Community-Acquired Pneumonia (CAP)

1
Community-Acquired Pneumonia (CAP)
2
Introduction

• Pneumonia is the 6th leading cause of death in
  the U.S.
• 90 of the deaths occur in persons over 65 years
  of age.
• The etiology is 50 idiopathic
• Only 20 with specific organism in clinical
  practice

3
Introduction

• According to the National Institutes of Health
  at any given time, the noses and throats of up
  to 70 of healthy people contain pneumococcus
  (the most common cause of bacterial pneumonia).
• The paradigm for any type of pneumonia is the
  balance between the patient's host defenses, the
  virulence of the potential pathogen, and the size
  of the exposure to the pathogen.

4
Definition

• Pneumonia defined as inflammation of the lung
  parenchyma pneumonia is characterized by
  consolidation of the affected part and a filling
  of the alveolar air spaces with exudate,
  inflammatory cells, and fibrin.

5
Classification and categorization of
bacterial pneumonia

• Anatomic/radiographic patterns of pneumonia
• Lobar pneumonia
• Bronchopneumonia
• Interstitial pneumonia
• Setting of infection
• Community-acquired pneumonia CAP
• Health careassociated pneumonia HCAP
• Nursing homeassociated pneumonia NHAP
• Hospital-acquired pneumonia HAP
• Ventilator-associated pneumonia VAP
• Aspiration pneumonia

6
Pneumonia types

• The 2005 ATS/IDSA guidelines distinguish the
  following types of pneumonia
• Community-acquired pneumonia (CAP) is defined as
  an acute infection of the pulmonary parenchyma in
  a patient who has acquired the infection in the
  community.
• Hospital-acquired (or nosocomial) pneumonia (HAP)
  is pneumonia that occurs 48 hours or more after
  admission and did not appear to be incubating at
  the time of admission.
• Ventilator-associated pneumonia (VAP) is a type
  of HAP that develops more than 48 to 72 hours
  after endotracheal intubation.

7
Pneumonia types

• Healthcare-associated pneumonia (HCAP) is defined
  as pneumonia that occurs in a non-hospitalized
  patient with extensive healthcare contact, as
  defined by one or more of the following
•       - Intravenous therapy, wound care, or
  intravenous chemotherapy within the prior 30
  days
•       - Residence in a nursing home or other
  long-term care facility
•       - Hospitalization in an acute care hospital
  for two or more days within the prior 90 days
•       - Attendance at a hospital or hemodialysis
  clinic within the prior 30 days

8
Bacterial pathogens of pneumonia

• Atypical organisms Mycoplasma pneumonia,
  Chlamydophila species (Chlamydophila psittaci,
  Chlamydophila pneumoniae) Legionella
  species,Coxiella burnetii , Bordetella pertussis
• Gram-positive bacteria S pneumoniae , S aureus
  ,Enterococcus (Enterococcus faecalis,
  Enterococcus faecium) Actinomyces israelii
  ,Nocardia asteroides
• Gram-negative bacteria Pseudomonas aeruginosa
  Klebsiella pneumoniae Haemophilus influenzae
  Escherichia coli Moraxella catarrhalis,
  Acinetobacter baumannii, Francisella tularensis
  ,Bacillus anthracis ,Yersinia pestis
• Anaerobic organisms Klebsiella,
  Peptostreptococcus, Bacteroides, Fusobacterium,
  and Prevotella

9

Frequency

• The most common etiologies of community-acquired
  pneumonia (CAP), listed in descending order of
  frequency are as follows
• Outpatient
• S pneumoniae
• M pneumoniae
• H influenzae
• C pneumoniae
• Respiratory viruses
• Inpatient, non-ICU
• S pneumoniae
• M pneumoniae
• C pneumoniae
• H influenzae
• Legionella species
• Aspiration
• Respiratory viruses
• Inpatient, ICU
• S pneumoniae
• S aureus
• Legionella species

10
Histopathology

• Lobar pneumonia Four stages of inflammatory
  response are classically described, as follows
• Congestion
• Red hepatization
• Gray hepatization
• Resolution

11
Mortality/Morbidity

• The average length of hospital stay for a patient
  diagnosed with pneumonia was 5 days
• Pneumonia and influenza together were the
  sixth-eighth leading cause of death in the United
  States

12
History / Symptoms

• Chest pain, dyspnea, hemoptysis (when clearly
  delineated from hematemesis), decreased exercise
  tolerance, and abdominal pain from pleuritis are
  also highly indicative of a pulmonary process
• Rust-colored sputum - Frequently associated with
  infection by S pneumoniae
• Currant-jelly sputum - Frequently associated with
  infection by Klebsiella species
• Foul-smelling or bad-tasting sputum - Often
  produced by anaerobic infections

13
History / Symptoms

• Nonspecific symptoms such as rigors or shaking
  chills, and malaise are common.
• Other nonspecific symptoms that may be seen with
  pneumonia include myalgias, headache, nausea,
  vomiting, diarrhea, and altered sensorium

14
Potential exposures - Travel, pets, occupation,
environment

• History of various exposures can be helpful in
  determining possible etiologies and the
  likelihood of bacterial pneumonia, as follows
• Exposure to contaminated air-conditioning or
  water systems -Legionella species
• Exposure to overcrowded institutions (eg, jails,
  homeless shelters) -S pneumoniae, Mycobacteria,
  Mycoplasma, Chlamydophila
• Exposure to various types of animals
• Cats, cattle, sheep, goats -C burnetii, B
  anthracis (cattle hide)
• Turkeys, chickens, ducks, or other birds -C
  psittaci
• Rabbits, rodents -F tularensis, Y pestis

15
(No Transcript)
16
Aspiration risks

• Patients at increased risk of aspiration with
• Alcoholism
• Altered mental status
• Anatomic abnormalities, congenital or acquired
• Dysphagia
• GERD
• Seizure disorder

17
Physical examination

• Approximately 80 are febrile - frequently
  absent in older patients
• A respiratory rate above 24 breaths/minute is
  noted in 45 to 70 of patients
• Most sensitive sign in elderly patients
• Tachycardia is common

18
(No Transcript)
19
Pneumonia Approach

• The following 3 aspects of disease are important
  in the management of pneumonia, in which
  diagnostic testing can play a pivotal role
• Determining the presence of pneumonia
• Assessing disease severity at the time of
  presentation
• Identifying the causative agent
• Differentiation between community-acquired
  pneumonia (CAP), health careassociated pneumonia
  (HCAP), hospital-acquired pneumonia (HAP), and
  other pulmonary pathology

20
Diagnosis

• Outpatients  Testing for a microbial diagnosis is
  usually not performed in outpatients.
• This is appropriate since empiric treatment is
  almost always successful.
• In one study of over 700 ambulatory patients
  treated for CAP, empiric antibiotics (a macrolide
  or fluoroquinolone in gt95 percent) were almost
  universally effective only 1 percent required
  hospitalization due to failure of the outpatient
  regimen
• The 2007 IDSA/ATS consensus guidelines suggest
  that routine tests to identify an etiology for
  CAP are optional for patients who do not require
  hospitalization
• An exception is in clinical or epidemiologic
  settings suggesting a critical microbe is the
  etiologic agent, in which tests for a microbial
  diagnosis are important

21
Diagnosis

• Critical microbes  Some microbes are critical to
  detect because they represent important
  epidemiologic challenges and/or serious
  conditions that require treatment different from
  standard empiric regimens. These organisms
  include
• Legionella species
• Influenza A and B
• Avian influenza
• Community-associated methicillin-resistant
  Staphylococcus aureus MRSA

22
Diagnosis

• The incidence of S. aureus in the HCAP and HAP
  groups were comparable (47 ) and significantly
  higher than in the CAP group (26 ).
• The rate of MRSA infection was also higher in
  HCAP and HAP patients compared to CAP (27 and 23
  versus 9 for CAP).

23
MDR pathogens

• Host risk factors for infection with MDR
  pathogens include
• Receipt of antibiotics within the preceding 90
  days
• Current hospitalization of 5 days
• High frequency of antibiotic resistance in the
  community or in the specific hospital unit
• Immunosuppressive disease and/or therapy
• Presence of risk factors for HCAP

24
Laboratory studies

• Diagnostic testing in patients with suspected
  pneumonia is driven mostly by the possibility
  that the results would significantly alter
  empiric therapy and management decisions and
  whether the test is likely to have a high yield.
• The following initial tests are indicated with
  suspected pneumonia
• Blood culture, prior to antibiotic therapy
• Sputum Gram stain and culture, prior to
  antibiotic therapy (if a good-quality,
  contaminant-sparse specimen containing lt10
  squamous epithelial cells per low-power field can
  be obtained)
• Sputum, serum, and/or urinary antigen test for
  Streptococcus pneumoniae
• Sputum and/or urinary antigen test for Legionella
  pneumophila
• Endotracheal aspirate for culture in intubated
  patients
• Culture and study of pleural fluid if effusion
  present
• Immune serologies for Mycoplasma pneumoniae,
  Chlamydophila pneumoniae, L pneumophila, and
  Coxiella burnetii - Results usually not available
  until several weeks after infection

25
Severity of Pneumonia

• Various systems to assess the severity of disease
  and risk of death exist and are in wide use,
  including
• PSI/PORT (ie, Pneumonia Severity Index/Patient
  Outcomes Research Team score)
• CURB-65 system (ie, confusion, urea of 7 mmol/L,
  respiratory rate of 30 breaths/min, and low
  systolic 90 mm Hg or diastolic 60 mm Hg blood
  pressure)

26
Imaging Studies

• Lobar pneumonias
• S pneumoniae homogenous parenchymal lobar
  opacities with air bronchograms round opacity
  stimulating a pulmonary mass, called round
  pneumonia.
• K pneumoniae lobar expansion with bulging of
  interlobular fissures as well as cavitations.
• L pneumophila Radiologic resolution tends to lag
  far behind clinical improvement (8 wk to clear).
• Bronchopneumonias
• S aureus Lobar enlargement with bulging of
  interlobular fissures can be seen in severe
  cases abscesses, cavitations (with air-fluid
  levels), and pneumatoceles are commonly seen
  30-50 of patients develop pleural effusions,
  half of which are empyemas.
• P aeruginosa usually all lobes are involved,
  with a predilection for the lower lobes necrosis
  and cavitation occur frequently pulmonary
  vasculitis can produce areas of pulmonary
  infarction that radiographically resembles
  invasive aspergillosis
• H influenzae Pleural effusion is present in
  approximately half of infected individuals.

27
Imaging Studies

• Aspiration pneumonias
• Gravity-dependent portions of the lungs (affected
  by patient positioning)
• The right lung is affected twice as often as the
  left lung

28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
(No Transcript)
33
Chest X-ray
34
Procedures

• Bronchoscopy with or without bronchoalveolar
  lavage (BAL) Lung tissue can be visually
  evaluated and bronchial washing specimens
  Nonbronchoscopic bronchoalveolar lavage,
  mini-BAL BAL can be performed without the use of
  a bronchoscope.
• Transtracheal aspiration for culture
• Thoracentesis
• Essential procedure in patients with a
  parapneumonic pleural effusion.

35
MORTALITY

• The mortality rate ranged from
• 5.1 for combined ambulatory and hospitalized
  patients
• 13 in hospitalized patients
• 36 in patients admitted to the ICU.

36
PREDICTORS OF MORTALITY

• Risk factors at presentation 
• British Thoracic Society BTS found a 21-fold
  increase in mortality in patients who had two or
  more of the following findings
• Blood urea nitrogen greater than 20 mg/dL (7
  mmol/L)
• Diastolic blood pressure less than 60 mmHg
• Respiratory rate above 30 per minute
• The presence of all three variables predicted a
  nine-fold greater risk for death with 70
  sensitivity and 84 specificity

37
PREDICTORS OF MORTALITY

• CURB-65 score
• These findings plus confusion (based upon a
  specific mental test or new disorientation to
  person, place, or time) and age greater than 65
  years
• Prediction rule for prognosis to determine
  whether a patient should be admitted to the
  hospital

38
(No Transcript)
39
Pneumonia Severity Index
40
Pneumonia Severity Index
41
Pneumonia Severity Index

• Classes I and II - Outpatient management
• Class III - Admission to an observation unit or
  for short hospital stay
• Classes IV and V - Treatment in inpatient setting
• Class I is 0-50 points - 0.1 mortality
• Class II is 51-70 points - 0.6 mortality
• Class III is 71-90 points - 0.9 mortality
• Class IV is 91-130 points - 9.3 mortality
• Class V is greater than 130 points - 27 mortality

42
Severe CAP

• Additional criteria that can help determine the
  need for ICU admission are the presence of 3
  minor criteria that compose the definition of
  severe CAP.Minor criteria are as follows
• Respiratory rate greater than or equal to 30
  breaths per minute
• Ratio of PaO2 to fraction of inspired oxygen (ie,
  PaO2/FiO 2 ) of less than or equal to 250
• Need for noninvasive ventilation (bilevel
  positive airway pressure BiPAP or continuous
  positive airway pressure CPAP)
• Multilobar infiltrates
• Confusion/disorientation
• Uremia (BUN greater than or equal to 20 mg/dL)
• Leukopenia (WBC count lt4000 cells/µL)
• Thrombocytopenia (platelet count lt100,000/µL)
• Hypothermia (core temperature lt36C)
• Hypotension requiring aggressive fluid
  resuscitation

43
Medication

• The goals of pharmacotherapy for bacteria
  pneumonia are to eradicate the infection, reduce
  morbidity, and prevent complications.

44
Treatment- CAP

• The regimens chosen by the IDSA/ATS guidelines
  mainly rely on macrolides (with or without a
  beta-lactam) or newer fluoroquinolones for
  outpatient therapy
• The guidelines promote the use of macrolides to
  provide coverage for both S. pneumoniae and
  atypical pathogens (particularly, M. pneumoniae
  and C. pneumoniae), which account for the
  majority of cases of CAP in ambulatory patients

45
Treatment- CAP

• In studies from different regions of the world,
  atypical pathogens account for 20 to 30 of
  cases of CAP
• Recent use of macrolide antibiotics is considered
  a risk factor for resistant S pneumoniae
• Monotherapy with a macrolide is not recommended
  for persons who received a macrolide antibiotic
  in the preceding three months.

46
Treatment

• Recommend one of the following oral regimens for
  HIGH RISK patients
• A respiratory fluoroquinolone
• Combination therapy with a beta-lactam effective
  against S. pneumoniae PLUS either a macrolide or
  Doxycycline
• Comorbidities or recent antibiotic use 
• The presence of significant comorbidities (ie,
  chronic obstructive pulmonary disease COPD,
  liver or renal disease, cancer, diabetes, chronic
  heart disease, alcoholism, asplenia, or
  immunosuppression).
• Use of antibiotics within the prior three months,
  increases the risk of infection with more
  resistant pathogens.

47
Treatment

• In previously healthy patients with no exposure
  to antibiotics within the previous 90 days, use
  the following 
• Macrolide or doxycycline
• In patients with comorbidities such as chronic
  disease of the heart, lung, liver, or kidneys
  diabetes mellitus alcoholism malignancy
  immunosuppression (drug- or disease-induced) or
  use of antimicrobials within the last 90 days,
  use the following
• Respiratory fluoroquinolone or beta-lactam plus
  macrolide

48
Inpatient Treatment

• Inpatient empiric antibiotic therapy Inpatient
  treatment of pneumonia, according to 2009 Joint
  Commission and the Centers for Medicare and
  Medicaid Services consensus guidelines, should be
  given within 6 hours of hospital admission (or in
  the emergency department if this is where the
  patient initially presented) and should consist
  of the following antibiotic regimens
• Non-ICU patients (choice of one option)
• Beta-lactam (IV or IM) plus macrolide (IV or PO)
• Antipneumococcal quinolone monotherapy (IV or
  IM) 
• Beta-lactam (IV or IM) plus doxycycline (IV or
  oral)
• If patient younger than 65 years with no risk
  factors for drug-resistant pneumococcus -
  Macrolide monotherapy (IV or oral)
• ICU Patients (choice of one option)
• Beta-lactam (IV) plus macrolide (IV)
• Beta-lactam (IV) plus antipneumococcal quinolone
  (IV)
• If patient has documented beta-lactam allergy -
  Antipneumococcal quinolone (IV) plus aztreonam
  (IV)

49
Inpatient Treatment

• Patients at increased risk of infection with
  Pseudomonas (acceptable for both ICU and non-ICU
  patients) (choice of one option)
• Antipseudomonal beta-lactam (IV) plus
  antipseudomonal quinolone (IV PO in non-ICU
  only)
• Antipseudomonal beta-lactam (IV) plus
  aminoglycoside (IV) plus one of the following
• Macrolide (IV)
• Antipneumococcal quinolone (IV PO in non-ICU
  only)
• If patient has documented beta-lactam allergy
  - Aztreonam (IV) plus aminoglycoside (IV) plus
  antipneumococcal quinolone (IV PO in non-ICU
  only)

50
MRSA

• For suspected infection with methicillin-resistant
  S aureus (MRSA)
• Vancomycin or linezolid may be added to the
  antibiotic regimen until the organism's identity
  and antibiotic sensitivities are known, at which
  point the medications can be adjusted accordingly

51
Aspiration pneumonia

• Aspiration pneumonia empiric therapy 
• The causative organisms in aspiration pneumonia
  have been noted to be similar to those of CAP or
  HCAP
• Patients with severe periodontal disease, putrid
  sputum, or a history of alcoholism with suspected
  aspiration pneumonia may be at greater risk of
  anaerobic infection.
• One of the following antibiotic regimens is
  suggested for such patients
• Piperacillin-tazobactam
• Imipenem
• Clindamycin or metronidazole plus a respiratory
  fluoroquinolone plus ceftriaxone

52
Clinical response

• Clinical response to antibiotic therapy should be
  evaluated within 48-72 hours of initiation.
• With appropriate antibiotic therapy, improvement
  in the clinical manifestations of pneumonia
  should be observed in 48-72 hours.
• Because of the time required for antibiotics to
  act, antibiotics should not be changed within the
  first 72 hours unless marked clinical
  deterioration occurs.

53
Clinical response

• With pneumococcal pneumonia, the cough usually
  resolves within 8 days and crackles heard on
  auscultation clear within 3 weeks.
• The timing of radiologic resolution of
  pneumococcal pneumonia varies with patient age
  and the presence or absence of an underlying lung
  disease.
• The chest radiograph usually clears within 4
  weeks in patients younger than 50 years without
  underlying pulmonary disease.
• Resolution may be delayed for 12 weeks or longer
  in older individuals and those with underlying
  lung disease.

54
Clinical response/Failure

• If patients do not improve within 72 hours, an
  organism that is not susceptible or is resistant
  to the initial empiric antibiotic regimen should
  be considered.
• Secondary to a complication such as empyema or
  abscess formation.
• Broadening the differential diagnosis to include
  noninfectious etiologies such as malignancies,
  inflammatory conditions, or congestive heart
  failure

55
Further Outpatient Care

• Patients should have a follow-up chest radiograph
  in approximately 6 weeks to ensure resolution of
  consolidation.
• Chest radiograph findings indicating
  nonresolution of symptoms should raise the
  consideration of an endobronchial obstruction as
  a cause of postobstructive pneumonia.

56
Pneumonia in Immunocompromised Pts

• Smokers, alcoholics, bedridden,
  immuno-compromised, elderly
• Common still common
• S. pneumo
• Mycoplasma
• Pneumocystis Carinii Pneumonia
• P. jirovecii
• Fever, dyspnea, non-prod cough (triad 50),
  insidious onset in AIDS, acute in other
  immunocompromised Pts
• CXR bilateral interstitial infiltrates
• Steroids for hypoxia
• TMP-SMZ still first line

57
Prevention

• Smoking cessation
• Vaccination per ACIP recommendations
• Influenza
• Inactivated vaccine for people gt50 yo, those at
  risk for influenza compolications, household
  contacts of high-risk persons and healthcare
  workers
• Intranasal live, attenuated vaccine 5-49yo
  without chronic underlying dz
• Pneumococcal
• Immunocompetent 65 yo, chronic illness and
  immunocompromised 64 yo

58
Complications

• Potential complications include the following
• Destruction and fibrosis/organization of lung
  parenchyma
• Bronchiectasis
• Necrotizing pneumonia
• Empyema
• Pulmonary abscess
• Respiratory failure
• Acute respiratory distress syndrome ARDS
• Ventilator dependence
• Death

59
THANKS