Respiratory: Pulomanry infection Flashcards
what is pneumonia
infection of lung parenchyma
when does pneumonia occur? examples?
when normal defenses are impaired
- impaired cough reflex
- damage to mucociliary escalator
- mucus plug
what are clinical features of pneumonia
- fever and chills
- productive cough with yellow-green (pus) or rusty (bloody sputum
- tachypnea
- pleuritic chest pain
- decreased breath sounds
- dullness to percussion
- elevated WBC count
how is the diagnosis for pneumonia made
- chest X-ray
- sputum gram stain and culture
- blood cultures
what are the 3 classical patterns seen on chest x-ray for pneumonia
- lobar pneumonia
- bronchopneumonia
- interstitial pneumonia
what characterizes lobar pneumonia
consolidation of an entire lobe of the lung
what is the most common cause of lobar pneumonia
usually bacteria
- Streptococcus pneumoniae
- Klebsiella pneumoniae
What are 4 phases of loar pneumonia
- congestion
- red hepatization
- gray hepatization
- resolution
why is there congestion in lobar pneumonia
due to congested vessels and edema
what causes red hepatization
due to exudate, neutrophils, and hemorrhage filling the alveolar air spaces, giving the normal spongy lung a solid consistency
what causes gray hepatization
due to degradation of red cells within the exudate
what is the most common cause of community-acquired pneumonia and secondary pneumonia and who usually gets it
Streptococcus Pneumonia
- middled-aged adults and elderly
what is secondary pneumonia
bacterial pneumonia superimposed on a viral upper respiratory tract infection
klebsiella pneumoniae impacts who
- malnourished and debilitated individuals
- elderly in nursing homes, alcoholics, and diabetics
what is clinical presentation for klebsiella pneumoniae
- enteric flora that is aspirated
- thick mucoid capsule results in gelatinous sputum ( currant jelly)
what complicates Klebsiella pneumoniae
abscess
what characterizes bronchopneumonia
scattered patchy consolidation centered around bronchioles
- multifocal and bilateral
what causes bronchopneumonia
Staphylococcus aureus Haemophilus influenzae Pseudomonas aeruginosa Moraxella catarrhalis Legionella Pneumophila
what is the 2nd most common cause of secondary pneumonia
Staphylococcus aureus
Staphylococcus aureus bronchopneumonia is complicated with what
abscess and empyema
empyema
pus in pleural space
what is a common cause of secondary pneumonia and pneumonia superimposed of COPD, leading to exacerbation of COPD
haemophilus influenzae
Pneumonia in cystic fibrosis patients
Pseudomonas aeruginosa
causes community-acquired pneumonia and pneumonia superimposed on COPD, leads to exacerbation of COPD
Moraxella Catarrhalis
what type of pneumonia does Legionella cause
- community acquired pneumonia
- pneumonia superimposed on COPD
- pneumonia in immunocompromised states
how is legionella pneumophila transmitted
from water source
how is Legionella best visualized
intracellular organism best visualized by silver stain
what characterizes interstitial atypical pneumonia
diffuse interstitial infiltrates
what symptoms presents with interstitial atypical pneumonia
mild upper respiratory symptoms
- minimal sputum
- low fever
‘atypical’ presentation
what causes interstitial (atypical pneumonia)
Mycoplasma pneumoniae chlamydia pneumoniae respiratory syncytial virus (RSV) Cytomegalovirus (CMV) Influenza virus Coxiella burnetii
what is the most common cause of atypical pneumonia
mycoplasma pneumoniae
who does mycoplasma pneumoniae impact
- young adults
- military recruits
- college students living in dormitory
what are complications with mycoplasma pneumoniae
- autoimmune hemolytic anemia (IgM against I antigen on RBCs causes cold hemolytic anemia)
- erythema multiforme
why is mycoplasma pneumoniae not visible on gram stain
lack of cell wall
What is the second most common cause of atypical pneumonia in young adults
Chlamydia pneumoniae
what is the most common cause of atypical pneumonia in infants
Respiratory syncytial virus (RSV)
what causes atypical pneumonia with post-transplant immunosuppressive therapy
Cytomegalovirus (CMV)
who is influenza virus usually seen in for atypical pneumonia
elderly
immunocompromised
preexisting lung disease
influenza virus atypical pneumonia increases the risk of what
superimposed S aureus or H. influenzae bacterial pneumonia
how does Coxiella Burnettii present atypical pneumonia?
- high fever ( Q fever)
who usually gets Coxiella Burnetti? how do they get it?
farmers and veterinarians
- coxiella spores are deposited on cattle by ticks or are present in cattle placentas
Coxiella is what type of oragnism
Rickettsial organism
how distinguishes Coxiella from the other Rickettsial species
- causes pneumonia
- does not require arthropod vector for transmission (survives as highly heat-resistant endospores)
- does not produce a skin rash
aspiration pneumonia is seen in patients at risk for what
aspiration
eg, alcoholics, and comatose patients
what causes aspiration pneumonia
anaerobic bacteria in oropharynx
eg. bacteroides, Fusobacterium, Paptococcus
how does aspiration pneumonia present in lungs? why?
right lower lobe abscess
- right main stem bronchus branches at a less acute angle than the left
what causes Tuberculosis
inhalation of aerosolized mycobacterium tuberculosis
what results in primary TB
- focal, caseating necrosis in lower lobe of lung
- hilar lymph nodes that undergo fibrosis and calcification, forming Ghon complex
what are the symptoms of primary TB? what about tests?
- usually asymptomatic
- positive PPD test
when does secondary TB occur
reactivation of mycobacterium tuberculosis
- commonly due to AIDS
- can be seen with aging
where in the lung does secondary TB usually occur?
apex of lung ( relatively poor lymphatic drainage and high O2 tension)
clinical features of secondary TB
fevers
night sweats
cough with hemoptysis
weight loss
what does biopsy reveal about secondary TB
caseating granulomas
how does TB stain
AFB stain reveals acid-fast bacilli
how and what does secondary TB lead to
forms cavitary foci of caseous necrosis
- may lead to miliary pulmonary TB or Tuberculous bronchopneumonia
Systemic spread often occurs in secondary TB and involve what common tissues
- meninges ( meningitis)
- cervical lymph nodes
- kidneys ( produces sterile pyuria)
- lumbar vertebrae ( Potts disease)
