Pneumonia (quiz 2, exam 1) Flashcards
infection of the __, __ and __ of the lung
- alveoli
- distal airways
- interstitium
pathogen in sufficient __ or __ to overwhelm __ has to reach the lower repiratory tract
- numbers
- virulence
- host defenses
4 routs of infection
- microaspiration (most common)
- gross aspiration (of secretions, vomit; pts: stroke, nuromuscular disorders)
- hematogenous spread (blood)
- aerosolization
over __ microorganisms that can cause community acquired pneumonia (CAP) and they include these 4 main categories
- viruses
- bacteria
- fungi
- parasites
patholgogically, the lung changes from its normal __ to __
- sponginess
- consolidation
4 pathological types
- lobar pneumonia
- bronchopneumonia
- interstitial pneumonia
- miliary pneumonia
lobar pneumonia involves __, and is relatively __
- entire lung
- homogenesouly
bronchopneumonia involes __ and shows up as __
- one or severa lobes (usually lower and posterior dependent portion of lungs)
- patchy consolidaiton
interstitial pneumonia is inflammation of the __, __, and __ and shows up on on CT as __
- interstitium
- alveolar walls
- connective tissue around broncho vascular tree
- patchy or diffuse; gray, honeycombing
miliary pneumonia has numerous discrete __ resulting from the spread of pathogens to the lungs via the __, and it appears __ on xray
- lesions
- blood stream (TB)
- speckled (miliary)
community acquired pneumonia includes these 2 types
- ambulatory treatment
- inpatient treatment
hospital acquired pneumonia (nosocomial)/healthcare associated pneumonie (HCAP) includes these 2 types
-ventilator-associated
non-ventilator associated
healthcare associated pneumonia (HCAP) differs in these 4 things
- etiologic organisms
- prognosis
- diagnostic algorithms
- treatment algorithms
2 other important pneumonias to note
- opportunistic pneumonia in immunocompromised pts (fungal, PCP in HIV)
- TB (mycobacterium)
pneumonia in residents of __ and __ have been treated as either CAP or nosocomial
- nursing homes
- long term care facilities
it affects __ adults per year and __% are admitted to hospital
- 4 million
- 20-25%
it is the __ most deadly infectious disease in US and the __ most common cause of death in US each year
- # 1
- 7th
epidemiology: highest rates during __ months and __% of pts hospitalized with pneumonia die
- winter
- 12-14%
according to IDSA and ATS guidlines, HCAP indluces any pt who
- was hospitalized in an acute care hosptial for 2 or more days within 90 days of the infection
- resided in a nursing home or long term care facility
- received recent intravenous antibiotic therapy, chemotherapy, or wound care within the past 30 days of the current infection
- attended a hosptial or hemodialysis clinic
risk factors for increased mortalitly from CAP: age older than 65 years
- increased incidence and severity
- 5th leading cause of death age>65 yo
- 4th for those >85
- present with less pronounced symptoms
- may not be able to mount a fever
- may present with only delirium/change in mental status
- have to have a high index of suspicion
- prophylaxis against CAP is critical in this age group (pneumococcal and influenza vaccines)
7 risk factors for increased mortalitly from CAP
- age >65 yo
- active malignancy
- HIV or immunocompromised
- neurologic disease
- congestive heart failure
- coronary artery disease
- diabetes
comorbidities as risk factors for CAP (5)
- asthma
- chronic obstructive pulmonary disease
- chronic renal failure
- liver disease
- substance use - alcohol and tobacco
most common pathogens
- Streptococcus pneumoniae (~70% of cases)
- Haemophilus influenzae
- Mycoplasma pneumoniae
- Chlamydophila (chlymydia pneumoniae)
- Staphylococcus aureus
- Morexalla catarrhalis
other pathogens: bacterial
- Klebsiella pneumoniae
- Legionella species
other pathogens: viral
- influenza
- adenovirus
- respiratory syncytial virus (RSV)
- parainfluenza
T or F: bacterial etiology more common than viral
true
CAP due to __ and __ is more common in __ months
- S. pneumoniae
- H. influenzae
- (other causes of CAP do not appear to have increased seasonal prevalence)
__ and __ are most often responsible for lethal pneumonia, and are the most frequent bacterial pathogens leading to intensive care unit admission
- S. pneumoniae
- Legionella
CAP DDx: aspiration pneumonia
- can lead to a clinical presentation indistinguishable from CAP
- the causal pathogens are more likely to be gram negative enteric pathogens and oral anaerobes
CAP DDx: TB should always be considered in pts with risk factors for TB acquisition which include
- recent time spent in an endemic region
- homelessness
- potential exposure to infected individuals in institutionalized or medical settings
CAP DDx: typically the presentation of pulmonary tuberculosis is more __ than that of CAP, though this is not absolute
chronic (pulmonary tuebrcuosis can present with similar symptoms as CAP)
CAP DDx-TB: empiric treatment of CAP with __ can delay diagnosis of tuberculosis
quinolones (they have antimycobacterial activity)
CAP DDx-TB: any pt presenting with __ should be screened for TB
symptoms of CAP and risk factors for TB acquisition
Streptococcus pneumoniae gram stain findings
gram positive diplococci
Mycoplasma pneumoniae gram stain finding
not seen on gram stain (but RBCs are clumped together)
Haemophilus influenzae gram stain findings
gram negative coccobacilli
Chlamydophila pneumoniae gram stain findings
not seen on gram stain
Staphyloccocus aureus gram stain findings
gram positive cocci in clusters
Moraxella catarrhalis gram stain findings
gram negative diplococci
atypical pathogens include __ and CAP caused by these agents classically have these symptoms
- C. pneumoniae
- M. pneumoniae
- Legionella species
- presents insidiously (not acute, like with the more common agents)
- low grade fever
- non-productive cough
- prominent extra-pulmonary complaints (including myalgias and GI related symptoms)
atypical pneumonia: __ is often responsible for what is often termed walking pneumonia; it is transmitted via __ and is commonly spread among __
- Mycoplasma
- respiratory droplets
- otherwise healthy individuals in close contact with one another (e.g. college dormitories or military barracks)
T or F: clinical presentation alone is adequate to differentiate between specific etiologic agents in CAP
false
CAP epidemiology: it is often difficult ot identify microbiologic agents in the lab, via culture or other means, because __ happens relatively frequently
polymicrobial infection
clinical condition: alcoholism
commonly encountered pathogens:
- Streptococcus pneumoniae
- anaerobes
- less commonly Klebsiella pneumoniae (jelly sputum)
clinical condition: COPD/smoking
commonly encountered pathogens:
- S. pneumoniae
- Haemophilus influenzae
- Moraxella cattarrhalis
- Legionella species
clinical condition: nursing home resident
commonly encountered pathogens:
- S. pneumoniae
- gram negative bacilli
- Haemophilus influenzae
- Staphylococcus aureus
- anaerobes
- Chlamydophila pneumoniae
clinical condition: poor dental hygiene
commonly encountered pathogens:
anaerobes
clinical conditino: HIV infection, early stage
commonly encountered pathogens:
- S. pneumoniae
- H. influenzae
- Mycobacterium tuberculosis
clinical condition: HIV infection, late stage
commonly encountered pathogens:
- S. pneumoniae
- H. influenzae
- Mycobacterium tuberculosis
- P. jiroveci (formerly Pneumocystis pneumoniae or PCP)
- Cryptococcus species (fungi)
- Histoplasma species (fungi)
clincial condition: influenza active in community
commonly encountered pathogens:
- influenza
- S. pneumoniae
- S. aureus (more common after someone has had the flu)
- Streptococcus pyogenes (aspiration can lead to anaerobic infection and chemical pneumonitis)
- H. influenzae
condition: suspected large colume aspiration
commonly encountered pathogens:
anaerobes (chemical pneumonitis, obstruction)
condition: structural lung disease (e.g. cystic fibrosis)
commonly encountered pathogens:
- Pseudomonas aeruginosa
- S. aureus
condition: injection drug use
commonly encounterd pathogens:
- S. aureus
- anaerobes
- M. tuberculosis
- S. pneumoniae
condition: exposure to birds (e.g. parrots, parakeets, and macaws)
commonly encountered pathogens:
Chlamydophila psittaci
condition: exposure to rats
commonly encountered pathogens:
Yersinia pestis (plague)
condition: exposure to rabbits
commonly encountered pathogens:
Francisella tularensis (tularemia)
condition: leukemia
commonly encountered pathogens:
Fungi
condition: children <1 year
commonly encountered pathogens:
respiratory syncytial virus (RSV)
condition: children 2-5 years
commonly encountered pathogens:
parainfluenza virus
condition: post-splenectomy
commonly encountered pathogens:
- S. pneumoniae (encapsulated organism)
- H. influenzae (encapsulated organism?)
condition: college student
commonly encountered pathogens:
- Mycoplasma pneumoniae
- C. pneumoniae
condition: military recruits
commonly encountered pathogens:
- Mycoplasma pneumoniae
- C. pneumoniae
- adenovirus
condition: travel to southwestern US
commonly encountered pathogens:
Coccidioides species
condition: exposure to aerosolized water, air conditioning
commonly encountered pathogens:
Legionella
CAP is a clinical diagnosis base on th
- patients history
- physical exam
- CXR
diagnosis: 3 important decisions to made with case of suspected CAP
- does the pt truly have pneumonia?
- what is the severity of the pneumonia?
- is hospitalization required?
there is no gold standard for the diagnosis of CAP but these 2 things are considered sufficient and highly suggestive of CAP
- new infiltrate on chest radiograph
- acute respiratory complaints (e.g. cough and dyspnea)