ClinMed Pneumonia Flashcards
Pneumonia definition
infection of the lower respiratory tract (distal airways, alveoli, and interstitium of the lung)
General cause of pneumonia
caused by proliferation of microbial pathogens at the alveolar level and the host’s response to those pathogens
World’s leading cause of death in children under 5?
pneumonia
Most common cause of hospital admissions other than women giving birth?
pneumonia
How do pathogens that cause pneumonia enter the body?
- aspiration of microorganisms from oropharynx
- hematogenous spread
- inhalation of pathogen
- extension from an infected pleural or mediastinal space
What are mechanical protective factors of host defense against pneumonia?
- hairs and turbinates in nares
- branching architecture of tracheobronchial tree
- mucociliary clearance
- gag reflex and cough mechanism
- normal flora
- alveolar macrophages
What is the role of alveolar macrophages in preventing pneumonia?
- initiate inflammatory response to bolster lower respiratory tract infections
- when capacity to ingest or kill microorganisms is exceeded, pneumonia manifests
What is the host inflammatory response to proliferation of microorganisms in the respiratory system?
- fever
- peripheral leukocytosis
- increased purlulent secretions
- alveolar capillary leakage
- capillary leaking results in radiographic infiltrate and rales on auscultation
- hypoxemia from alveolar filing
- decreased lung compliance
risk factors for pneumonia
- recent URI
- children <2; elderly >70
- smoking
- EtOH abuse
- lung disease or other serious disease
- toxic inhalation
- difficulty coughing d/t stroke or other condition
- difficulty swallowing
- immunosuppresion
- malnutrition
- ICU admission; intubation
symptoms of pneumonia
- acute onset of fever, cough w/ or w/o sputum, dyspnea
- Others: rigors, sweats, chills, chest discomfort, pleurisy, hemoptysis, fatigue, myalgia, anorexia, headache, abdominal pain
physical exam signs of pneumonia
- fever >100.4
- cough w/ or w/o sputum
- tachypnea
- tachycardia
- hemoptysis
chest exam signs of pneumonia
- dullness to percussion
- increased fremitus
- rhonchi
- rales
- egophony
- abdominal tenderness
crackles
- aka rales
- intermittent and brief
- crackling, clicking or rattling
- heard during inspiration
- can be fine or course
fine crackles
soft, high-pitched, and brief
course crackles
-louder, lower pitched crackles
cause of crackles
- air opens small airways that are sticky or adherent w/ fluid, mucous or pus
- d/t abnormalities in lung parenchyma or airways
wheeze
- aka sibilant wheeze
- continuous sound heard during inspiration or expiration
- high pitched, musical, like a hiss
- occur in smaller bronchi (asthma)
cause of wheezing
passage of air through narrowed airways
rhonchi
- AKA sonorous wheeze
- continuous sound heard during inspiration or expiration
- loud, low, coarse sound like a snore
- tend to occur from larger bronchi
- clear w/ cough
community acquired pneumonia (CAP)
occurs outside of hospital or onset begins <48 hrs after admission
healthcare-associated pneumonia (HCAP)
- subset of CAP
- occurs in non-hospitalized patient w/ healthcare contact
- ex: recent hospitalization, dialysis, resident in nursing home, home infusion care, home wound care, immunocompromised
nosocomial-hospital acquired pneumonia (HAP)
developed >48 hrs after admission, excluding pneumonia present at time of admission
ventilator-associated pneumonia
- type of HAP
- develops <48-72 hrs after ET intubation
what are atypical organisms?
- cannot be cultured on standard media or seen in Grams stain
- resistant to all beta-lactam agents
- treat w/ macrolide, fluoroquinolone or tetracycline
What are the typical bacteria that cause pneumonia in adults?
- S. pneumonia
- H. flu
- S. aureus
- Group A strep
- M. catarrhalis
what is the most common pathogen that causes pneumonia in adults?
streptococcus pneumoniae
what are atypical bacteria that cause pneumonia in adults?
- mycoplasma pneumonia
- legionella sp.
- chlamydophyla pneumonia
what are some viruses that can cause pneumonia in adults?
influenza A and B
which pathogens are responsible for pneumonia in the first 3 mos of life?
- group B strep
- e. coli
most common cause of pneumonia in the first 5 yrs of life?
viruses:
- RSV
- parainfluenza
- influenza
- adenovirus
- rhinovirus
pathogens more likely to cause pneumonia after the age of 5?
- incidence of pneumonia decreases in general
- bacterial pathogens increase
- ex:
- s. pneumoniae
- chlamydiophila pneumoniae
- mycoplasma pneumoniae
manifestations of CAP
- indolent
- febrile w/ tachycardia
- possible chills/sweats
- cough w/ or w/o sputum
- possible SOB
- possible pleurisy
- GI symptoms (nausea, vom., diarrhea)
- possible fatigue, HA, myalgia, arthralgia
exam findings of CAP
- vary w/ degree of pulmonary consolidation and pleural effusion
- increased RR
- use of accessory muscles
- possible increased (consolidation) or decreased (pleural effusion) tactile fremitus
- dull percussion
- crackles
- possible pleural friction rub
differential diagnosis for CAP
- acute bronchitis
- acute exacerbation of chronic bronchitis
- heart failure
- PE
- hypersensitivity pneumonitis
- radiation pneumonitis
possible labs to run for CAP
- gram stain and sputum culture (obtain before abx)
- blood cultures
- CBC w/ diff
- CMP
- ABG
- pneumococcal and legionella urinary Ag test (not time sensitive to starting abx)
- CRP
- procalcitonin
What is considered a good-quality specimen for a gram stain w/ CAP?
- more than 25 WBC and <10 epithelial cells
- difficult for elderly
what are the indications for an ABG in a patient w/ CAP?
hypoxemia
what is the expected CBC result in a patient w/ CAP?
leukocytosis
when is a CXR indicated for pneumonia? (view is PA and lateral)
- hypoxemia
- respiratory distress
- failure of abx therapy
- hospitalized patients
purpose of CXR in diagnosis of pneumonia
- confirm the diagnosis and help assess severity and response to therapy over time
- lag behind signs and sx, so needs repeated in 24-48 hrs
CXR results in patient w/ lobar pneumonia
- local
- seen in s. pneumoniae, h. flu, and legionella
CXR results of bronchopneumonia
- multifocal/lobular patchy infiltrates
- seen in staph, legionella, gram neg,. mycoplasma, chlamydia, viruses
CXR results of interstitial pneumonia
- fine, diffuse, granular infiltrates
- seen in infulenza, CMV, pneumoncystis carinii
CXR results of lung abscess
- lung tissue and cavity formation
- seen in anaerobes
CXR results of nodular lesion
- multiple or single nodular legions
- seen w/ histoplasmosis, coccidiomycosis, cryptococosis
mortality rate of pneumonia
- 12-14% if hospitalized
- 35% in ICU
- 1-5% if not hospitalized
indices used to determine if a patient w/ CAP should be admitted to the hospital?
- pneumonia severity index (PSI)
- CURB-65
- they can’t determine if pt should be in ICU
pneumonia severity index (PSI)
- aka patient outcomes research team (PORT) score
- used to ID patients at low risk of dying and therefore the need for hospitalization or not
- if categorized as 1-3, treat as outpatient
- if categorized as 4-5, admit to hospital
CURB-65 stands for?
- C: confusion
- U: BUN >19mg/dL
- R: RR > 30
- B: BP < 90/60
what is CURB-65?
- used to ID need for hospitalization in patients > 65 w/ CAP
- 0-1: outpatient
- 2: short in patient stay
- 3-5: admit, possible ICU
two general guidelines for abx therapy in tx of CAP
prompt initiation of medication to which the etiologic pathogen is susceptible
how do you treat CAP?
- do not delay initial abx treatment if ordering labs
- use empiric logic based on acuity, risk factors and local abx resistance patterns
possible meds for CAP tx
- if healthy: macrolide, doxycycline
- if comorbid conditions: fluoroquinolone, macrolide
monitoring parameters w/ CAP
- fever and leukocytosis usually resolves in 2-4 days
- CXR abnormalities resolve in 4-12 weeks (re do in 4-6 weeks)
- relapse or recurrence could indicate underlying neoplasm
vaccines available in US for CAP
- pneumococcal conjugate vaccine (Prevnar13)
- pneumococcal polysaccharide vaccine (Pneumovax23)
indication for prevnar13
- infants: series of 4 doses
- >65: 1 dose if not previously immunized
indication of pneumovax23
adults > 65: 1 dose at least 1 year after prevnar13 or every 5 years
who is at risk of HCAP?
- nursing homes
- undergone IV therapy (chemo) or wound care w/i 30 days
- hospitalized for >2 days w/i 90 days
- attended hospital or hemodialysis center w/i 30 days
causative pathogens of HCAP
- s. pneumoniae
- p. aeruginosa
- gram neg. bacteria
significance of being infected w/ a resistant organism
worsened mortality and morbidity
symptoms associated w/ HCAP
resemble CAP but more subtle:
- cough
- altered mental status
- anorexia, weakness, restlessness, agitation, falling, incontinence
- dyspnea less common
signs associated w/ HCAP
- diminished or absent responsiveness
- fever
- tachycardia, tachypnea
- sputum production
- wheezes/crackles
- noisy, wet breathing
what is the 2nd most common cause of infection among hospital inpatients and leading cause of death d/t infection?
nosocomial pneumonia
how to distinguish nosocomial pneumonia from CAP?
- different infectious causes
- different abx susceptibility patterns (higher incidence of drug resistance)
what is the primary cause of nosocomial pneumonia?
microaspiration
risk factors of VAP
- colonization of the oropharynx w/ pathogenic microoganisms
- aspiration of these organisms from oropharynx into lower respiratory tract
- compromise of the normal host defense mechanisms
What is the frequency of VAP?
- highest risk in first 5-14 days of mechanical ventilation
- cumulative risk of patients ventilated for as long as 30 days is as high as 70%
pathogenesis of VAP
- ET tube can damage tracheal mucosa –> facilitates tracheal colonization
- pathogenic bacteria form on tubes surface that protects them from abx and host defenses
- ET tube may prevent large vol. aspiration
- overwhelming of host defenses
What are the most important multi-drug resistant pathogens that cause nosocomial pneumonia?
- p. aeruginosa
- MRSA
clinical manifestations of VAP
generally same as CAP:
- fever
- leukocytosis
- increase respiratory secretions
- pulmonary consolidation
- tachypnea, tachycardia, worsening oxygenation, increased minute ventilation
reasonable clinical criteria for diagnosing VAP
New and persistent (>48) or progressive radiographic infiltrate + 2 of the following:
- temp >38 degrees C or <36 degrees C
- leukocytosis >10,000
- leukopenia <5,000
- purulent tracheal secretions
- gas exchange degradation
Major difference between VAP and CAP
VAP has a markedly lower incidence of atypical pathogens except legionella
treatment of VAP
- empiric treatment started once diagnostic specimens obtained
- once etiology diagnosis is made, modify abx for specific pathogen if needed
hospital acquired pneumonia (HAP)
develops more than 48 hrs after admission to the hospital in a non-intubated patient
HAP is similar to what
VAP
difference b/w HAP and VAP
HAP:
- lower frequency of non-multi drug resistant pathogens (monotherapy)
- better underlying host immunity
General pneumonia bugs
- gram +
- gram -
- other
- viral
- fungal
- HIV
gram + bugs
- strep pneumonia
- staph aureus
characteristics of strep pneumoniae infection
- rust colored sputum**
- pleurisy
- chest exam: signs of consolidation, dullness to percussion, increased tactile fremitus, egophoony, inspiratory rales
- CXR: lobar pneumonia
predisposing factors associated w/ strep pneumoniae infection
- alcoholism
- asthma
- HIV
- chronic cardiopulmonary disease
- hematologic disorders (sickle cell, splenectomy)
What is the most common cause of atypical pneumonia in adults?
mycoplasma pneumoniae
characteristics of a mycoplasma pneumoniae infection?
- younger patients (college students)
- flu-like symptoms
- causes bulbous myringitis***, myalgia, skin rash
- PE: normal w/ consolidation and possible crackles/rhonchi
mycoplasma pneumonia is also known as what
walking pneumonia
general gram negative bugs
- m. cat
- h. flu
- klebsiella pneumonia
- e. coli
- pseudomonas aeruginosa
gram negative infections assoicated w/ pnumonia
- chronically ill and/or immunocompromised
- usually d/t aspiration of contaminated secretions
- major source of HAP
m. cat
- diplococci
- preexisting lung disease
- elderly
- corticosteroid or immunosuppressive therapy
h. flu
- coccobacilli
- follows URI
- chronic cardiopulm disease
- COPD, bronchiextasis, CF, ETOH, DM
klebsiella pneumoniae
- associated w/ cavity lesions
- encapsulated rods
- ETOH abuse
- DM
- Current jelly sputum***
- aspiration pneumonia
e. coli
- rarely community acquired
- common in infants 0-2 mos old (birth canal)
pseudomonas aeruginosa
- immunocompromised
- CF
- bronchiectasis
- aspiration pneumonia
- green sputum
general “other” types of pneumonia
- mycoplasma pneumoniae
- legionella pneumoniae
- chlamydia pneumoniae
- anaerobes
legionella pneumonae infection high points
- associated w/ contaminated water sources
- similar symptoms yet sicker:
- toxic
- neuro sx
- has urine antigen testing
chlamydia pneumonia infection high points
- similar to mycoplasma infection but longer lasting
- sore throat w/ hoarseness
- more common in closed populations
anaerobic pneumonia high points
- foul-smelling purulent sputum
- do not do sputum culture other than by transthoracic (no oral flora contamination)
- imaging: lung abscess, necrotizing pneumonia, empyema
lung abcess
thick-walled solitary cavity surrounded by consolidation and air-fluid level
necrotizing pneumonia
multiple areas of cavitation w/i an area of consolidation
empyema
presence of purulent pleural fluid and may accompany lung abcess or necrotizing pneumonia
general viral bugs
- influenza
- RSV
viral pneumonia
- inflammatory disease of the lungs d/t a viral infection
- most result from exposure of a susceptible non-immune person to infection in the form of aerolized secrestions
overall, what are the leading causes of viral pneumonia?
- influenza a
- RSV
other causes in adults and children of viral pneumonia
- adults: inluenza a, b, c, H1N1, adenovirus, parainfluenza, and coronavirus
- children: same as above plus rubeola and RSV
misc. other viral causes of pneumonia
- CMV (immunocompromised)
- varicella
- herpes
- enterovirus
- EBV
tx of viral pneumonia
- antivirals
- rest
- increase fluids
- no ETOH/smoking
- breathing exercises
- antipyretics and antitussives for symptoms
general fungal bugs
- histoplasma capsulatum
- blastomycosis
- coccidiodes immitis
facts about fungal infections in pneumonia
- inhalation of spores is usual mechanism
- may disseminate after infecting lung
- azoles are tx
histoplasmosis
- geographically: ohio river valley, MO, OK
- associated w/ bird/bat guano, cave exploration/soil
- self limiting
- fever, HA, non-productive cough 2 weeks after exposure
CXR in histoplasmosis
- may look horrible (5 lobe pneumonia)
- scarring of lymph nodes
- granulomatos dz (looks like tb)
- body walls off granulomas so will look like hard calcifications
tx of histoplasmosis
- nothing at first
- then amphoteracin, sporanox, azoles
blastomycosis
- may affect skin
- usually in persons from Mississippi
- lives in soil - hunters get it
- flu like illness
- can go to skin, bone, cns
- present similarly to histoplasmosis
coccidiomycosis
- geographical: CA, AX, NM, TX
- most resolve spontaneously
- organisms in soil
S/S of coccidiomycosis
- erythema nodosum and multiforme in 10-50%
- many may be asymptomatic
- symptoms could include fever, pleuritic SP, dry cough and SOB
- disseminated can lead to CNS changes, lymphadenopathy and skin changes
CXR in coccidiomycosis
- lymphadenopathy
- may have abscess in lung - need tx
What bugs are associated w/ HIV related pneumonia? (3)
- aspergillus
- cryptococcus
- p. carinii/Jiroveci
cryptococcus
- sporadically in southern OK
- associated w/ bird (pigeon) droppings** in soil
bugs associated w/ ETOH (3)
- s. pneumo
- gram - bacilli
- anaerobes
bugs assoicated w/ IVDU (3)
- staph
- Tb
- anaerobes
