Nichols Doc Flashcards
Infiltrate
The term for a radiologic manifestation of pneumonia or edema or hemorrhage
Consolidation refers to
manifestations of alveoli filled with with water, blood, pus
Most types of pneumonia start how?
acute inflammation due to neutrophil prescence
Most types of pneumonia go on to the subacute phase around the 3 day mark when…
macrophages replace neutrophils….Think of Macrophages as the garbage clean-up of the cell.
Alveolar non-necrotizing pneumonia is most commonly due to what>
Strep Pneumo, Legionella, or Mycoplasma
Alveolar necrotizing pneumonia is often due to>
Staph aureus, Klebsiella, Pseudomonas
Strep Pneumo stains what and look like what
Gram positive (purple) Lancet shaped diplococci
Pneumolysin is a virulence factor for which bug and what does it do>
Strep Pneumo, It binds to cholesterol in cell membranes and forms pores at that area. The cells it binds to are erythrocytes and leukocytes.
ALSO…It is the reason that sputum in Strep Pneumo is rusty, the pneumolysin lyses red blood cells and the iron is absorbed into the sputum and coughed up
Four phases of Pneumococcal Lobar Pneumonia: Gross Path
Congestion: Serous, frothy, blood tinged fluid in alveoli
Red Hepatization: Days two and 3
Grey Hepatization: Day 4-7
Resolution- Day 8
Microscopic Pathology of Pneumococcal Pneumonia
Phase 1- Engorged Septal capillaries, edema fluid, bacteria,
Phase 2- Continuing Congestion, extravasation of red cells, infection spreading through pores of kohn
Phase 3- degenerating dead cells, fibrin nets through pores of kohn, foamy macros
Symptoms of strep pneumo in younger ppl
single severe shaking chill (rigor), fever, cough with RUSTY SPUTUM, pleuritic chest pain
Symptoms of pneumococcal strep pneumo in older ppl
confused, tired, cold, may not have cough or fever
Signs of strep pneumo
Fever, Tachypnea, pulmonary Rales, dullness to percussion, chest x-ray shows lobar consolidation.
In what % of strep pneumo cases is a blood culture positive
Less than 25%.
Urine test for strep pneumo
Pretty good
Treatment for strep pneumo
Any beta lactam
Microbiology of Legionella
gram neg
Pathogenesis of LEgionella
Live in warm water. Can hide inside amoeba. Once they are inhaled or aspirated they attach to respiratory epithelium by pili or flagella. After they are phagocytosed they prevent phagosome lysosome fusion.
Gross pathology of Legionella
Bulging Firm rubbery area of consolidation
What is unique about the microscopic pathology of Legionella
Tons of macrophages early on.
SYmptoms of Legionella
Chills, rigor, high fever, dyspnea, headache, DIARRHEA, myalgia, chest pain. GI symptoms suggest Legionella
Neurologic signs that suggest Legionella
confusion
Blood test results that suggest Legionella
hyponatremia (sodium less than 130)
Best way to test for legionella
Urine test….they wont grow on gram stain, you can sometimes see them on Dieterle stain but its hard to differentiate them from debris
Treatment of Legionella
Newer macrolides (azithromycin) or quinilones (levlofloxacin)
When is Mycoplasma most common
Fall and winter
If a bunch of high school kids or college kids get a walking pneumonia, it is most likely
Mycoplasma
What do Mycoplasma Pneumoniae look like on Gram stain
Invisible
Microscopic pathology to note for mycoplasma
Alveolar type 2 hyperplasia
Symptoms of mycoplasma to note
headache, anorexia, malaise, dry cough!!!
Signs to note for mycoplasma
maculopapular skin rash
Treatment
Azithromycin or levofloxacin
Staph Aureus risk factors
staph skin infection, nursig home residence, recent hospitalization, endotracheal intubation
Virulence factors for staph aureus
exotoxins, protein A which binds to TNF receptor and opens up a path for invasion, drug resistance
Gross path for staph aureus
PLUM COLORED LUNGS, BLOODY FLUID COMES OUT ON SECTIONING< MANY SMALL ABCESSES, some pleuritis and effuision
Symptoms of staph
cough comes on late, dyspne, fever, chills
Diagnosis
Gram stain, look for leukocytosis on CBC
Treat staph with
oxacillin for meth sensitive or vancomycin for mrsa
Pseudomonas mostly always affects patients who are where?
Hospital
Pathogenesis of Pseudomonas
once ingested it attaches to resp epithelium. Resistant to many common ABs
Virulence of Pseudomonas
Resistant to many abs, forms a biofilm,
Gross pathology of pseudomonas to note
firm red areas of hemorrhagic consolidation +/- yellow areas of consolidation with hemorrhage
Microscopic path to note for pseudomonas
acute necrotizing alveolitis, with long thin bacili invading blood vessels.
Symptoms for pseudomonas
Productive cough, confusion, dyspnea, fever chills,
Helpful hints for Dx of pseudomonas
Look for long thin gram negative bacilli with pointed ends. Culture should have a sweet grape like odor
Treat pseudomonas with
a beta lactam that works and a quinilone
Major risk factor for TB
HIV
other TB risk factors
Man, poor, black, Spring time, Elderly
What are the four possible outcomes after inhalation
1) Clearance 2) Primary Infection 3) Latent infection 4) Reactivated infection
Gross Pathology
Caseating granuloma, Gray-white, central necrosis
What is a ghon foci
1.5 cm gray white caseating granuloma with central necrosis
What is a ghon complex
A ghon foci with hilar lymph node involvement
Microscopic pathology of TB
Multinucleated giant cells with a lymphocyte collar, few dark red beaded bacili on acid fast stain. Sometimes neutrophilic necrotizing pneumonia
Symptoms to note for TB
night sweats, anorexia, wt. loss, fever, VERY FEW RESPIRAOTRY Symptoms. May have mild cough with hemoptysis
Diagnosis of TB
chest x ray showing consolidation of upper lobes. Chest x-ray and acid fast culture should get you where you need to go.
What is one giveaway for TB
Pneumonia associated with hilar lymphadenopathy
Treat for TB
RIPE for 8 weeks, RI for 18
TB wanna-be
Histoplasmosis
Most Histoplasmosis infections are mild, but some can be severe under what circumstances
AIDS, immunosuppresion therapy for transplants
Pathogenesis of histo
Inhalation, bat crap and chicken crap. Much like TB, the spores get into the alveoli, are phagocytosed but not killed nless they are activated by T cells which have had antigen presented to them. Granulomas form.
Symptoms of histoplasmosis
Fever, chills cough, anorexia, SUBSTERNAL CHEST PAIN THAT IS WORSE ON INHALATION
Diagnosis of histo
biopsy, culture, antigen test. Biopsy can yield definite diagnosis, culture takes up to 6 weeks
Treatment of histo
itraconazole for mild-moderate, amphotericin for severe
Aspergillus pneumonia
remember 45 degree branching septate hyphae
Classic triad of aspergillous symptoms
fever, pleuritic chest pain, hemoptysis
Diagnosis of aspergillous
Biopsy, culture, serum test for galactomannan
Be sure to differentiate aspergilous pneumonia from aspergillous colonization and allergic bronchopulmonary aspergillosis
ok
Cryptococcal pneumonia comes from
Cryptococcus fungi
Is cryptococal pneumonia common?
No way….seen rarely in AIDS pts, or other immunosuppresed pts. Never in children. More common in blacks
DX of cryptococcus
Culture is fast and easy on standard media. takes less than 48 hours. Serum antigen test is pretty easy in folks with immunodeficiency
What percentage of lung cancers develop in active or recently active smokers
85%
The three major types of lung cancer
small cell 15%, squamous cell 20%, adenocarcinoma 40%
adenocarcinoma
malignant epithelial tumor with glandular features
Most common mutation in adenocarcinoma
KRAS
5 Patterns of adenocarcinoma
Acinar (making glands), papillary, micropapillary (bad prognosis), solid (also bad), lepidic (spreading within alveoli better prognosis).
Treatment of adenocarcioma
surgery ir early stage, erlotinib (for EGFR mutation)
Adenocarcinoma is the most likely cancer to be responsive to targeted therapy
truth
bronchioalveolar carcinoma is now called
adenocarcinoma in Situ
Adenocarcinoma in situ is cahracterized by what?
non-destructive growth along intact alveoloar septa
Two types of adenocarcinoma in situ
mucinous and non-mucinous
Non-mucinous found predominantly in who and characterized by what
smokers, ground glass, EGFR mutation, evolves from terminal respiratory unit (type II pneumocytes and Clara Cells)
Mucinous
Evolves from broonchiolar epithelium, commonly presesnts as pneumonia type infiltrate on x-ray, KRAS mutation
Symptoms of adenocarcinoma in situ
Most have none. If they do have symptoms though, they often mimic pneumonia with productive cough
How is adenocarcinoma in situ diagnosed?
Discovered on radiology (nodules frequently have ground glass appearance) but a biopsy or cytology needed for actual diagnosis.
Treatment of Adeno in situ
surgical resection, if inoperable: Erlotinib for EGFR positive tumors, Paclitaxel for EGFR negative
What paraneoplastic syndrome might squamous cell carcinoma cause
Hypercalcemia due to production of a parathyroid hormone like substance
Where does sqquamous cell carcinoma arise>
2/3 aris from main, lobar, segmental, or subsegmental bronchi….centrally
What type of lung cancer is most likely to cavitate
squamous
Squamous is also associated with these other complications
post-obstructive pneumonia, mucous lugging, abcess, bronchiectasis.
Symptoms of squamous cell carcinoma
cough with hemoptysis, dyspnea, weight loss, anorexia
Major mode of diagnosis for squamous cell
H&E stain of biopsy,
Most common gene mutation in squamous cell
k63,, nearly 100%
What is the most aggressive lung cancer type
Small cell carcinoma
Where is small cell carcinoma typically located
Central, parabronchial, multifocal necrosis and metastatic tumor in lymph nodes and liver, bones, brain, adrenal
Signs of small cell carcinoma
facial, cervical, arm edema. Venous engorgement, Pemberton’s sign= development of facial flushing
Diagnosis
H&E stain biopsy
Primary sites of lung metastases
breast, colon, stomach
Gross path of metastatic lung cancer
small, numerous (generally smaller than primary neoplasms), rounder, more evenly contoured, generally peripheral and not endobronchial
Larger cannonball metastases most commonly from
breast
What is lymphangitic carcinomatosis
When metastatic disease fills lymphatics and infiltrates interstitium without creating masses
Diagnosis
radiology detects them but biopsy is required because fungal, mycobacterial and autoimmune diseases have similar appearances
What are some risk factors for pulmonary embolism that you are likely to forget
oral contrceptives, ptregnancy
Do small emboli usually cause infarction>
generally not because of dual blood supply
What about intermediate emboli
Can cause infarction if bronchial circulation is poor
Large emboli
Can cause saddle embolus where the block the pulmonary trunk. may cause cor pulmonale and immediate death
Pneumocystis jirovecii is what type of microorganism
fungus
Pneumocystis jirovecci most commonly infects what type of pts
AIDS…its an opportunistic bacteria. The prototype pneumonia in immunocompromised pts
Characteristics of pneumocystis infection?
Heavy consolidation
Symptoms of pneumocystis
insidious onset of progressive dyspnea, cough, fever
Signs of pneumocystis
Elevated LDH. decreased diffusion capacity
DX of pneumocystis
detection of bug in sputum stains, immunostains (regular method)cyst stains such as methenamine silver
Treatment of Pneumocystis
Trimethorphim
Prognosis
93% survival in AIDS pts
Most common presentation of pulmonary embolism
Dyspnea
Fat embolism is what?
globules of fat travelling in the vascular circulation
Fat embolism syndrome features
hypoxemia, neurological impairment and petechial rash (1-3 days after trauma)
fat embolism most commonly follows
single long bone fractures and bilateral femoral fractures
Symptoms of fat embolism
dyspnea, confusion
DX:
Be sure there is arterial hypoxemia, cerebral dysfunction, skin rash.
Air embolism
gas present in circulation
How does it happen
most common is the disconnection or breakage of vascular catheterization, keeping the pt upright when inserting catheter, deep inspiration during inertion or removal, surgery with an opening higher than the heart, traumatic blod vessel rupture,
Symptoms of air embolism
dyspnea, sense of impending doom, lightheadedness or dizzines
signs of air embolism
gasp or cough when air enters pulmonary circulation, mill wheel heart murmur, tachypnea, tachycardia,
Acute lung injury
non-cardiogenic pulmonary damage manifested by edema with an inflammatory or fibrosing response
Characteristics of acute lung injury
starts as interstitial edema which moves into alveolus. It is due to dysregulated inflammation. Increased permeability of microvascular barriers leads to extravascular accumulation of protein rich fluid.
Histologic hallmark of the exudative phase of acute lung injury
alveolar hyaline membranes
Histologic hallmark of proliferative phase
chronic interstitial inflammation
PaO2/FiO2 over 200
needs to be presesnt
What is radiation pneumonitis
acute lung injury occuring 1-2 mths after radiation
micropathology of radiation pneumonitis
atypical type 2 pneumocyte hyperplasia and blood vessel injury
Viral pneumonia tends to be interstitial
true
Influenza and RSV are the most common viral pneumonias
true
Cytomegalovirus causes interstitial pneumonia in immunocompromised pts.
true
Foamy Macrophages are characteristic of which time frame of bacterial pneumonia
subacture (day 3 and after)
Pneumococcal Pneumonia typically causes an alveolar exudate that is rich in what?
FIbrin
For Legionella think ADAM….
He is in a warm pool, in an amoeba brand swimsuit, firm, bulging, rubbery mass, confused, shitting himself, with low sodium (salt rings around lips) AT THE SPORTSPLEX
Staph Chest x-ray findings
Alveolar consolidation in a bronchopneumonic pattern, rapidly progressive- bilateral- multilobar abscesses and pleural effusions
