PNEUMONIA

Dr. Nooruddin Jaffer

Professor of Medicine.

Definition

• Syndrome caused by acute infection caused by a wide variety of microorganisms, characterized by clinical and/or radiological signs of consolidation of a part or parts of one or both lungs.

Definition

• “Pneumonitis” is used as synonym for pneumonia when inflammation of lung has resulted from a non-infectious cause e.g chemical or radiation injury.

Clinical Definition

• Symptoms of acute LRT infection a) Cough, sputum,chest painb) Fever,sweating,shiver, aches and pains

• New focal chest signs on examination • OR• New radiographic pulmonary infiltrates

Epidemiology

• Common and serious illness despite antibiotics and vaccines

• Sixth leading cause of death and number one infectious death in USA

• Overall incidence rate is 170 (per 10,000) and increases with age, with an incidence of 280 for those 65 years of age or older

• Outpatient mortality 1- 5 % , inpatient mortality approaches 25 %, greater if an ICU admission is required

Epidemiology

Risk Factors• Advanced age

• chronic illnesses

• Cigarette smoking

• Dementia

• Malnutrition

• Previous episode of pneumonia

• Splenectomy

Etiology of Community Acquired Pneumonia

• Pathogen not defined in as many as 50 % patients even with extensive diagnostic testing

• S. pneumoniae is the leading cause of CAP

• H. influenzae ( type B), S. aureus, and gram (-) bacteria each account for 3 to 10 %

• Staph aureus CAP is usually seen in the elderly and as post-influenza pneumonia

Etiology of Community Acquired Pneumonia

• P. aeruginosa causes CAP in neutropenia, cystic fibrosis, HIV infection & bronchiectasis

• N. meningitidis, M. catarrhalis & S. pyogenes can occasionally cause CAP

• Anaerobic organisms are implicated in aspiration pneumonia and lung abscess

• MRSA, M. tuberculosis, and certain viral agents are common in nursing-home patients

Causes of community acquired pneumonia in North America

• Streptococcus pneumoniae 20 - 60

• Hemophilus influenzae 3 - 10

• Staphyloccus aureus 3 - 5

• Gram-negative bacilli 3 - 10

• Aspiration 6 - 10

• Miscellaneous 3 - 5

• Legionella sp. 2 - 8

• Mycoplasma pneumoniae 1 - 6

• Chlamydia pneumoniae 4 - 6

• Viruses 2 - 15

Outpatient Pneumonia without Comorbidity and 60 years or Younger

ORGANISMS

• S. pneumoniae

• M. pneumoniae

• Respiratory viruses

• C. pneumoniae

• H. influenzae

MISCELLANEOUS

• Legionella

• S. aureus

• M.. Tuberculosis

• endemic fungi

• anaerobic Gram-negative bacilli

Outpatient Pneumonia with Comorbidity and/or 60 years or Older

ORGANISMS

• S. pneumoniae

• Respiratory viruses

• H. influenzae

• Anaerobic Gram-negative bacilli

• S. aureus

MISCELLANEOUS

• M. catarrhalis

• Legionella

• M. tuberculosis

• Endemic fungi

Hospitalized Patients with Community Acquired Pneumonia

ORGANISMS

• S. pneumoniae• H. influenzae• Polymicrobial (including

anaerobic bacteria)• Anaerobic gram-negative

bacilli• Legionella• S. aureus• C. pneumonia• Respiratory viruses

MISCELLANEOUS

• M. pneumoniae

• M. catarrhalis

• M. tuberculosis

• Endemic fungi

Severe Hospitalized Community Acquired Pneumonia

ORGANISMS

• S. pneumonia

• Legionella

• Anaerobic gram-negative bacilli

• M. pneumoniae

• Respiratory viruses

MISCELLANEOUS

• H. influenzae

• M. tuberculosis

• Endemic fungi

PATHOGENESIS

Predisposing conditions

1-Suppressed cough reflex

2-Impaired mucociliary activity

3-Reduced phagocytic activity of alveolar macrophages and neutrophils

4-Impaired immunoglobulins

Routes of Entry

• Aspiration

• Inhalation

• Colonization

• Hematogenous spread

Classification

• Community acquired pneumonia

• Hospital acquired (nosocomial) pneumonia

• Aspiration pneumonia

• Immunocompromised host pneumonia

Typical or Atypical CAP ?

• Difficult to differentiate on clinical grounds alone

• The term ‘atypical’ is used to refer to a group of organisms rather than a clinical picture

Clinical Features

SymptomsRespiratory• Cough 90%• Sputum 70%• Dyspnoea 70%• Chest pain 65%• URT symptoms 33%• Haemoptysis 15%

Clinical FeaturesSymptomsNon-Respiratory• Fever 90%• Vomiting 20%• Confusion 15%• Diarrhoea 15%• Rash 5%• Abdominal pain 5%

Clinical Features

Signs• Fever 90%• Tachypnoea 80-90%• Tachycardia 80-90%• Crackles & 80-90%• Bronchial breathing 80-90%• Hypotension 20%• Confusion 15%• Herpes labialis 10%

Investigations

• In community • clinical diagnosis is enough if patient is stable.

Patients who do not respond to empiric therapy, consideri-Chest X-rayii-Sputum gram stain & culture

Test(s) in those who require hospital admission

• Chest X-Ray• Full blood count• Urea / Creatinine, Electrolytes, Sugar, LFT’s• CRP- if available? (BTS)• Arterial Blood Gases / Pulse oximetry• Blood culture, Sputum Gram stain & Culture,

AFB smear & culture (in selected patients)• Routine serologic testing is not recommended

Adequate Sputum Sample

• Less than10 buccal squamous epithelial cells per low power field

• More than 25 neutrophils per low power field

• Leucocyte to squamous epithelial cell ratio greater than 5

DIAGNOSIS

DIAGNOSIS

Sputum Gram Stain

Invasive diagnostic techniques

• Transtracheal aspiration

• Bronchoscopy with a protected brush catheter

• Bronchoalveolar lavage with or without balloon

protection

• Direct needle aspiration of the lung

Features of Severe Pneumonia

• ‘Core’ clinical adverse prognostic features

(CURB) • Confusion• Urea > 7 mM (>19.1 mg/dL) • Resp.rate >30 /min• Blood Pressure: Systolic BP < 90 mm Hg and/or

diastolic BP ≤ 60 mmHg• NOTE: Patients with 2 or more CURB are at high

risk of death

Severity assessment in CAP in thecommunity (CRB-65 score) UPDATED 2004

• Confusion• Respiratory rate = 30/min• Blood pressure (SBP < 90mmHg or DBP =

60mmHg)• Age = 65 years

• Score 1 point for each feature present

Severity assessment in CAP in thecommunity (CRB-65 score) UPDATED 2004

• 1-2 suitable for home treatment

• 3-4 Needs hospital referral

Additional Clinical Adverse Prognostic Features

• PO2<60 mm or O2 saturation < 90 %

• Bilateral or multilobar (>2 lobes) infiltrates on

chest radiograph

SEVERE CAP

There is no universally accepted definition of severe CAP:

1. Respiratory frequency >30 breaths min at admission

2. Severe respiratory failure defined by a Pao2/Flo2 ratio <250

3. Requirement for mechanical ventilation

4. Chest radiograph showing a) bilateral involvement b) involvement of multiple lobes c) an in the size of the opacity by 50 % within 48 h of admission

5. Shock ( SBP < 90 mmHg or DBP < 60 mmHg)

6. Requirement for vasopressors for more than 4 h

7. Urine output < 20 ml/h or acute renal failure requiring dialysis

Management(subset of patients)

• Group I : Outpatients with no h/o cardiopulmonary disease and no modifying factors.

• Group II : Outpatients with cardiopulmonary disease(eg. CCF or COPD) and/or other modifying factors.

Management(subset of patients)

• Group III : Inpatients not admitted to the ICU, who have the following:

• a) Cardiopulmonary disease, and/or other modifying factors including being from a nursing home)

• b) No cardiopulmonary disease, and/or other modifying factors.

Management(subset of patients)

• Group IV : ICU-admitted patients who have the following:

• No risk for Pseudomonas aeroginosa

• Risks for Pseudomonas aeroginosa

General Management of CAPIn the community

• Not to smoke, to rest and drink plenty of fluids

• Pleuritic chest pain should be relieved using simple analgesics like Paracetamol

• Review of patients in the community is recommended after 48 hours, those who fail to improve should be considered for hospital admission

Decision to Hospitalize

• 1. Age over 65 yr1. Age over 65 yr• 2. Presence of coexisting illnesses or other findings2. Presence of coexisting illnesses or other findings• a. COPD, bronchiectasis, cystic fibrosis

• b. Diabetes mellitus

• c. Chronic renal failure

• d. Congestive heart failure

• e. Chronic liver disease of any etiology

• f. Previous hospitalization within 1 yr

• g. Suspicion of aspiration

• h. Altered mental status

• i. Postsplenectomy state

• j. Chronic alcohol abuse or malnutrition

Decision to Hospitalize

• 3. Physical findings3. Physical findings

• a. Respiratory rate > 30 breaths/min• b. DBP 60 mmHg or a SBP 90 mmHg • c. Temperature >38.3º C (101º F)• d. Extrapulmonary sites of disease e.g, presence of septic arthritis, meningitis, etc. • e. Confusion and/or decreased level of consciousness

Decision to Hospitalize• 4. Laboratory findings4. Laboratory findings

• a. WBC <4,000/mcL or >30,000/mcL

• b. Pao2 <60 mmHg or Paco2 of >50 mmHg on room air.

• c. Need for mechanical ventilation.

• d. Serum creatinine >1.2 mg/dl or BUN >20 mg/dl (>7 mmol/L)

• e. Unfavorable chest radiographic findings:- more than one lobe involvement - presence of a

cavity- rapid radiographic spread - pleural effusion

• f. Hct of <30 % or hemoglobin <9 g/dl

• g. Evidence of sepsis or organ dysfunction as manifested by a metabolic acidosis, an increased PT, an increased PTT, decreased platelets, fibrin split products > 1:40

General Management of CAPIn hospital

• All patients should receive supplemental oxygen

• Assess for volume depletion • CXR should be repeated in patients not

showing clinical response• Role of Bronchoscopy ? (Retained

secretions, Samples for culture, Exclude endobronchial abnormality)

Therapy Principles

• All admitted patients should receive first antibiotic dose within 8 hours of arrival to the hospital

• All populations should be treated for the possibility of atypical pathogens

• Upto 10% of all CAP patients will not respond to initial therapy. A diagnostic evaluation is mandatory

What antibiotics to use ?

Group 1: Outpatients, age < 60, no cardiopulmonary disease

• Erythromycin or other Macrolides (Erythromycin is not active against

H.influenzae and newer macrolides are better tolerated)

• Amoxicillin (high dose)• Amoxicillin/Clavulanate• Doxycycline (many isolates of S.pneumo are

resistant to tetracycline)

What antibiotics to use?

Group 2: Outpatients, age >60, with co-existing diseases and/or modifying factors

• Amoxicillin + Macrolide• Amox/Clav + Macrolide• Cefuroxime + Macrolide• Antipneumococcal fluoroquinolone (used alone)

What antibiotics to use?

Group 3: Inpatients, not in ICU• Intravenous Beta-lactam (Cefotaxime,

Ceftriaxone) + Intravenous/Oral Macrolide

• Intravenous antipneumococcal FQ

used alone (Levofloxacin, Sparfloxacin, Grepafloxacin)

What antibiotics to use?

Group 4: ICU-admitted patients

• No risk for Pseudomonas aeruginosa

Intravenous Beta Lactam (Cefotaxime, Ceftriaxone, Penicillin/Beta lactamase inhibitor)

+

IV Macrolide or IV Fluoroquinolone

What antibiotics to use?

Group 4: ICU-admitted patients

• Risks for Pseudomonas aeruginosa

Selected intravenous antipseudomonal Beta-lactam (Cefepime, Imipenem/Meropenem, Piperacillin/Tazobactam) + Intravenous antipseudomonal quinolone (Ciprofloxacin) or Intravenous aminoglycoside

Clinical Response

• Most patients with CAP will have an adequate response within 3 days

Switch to oral therapy

• Resolution of fever for >24 hrs.

• Resolution of tachypnoea

• Pulse < 100 beats /min• Resolution of

hypotension• Hydrated and taking

oral fluids

• Absence of hypoxia

• Improving white cell count

• Non-bacteremic infection

• No concern over GI absorption

Duration of therapy

• Patients managed in community and admitted non-severe uncomplicated pneumonia:

07 DAYS THERAPY IS ENOUGH

Duration of therapy

• Patients with severe microbiologically undefined pneumonia:

10 DAYS THERAPY IS PROPOSED

• Patients suffering from legionella, staphylococcal, or Gram negative enteric bacilli pneumonia:

• 14-21 DAYS THERAPY IS RECOMMENDED

Complications of Pneumonia

COMPLICATIONS

Non Resolving Pneumonia

Consider other diagnosis • TB• Lung Cancer• Fungal pneumonia• Foreign body inhalation• BOOP, Eosinophilic pneumonias, Sarcoidosis• Pulmonary embolism• Pulmonary hemorrhage• Heart failure

Correct Diagnosis but Fail to Respond

• Host: Obstruction, Foreign body, Superinfection, Empyema

• Drug: Error in drug selection, dose or route, Compliance, Drug interaction

• Pathogen: Nonbacterial, Resistant

SOME FACTS ABOUT CAP

• The etiologic agent causing CAP cannot be accurately predicted from clinical or radiological features

• The term ‘atypical pneumonia’ should be abandoned• Elderly patients with CAP more frequently present

with non specific symptoms and are less likely to have fever

• Radiological resolution lags behind clinical improvement

• Radiological resolution is slow in the elderly and cases of multilobar involvement.

Prevention

• 23-valent polysaccharide pneumococcal vaccine

• 90 percent of the serotypes are included in the 23 valent vaccine

• 70 % response in the general population• Lower in immunocompromised patients and those

on maintenance dialysis

Prevention

• Target hosts at greatest risk for pneumococcal disease

- > 65 yrs - Chronic cardiovascular and pulmonary disease - Metabolic diseases, alcoholism, cirrhosis, nephrotic

syndrome - Immunosuppression, asplenia - Lymphoma, multiple myeloma

Prevention• Influenza vaccine• Younger patients at risk

- Chronic cardiovascular and pulmonary diseases

- Renal and metabolic disease

- Immune deficiency

- Nursing home residents and health care workers

Thank You!Thank You!