Respiratory Infections | Jindal Chest Clinics

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• Respiratory Infections
• Pneumonia

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What is Respiratory infection?

• An inflammation of the mucous membranes of your
  mouth, nose, airways and/ or lung parenchyma
  brought on by a virus or bacteria is known as a
  respiratory infection.

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Types of Respiratory infections

• Upper Respiratory Infections Infections in the
  mouth, nose and throat - Sinusitis, Tonsillitis,
  Pharyngitis, Laryngitis etc.
• Lower Respiratory Infections Infections of the
  trachea, bronchi and lung parenchyma -
  Tracheo-bronchitis, Chronic bronchitis,
  Pneumonias, Lung abscess, Bronchiectasis
• Pleural Infections Pleurisy, Pleural effusion,
  Empyema

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Pneumonia or Pneumonitis

• Pneumonia Alveolar infection resulting from
  the invasion and overgrowth of microorganisms in
  lung parenchyma.
• Classification
• Anatomical- Depending upon the part of the lung
  involved Lobar / segmental
• Bronchopneumonia
• Microbiological Depending upon the type of
  organism responsible for infection
• Empirical Depending upon the setting of
  occurrence of pneumonia

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Commonly recognized CLASSIFICATION OF PNEUMONIAS

• Community-acquired pneumonia - infection in a
  non-hospitalized population.
• Health-Care associated pneumonia (HCAP)
• Hospital-acquired pneumonia
• Ventilator-associated pneumonia
• Pneumonia in an Immunosuppressed individual.

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Microbiological Classification

• A. Bacterial Pneumococal, H. influenzae,
  Atypical, Staphylococcal, Gram ve, Anaerobic,
  and others
• B. Mycobacterial Caused by Tubercle bacillus
• C. Viral Respiratory Syncytial Virus, Corona,
  others
• D. Fungal Aspergillus, Mucor, Cryptococcus,
  others
• E. Chemical Inhalation of acid and other
  chemical vapours

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Homeostasis - unbalanced in CAPThe germ is
NOTHING the soil is EVERYTHING
Louis Pasteur
1895

• Infection occurs whenever there is disturbance in
  the homeostasis normally maintained by the
  interaction between the
• Host
• Pathogen and
• Environment

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HOST Impaired immune function Comorbid
illness Prior surgery/antibiotics

• PATHOGEN
• Inoculum
• - Virulent strain (MDR)

ENVIRONMENT Infected air, water, fomites,
instruments Cross-contamination
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Risk Factors

• Increased prevalence/ occurence
• Comorbidities DM, CAD, CHF, neurologic disease,
  Immunosuppression, active malignancies, HIV
  infection, Cortico-steroid use
• Increasing age, Age gt 65 yrs,
• Recent influenza, Bacteraemia, leukopenia,
• Alcoholism, Tobacco-smoking, Air-pollution
• Exposure/s to child in a day care centre

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• Risk for enteric gram ve infections
• Recent antibiotic therapy
• Underlying cardiopulmonary disease
• Resident of a nursing home
• Multiple medical co-morbidities
• Risk for P. aeruginosa
• Structural lung disease (Bronchiectasis, CF)
• BSA therapy for gt 7 days in the past month
• Corticosteroids (at least 10 mg predn/day)
• Malnutrition

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Clinical features

• Symptoms
• General Fever, pains, night sweats
• Respiratory Cough/sputum, dyspnea, chest pain,
  hemoptysis, others
• Signs
• General Rash, hemorrhage
• Chest Normal, crackles, bronchial, wheeze
• Systemic Meningitis, carditis

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Differential Diagnosis

• Pulmonary tuberculosis
• Pulmonary infarction
• Vasculitis
• Eosinophilic pneumonia
• Collapse, Malignancy
• Loculated effusion
• Uncommonly ILD, Organizing Pneumonia

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Complications

• Pulmonary Para-pneumonic effusion
• Empyema, Broncho-Pleural Fistulae
• Cavitation, Lung abscess, Pneumothorax
• Sputum impaction, collapse
• ARDS, Respiratory failure
• Systemic Deep vein thrombosis, Ectopic
  abscesses, Pericarditis, Myocarditis, Renal
  failure Hepatitis, Meningo-encephalitis
• Multi-organ failure

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Role of diagnostic tests

• CXR
• CT chest only in those with non-resolution or for
  assessment of complications
• Bl. Culture in hospitalized patients
• Sputum/BAL smear and culture for hospitalized
  patients
• Sputum for AFB
• Diagnosis of Community Acquired Pneumonia is
  largely clinical and CXR based in the out-patient
  setting.

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General Laboratory Tests

• Leucocytosis (polymorphonuclear)
• Raised ESR
• Arterial blood gases
• S. electrolytes liver renal function tests
• Blood sugar
• H.I.V. serology
• Blood cultures
• Others

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Chest Roentgenography

• New infiltrates / opacities
• Alveolar shadows consolidation
• Lobar / segmental / others
• Pleural effusion / pneumothorax
• Air cysts / cavities
• Interstitial / miliary shadows
• Hilar L.N. infiltrates

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Chest radiographs

• False-negative
• Interstitial lung dis
• PJP pneumonia
  
• Miliary TB
• Dehydration
• Neutropenia
  
• 
  

• False-positive
  
• Early course
• Vasculitis
• Atelectasis
• CHF
• Pulmonary infarcts
• Malignancies
• Miscellaneous

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Microbiological tests

• Blood culture- Positive in around 25 indicator
  of severity
• Sputum smear and culture- Rapid, inexpensive,
  variable sensitivity specificity
• Serology- Initial testing only if onset gt 7 days,
  or severe or unresponsive to ?-lactams
• Legionella urine antigen- Highly specific
  sensitive intubated patients with severe disease

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Pulmonary Samples for Diagnosis

• Sputum / induced sputum
• Bronchoscopic
• - Washings
• - Bronchial / bronchoalveolar lavage
• - Biopsy (bronchial / TBLB)
• - Needle aspiration
• Transthoracic needle biopsy
• Transtracheal aspiration
• Pleural aspirate / biopsy
• Thoracoscopic specimens

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Assessment of Severity

• Routine Clinical Assessment
• Host factors
• General indicators Fever, Leucocytosis, blood
  cultures, C Reactive Protein
• Clinical Scoring System
• Micro organism pattern
• Biomarkers

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Clinical Assessment Scores

• CURB 65, CRB
• Pneumonia Severity Index (PSI)
• Apache scoring system (APACHE II)
• Others

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Procalcitonin (PCT)

• Inflammatory biomarker
• Acute phase reactant primarily produced by liver
  in bacterial infections
• Inhibited by viral related cytokines
• Increased PCT helps to identify patients who
• - Benefit from antibiotics
• - Increased risk of death
• PCT-guided group had significantly less
  antibiotic use and duration of therapy
  

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Management of CAP

• Anti-microbial therapy - Antibiotics
• Supportive symptomatic therapy Fever,
  Dehydration, Systemic symptoms
• Stabilization of severity parameters
  De-oxygenation, Organ failure, Shock
• Treatment of complications Empyema, Cavitation,
  BP Fistulae
• Management of drug-toxicities
• Preventive strategies

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Indications for empiric combination therapy in CAP

• Presence of comorbid medical conditions
• Chronic heart, lung, liver or renal disease
• Diabetes mellitus
• Alcoholism
• Malignancies
• Use of antimicrobials within the previous 3
  months
• Severe CAP with or without comorbidities

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Out-patients Recommendations

• No cardiopulmonary disease / No disease modifying
  factors
• ß-lactam, macrolide, doxycycline
• Cardiopulmonary disease / disease modifying
  factors
• Beta lactam macrolide (or doxy)

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Inpatient Recommendations

• Non-severe CAP
• ß-lactam or macrolide
• Severe CAP/No risk factor for Pseudomonas
• IV Beta lactam azithromycin
• Severe CAP/Risk factor for Pseudomonas
• IV anti-pseudomonal ß-lactam anti-pseudomonal
  fluoroquinolones
• IV antipseudomonal ß-lactam amino-glycoside
  azithromycin

Fluoroquinolones should be used judiciously
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Duration of therapy

• Duration of therapy
• Pneumococcus, Gram negative bacteria - 7 to 10 d
• M. pneumoniae C. pneumoniae - 10 to 14 d
• Legionella, Pseudomonas, Staph. aureus 14 to 21
  d
• Switch to Oral Therapy
• Improvement in cough and dyspnea, afebrile (lt 100
  F) on two occasions 8 h apart, WBC count
  decreasing, functioning GIT with adequate oral
  intake

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Non-Resolving Pneumonia

• Antimicrobial failure
• Patient noncompliance, improper dosing regimen,
  resistant pathogen, unusual or unsuspected
  pathogen
• Infectious complications
• Empyema, endocarditis, super-infection
• Incorrect diagnosis
• Malignancy, pulmonary embolism, other
  noninfectious etiologies

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Severe Pneumonia/ Clinical Failure

• Death
• Need for mechanical ventilation
• RR gt 25 / min
• SaO2 lt 90 PaO2 lt 55 mmHg
• Hemodynamic instability
• Less than 1oC decline in admission temp. of gt
  38.5oC
• Altered mental state

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Causes of Clinical Failure

• Antimicrobial failure
• Patient noncompliance, improper dosing regimen,
  resistant pathogen, unusual or unsuspected
  pathogen
• Infectious complications
• Empyema, endocarditis, superinfection
• Incorrect diagnosis
• Malignancy, pulmonary embolism, other
  noninfectious etiologies

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Prevention

• Pneumococcal influenza vaccine
• Immune-competent patients gt 65 yr
• Persons lt 65 yr - CHF, COPD (not asthma),
  diabetes mellitus, alcoholism, chronic liver
  disease, asplenia etc.
• Immunosuppressed states (HIV infection,
  leukemia-lymphoma, immunosuppressive therapy
  etc.)
• Can be given immediately (after CAP)

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Nosocomial Pneumonias

• Hospital-acquired pneumonia - pneumonia 48 hours
  or more after admission, and was not incubating
  at the time of admission
• Ventilator-associated pneumonia - pneumonia that
  arises more than 48-72 hours after endotracheal
  intubation

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DEFINITIONS

• Hospital Acquired Pneumonia (HAP)
• 48 h after hospital admission (excluding an
  incubating infection)
• Early onset HAP vs Late onset HAP
• Ventilator Associated Pneumonia (VAP)
• 48-72 h after endotracheal intubation
• Early onset VAP vs Late onset VAP
• Health Care Associated Pneumonia (HCAP)
• i. hospitalized in an acute care hospital 2days
  in
• preceding 90 days
• ii. nursing home or long-term care facility
  resident
• iii. recent iv chemotherapy, or wound care
  within past 30 days
• iv. attended a hospital or hemodialysis clinic

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DIAGNOSIS OF HAP

• Clinical Chest X ray Microbiology

• New onset fever
• Purulent expectoration
• Tachycardia, Tachypnoea
• Leukocytosis / Leukopenia
• Need of higher FiO2
• Clinical diagnosis high sensitivity, low
  specificity
• empiric treatment

• Microbiology
• to identify etiology
• de-escalate therapy
• decide duration of therapy

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DRUG RESISTANCE Factors

•   Sicker inpatient population
• Immuno-compromised patients
• New procedures instrumentation
• Emerging pathogens
• Complacency regarding antibiotics
• Ineffective infection control and compliance
• Increased antibiotic use

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Management strategies summary
HAP, VAP or HCAP suspected
Obtain lower respiratory tract (LRT) sample for
culture (quantitative or semi-quantitative) and
microscopy
Begin empiric antimicrobial therapy using local
microbiological data
Days 2 and 3 check cultures and assess clinical
response (temperature, WBC, chest X-ray,
oxygenation, purulent sputum, haemodynamic
changes and organ function)
Clinical improvement at 4872 hours
No
Yes
Cultures
Cultures
Cultures
Cultures- -
Adjust antibiotic therapy, search for other
pathogens,
De-escalate antibiotics, if possible,
Search for other pathogens,complications etc
Consider stoppingantibiotics
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SUMMARY

• Community Acquired Pneumonia are common, mostly
  diagnosed on clinical and radiological criteris.
• Hospital aquired pneumonias are associated with
  excess mortality ?initiate prompt appropriate
  adequate therapy
• Pathogens for HAP are distinct from one hospital
  to another, specific sites within the hospital,
  and from one time period to another
• Avoid overuse of antibiotics, focus on accurate
  diagnosis, tailor therapy to recognized pathogen
  and shorten duration of therapy to the minimum
  effective period
• Apply prevention strategies aimed at modifiable
  risk factors