Pneumonia Flashcards
What is pneumonia?
acute infection of the lung parenchyma
What is the most common cause of death due to infection?
pneumonia
What are the risk factors for pneumonia?
alcohol abuse
immunocompromised
lung disease
institutionalization
age >70
How does infection for pneumonia occur?
inhalation of airborne particles
-ex: TB, influenza, Legionella
aspiration of oropharyngeal secretions
-silent aspiration happens all the time
-most common cause
hematogenous spread
How do gross aspirations occur?
changes in consciousness
-alcoholics, drug abuse, seizures, respiratory arrest
Describe respiratory defences.
preventing foreign material from entering lungs:
-hairs lining nasal passages
-ciliated cells
-mucous production
-salivary enzymes
present in lung tissue:
-macrophages
-PMNs
-antibodies
ANY DEFECT CAN COMPROMISE HOST TO INVADING PATHOGENS
True or false: our lungs are normally incoluated with microorganisms from URT and inhaled aersols but pneumonia rarely occurs
true
What happens when there is a host defect in their respiratory defences?
lung being exposed to increased amount of microorganisms for sufficient period to cause inflammatory changes
Which organisms are responsible for community acquired pneumonia?
streptococcus pneumoniae (30-60%)
haemophilus influenzae (2-20%)
staphylococcus aureus (1-5%)
mycoplasma pneumoniae (5-10%, 17-37% in young + healthy)
chlamydia pneumoniae (4-6%)
legionella-uncommon in SK
viral (2-15%, likely higher)
Which organism is likely to cause pneumonia in a young, and healthy individual?
mycoplasma pneumoniae
Which organism is likely to cause pneumonia in someone with COPD or a smoker?
haemophilus influenzae
Which organism represents the “atypical” of pneumonia? What is the main difference?
mycoplasma pneumonia
hits both lobes of lung, S. pneumonia only hits one
True or false: you can differentiate between M. pneumonia and S. pneumonia being the cause of pneumonia through an X-ray
false
Which organisms are the likely cause of hospital acquired pneumonia?
klebsiella pneumoniae
E coli
enterobacter
proteus
pseudomonas aeruginosa
staph aureus (higher than CA)
anaerobes
s. pneumoniae
Which organisms represent 60% of hospital acquired pneumonia?
klebsiella pneumonia
proteus
E. coli
enterobacter
Which host factors can influence the causative organism of pneumonia?
heart, lung disease, DM
recent antibiotics (within last 3 months)
aspiration, cystic fibrosis
COPD
Which illnesses are most commonly associated with recurrent pneumonia?
COPD
heart failure
What are patient factors that can modify the causative organism of pneumonia?
heart, lung disease, DM
recent antibiotics (within last 3 months)
aspiration, cystic fibrosis
Which illnesses are most commonly associated with recurrent pneumonias?
COPD
heart failure
What are the signs and symptoms of pneumonia?
fever (may be high [>39C] or low grade)
chills
dyspnea
cough (productive or non-productive)
rust colored sputum or hemoptysis
pleuritic chest pain (stabbing)
other nonspecific symptoms (aches, fatigue, loss of appetite)
ABRUPT ONSET
What is the clinical presentation of pneumonia during a physical exam?
tachypnea
tachycardia
dullness to percussion
diminished breath sounds over affected area
inspiratory crackles
What can laboratory findings help determine for pneumonia?
low oxygen saturation
elevated WBC
sputum sample-may reveal PMNs and causative organism
Where does the difficulty lie with diagnosing pneumonia?
distinguishing bacterial from viral
if bacterial, which micro-organism
What is the issue with using sputum specimens to diagnose pneumonia?
difficult in children
normal flora always present=sample often contaminated
When are sputum specimens used to diagnose pneumonia?
not recommend for CAP
for inpatients with severe disease or suspected MRSA or P.aeruginosa
When are blood cultures used for diagnosing pneumonia?
not routinely recommended unless severe CAP or empirically treated for MRSA or P.aeruginosa
What are the many tools that are used in diagnosing pneumonia?
sputum specimen
blood culture
pleural fluid can be cultured
serology
WBC
chest x-ray
other (oxygen saturation or arterial blood gases)
What is required to make a diagnosis of pneumonia?
chest x-ray
What should a normal chest x-ray look like?
lots of black in the rib cage (black=air)
What is the pneumonia severity score used for?
predict the risk of death from pneumonia for anyone over the age of 50
-algorithm used to determine if a patient should be admitted
to hospital
Even if the pneumonia severity score says a patient can be treated as an outpatient, what else must this patient be able to do if they are to be treated as an outpatient?
take oral fluids and antibiotics
comply with outpatient care
carry out activities of daily living
What are the goals of therapy for treating pneumonia?
eradicate the microorganism
resolve signs and symptoms
reduce risk of complications and hospitalizations
reduce risk of adverse effects
minimize the development of antimicrobial resistance
What are the general treatment measures for pneumonia?
bed rest
hydration
nutrition
analgesic/antipyretics
oxygen for hypoxemia (not CAP)
cough suppression (better at night, not ideal to suppress)
drainage of empyema/abscess
What is the mainstay of therapy for pneumonia?
antibiotics
-should be initiated promptly, as soon as diagnosis is
confirmed
-appropriate antimicrobial samples should be obtained but
should not delay antibiotics
What are the top three pathogens for pneumonia?
streptococcus pneumoniae
haemophilus influenzae
mycoplasma pneumoniae
What are the reasons for the attraction of fluoroquinolones? What is the main issue?
potent and broad spectrum activity
good kinetics (OD dosing)
issue: resistance (reserve quinolones)
What is first line treatment for CAP (adult mild to moderate, no comorbidities & no risk factors for MRSA or P.aeruginosa)? List the dosing.
amoxicillin 1000mg TID
doxycycline 100mg BID
clarithromycin 500mg BID or 1000mg OD
azithromycin 500mg first day, then 250mg x 4 days OR 500mg OD x 3 days
macrolides only if local pneumococcal resistance is <25%
What are the resistance rates in Saskatoon of strep pneumoniae to macrolides?
outpatient: 19%
inpatient: 21%
blood isolates: 43% (few isolates)
What are risk factors for MRSA or P.aeruginosa?
prior respiratory isolation of MRSA or P. aeruginosa
OR recent hospitalization AND receipt of parenteral antibiotics in last 90 days
What are the co-morbidities that should be kept in mind when choosing an antibiotic for pneumonia?
chronic heart, lung, liver, or renal disease
diabetes mellitus
alcoholism
malignancies
asplenia
What are the choices of antibiotics for pneumonia when the patient has comorbidities but not risk for MRSA or P. aeruginosa? List the dosing.
amoxiclav 500/125mg TID or 875/125mg BID
cefuroxime axetil 500mg BID
cefprozil 500mg
ANY ONE BETA-LACTAM AGENT LISTED ABOVE PLUS:
clarithromycin, azithromycin, or doxycyline
OR monotherapy with:
levofloxacin 750mg OD x 5 days
moxifloxacin 400mg OD
In regions with high rates (>25%) macrolide resistant S.pneumoniae, what should be considered for treatment?
consider alternative agent including in those with no comorbidities
What is the duration of therapy for outpatient tx of CAP?
5 days providing clinical stability is reached
True or false: in moderate severity CAP there was no difference between beta-lactam alone, macrolide and beta-lactam and fluoroquinolone therapy
true
What should be taken into consideration when a pathogen has been identified?
adjust therapy based on sensitivity results
choose agent that is most effective or has the most evidence
has fewest adverse effects
convenience/lowest cost
How long does it take most patients to reach clinical stability? What is clinical stability?
48-72hr
resolution of vital sign abnormalities
-HR, RR, BP, oxygen saturation, temp
What are some outpatient cases of pneumonia that require longer treatment?
S. aureus or Ps. aeruginosa: 7 days
longer if complications
What percent of the population has colonization of S. pneumoniae at any given time?
25%
often follows a viral URTI
What is a characteristic symptom of pneumonia caused by S. pneumoniae?
one shaking chill followed by a high temperature
pleuritic chest pain and headache are common
Which group of patients are at risk from pneumonia caused by S. pneumoniae?
spleenic dysfunction or asplenia
diabetes
renal disease
cardio-pulmonary disease
What are the choices of antibiotics for pneumonia caused by S. pneumoniae? List the dosing.
pencillin G: 5-10 M units/d IV or IM
oral penicillin V or amoxicillin
alt: cefazolin or erythromycin or FQ
What is the cause of penicillin resistance for S. pneumoniae?
reduced affinity for PBP or change in amount of PBP present
What is the treatment of pneumonia caused by PRSP?
low level resistance: penicillin IV (high dose) OR amoxicillin
(high dose) OR cefuroxime
high level resistance: penicillin G 2MU IV q6h OR cefotaxime
OR ceftriaxone OR resp. FQ
Which patients see higher levels of pneumonia caused by S. aureus?
debilitated patients
cystic fibrosis
What can S. aureus release?
enzymes and endotoxins which lead to empyema and abscess
What is the treatment of pneumonia caused by MSSA?
cloxacillin: 8-12g/d IV (up to 2g q4h)
alt: cefazolin, clindamycin, or vancomycin
What is the treatment of pneumonia caused by MRSA?
vancomycin
linezolid
tigecycline
Which group of patients tend to see higher levels of pneumonia caused by H. influenza?
COPD
kids
elderly
can follow URTI
What is the treatment of pneumonia caused by non-BL producing H. influenzae?
ampicillin 6-8g/day IV (given q6h)
amoxicillin 3g/d po
What is the treatment of pneumonia caused by BL producing H. influenzae?
amoxiclav
2nd gen cephalosporin (cefuroxime)
3rd gen cephalosporin (cefotaxime or ceftriaxone)
FQ
azithromycin
clarithromycin
doxycycline
Which organisms colonize the URT of hospitalized patients?
aerobic gram negative rods
What are the options for empiric therapy of a hospitalized patient with pneumonia?
3rd gen cephalosporin
carbapenem
piperacillin/tazobactam
Which patients tend to have higher incidence of pneumonia caused by Ps. aeruginosa?
underlying lung damage
cystic fibrosis
What are some symptoms of pneumonia caused by Ps. aeruginosa?
fever
chills
cough
green sputum with characteristic smell
Which FQ has adequate activity against pseudomonas?
ciprofloxacin
What is the treatment of pneumonia caused by Ps. aeruginosa?
piperacillin/tazobactam + cipro or AMG
ceftazidime + cipro or AMG
ciprofloxacin + AMG
cefepime + cipro or AMG
meropenem + cipro or AMG
How do the symptoms of pneumonia caused by mycoplasma pneumoniae tend to appear?
symptoms appear more viral in nature:
-congestion, sore throat, chest pain, cough, etc
What are the triad of symptoms for mycoplasma pneumoniae?
maculopapular rash
arthritis
pneumonia
What is the treatment for pneumonia caused by M. pneumoniae?
erythromycin 250mg QID (or any macrolide) OR doxycycline
alt: FQ
What is the morphology of Legionella pneumophilia?
aerobic gn rod
What is the incubation period of Legionella pneumophilia?
up to 10 days
What are the common symptoms of an infection by Legionella pneumophilia?
fever
chills
malaise
myalgia
headache
cough
GI problems
True or false: Legionella pneumophilia is common in SK
false
What is the treatment for Legionella pneumophilia?
azithromycin
alt: resp FQ
rifampin may be added
What is the morphology of chlamydophilia pneumoniae?
obligate intracellular gn
What are the symptoms of an infection by chlamydophilia pneumoniae?
low grade fever
nonproductive cough
normal WBC
may report pharyngitis and hoarseness in prior weeks
What is the treatment for pneumonia caused by chlamydophilia pneumoniae?
doxycyline or macrolide
alt: FQ
What may occur from aspiration pneumonia?
atelectasis
hemorrhage
pulmonary edema
some patients develop secondary bacterial pneumonia due to decreased defenses
How long does it take patients to improve within onset of effective antibiotics?
2 days
True or false: chest x-ray resolution takes a while
true
3 weeks in young healthy adults
up to 12 weeks in elderly or in those with complicated infection
What can be used as indicators of efficacy in pneumonia treatment?
decreased cough, dyspnea, and RR
decreased fever
decreased sputum production
improved oxygenation
normalization of WBC
What are the reasons for treatment failure of pneumonia?
non-adherence
complication, spread of infection
superinfection
misdiagnosis of non-infectious causes
What are other considerations for a monitoring plan in pneumonia?
duration of therapy
route of administration
should patient be hospitalized
adherence
other drug therapy required (ex: antiypyretics)
non-drug therapy
What are the pneumococcal vaccines?
23 valent polysaccharide
13 valent polysaccharide
Who should receive the 23 valent polysaccharide vaccines?
anyone over 65
patients with risk factors (COPD, HF, alcoholism, diabetes)
