CommunityAcquired Pneumonia

1
Community-Acquired Pneumonia

• Joanna M. Delaney, D.O.
• Georgetown University /
• Providence Hospital
• June 8, 2007

2
Objectives

• Describe the common pathogenesis and pathogens of
  pneumonia
• Discuss diagnosis and initial management of
  community acquired pneumonia (CAP)
• Understand features of the Pneumonia PORT
  Severity Index
• Discuss the IDSA/ATS guidelines and
  recommendations for final antibiotic choice
• Understand issues in basic management for
  pneumonia in children, nursing home patients, and
  immunocompromised patients.

3
Epidemiology

• Unclear! Few population-based statistics on the
  condition alone
• CDC combines PNA with influenza for morbidity
  mortality data
• PNA influenza 7th leading causes of death in
  the US (2001)
• Age-adjusted death rate 21.8 per 100,000
• Mortality rate 1-5 out-Pt, 12 In-Pt, 40 ICU
• Death rates increase with comorbidity and age
• Affects race and sex equally

4
Community Acquired Pneumonia

• Infection of the lung parenchyma in a person who
  is not hospitalized or living in a long-term care
  facility for 2 weeks
• 5.6 million cases annually in the U.S.
• Estimated total annual cost of health care 8.4
  billion
• Most common pathogen S. pneumo (60-70 of CAP
  cases)

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Nosocomial Pneumonia

• Hospital-acquired pneumonia (HAP)
• Occurs 48 hours or more after admission, which
  was not incubating at the time of admission
• Ventilator-associated pneumonia (VAP)
• Arises more than 48-72 hours after endotracheal
  intubation

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Nosocomial Pneumonia

• Healthcare-associated pneumonia (HCAP)
• Patients who were hospitalized in an acute care
  hospital for two or more days within 90 days of
  the infection resided in a nursing home or LTC
  facility received recent IV abx, chemotherapy,
  or wound care within the past 30 days of the
  current infection or attended a hospital or
  hemodialysis clinic
• Guidelines for the Management of Adults with HAP,
  VAP, and HCAP. American Thoracic Society, 2005

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Pathogenesis

• Inhalation, aspiration and hematogenous spread
  are the 3 main mechanisms by which bacteria
  reaches the lungs
• Primary inhalation when organisms bypass normal
  respiratory defense mechanisms or when the Pt
  inhales aerobic GN organisms that colonize the
  upper respiratory tract or respiratory support
  equipment

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Pathogenesis

• Aspiration occurs when the Pt aspirates
  colonized upper respiratory tract secretions
• Stomach reservoir of GNR that can ascend,
  colonizing the respiratory tract.
• Hematogenous originate from a distant source and
  reach the lungs via the blood stream.

9
Pathogens

• CAP usually caused by a single organism
• Even with extensive diagnostic testing, most
  investigators cannot identify a specific etiology
  for CAP in 50 of patients.
• In those identified, S. pneumo is causative
  pathogen 60-70 of the time

10
Streptococcus pneumonia

• Most common cause of CAP
• Gram positive diplococci
• Typical symptoms (e.g. malaise, shaking chills,
  fever, rusty sputum, pleuritic hest pain, cough)
• Lobar infiltrate on CXR
• Suppressed host
• 25 bacteremic

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Atypical Pneumonia
Pneumonia

• 2 cause (especially in younger population)
• Commonly associated with milder Sxs subacute
  onset, non-productive cough, no focal infiltrate
  on CXR
• Mycoplasma younger Pts, extra-pulm Sxs
  (anemia, rashes), headache, sore throat
• Chlamydia year round, URI Sx, sore throat
• Legionella higher mortality rate, water-borne
  outbreaks, hyponatremia, diarrhea

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Viral Pneumonia

• More common cause in children
• RSV, influenza, parainfluenza
• Influenza most important viral cause in adults,
  especially during winter months
• Post-influenza pneumonia (secondary bacterial
  infection)
• S. pneumo, Staph aureus

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Other bacteria

• Anaerobes
• Aspiration-prone Pt, putrid sputum, dental
  disease
• Gram negative
• Klebsiella - alcoholics
• Branhamella catarrhalis - sinus disease, otitis,
  COPD
• H. influenza
• Staphylococcus aureus
• IVDU, skin disease, foreign bodies (catheters,
  prosthetic joints) prior viral pneumonia

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Diagnosis and Management
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Guidelines

• American Thoracic Society
• Guidelines for the Management of Adults with CA
  (2001)
• Infectious Diseases Society of America
• Update of Practice Guidelines for the Management
  of CAP in Immunocompetent adults (2003)
• ATS and IDSA joint effort
• IDSA/ATS Consensus Guidelines on the Management
  of CAP in Adults (March 2007)

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Guidelines

• 2001 ATS 2003 IDSA Guideline Update
• Expert panels
• Evidence-based recommendations
• Recommend patient stratification to identify
  likely pathogens and suggested empiric abx
• Site of care
• Presence of cardiopulmonary disease
• Presence of modifying factors

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Clinical Diagnosis

• Suggestive signs and symptoms
• CXR or other imaging technique
• Microbiologic testing

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Signs and Symptoms

• Fever or hypothermia
• Cough with or without sputum, hemoptysis
• Pleuritic chest pain
• Myalgia, malaise, fatigue
• GI symptoms
• Dyspnea
• Rales, rhonchi, wheezing
• Egophony, bronchial breath sounds
• Dullness to percussion
• Atypical Sxs in older patients

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Clinical Diagnosis CXR

• Demonstrable infiltrate by CXR or other imaging
  technique
• Establish Dx and presence of complications
  (pleural effusion, multilobar disease)
• May not be possible in some outpatient settings
• CXR classically thought of as the gold standard

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Infiltrate Patterns
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Clinical Diagnosis Recommended testing

• Outpatient CXR, sputum Cx and Gram stain not
  required
• Inpatient CXR, Pox or ABG, chemistry, CBC, two
  sets of blood Cxs
• If suspect drug-resistant pathogen or organism
  not covered by usual empiric abx, obtain sputum
  Cx and Gram stain.
• Severe CAP Legionella urinary antigen, consider
  bronchoscopy to identify pathogen

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Clinical Diagnosis

• Assess overall clinical picture
• PORT Pneumonia Severity Index (PSI)
• Aids in assessment of mortality risk and
  disposition
• Age, gender, NH, co-morbidities, physical exam
  lab/radiographic findings

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IDSA Outpt Management in Previously Healthy Pt

• Organisms S. pneumo, Mycoplasma, viral,
  Chlamydia pneumo, H. flu
• Recommended abx
• Advanced generation macrolide (azithro or
  clarithro) or doxycycline
• If abx within past 3 months
• Respiratory quinolone (moxi-, levo-, gemi-), OR
• Advanced macrolide amoxicillin, OR
• Advanced macrolide amoxicillin-clavulanate

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IDSA Outpt Management in Pt with comorbidities

• Comorbidities cardiopulmonary dz or
  immunocompromised state
• Organisms S. pneumo, viral, H. flu, aerobic GN
  rods, S. aureus
• Recommended Abx
• Respiratory quinolone, OR advanced macrolide
• Recent Abx
• Respiratory quinolone OR
• Advanced macrolide beta-lactam

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IDSA Inpt Management-Medical Ward

• Organisms all of the above plus polymicrobial
  infections (/- anaerobes), Legionella
• Recommended Parenteral Abx
• Respiratory fluoroquinolone, OR
• Advanced macrolide plus a beta-lactam
• Recent Abx
• As above. Regimen selected will depend on nature
  of recent antibiotic therapy.

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IDSA Inpt Management-Severe/ICU

• One of two major criteria
• Mechanical ventilation
• Septic shock, OR
• Two of three minor criteria
• SBP90mmHg,
• Multilobar disease
• PaO2/FIO2 ratio
• Organisms S. pneumo, Legionella, GN, Mycoplasma,
  viral, ?Pseudomonas

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IDSA Inpt Management Severe/ICU

• No risk for Pseudomonas
• IV beta-lactam plus either
• IV macrolide, OR IV fluoroquinolone
• Risk for Pseudomonas
• Double therapy selected IV antipseudomonal
  beta-lactam (cefepine, imipenem, meropenem,
  piperacillin/tazobactam), plus
• IV antipseudomonal quinolone
• -OR-
• Triple therapy selected IV antipseudomonal
  beta-lactam plus
• IV aminoglycoside plus either
• IV macrolide, OR IV antipseudomonal quinolone

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Switch to Oral Therapy

• Four criteria
• Improvement in cough and dyspnea
• Afebrile on two occasions 8 h apart
• WBC decreasing
• Functioning GI tract with adequate oral intake
• If overall clinical picture is otherwise
  favorable, can can switch to oral therapy while
  still febrile.

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Management of Poor Responders

• Consider non-infectious illnesses
• Consider less common pathogens
• Consider serologic testing
• Broaden antibiotic therapy
• Consider bronchoscopy

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Prevention

• Smoking cessation
• Vaccination per ACIP recommendations
• Influenza
• Inactivated vaccine for people 50 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

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Pneumonia in Children Dx

• Symptoms
• Infants non-specific manifestations
• Fever, poor feeding, irritability, vomiting,
  diarrhea, URI Sx, cough, respiratory distress
• Older children more specific
• Fever, cough, chest pain, tachypnea, tachycardia,
  grunting, nasal flaring, retracting. Cyanosis
  usually very late.
• Signs/Physical exam
• RR 60 for all ages
• Hypoxia
• Rales, wheezes, crackles, coarse breath sounds

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Pneumonia in Children Pathogens

• 0-4 wks GBS, GN enterics, Listeria
• 4-12 wks C. trachomatis, GBS, GN enterics,
  Listeria, viral (RSV/parainfluenza), B. pertussis
• 3 mos-4 yrs Viral, S. pneumo, H. influenza, M.
  catarrhalis, Grp A Strep, Mycoplasma
• 5yrs Mycoplasma (5-15yrs), C. pneumo, S.
  pneumo, viral

33
Pneumonia in the Elderly

• Prevention important
• Presentation can be subtle
• Antibiotic choice in CAP is same as other adults
• Healthcare associated pneumonia
• Consider S. aureus (skin wounds) and GN bacteria
  (aspiration)
• Pneumonia in Older Residents of Long-term Care
  Facilities. AFP 2004 70 1495-1500.

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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

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New Guideline
36
IDSA/ATS 2007 Guideline

• Hospital Admission Decision
• CURB-65 criteria (confusion, uremia, RR, low BP,
  age 65 yrs or greater) or PSI can be used to ID
  candidates for outpt management
• Diagnostic Testing
• Acknowledges the low yield and infrequent
  positive impact on clinical care
• Outpt testing for etiologic Dx remain optional
• Inpt testing for etiologic Dx recommended for
  specific indications
• Antimicrobial therapy essentially unchanged

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Summary

• Use overall clinical presentation to guide
  therapy
• The admission decision is an art of medicine
  decision
• Use risk factors and guidelines to assist with
  clinical judgement

38
References

• American Thoracic Society. Guidelines for the
  Management of Adults with Community-acquired
  Pneumonia. Am J Respir Crit Care Med 2001 Vol.
  1631730-1754.
• Mandell LA, Bartlett JG, Dowell SF, File TM Jr,
  Musher DM, Whitney C. Update of practice
  guidelines for the management of
  community-acquired pneumonia in immunocompetent
  adults. Clin Infect Dis 2003 Dec
  137(11)1405-33.
• Mandell LA, Wunderink RG, Anzueto A, Bartlett
  JG, Campbell GD, Dean NC, Dowell SF, File TM Jr,
  Musher DM, Niederman MS, Torres A, Whitney CG.
  Infectious Diseases Society of America/American
  Thoracic Society consensus guidelines on the
  management of community-acquired pneumonia in
  adults. Clin Infect Dis 2007 Mar 144 Suppl
  2S27-72.
• Arch Ped Adol Med 1995 149 283-7.