Pneumonia

ד"ר אורי לקסרמכון הראה

בית החולים האוניברסיטאי הדסה

DEFINITIONS

• Pneumonitis is a general term for inflammation of the lungs.

• Pneumonia is an inflammation of the lungs with consolidation, usually due to an infectious agent.

Pneumonia:“The Old Man’s Best Friend”

• Sixth leading cause of death in the US

• Leading infectious cause of death in the US

Case Presentation 1

• Mr “T” , a 45 year old male• Fever, and rigors started 12h earlier• Cough with purulent sputum • Looks unwell, pale • Tachycardia, tachypnea (20 breaths/min)• On chest examination: signs of RLL

consolidation

Case presentation 1

Case presentation 2

• Mr “A” , a 45 year old male• Fever - low grade, intermittent, started one

week ago. • Dry cough with occasional mucoid sputum • Looks unwell and pale. No signs of distress• On examination: few crackles over LUL

Case presentation 2

Clinical Management • Assessment

– Diagnosis– Severity– Etiology (pathogen)

• Treatment– Antibiotic Rx

• Empiric• Specific

– Supportive treatment

Clinical Presentation

• Fever +/- rigors

• Cough – dry or productive

• Chest pain

• Dyspnea, respiratory distress

• Crackles +/- signs of consolidation

• Abnormal X-ray

Chest X-Ray

Important in order to• Distinguish pneumonia from acute

bronchitis

• Identify complications– Abscess / cavitation– Pleural effusion

• Monitor progress

RLL Infiltrate

Pathogens - Common

• Streptococcus pneumoniae• Haemophilus influenzae• Mycoplasma pneumoniae• Chlamydia pneumoniae• Respiratory viruses

S. pneumoniae is the most common pathogen in CAP!

Pneumococcal Pneumonia:

Right upper-lobe consolidation with air

bronchogram.

Grainger & Allison's Diagnostic Radiology: A Textbook of

Medical Imaging, 4th edition (2001)

Pneumococcal pneumonia:

Grainger & Allison's Diagnostic Radiology: A Textbook of

Medical Imaging, 4th edition (2001)

Bilateral lower-zone consolidation (arrows). Although pneumococcal pneumonia is typically unifocal, multifocal involvement is not uncommon.

Typical broncho-pneumonic pattern.

Grainger & Allison's Diagnostic Radiology :

A Textbook of Medical Imaging, 4th edition (2001)

H. Influenzae pneumonia:

The CXR shows two patterns that are common with this infection: In the lower zone consolidation is homogeneous, whereas in the mid and upper zones it is heterogeneous and nodular.

Grainger & Allison's Diagnostic Radiology :

A Textbook of Medical Imaging, 4th edition (2001)

Mycoplasma pneumoniae pneumonia:

Viral Pneumonia

• Epidemic - Influenza virus, SARS

• Sporadic - RSV, adenovirus, parainfluenza, varicella, measles, (hantavirus)

• CXR - interstitial pattern

• May be complicated by bacterial superinfection!

The predominant opacities are 5–10 mm nodules, confluent in parts.

Grainger & Allison's Diagnostic Radiology :

A Textbook of Medical Imaging, 4th edition (2001)

Varicella pneumonia:

Measles pneumonia. An example of a widespread primary viral pneumonia with

extensive bilateral confluent consolidation.

Grainger & Allison's Diagnostic Radiology: A Textbook of

Medical Imaging, 4th edition (2001)

Other Pathogens

• Gram negative – Klebsiella pneumoniae, E. Coli, Pseudomonas

• Staph. aureus • Anaerobes • Legionella • (Endemic fungi)• Tuberculosis

Legionella Pneumonia

• Increased risk in:– elderly– co-morbid illness– immunosuppressed

• Extra-pulmonary manifestations:– Neurologic– Gastrointestinal – Articular

Legionella Pneumonia

• Recommended treatment:– Macrolides

– Fluoroquinolones

• Suspect anaerobic bacteria in the presence of:– Predisposing condition for aspiration– Periodontal disease – Putrid sputum – Failure to recover likely pulmonary

pathogens with cultures of expectorated sputum

– Radiological evidence of pulmonary necrosis

Anaerobic Pneumonia

Anaerobic Pneumonia

• Increased risk of complications:– lung abscess

– pleural empyema

• Recommended treatment:– Clindamycin

– Amoxicillin/Clavulanic Acid

Typical vs. Atypical Pneumonia

TypicalAtypical

OnsetAbruptSubacute

SymptomsHigh fever, Rigors

Pleurisy, Purulent sputum

Mild fever, Mucoid sputum

Physical Examination

ConsolidationCrackles

WBCHighVariable/ Normal

CXRLobar, SegmentalInterstitial

PathogensS. pneumoniae, H. influenzaeMycoplasma, Chlamydia

Clinical Management

The clinical setting in which pneumonia occurs is important in

determining the likely pathogen(s).

Clinical Setting of Pneumonia

• Community acquired pneumonia (CAP)• Nosocomial pneumonia • Nursing home residents• Recent antibiotic therapy • Age (elderly, neonate)• Aspiration pneumonia• Geographical location/recent travel• Immunocompromised host

Clinical Setting:

Community Acquired Pneumonia• S. pneumoniae• H. influenzae• Mycoplasma pneumoniae• Chlamydia pneumoniae• Respiratory viruses

S. pneumoniae is the most common pathogen in CAP, no matter what the clinical context!

Clinical Setting:

Hospital Acquired Pneumonia

Early onset (<5 days) - increased risk of:• Gram negative • S. aureus• Drug resistant S. pneumoniae• Legionella

Similar pattern in nursing home residents!

Clinical Setting:

Hospital Acquired Pneumonia

Late onset (≥5 days) – pathogens with multidrug resistance likely:• Methicillin resistant S. aureus (MRSA)• Pseudomonas, Acinetobacter

Local epidemiology very important!

Clinical Setting:

Recent Antibiotic Therapy

•Definition: course of antibiotics for any infection in the past 3 months•Increased risk of:

– Drug resistant S.pneumoniae– Gram negative bacilli

Clinical Setting:

Elderly Patient

Increased risk of:

• drug resistant S. pneumoniae

• Legionella

Clinical Setting:

Geographical Location

• Consider recent travel!• Geographical patterns of drug resistance (S. pneumoniae)• Locations endemic for:

– TB– Fungi (histoplasma)– Viruses (SARS, avian flu)

Diagnostic Testing• CXR• Pulse oximetry or arterial blood gases

In hospitalized patients also:• Blood count• Electrolytes, renal function, liver function• Cultures:

– Sputum gram stain and culture– 2 Blood cultures– Pleural fluid biochem., gram stain & culture

Diagnostic Testing: Cultures

• Cultures probably not justified in ambulatory pts.

• Low sensitivity of cultures: 40-60% of patients are not diagnosed despite extensive testing.

• Incidence of mixed infection unclear• In immunocompromised hosts,

invasive techniques often required due to wider range of potential pathogens.

Sputum Gram Stain: Infectious Diseases Society of America

Guideline 2000

Recommend using Gram's stain to narrow initial empiric therapy in patients

Clinical Management

The severity of a case of pneumonia determines:

• Placement (ambulatory care, hospitalization, intensive care)

• Tolerance for potential treatment failure• Supportive treatment needs• Prognosis

PORT Clinical Prediction Rule:Criteria for Determining Severity (1)

I. Demographic• Age • Sex• Nursing home

residence

II. Comorbidity

• Cancer

• Chronic liver disease

• Heart failure

• Cerebrovascular disease

• Chronic renal disease

PORT Clinical Prediction Rule:Criteria for Determining Severity (2)

III. Physical Findings• Altered mental

status• Tachypnea• Hypotension• Fever / Hypothermia• Tachycardia

IV. Laboratory• Acidosis• Azotemia• Hyponatremia• Hyperglycemia• Anemia• Hypoxemia• Pleural effusion

PORT Rule:

Mortality by Risk Class

0.1 0.62.8

8.2

29.2

05

1015

2025

3035

I II III IV V

PORT Class

Mo

rtal

ity

(%)

Fine et al., N Engl J Med (1997) 336: 243–50

ClassScore

I-

II≥70

III71-90

IV91-130

V>130

Initial Site of CareAmbulatory Hospital Ward ICU

• Factors:

– PORT risk class

– Psychosocial factors

– Co-morbidities

Prediction rules are meant to contribute to, rather than supersede, physician judgement!

Clinical Management • Assessment

– Diagnosis

– Etiology (pathogen)

– Severity

• Treatment

– Antibiotic Rx

– Supportive treatment

Macrolides

Erythromycin(PO), IV

RoxithromycinPO

AzithromycinPO, IV

ClarithromycinPO

“advanced macrolides” (A-Macs)

Drug Resistant Pneumococcus

• Refers to resistance to Penicillin – Intermediate level MIC 0.1-1.0 mcg/ml – High level MIC >2.0 mcg/ml

• In vitro co-resistance to other AB

• In vitro resistance does not always predict clinical treatment failure.

Drug Resistant Pneumococcus:

Risk Factors

• Geographic areas with high prevalence

• Age > 65

• Recent -lactam therapy (within 3 mo)

• Exposure to children in day care centers

• Multiple co-morbidities

• Immunosuppression

Empiric Antibiotic Therapy

• Empiric therapy is chosen to cover the most likely pathogens in the individual patient. Consider:– Typical vs. atypical pneumonia syndrome– Comorbid illness– Resistant Streptococci or gram negative

bacteria– Old age/ residence in nursing facilities – Risk of aspiration

Empiric Antibiotic Therapy

• In severely ill patients - low failure rate is imperative

• Caution in immunocompromised hosts• Important to:

–Monitor clinical response–Revise according to culture results

Supportive Treatment

• Appropriate monitoring

• Oxygen, ventilatory support

• Fluids, electrolytes and nutrition

• Bronchodilators

• Physiotherapy

Patient Not Responding to Treatment• Patient not receiving treatment

non-compliance, enteral drug not absorbed, staff error

• Resistant organism • Suppurative complication

lung abscess, pleural empyema, obstructed bronchus

• Alternative diagnosis• Drug fever

Patient Not Responding to TreatmentSuppurative Complications : Empyema

Patient Not Responding to TreatmentSuppurative Complications : Lung Abscess

Prevention

• Stop smoking!

• Influenza vaccine

• Pneumococcal vaccine (Pneumovax)

• Prevent aspiration