surface IgE by antigen
What is the very first thing that happens with mast cell activation? What are the two major events that this causes?
- Dump preformed histamine granules
- Vasodilation of arterioles
- Increased permeability of the postcapillary venule
What are the leukotrienes that are made from mast cells that promote continued inflammation? What do these cause (3)?
LTC4
LTD4
LTE4
Vasoconstriction of blood vessels, increased capillary permeability, and induce bronchoconstriction
What is the protein that eosinophils release to cause continued inflammation?
Major basic protein
What are the s/sx of asthma?
Episodic dyspnea and wheezing
What are the two findings of an alveolar lavage in a patient with asthma?
- Curschmann spirals
- Charcot Leyden crystals
What are the four major nonallergic causes of asthma?
- Exercise
- Viral infx
- ASA
- Occupational exposures
What are the three major features of ASA induced asthma?
- Asthma
- ASA induced bronchospasm
- Associated with nasal polyps
Adult with nasal polyps and asthma = what type of asthma?
ASA intolerant asthma
Child with nasal polyps and asthma = what type of asthma?
CF induced asthma
What is bronchiectasis?
Chronic, necrotizing inflammation causes dilation of the bronchi, causing air trapping (think about blowing through a straw vs blowing through a large pipe)
What causes bronchiectasis in CF pts?
Plugging of airway causes chronic infections and inflammation
What is the causes of kartagener syndrome? What are the s/sx of this (3)?
- Defect in the dynein arm of cilia, preventing movement of the cilia
- Recurrent asthma
- Infertility
- Situs inversus
What causes the bronchiectasis in kartagener syndrome?
Impaired ciliary movement causes infx.
What causes bronchiectasis with a tumor or FB?
Block causes infx and inflammation behind it.
What is allergic bronchopulmonary aspergillosis? In what two patients is this usually seen? Why is there an increased incidence of bronchiectasis with this?
- Hypersensitivity reaction to aspergillus
- Asthmatics and CF pts
- Inflammation of the airway
What are the clinical features of bronchiectasis?
- Cough
- Dyspnea
- Foul smelling sputum
What causes the foul smell of the sputum with bronchiectasis?
Blockage causes the sputum to stew
What are the complications with bronchiectasis?
Hypoxemia with cor pulmonale, and secondary amyloidosis
What causes the hypoxemia with bronchiectasis?
trapping of CO2 behind the obstruction
What causes the secondary amyloidosis seen in bronchiectasis?
Chronic inflammation produces SAA, converts to AA amyloid
—What causes primary amyloidosis?—
—overproduction of amyloid light chain from plasma cells—
Pleomorphic, keratin-positive epithelial cells in a background of lymphocytes on histological examination = ?
Nasopharyngeal carcinoma
What is FVC?
Amount of air that can be forcibly expired after a deep inspiration
What is FEV1?
Amount of air that can be expelled in a 1 second period
What are charcot-Leyden crystals? What are these seen in?
- Aggregates of MBP
- Asthma