Respiratory Facts Flashcards
Mild hemoptysis amount?
5 to 10cc in 24 hours
Moderate hemoptysis amount?
Up to 100cc in 24 hours
Massive hemoptysis amount?
100-200cc in 24 hours
Seven causes of hemoptysis?
Very ITchy ITCH makes you cough
Vascular Inflammatory Trauma Infection Tumor Cardiac Hematological
Infections that lead to hemoptysis?
Bronchiectasis, bronchitis, tuberculosis, lung abscess, CF
Vascular causes that lead to hemoptysis?
Pulmonary infarction, arteriovenous malformation
Causes of inflammation that leads to hemoptysis?
Wegener’s, Goodpasture, Diffuse alveolar hemorrhage
Cardiac causes that lead to hemoptysis?
Mitral valve disease, acute left ventricular failure
Hematological causes that lead to hemoptysis?
Blood dycrasias (aka blood disorder), anticoagulation
Which circulation to the lung is to blame for most hemoptysis?
Bronchial (high pressure, comes from left ventricle)
What is bronchiectasis?
Dilated airways
Key questions to ask about cough?
Onset, duration, character, nocturnal, precipitating factors, relieving factors, sputum, hemoptysis, association
How long must a cough last to be chronic?
More than 8 weeks
What causes chronic cough?
Pertussis, TB, foreign body, asthma, drugs, bronchiectasis, interstitial lung disease (ILD)
What causes a dry cough?
GERD, Drugs (like an ACE inhibitor), acute epiglotitis
When do asthmatics tend to cough more?
Night and early morning
What are usual precipitating factors of a cough in asthmatics?
Emotion, weather (rain, wind, cold), dust, allergies, exercise, drugs
What do you want to consider when assessing sputum?
Color, volume, consistency, pattern
What associations with a cough are important to know?
Breathlessness, sputum, chest pain, wheeze, hoarseness, post-nasal drip
What are the three most common causes of chronic cough?
Asthma, GERD, and post-nasal drip (aka upper airway cough syndrome)
An FEV1/FVC ratio below what is considered obstructive?
70%
In using spirometry to diagnose asthma, we want to see what % increase in FEV1/FVC after bronchodilator use in order to diagnose? What mL improvement in FVC or FEV1?
12% in FEV1/FVC
200 mL in FEV1 or FVC
If you suspect someone has asthma but their spirometry does not confirm this diagnosis, what test do you perform next?
Methacholine challenge test. Administer small amount of methacholine and test reactivity then administer bronchodilator and assess if there is rebound
How do you treat GERD?
Conservatively you have the patient stop smoking and/or elevate the head of their bed
Or antacid therapy like a proton pump inhibitor or an H2 blocker
How long can a person normally have a cough post-infection?
Up to six weeks
What is a D-dimer test?
Looks for a small protein present in the blood after a clot is degraded
Best negative predicative value for a PE
BUT if its negative and the clinical suspicion of a PE is high (i.e. high Wells score) then order the CT
What does a Wells score assess?
The clinical probability that a patient has a PE
- 3 pts for clinical symptoms of a DVT
- 3 pts for diagnosis less likely PE
- 1.5 pts for immobilization for more than 3 days or surgery in the last 4 weeks
- 1 .5 pts for previous DVT/PE
- 1 pt for hemoptysis
- 1 pt for malignancy
- 1 pt for HR over 100bpm
What is the most common finding on EKG in a person with a PE?
Sinus tachycardia
or S1/Q3/T3 (I have no idea what this means)
What is cardiac tamponade?
Accumulation of fluid in the pericardial sack; can cause pulmonary edema
What do pleural effusions do to structures in the mediastinum?
Push away from the effusion
What does lung collapse do to structures in the mediastinum?
It pulls toward it
NOTE: He said that a tension pneumothorax is not “collapsing” its high pressure pushing everything away like an effusion
Three bacterial causes of pharyngitis?
- Streptococcus pyogenes
- Neisseria gonorrhea
- Corynebacterium diphtheria (in unvaccinated)
Basic microbio of strep pyogenes
Gram + cocci in chains
Beta hemolytic
Group A carbohydrate, M protein, lipotechoic acid on surface. Also has hyaluronic capsule
What toxin causes scarlet fever?
SPE toxin (SPE-A to be specific) from strep pyogenes
How is the rash seen in Scarlet fever described?
“sandpaper rash”
Secondary complications from strep pyogenes?
Rheumatic fever (M protein cross reactivity with cardiac myosin). After pharyngitis form only.
Glomerulonephritis due to type III hypersensitivity (immune complexes). After pharyngitis or skin forms
What two strep pyogenes enzymes help it spread in a host?
Hyalurinidase and DNase B
What antibody do we look for to see if someone recently had a strep pyogenes infection/is at risk for rheumatic fever?
Anti-streptolysin O antibody
Streptolysin O is a hemolysin that lyses RBCs
Micro of corynebacterium diphtheria?
gram + rod (non-spore forming!)
Clinical manifestations that should clue you into diphtheria?
Pseudomembrane & bull neck (massive lymphadenopathy)
What is the diphtheria toxin? Where is it coded?
A-B type toxin encoded on a bacteriophage (lysogenic conversion)
Describe what the diphtheria toxin does
ADP ribosylates EF-2 (elongation factor 2) and inhibits protein synthesis. This obviously kills the cell
Damages heart, nerves, kidneys, etc by binding to Heparin-binding epidermal growth factor receptor
Microbio of bordetella pertussis
Gram - rod (coccobacillus)
Three stages of pertussis
- Catarrhal (cough, rhinorrhea)
- Paroxysmal (coughing spasms, whoop, cyanosis, vomiting)
- Convalescent (decreasing but continuing symptoms)
What stage of pertussis is a person most contagious?
Catarrhal
How does pertussis stick in our URT?
It adheres to ciliated epithelium via pili/fimbriae, pertactin, and filamentous hemagglutinin (FHA)
What type of agar plate is used for pertussis?
Bordet-gengou plates
What toxins does pertussis release?
- Pertussis Toxin - an A-B type toxin that ADP-ribosylates G protein and increases cAMP. Localized tissue damage and systemic toxicity
- Trachael Cytotoxin (TCT): a peptidoglycan building block derivative that destroys the ciliated epithelium and the mucociliary escalator
Systemic toxicity of the pertussis toxin?
Hypoglycemia, leukocytosis, neurological damage
What is in the current pertussis vaccine?
pertussis toxoid + FHA
If you see “sudden shaking chills episode” and “rust-colored sputum” in a question stem you should immediately think what?
Streptococcus pneumoniae
What pathogen is the most common cause of community acquired pneumonia?
Streptococcus pneumonia
What three pathogens typically cause atypical pneumonia?
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Respiratory viruses like influenza, adenovirus, parainfluenza, and RSV
Haemophilus influenzae pneumonia is more common in what population?
smokers
What type of pneumonia do people get after influenza virus?
Staph aureus
What type of pneumonia do people with CF typically get?
Pseudomonas aeruginosa
Typical vs. atypical onset of pneumonia?
Typical is rapid onset, more severe symptoms, productive cough, purulent sputum and CXR with dense consolidation
Atypical slower onset, less severe symptoms (“walking pneumonia”), non-productive cough, a little white phlegm, and patchy interstitial infiltrates on CXR
Microbio of streptococcus pneumoniae
Gram + diplococci
alpha hemolytic
Carbohydrate capsule (target of vaccine)
Diseases caused by streptococcus pneumonia?
MOPS!
Meningitis
Otitis media
Pneumonia
Sinusitis
How does streptococcus pneumonia damage our cell membranes?
Releases pneumolysin, a toxin that binds cholesterol in our cell membranes
Four stages of pneumonia?
- Serous
- Early consolidation - numerous bacteria, few PMNs
- Late consolidation - numerous PMNs
- Resolution - effective Ab response, macrophages clear debris
No permanent damage if the patient survives
Microbio of Legionella pneumophila
Gram - rod
Stains irregularly and needs a silver stain or buffered charcoal yeast extract (BYCE) with iron and cysteine
Diseases caused by Legionella pneumophila?
Legionnarie’s disease
Pontiac fever (flu-like)
What is special about encountering the Legionella pneumophila pathogen?
It’s environmental only. Must be aerosolized in water for us to breathe in.
It goes directly into our alveoli
Is Legionella pneumophila contagious?
No, we’re a dead-end host
What medium is needed to diagnose Legionella pneumophila?
Buffered charcoal yeast (BCYE)
Where does Legionella pneumophila replicate?
Intracellularly in our macrophages (thus we need cell-mediated immunity)
Microbio of Mycoplasma pneumoniae
wall-less, lacks peptidoglycan
lacks definite shape
doesn’t gram stain
What disease does Mycoplasma pneumoniae cause?
Tracheobronchitis/atypical walking pneumonia
Typically in children and young adults
Where does Mycoplasma pneumoniae colonize?
URT - does not reach alveoli
What does Mycoplasma pneumoniae require for multiplication?
Our sterols
How do you treat Mycoplasma pneumoniae?
Erythromycin, doxycycline
What is special about Mycoplasma pneumoniae inflammation?
It’s monocytic, not neutrophilic
How does Mycoplasma pneumoniae cause damage?
Peroxide and superoxide
Community-acquired respiratory distress syndrome (CARDS) toxin (similar to pertussis toxin –> leads to a broken mucociliary escalator)
Stimulation of autoimmune IgM that binds to RBCs –> diagnose with cold hemagluttinin
Microbio of Pseudomonas aeruginosa
Gram - rod, aerobic
Opportunistic environmental pathogen
What diseases does Pseudomonas aeruginosa cause?
Swimmer’s ear and infections in CF patient lungs
Systemic effects in immunocompromised and burn patients
Why is Pseudomonas aeruginosa particularly bad in CF lungs?
It produces a mucus called alginate that normally makes an antiphagocytic biofilm… add that on top of lungs that already have thick mucus and you get a very bad situation
What three endogenous pathogens cause acute sinusitis?
- Streptococcus pneumoniae
- Non-typeable Haemophilus influnenzae
- Moraxella catarrhalis
How do you treat sinusitis?
Antibiotics, anti-inflammatory agents, decongestants, fluids
How does streptococcus pneumoniae evade host defenses?
Antiphagocytic capsule + sIgA protease
Three manifestations of otitis media?
- Acute otitis media
- Chronic suppurative otitis media
- Otitis media with effusion
What endogenous pathogens cause acute otitis media?
The same ones that cause sinusitis!
- Streptococcus pneumoniae
- Non-typeable Haemophilus influnenzae
- Moraxella catarrhalis
Treatment for otitis media?
Antibiotics, surgery to remove adenoids (for recurrent cases), and myringotomy tubes in the tympanic membrane
Microbio of haemophilus influenzae
Gram - coccobacillus
carbohydrate capsule (target of type B vaccine)
unencapsulated = nontypeable
What does nontypeable haemophilus influenzae cause?
Otitis media, sinusitis, pneumonia
What type of agar does haemophilus influenzae need?
Chocolate agar
How does haemophilus influenzae evade host defenses?
Type B has an antiphagocytic capsule
Nontypeable has LPS (toxin)
Also sIgAse (not 100% effective as sIgA can still work)
Major pathogen causing otitis externa (swimmer’s ear)?
Pseudomonas aeruginosa
What causes chronic otitis externa?
Usually over cleaning of the ear canal
It’s itchy, and not painful
What causes “malignant” otitis externa?
invasive Pseudomonas aeruginosa
Where is Pseudomonas aeruginosa encountered?
In the environment! Water, soil, air, food, catheters, endotracheal tubes (why you can’t bring flowers into the ICU)
What usually keeps Pseudomonas aeruginosa in check?
PMNs
So serious infections usually in those who are neutropenic
Where does Pseudomonas aeruginosa multiply?
Simple requirements… can do it everywhere. Even in disinfectants and cleaning materials.
Does not ferment. For whatever that is worth.
How does Pseudomonas aeruginosa cause damage?
Exotoxin A (similar to diphtheria toxin), type 3 secreted toxin, and numerous enzymes like phospholipase, protease, elastase
Why is treating Pseudomonas aeruginosa problematic?
It’s highly resistant to numerous antibiotics
What is the most common cause of lobar pneumonia in an otherwise healthy adult?
Streptococcus pneumoniae
What are the characteristics of dimorphic fungi?
Yeast in body temperature (37*C); mold in environmental and culture temperature (“mold in the cold”)
Your patient presents with cough and shortness of breath two weeks after exploring caves in the Mississippi River valley. What pathogen do you suspect?
Histoplasma
Your patient is a truck driver who just came back New Mexico. He has diarrhea, fever, and dyspnea. What pathogen do you suspect?
Coccidioides
Valley Fever!
What three diseases does aspergillus mold cause?
- Aspergilloma - colonization in a pre-existing cavity (“fungus ball”)
- Invasive pneumonia - very rare and in the immunocompromised
- Allergic Bronchopulmonary Aspergillosis (ABPA) - hypersensitivity rxn in asthmatics or CF patients
What will be high in a patient with ABPA’s blood?
IgE and eosinophils
due to the hypersensitivity rxn to the mold
A 24-year-old sex worker comes to you complaining of a four-week history of worsening cough, dyspnea, and fever. Her CXR shows diffuse infiltrates and her sputum sample shows “cotton candy” exudates. What pathogen do you suspect?
Pneumocystis
What type of pathogen is most likely to cause pneumonia in alcoholics?
Klebsiella pneumoniae
current jelly sputum!
What are two complications of S. aureus pneumo?
- Abscess
2. Empyema
How do you diagnose Legionnarie’s Disease
Urine antigen
If you see a multinucleated syncytial cell on gram stain what pathogen causing atypical pneumo should you suspect?
RSV - Respiratory Syncytial Virus
If you see multiple species (mostly anaerobes) of multiple morphologies on gram stain, what type of pneumonia should you expect?
Aspiration pneumonia (organisms from the oral cavity are now in the lungs!)
What organism causes Ghon complexes?
Mycobacterium tuberculosis
What is Mycobacterium Avium-Intracellular Complex (MAC)?
Obtained from the environment; causes infections in many organ systems (example: diarrhea in HIV patients; lymphadenitis in children)
** Lady Windermere Syndrome because it affects healthy, older women
What type of fungi is Pneumocystis jirovecci? What does it cause?
Opportunistic yeast that causes infection in immunocomprised patients (HIV, transplantation, those on long-term corticosteroids or TNF alpha inhibitors)
What do you use to treat and prophylax HIV patients with to prevent P. jirovecci?
Bactrim (trimethoprim-sulfamethoxazole)
If gram stain is descried as “cotton candy” exudate or silver stain is described as “crushed ping pong balls” what pathogen should you suspect?
Pnumocystis jirovecci
What type of fungi is Cryptococcus? What does it cause?
Yeast associated with soil, bird droppings, chicken coops, barns
Causes “wax and wane” meningitis in immunocompromised
Describe Cryptococcus morphology
Round, 5-15 um, surrounded by a thick, gelatinous capsule (**imp according to B&B); narrow based budding
What type of fungi is Histoplasma? Where is it endemic to and how do we get it?
Dimorphic
Endemic to Mississippi River valley. Present in soil where growth is stimulated by bird and bat guano (high in caves!!)
Describe Histoplasma morphology (yeast AND mold phases)
Yeast: very small (3-5um), narrow based budding, forms in macrophages (you will see tons inside a macrophage)
Mold: Characteristic tuberculate macroconidia (circular mold cells with spikes)
If you see “tuberculate macroconidia” in reference to a fungi, which one is the question referencing?
Histoplasma
Four B’s of blastomyces?
Broad
Based
Budding
Bone & skin (systemic effects)
What type of fungi is Blastomyces? Where is it endemic to?
Dimorphic fungi
Endemic to Mississippi River Valley & Great Lakes
Blastomyces morphology (yeast AND mold forms)?
Yeast: big (8-10um), thick refractile wall, broad based budding (**key)
Mold: Lollipop or pear-shaped microconidia
What type of fungi is Coccidioides? Where is it endemic to and how do we get it?
Dimorphic
Endemic to Southern California and the Southwest US. Most cases occur in Arizona (“Valley Fever”)
Gets kicked up from soil in dust storms or wind and we inhale
Describe Cocciodies morphology (yeast AND mold forms)?
Yeast: LARGE (250um) spherule filled with endospores
Mold: Barrel shaped conidia that alternate with empty cells (easily separated and aerosolized this way)
What type of fungi is Aspergillus? Most common species?
Mold
Most common: A. fumigatus
What is the morphology of aspergillus?
Thin septate hyphae; Y-shaped with branching at ~45 degrees
What type of fungi is Zygomycetes? Three most common types?
Mold
Rhizopus, Mucor, Lichtemimia
What predisposes someone to a Zygomycetes infection?
Neutropenia, diabetes mellitus, and corticosteroid usage
What does Zygomycetes quickly cause?
Tissue necrosis
How does Zygomycetes disseminate throughout the body?
Hematogenously and by direct extension
What is the morphology of Zygomycetes?
Broad, ribbon-like hyphea; pauci-septate (rare septations), and branches at ~90 degrees
Does genetics play a role in susceptibility to fungal infections?
Yes, inflammatory cytokines, cell receptors, and clotting factors like plasminogen have been show to have variants that increase susceptibility to fungi
What SNP in TLR-4 shows an increased susceptibility for invasive aspergillosis?
S4+
AND if the bone marrow recipient or donor was positive for Cytomegalovirus there was a slight increased risk (highest was S4+ with or with CMV+)
What is our first line of defense against fungi entering the respiratory tract? The second?
First: mucociliary escalator
Second: Phagocytes
What type of therapy increases the susceptibility of Coccidiomycosis reactivation?
TNF alpha
What type of immune cell is important for host defense against Coccidiomycosis?
T cell
DTH associated with recovery
Key protective immune response against Histoplasma?
Macrophages (where they live!) and T cell immunity
How are Crytopcoccus protected against phagocytosis?
Large capsule
+ other virulence factors like sialic acid and capsular polysaccharide
What type(s) of immune cells are protective for Cryptococcus?
Innate, B, and T cell
Radiologic findings in Pneumocystis jirovecci?
Infiltrates are characteristically diffuse
“ground glass” appearance
When diagnosing acute invasive aspergillosis, at what stage do you want to Dx and begin treatment?
During the halo stage (less than 5 days)
What is the progression of aspergillosis on CT scan?
Halo (5 days) –> increasing size and decreasing halo (1 week) –> stabilization –> air crescent
Other clinical presentations of invasive aspergillosis?
Sino-orbital disease, cerebritis, cutaneous infection
What kind of imaging do you want to obtain for an immunocompromised patient who you suspect has a lung infection?
CT
Much higher sensitivity and specificity than CXR for immunocompromised patients
What two, non-invasive blood tests can help establish an aspergillosis diagnosis?
- Galactomannan (cell wall carbohydrate found in Aspergillus and Penicillium)
- B-glucan (present in the cell wall of most fungi except Cryptococcus and agents of Mucormycosis)
Is and aspergillus PCR available?
No commercially in the US
Studies show that combining the non-commercial ones available with galactomannan testing may be a better screening than GM alone?
Antigen testing can be used for the detection of which fungi?
Histoplasma, Blastomycosis, Cryptococcus
B glucan testing can be used for which fungi?
Pneumocystis and Aspergillus
What is a solitary pulmonary nodule?
Single, spherical, well-circumscribed radiographic opacity that measures up to 3cm in diameter
Completely surrounded by aerated lung.. No atelectasis, pneumonia, hilar enlargement or pleural effusion
What percentage of lung masses over 3 cm are malignant?
80-90%
40% of solitary pulmonary nodules are what? 15% are what?
40% are inflammatory tissue (granulomas)
15% are bening neoplasms like hamartomas, lipomas, fibromas, cysts, etc
What is the most common type of lung cancer?
Adenocarcinoma
What is the most common type of benign tumor of the lung?
Hamartoma
What is a hamartoma?
Normal tissue that is disorganized. Composed of cartilaginous nests surrounded by connective tissue and mature fat cells
Can be parenchymal or central location
Fat is identified in 54% of lesions. Calcifications is identified in 15-30% of lesions
What finding on CT scan is pathognomonic of pulmonary hamartoma?
“popcorn calcification”
What is a bronchogenic cyst?
An abnormal detachment of the primitive foregut
Clinical presentation varies from respiratory distress in a newborn to an incidental finding in an adult
Benign lesions that do not metastasize
What is a carcinoid tumor?
A low-grade neoplasm of neuroendocrine cells
May arise centrally or peripherally
How do carcinoid tumors present?
With cough, hemoptysis, secondary post-obstructive pneumonia (recurrent in the same location)
Sometimes symptoms related to the secretion of compounds can cause diarrhea, flushing (serotonin secretion causing carcinoid syndrome)
What is carcinoid syndrome?
Diarrhea and flushing caused by the secretion of serotonin from carcinoid tumors
Usually only if metastatic or huge
How does a carcinoid tumor usually look on bronchoscopy?
“like a raspberry”
very red, very vascular
How do carcinoid cells appear on histology?
Tumor cells are arrange in small groups and nests
In typical carcinoid tumors there are no mitotic figures or necrosis present
Carcinoid tumor cells can be identified by using immunohistochemistry chemistry for what two markers?
Synaptophysin and Chromogranin
How do carcinoid tumor nuclei appear on histology?
“salt-n-pepper”/speckled light and dark appearance
What type of lung tumor is most common in women and those who never smoked?
adenocarcinoma
Where in the lung does adenocarcinoma develop?
The periphery
What gene mutations are associated with adenocarcinoma?
EGFR and ALK
very low percentage though
What is the growth pattern of adenocarcinoma in situ?
it spreads along the alveolar spaces on the lung and does not invade the stroma/vessels or pleura
How does adenocarcinoma in situ normally present?
“Pneumonia” that doesn’t resolve
But generally asymptomatic
How does adenocarcinoma in situ appear on CT?
Ground glass opacity
What are the two types of adenocarcinoma in situ?
Mucinous and serous
Thyroid Transcription Factor 1 (TTF-1) is normally expressed in what two types of lung tumors?
Small cell and adenocarcinoma
NOT typical for squamous cell
What type of lung cancer is highly associated with smoking?
Squamous cell carcinoma & small cell carcinoma
Where in the lung is squamous cell typically found?
Central (think where the smoke gets!)
What features are key identifies are squamous cell carcinoma?
Intercellular bridges and keratinization (keratin pearls!)
What are the pre-cursor intra-epithelial dysplasia steps seen in squamous cell carcinoma of the lung?
Normal –> squamous metaplasia –> dysplasia –> carcinoma in-situ –> invasive carcinoma
What is the most aggressive type of lung cancer?
Small cell carcinoma
Small cell carcinoma is derived mostly from what cell type?
Neuroendocrine cells that line the airways
Where does small cell carcinoma arise in the lung?
Centrally
Generally non resectable
How does small cell lung cancer appear on histology?
Small, high N:C ratio, cells stream & mold against each other
What is a paraneoplastic syndrome?
Clinical syndrome that occurs in patients with malignancies, often due to compounds secreted by the tumor
Often predate the clinical appearance of the tumor
What is Lambert-Eaton Syndrome?
Antibody against pre-synaptic Ca2+ channels that blocks the release of Acetylcholine
Main symptom is weakness (similar to Myasthenia Gravis)
What two hormones does small cell carcinoma release? What are the effects of this?
Antidiuretic hormone (ADH) –> hyponatremia
Adrenocorticotropic hormone (ACTH) –> Cushing’s syndrome (too much cortisol)
What hormone does squamous cell carcinoma release? What is the effect of this?
Parathormone, PTH-like peptide
Causes hypercalcemia