Pneumonia Charles B. Lehman, MD College of Community Health Sciences University of Alabama

PneumoniaCharles 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 consolidationLeft lower lobe opacity in patient with pneumococcal pneumonia.

Interstitial infiltratesNodular opacities in the right lower lobe in patient with mycoplasma pneumonia.

CavitationLung abscess with air-fluid level in right lung in first image. Next image is of necrotizing pneumonia in the left lung


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.


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 testingBlood 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 testingSputum 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 evaluationPredisposing 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.


Gram negative bacilli

E. coli

Serratia

K. pneumoniae

Acinetobacter

P. aeruginosa

Enterobacter

Uncommon in CAP except in patients with severe disease requiring ICU admission


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 treatmentPneumonia 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.


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


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


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.


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 treatmentCURB-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 treatmentSevere 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 treatmentEmpiric 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


Co-morbidity

Alcoholism

COPD

Post-CVA aspiration

Post-obstruction of bronchi

Influenza

Local resistance of S. pneumoniae to macrolides > 25%


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 treatmentNon-ICU patients

S. pneumoniae most common pathogen

Respiratory viruses

Less common:

M. pneumoniae

H. influenzae

C. pneumoniae

Legionella

CAP: inpatient treatmentNon-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 treatmentNon-ICU patients with COPD

Primary regimens:


Moxifloxacin 400 mg q24

Alternative regimens:

Ceftriaxone 1 gm q24 + azithromycin 500 mg q24

Ertapenem 1 gm q24 + azithromycin 500 mg q24

CAP: inpatient treatmentEmpiric 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


Primary regimens:

(Ceftriaxone 1-2 gm q24 or Unasyn 3 gm q6) + azithromycin 500 q24


Moxifloxacin 400 q24

If CA-MRSA suspected add:

Vancomycin 15-20 mg/kg q8-12

Linezolid 600 IV q12


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 treatmentResponse 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 treatmentChange to oral therapy

Clinical improvement

Hemodynamically stable

Normally functioning GI tract

CAP: inpatient treatmentChoice 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 treatmentDuration 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 treatmentDuration 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 treatmentDuration 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 treatmentNon-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 treatmentNon-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

48 hours or more after admission, did not appear present on admission

Ventilator-associated pneumonia

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 HCAPMRSA

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 HCAPOther 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

HCAPEtiologies

S. aureus (often MRSA)

Gram (-) enterics which may be MDR (E. coli, K. pneumoniae, enterobacter, Serratia)

P. aeruginosa

Acinetobacter

HCAPEmpiric 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

HCAPEmpiric treatment

Controversy exists regarding uniqueness of HCAP

Duration of therapy is not well-defined

Therapy should be streamlined once culture results area available

HAP/VAPSubtypes

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/VAPEarly-onset

Ceftriaxone 1 gm q24 or

Unasyn 3 gm q6 or

Ertapenem 1 gm q24 or

Levofloxacin 750 q 24

HAP/VAPLate-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

Documents

Pneumonia Charles B. Lehman, MD College of Community Health Sciences University of Alabama