Pneumonia
Charles B. Lehman, MD
College of Community Health Sciences
University of Alabama
Diagnosing pneumonia

Clinical evaluation

Chest x-ray with or without microbial testing
Clinical evaluation

Common clinical features:

Cough

Fever

Pleuritic chest pain

Dyspnea

Sputum production

GI: nausea, vomiting, diarrhea

Mental status changes
Clinical evaluation


Physical exam:

80% will be febrile

Tachypnea, especially in elderly patients

Tachycardia

Audible crackles

Evidence of consolidation
Lab findings:

Leukocytosis with left shift

Leukopenia can occur and is an ominous sign
Clinical evaluation: chest x-ray

Radiologic evaluation

Presence of infiltrate on plain chest x-ray is gold standard for diagnosis

Should be obtained whenever diagnosis is suspected

Recommendations less clear when viral infection suspected but should be obtained
in patients with an abnormal vital sign, especially tachypnea.
Lobar consolidation
Left lower lobe opacity in patient with pneumococcal pneumonia.
Interstitial infiltrates
Nodular opacities in the right lower lobe in patient with mycoplasma pneumonia.
Cavitation
Lung abscess with air-fluid level in right lung in first image. Next image is of necrotizing pneumonia in the left lung
Clinical evaluation: chest x-ray

Considerable variation in reading between different radiologists

Even more between ED physicians and radiologists

High-resolution CT is a much better test but generally not necessary
to make a diagnosis.
Clinical evaluation: chest x-ray


Other causes for chest x-ray which can look like pneumonia

Malignancy

Hemorrhage

Pulmonary edema

Pulmonary embolism with infarction

Inflammation due to non-infectious causes
CT can be used to clarify cases when clinical picture is consistent with
pneumonia but chest x-ray is negative.
Clinical evaluation: microbial testing

Outpatients: testing is optional

Hospitalized patients with specific indications should have blood
cultures and sputum Gram stain and culture.

Severe CAP requiring ICU admission should have blood cultures,
Legionella and pneumococcus urinary antigen tests and sputum
culture.

Other tests indicated with specific findings
Clinical evaluation: microbial testing
Blood cultures

Blood cultures are positive in 7 to 16% of hospitalized patients with S.
pneumococcus accounting for 2/3 of positive cultures.

Arguments to obtain blood cultures:


Establishes a diagnosis when likely pathogen found

In many cases is the only test done and is primary source for microbiologic data for
many hospitals

Isolates are an important resource for tracking resistance patterns in S.
pneumoniae which provide data for evaluating vaccines.
Arguments against:

Relatively low rate of positives

Rarely lead to modification of therapy
Clinical evaluation: microbial testing
Sputum cultures

Sputum cultures

ICU admission

Failure of antibiotic therapy

Cavitary lesions

Active alcohol abuse

Severe obstructive of structural lung disease

Immunocompromised host

Pleural effusion

Epidemic pneumonia
Clinical evaluation
Predisposing conditions

Altered mental status which can lead to micro/macro aspiration (stroke,
seizure, intoxication, anesthesia)

Smoking

Alcohol

Hypoxemia

Acidosis

Toxic inhalations

Pulmonary edema

Uremia

Malnutrition
Clinical evaluation: predisposing
conditions

Immunosuppresive agents

Mechanical obstruction of a bronchus

Advanced age

Cystic fibrosis

Bronchiectasis

COPD

HIV

Viral respiratory tract infection, especially influenza

Lung cancer
Microbiology: bacteria

S. pneumoniae: most common cause

H. influenzae: more common in elderly and patients with underlying
pulmonary disease (COPD, cystic fibrosis)

M. pneumoniae: most common atypical cause, highest rates in school-aged
children, military recruits and college students.

C. pneumoniae

Legionella: transmitted by aerosols containing the bacteria such as showers,
grocery store misters, cooling towers, whirlpool spas and fountains.
Microbiology: bacteria


Gram negative bacilli

E. coli

Serratia

K. pneumoniae

Acinetobacter

P. aeruginosa

Enterobacter
Uncommon in CAP except in patients with severe disease requiring ICU
admission
Microbiology: bacteria


S. aureus

Usually in older adults or younger patients who are recovering from influenza

Associated with severe necrotizing pneumonia
Group A streptococcus

Can cause fulminant pneumonia with early empyema even in young competent
hosts.

Anaerobes (aspiration and lung abscess)

Neisseria meningitidis

M. tuberculosis
Microbiology: viruses

Influenza

Can cause primary pneumonia, more likely to cause secondary bacterial pneumonia

Parainfluenza viruses

RSV

Adenovirus

Human metapneumovirus

Severe acute respiratory syndrome (SARS)

Middle East respiratory syndrome coronavirus (MERS-CoV)

Other coronaviruses
Microbiology: viruses

Hantavirus (ARDS)

Avian influenza: considered a possible source for next global influenza
pandemic.

Varicella
Microbiology: fungi


Usually occur in immunocompromised hosts

Neutropenia

Immunosuppressive therapy

HIV
Usually endemic to particular areas
Microbiology: fungi


Cryptococcus

Found world-wide

Infection often asymptomatic in immunocompetent hosts
Histoplasma

Most common in Ohio and Mississippi River valleys

Less than 5% develop symptoms with low-level exposure

Coccidioides (Sonoran desert regions)

Aspergillosis

P. jirovecii
Microbiology: bioterrorism

Bacillus anthracis (anthrax)

Yersinia pestis (plague)

Francisella tularensis (tularemia)

C. burnetti (Q fever)
Inpatient vs. outpatient treatment

Hospital admission rates vary widely

Rates often are not related to local disease severity

Physicians often overestimate patient risk of short-term mortality

Many unnecessary admissions as a result
Inpatient vs. outpatient treatment
Pneumonia Severity Index


Step 1 risk factors:

Age > 50

Coexisting conditions: cancer, CHF, cerebrovascular disease, renal disease or liver
disease

Physical exam: AMS, heart rate >= 125, respiratory rate >= 30, SBP < 90,
temperature < 35 (95) or > 40 (104)
If one or more Step 1 risk factors are present then evaluation proceeds to
Step 2.
Inpatient vs. outpatient treatment
Pneumonia Severity Index

Class I: no predictors

Class II: <= 70

Class III: 71–90

Class IV: 91-130

Class V: > 130
PSI and mortality by class
Class
Points
Mortality
I
No predictors
0.1
II
<= 70
0.6
III
71-90
0.9
IV
91-130
9.3
V
> 130
27.0
Inpatient vs. outpatient treatment
Pneumonia Severity Index

Measuring impact using Pneumonia PORT cohort

Strategy 1: outpatient therapy for class I or II, brief observation for class III
and admission for class IV or V:

31% fewer admissions

19% more would have been assigned to observation

4.3% admitted to ICU

< 1% mortality
Inpatient vs. outpatient treatment
Pneumonia Severity Index

Measuring impact using Pneumonia PORT cohort

Strategy 2: same as strategy 1 except that all patients with hypoxemia were
admitted:


26% reduction in admissions

13% assigned to observation

1.6% admitted to ICU

Mortality < 1%
Either set of recommendations would have recommended inpatient therapy
for 5 of the 6 patients who died following an initial course of outpatient
therapy.
Inpatient vs. outpatient treatment
Pneumonia Severity Index


CAPITAL trial (Canada)

Admission rate for low risk (class I, II or III) patients dropped from 49 to 31%

No negative effects on patient quality of life or adverse medical outcomes (ICU
admission, mortality, readmission or complications).
EDCAP (US)

Increased proportion of low-risk patients treated in outpatient setting

No statistically significant difference in safety outcomes
Inpatient vs. outpatient treatment
CURB-65 score

Confusion

Urea (BUN > 20)

Respiratory rate (>30)

Blood pressure (SBP < 90 or DBP < 60)

Age > 65

0-1: outpatient treatment

2: admission

>= 3 should be assessed for ICU admission
Inpatient vs. outpatient treatment
Severe CAP score



Major criteria:

pH < 7.30 (13 points)

SBP < 90 (11 points)
Minor criteria:

RR > 30 (9)

PaO2/FiO2 < 250 (6)

BUN > 30 (5)

Age > 80 (5)

Multilobar/bilateral infiltrates (5)
Score > 10 predicts progression to severe CAP
CAP: outpatient treatment
Empiric therapy

Chest x-ray which demonstrates pneumonia

Risk stratification with CURB-65 or PSI

Distinguish CAP from HCAP

Microbiologic testing is optional

Blood cultures

Sputum if quality sample can be obtained
CAP: outpatient treatment
Empiric therapy


Co-morbidity

Alcoholism

COPD

Post-CVA aspiration

Post-obstruction of bronchi

Influenza
Local resistance of S. pneumoniae to macrolides > 25%
CAP: outpatient treatment
Empiric therapy



No co-morbidities, local macrolide resistance < 25%

Azithromycin 500 x 1 dose then 250 mg/day

Clarithromycin 500 mg BID for 7 days
If patient had antibiotics within 3 months:

Above plus amoxicillin 1 gm TID or Augmentin 1000/62.5 2 tabs BID

Levofloxacin 750 mg qD
If co-morbidity present:

Levofloxacin 750 mg qD x 5 days
CAP: inpatient treatment
Non-ICU patients

S. pneumoniae most common pathogen

Respiratory viruses

Less common:

M. pneumoniae

H. influenzae

C. pneumoniae

Legionella
CAP: inpatient treatment
Non-ICU patients


Primary regimens:

Ceftriaxone 1 gm q24 + azithromycin 500 mg q24

Ertapenem 1 gm q24 + azithromycin 500 mg q24
Alternative regimens:

Levofloxacin 750 mg q24

Moxifloxacin 400 mg q24
CAP: inpatient treatment
Non-ICU patients with COPD


Primary regimens:

Levofloxacin 750 mg q24

Moxifloxacin 400 mg q24
Alternative regimens:

Ceftriaxone 1 gm q24 + azithromycin 500 mg q24

Ertapenem 1 gm q24 + azithromycin 500 mg q24
CAP: inpatient treatment
Empiric therapy, ICU patients

Patients admitted to an ICU are more likely to have resistant pathogens
including community-associated MRSA and Legionella

Suspicion for P. aeruginosa


Chronic or structural lung disease

Known prior colonization
Suspicion for CA-MRSA

Post-influenza

IV drug use

Gram (+) cocci in clusters on Gram stain
CAP: inpatient treatment
Empiric therapy, ICU patients


Primary regimens:

(Ceftriaxone 1-2 gm q24 or Unasyn 3 gm q6) + azithromycin 500 q24

Levofloxacin 750 mg q24

Moxifloxacin 400 q24
If CA-MRSA suspected add:

Vancomycin 15-20 mg/kg q8-12

Linezolid 600 IV q12
CAP: inpatient treatment
Empiric therapy, ICU patients

If P. aeruginosa suspected:

Beta-lactam (Cefepime 2 gm q12 or Zosyn 3.375 gm q4 or ceftazidime 2 gm q8 or
meropenem 1 gm q8)

Fluoroquinolone (levofloxacin 750 q24 or ciprofloxacin 400 q8) or tobramycin 5
mg/kg q24 and azithromycin 500 q24
CAP: inpatient treatment
Response to therapy

Some improvement usually seen within 48 to 72 hours

Resolution of symptoms and radiographic findings takes longer

Crackles can persist for weeks

As many as 87% of patients continue to report at least one symptom at 39
days

Takes 6-8 weeks for a chest x-ray to clear and can take up to 12 weeks in
patients with underlying lung disease
CAP: inpatient treatment
Change to oral therapy

Clinical improvement

Hemodynamically stable

Normally functioning GI tract
CAP: inpatient treatment
Choice of oral therapy

Base on culture results if possible

Use oral medications from same drug class

No need to cover for S. aureus or gram (-) bacilli unless isolated from a good
quality sputum specimen

Choice depends on risk of resistant S. pneumoniae and the initial IV regimen
CAP: inpatient treatment
Duration of hospitalization


Can go home when:

On oral medications

No other active medical problems

Appropriate environment for discharge
Not necessary to keep patient for observation after changing to oral
antibiotics.
CAP: inpatient treatment
Duration of therapy

Minimum of 5 days

Should be afebrile for 48 hours

No more than 1 clinical instability factor

Heart rate > 100

Respiratory rate > 24

SBP < 90
CAP: inpatient treatment
Duration of therapy

Longer duration needed if:

Initial therapy was not active against a subsequently identified pathogen

Extrapulmonary infection identified (meningitis, endocarditis)

P. aeruginosa, S. aureus or Legionella infections

Necrotizing pneumonia, empyema or lung abscess
CAP: inpatient treatment
Non-responding patients


Progressive pneumonia or clinical deterioration

Requirement of ventilator support

Development of septic shock
Absence of delay of achieving clinical stability after 72 hours
CAP: inpatient treatment
Non-responding patients

Unusual organisms not covered by empiric therapy

Patient-related factors


Severity of illness

Neoplasia

Aspiration pneumonia

Neurologic disease
Infectious complications

Empyema

Superimposed nosocomial pneumonia
HAP, VAP and HCAP

Hospital-acquired (nosocomial) pneumonia


Ventilator-associated pneumonia


48 hours or more after admission, did not appear present on admission
48-72 hours after endotracheal intubation
Healthcare-associated pneumonia

IV therapy, wound care or IV chemotherapy within 30 days

Residence in a nursing home or other long-term care facility

Hospitalization in an acute care hospital for 2 or more days within the last 90 days

Attendance at a hospital or hemodialysis clinic within 30 days
HAP, VAP and HCAP

Drug selection should be based on risk factors for multi-drug resistant
organisms

Recent antibiotic therapy

Resident flora in the hospital or ICU

Presence of underlying diseases

Available culture data
HAP, VAP and HCAP
MRSA

Vancomycin or linezolid should be added

Should be discontinued if not isolated in cultures

If MSSA later isolated should replace above with nafcillin or oxacillin
HAP, VAP and HCAP
Other considerations

Combination therapy for Gram (-) organisms often used but no conclusive
evidence to support this practice

Legionella should be covered, especially if known to be present in the
hospital water supply

Anaerobes in patients with recent abdominal surgery or aspiration
HCAP
Etiologies

S. aureus (often MRSA)

Gram (-) enterics which may be MDR (E. coli, K. pneumoniae, enterobacter,
Serratia)

P. aeruginosa

Acinetobacter
HCAP
Empiric treatment

Vancomycin 15-20 mg/kg q8-12

Cefepime 2 gm 12 or Zosyn 4.5 gm q6 or meropenem 1 gm q8

Doripenem should not be used

Linezolid 600 IV q12 can be substituted for vancomycin

If Legionella suspected should use a fluoroquinolone or add azithromycin 500
mg q24
HCAP
Empiric treatment

Controversy exists regarding uniqueness of HCAP

Duration of therapy is not well-defined

Therapy should be streamlined once culture results area available
HAP/VAP
Subtypes

Early-onset: no other risk factors for MDR, < 5 days in the hospital


S. pneumoniae, S. aureus, H. influenzae, enteric Gram (-) bacilli
Late onset: >= 5 days in the hospital, risk factors for MDR organisms

S. aureus, often MRSA

Gram (-) enterics

ESKAPE organisms (E. coli, Serratia, Klebsiella, acinetobacter, pseudomonas and
enterobacter) etiology in about 80% of patients
HAP/VAP
Early-onset

Ceftriaxone 1 gm q24 or

Unasyn 3 gm q6 or

Ertapenem 1 gm q24 or

Levofloxacin 750 q 24
HAP/VAP
Late-onset

Meropenem 1 gm q8, Zosyn 4.5 gm q6 or cefepime 2 gm q12

Add vancomycin 15-20 mg q8-12 if MRSA suspected

Imipenem preferred over meropenem if acinetobacter is suspected

Add levofloxacin if Legionella suspected