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PNEUMONIA. ALOK SINHA Department of Medicine Manipal College of Medical Sciences Pokhara , Nepal. Acute respiratory illness of varied aetiology associated with recently developed radiological opacities which can be- Segmental Lobar Multilobular. - PowerPoint PPT Presentation
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PNEUMONIA
ALOK SINHADepartment of Medicine
Manipal College of Medical SciencesPokhara, Nepal
• Acute respiratory illness of varied aetiology associated with recently developed radiological opacities which can be-• Segmental• Lobar• Multilobular
.
Pneumonia is parenchyma/alveolar inflammation of lungs and abnormal alveolar filling with fluid.
Pneumonia is parenchyma/alveolar inflammation of lungs and abnormal alveolar filling with fluid.
Type of V/Q mismatch ??
ClassificationClassificationAnatomic or Pathologic • Lobar (or segmental) pneumonia
• infection of a single lobe often due to Streptococcus pneumoniae (some times segmental)
• Multilobar pneumonia(Broncho pneumonia) • involves more than one lobe, and it often
causes a more severe illness
• Interstitial pneumonia • involves the areas in between the alveoli
Atypical pneumonia • caused by agents such as
Mycoplasma Legionella Chlamydia Coxiella burnetii
• clinical features of these pneumonias can differ from pneumococcal disease
• Account for 20% cases of pneumonia
Combined clinical classificationCombined clinical classification
• Community-acquired pneumonia (CAP)
• Hospital-acquired pneumonia(nosocomial)
Community-acquired pneumonia (CAP) is an infection of the alveoli, distal airways, and interstitium of the lungs that occurs outside the hospital setting
Characterized clinically by: • Fever • Chills• Cough • Pleuritic chest pain • Sputum production • At least one opacity on chest radiography
Epidemiology Incidence:
• 800–1500 cases per 100,000 persons annually
~20% require hospitalization Age
• Incidence highest at extremes of age
Sex • Rate higher among men than among women
Seasonality • More common during the winter/spring months
• Low mortality rate in adults < 1% at home
• Is high in children-20% of childhood deaths
• Most cases in previously healthy persons
• Impairment of local defense mechanism predisposes to Pneumonia
Risk Factors Independent risk factors for CAP include:
• Alcoholism [relative risk (RR) 9] • Cigarette smoking
• Asthma (RR 4.2)
• Immunosuppression (RR 1.9)
• Corticosteroid therapy• Multiple myeloma• Spleenectomy• H.I.V.
• Age >70 years (RR 1.5 vs. 60–69 years)
• URTIs• Pre existing lung disease
Etiology
Common S. pneumoniae - most common cause of
community-acquired bacterial pneumonia H. influenzae K. pneumoniae
Uncommon S. aureus S. pyogenes P. aeruginosa N. meningitidis
Rare Y. pestis B. pseudomallei Acinetobacter calcoaceticus
• S pneumoniae -common cause of bacterial pneumonia. Colonizes upper respiratory tract and can cause the following: • a) disseminated invasive infections, including
bacteremia and meningitis• b) pneumonia and other lower respiratory tract
infections• c) upper respiratory tract infections, including otitis
media and sinusitis
• H influenzae often is associated with debilitating conditions such as asthma, COPD, smoking, and a compromised immunesystem
• K pneumoniae -severe necrotizing lobar pneumonia in patients with chronic alcoholism,diabetes, or COPD
• S aureus in intravenous drug users. in hospitalized patients, with prosthetic
devices, people with a recent influenza virus infection, and in individuals with cystic fibrosis
• L pneumophila infections occur either
sporadically or as local outbreaks from contaminted air conditioners
Microaspiration of oropharyngeal secretions colonized with pathogenic microorganisms • S. pneumoniae• H. influenzae
is most common route – Community acquired pneumonia
Gross aspiration • Central nervous system disorders that affect
swallowing (e.g., stroke, seizures) • Impaired consciousness (e.g., in alcoholism,
IV drug use) • Anesthesia or intubation • Pathogens include anaerobic organisms and
gram-negative bacilli -Common in Hospital acquired pneumonia
Other less important Aerosolization Hematogenous spread Contiguous spread from another site
Clinical features = Symptoms + SignsClinical features = Symptoms + Signs
Stages of pneumonia
Consolidation Red hepatization Gray hepatization resolution
History
Most typical signs/symptoms – depends upon the stage of diseaseFever Cough
• Nonproductive initially • productive of purulent sputum latter
stages Pleuritic chest pain
• Occasionally referred to the shoulder or anterior abdominal wall & associated with upper abdominal tenderness
Chills and/or rigors Dyspnea
Frequent signs/symptoms
Headache Nausea Vomiting Diarrhoea Fatigue Arthralgia/myalgia new-onset or worsening confusion (in elderly patients)
herpes labialis
endobronchial plug of blood, sputum, mucus & debris
Character of sputum produced may suggest a particular pathogen • Pneumococcal pneumonia bloody or
rust-colored
• Pseudomonas, Haemophilus- green sputum
• Anaerobic infections- foul-smelling and
bad-tasting • Klebsiella or pneumococcal species-
Currant-jelly
Physical examination
• Fever • Tachypnea (Accessory muscles – active)• Tachycardia• Cyanosis
Chest examination • Chest expansion – restricted • Percussion - impaired • Increased tactile and vocal fremitus• BRONCHIAL BREATH SOUNDS present • Egophony & Whispering pectoriloquy • Crackles • Pleural friction rub
Differential Diagnosis Infections
• Lung abscess • Bronchitis
Noninfectious illnesses • Pulmonary embolism • Pulmonary hemorrhage • Pulmonary edema • Pulmonary fibrosis/scarring • Inflammatory disorders
• Sarcoidosis • Wegener’s granulomatosis • Other rheumatologic/vasculitic diseases
• Lung cancer • Hypersensitivity pneumonitis • Bronchiolitis obliterans organizing pneumon (BOOP)
Assess pneumonia severity • Pay attention to vital signs, including oxygen
saturation • Always count the respiratory rate yourself for
1 min The single most useful clinical sign of
severity is a respiratory rate of >30/min in a person without underlying lung disease
CURB65 SCORECURB65 SCORE
7 mmol/l or 42mg/dl (Blood Urea Nitrogen>19)
The main objectives of investigating patients with a clinically based diagnosis of pneumonia are: • to obtain radiological confirmation of diagnosis
• exclude other conditions that mimic pneumonia
• to obtain a microbiological diagnosis • to assess the severity of pneumonia• to identify the development of complications
Good morning !
Where we stopped last time ?
INVESTIGATIONSDepends on the severity of diseasesCURB65 score 0 can be managed empiricallyScore 1-2:
a. Sputum examination with gram & ZN stain b. Blood culturec. Serology-Acute & convalescent titers
Score > 2: All the bove +a. Tracheal aspirateb. B.A.L.c. Serology-Legionella antigen in urine Pneumococcal in sputum & bloodd. Throat swab and pleural fluid if present
Laboratory Tests
Nonspecific studies Complete blood count Serum electrolyte and glucose measurements
Blood urea nitrogen (BUN) and creatinine measurements
Arterial blood gas & Pulse oximetry
Sputum stains and culture Gram’s stain
• Useful in screening a sputum sample for suitability for culture and in making a presumptive etiologic diagnosis
A sputum sample with
• >25 white blood cells (WBCs) • <10 squamous epithelial cells per low-power field is suitable for culture
• Most common: presence of gram positive diplococci – S. Pneumonae
Other sputum stains that may be helpful in some patients • Stains for
•Acid-fast bacilli •Pneumocystis •Fungi •Cytology (malignancy)
• Rapid antigen testing for viral pathogens (e.g.Influenza)
Sputum culture
Results should always be correlated with those of Gram staining (of sputum)
If an organism is isolated from sputum and is morphologic correlate is not seen on Gram staining, the isolate may be colonizing the upper airway
Certain microorganisms, if isolated from sputum, should always be considered pathogens. These include:• M. tuberculosis• Legionella spp.• Blastomyces dermatitidis• Histoplasma capsulatum• Coccidioides immitis
(Only about one-third of elderly patients admitted with CAP produce sputum suitable for culture)
Blood culture
Indications: • Hyperthermia (body temperature >38.5°C)• Hypothermia (body temperature <36°C)• Homeless• Alcohol abuse
All patients admitted to the hospital for CAP should have 2 sets of blood cultures done before initiation of antibiotic therapy (positivity rate: 6–20%)
Most common isolates• S. pneumoniae (~60%) • S. aureus• Escherichia coli
Detection of antigens of pulmonary pathogens in urine
S. pneumoniae • The antigen detected for up to 1 month after
the onset of pneumonia• results can be available in 15 min
L. pneumophila • when Legionnaires’ disease is strongly suspected• Rapidly progressive pneumonia
Urine antigen test most frequently used diagnostic method for Legionnaires’ disease
Serology Detection of IgM antibody 4-fold rise in titre of antibody to a
particular agent between acute & convalescent phase indicates is the cause of CAP
Useful for epidemiological study
ImagingImaging
Chest x-ray • Diagnostic test of choice for pneumonia
• May show Lobar or segmental consolidationBronchopneumonic pattern Interstitial infiltrates Cavitation Associated pleural fluid, etc
The common patterns in pneumonia are-
segmental or lobar pneumonia – • Strep. pneumoniae • Mycoplasma. pneumoniae • Legionella. pneumophila • Staph. aureus • C pneumoniae • Mycobacterium tuberculosis
Right upper lobe pneumonia
Segmental pneumonia
Air bronchogram
Left upper lobe pneumonia
Left upper lobe consolidationSame patient as in previous one
3rd segment left upper lobe
.
• Multifocal bilateral segment or lobar opacities (Broncho pneumonia) – S aureusC burnetiiS pneumoniae
Broncho pneumonia
•Pneumatoceles (thin-walled cavities) S aureusStreptococcus pyogenesP carinii
Pneumatoceles
High-resolution CT • Occasionally detects pulmonary
opacities in patients with symptoms and signs suggestive of pneumonia and negative chest x-ray
• More likely than chest radiography to show bilateral involvement, pleural fluid/empyema, adenopathy, etc.
Bronchoscopy/ bronchoalveolarlavage /lung biopsy
(BAL)
• To obtain material for further studies when the diagnosis defies other diagnostic efforts
• patient does not improve despite empirical therapy
1. Oxygen
2. Fluid balance 3. Antibiotic treatment
4. Treatment of pleural pain
5. Physiotherapy
Oxygen Should be administered to all patients to
maintain • PaO2 ≥ 60 mmHg
• SpO2 ≥ 92%
High concentrations (> 35%) & humidified oxygen used in all patients (who do not have hyper capnia associated with COPD)
Assisted ventilation should be considered at an early stage in those who remain hypoxaemic despite adequate oxygen therapy
Risk factors for antimicrobial resistance
Age >65 years, β-lactam therapy within the past 3 months
Alcoholism Immunosuppressive illness Multiple medical comorbidities Severity of illness
Outpatient Patients with no comorbidities and no risk
factors for drug-resistant S. pneumoniae (DSRP) infection
Macrolides
• Clarithromycin (250 - 500mg PO bd for 7 days)
• Azithromycin (500 mg PO once, then 250 mg/d PO for 4 days or 500 mg/d PO for 3 days or 2 g PO once)
Doxycycline (100 mg PO bid for 7–10 days)
or
or
Patients with comorbidities • COPD • diabetes• renal or congestive heart failure • malignancy • Risk DRSP infection or a high DRSP prevalence in
the community • One of the following
Quinolone with enhanced activity against S. pneumoniae
• Levofloxacin (500–750 mg PO qd) or • Moxifloxacin (400 mg PO qd) or • Gatifloxacin (400 mg PO qd)
Cefpodoxime 200 mg PO bid third generation cephalosporin active against most Gram
positive and Gram negative organisms except Pseudomonas
Cefprozil 500 mg PO bid second-generation cephalosporins greater Gram-negative
spectrum & some activity against Gram + cocci
Amoxicillin 1000 mg PO tid; or Amoxicillin/Clavulanic acid 625 mg PO tid
+• Macrolide (clarithromycin or azithromycin dosed as
above) or • Doxycycline dosed as above
or
or
Severely ill patients
Consider coverage for methicillin-resistant S. aureus (MRSA) as well • vancomycin (1 g IV q12h)
until microbiology data become available Monotherapy with a quinolone is not
recommended for severely ill patients with CAP
In most patients • 7-10-day course is adequate
Treatment usually required for longer in patients with • Legionella • staphylococcal • Klebsiella pneumonia
How long to treat ?
Oral antibiotics adequate unless the patient has • Severe illness • Impaired consciousness • Loss of swallowing reflex • Malabsorption
MonitoringMonitoring
Outpatients Follow up within 48 h
warning signs of pneumonia exacerbation:• Symptoms not improving or new symptoms
Shortness of breath while walking on level ground (assuming no underlying lung disease)
Temperature of >38.5°C (101.3°F) New onset of confusion or pleuritic chest pain Hemoptysis
Inpatients
• Monitor Temperature curve WBC count for resolution
• Follow up on culture results and adjust therapy accordingly Watch for superinfection with S aureus
Monitor comorbid conditions (e.g., COPD, renal disease)
Follow up to ensure radiographic clearance of pneumonia
•Radiological resolution in pneumonia lag behind clinical improvement for several weeks
• Time taken for radiological resolutionNonsmokers <50 years who lack underlying lung disease: 6 weeks
Elderly patients with COPD: 8–12 weeks
• Up to 2% of patients hospitalized with CAP have cancer in the lung (with pneumonia distal to an obstructed bronchus)
50% of these cancers are evident on the initial chest film
50% manifest as failure of pneumonia resolution & are diagnosed at broncho scopic evaluation for unresolving pneumonia
When pneumonia fails to improve despite treatment
1.Reconsider the diagnosis • Is another illness presenting as pneumonia? • treating the wrong pathogen?
Treated for conventional bacterial causes of pneumonia, but is actually due to M. tuberculosis or to Pneumocystis or another fungus?
2. Treating the right pathogen with wrong drug? • using nafcillin or cloxacillin to treat S. aureus
and patient is infected with MRSA, should be using vancomycin or linezolid
3. Complicated pleural effusion Pleural effusion is seen in ~40% of patients
hospitalized for CAP – parapneumonic effussion
Indication for draining • pH of <7• glucose level of <2.2 mmol/L (40 mg%)• LDH content of >1000 units • positive on Gram’s staining or culture • If the effusion is >1 cm in lateral decubitus X ray
4. Is there a mechanical reason for the patient’s failure to improve
an obstructed bronchus due to carcinoma
5. Have you overlooked an undrained or metastatic pyogenic focus • empyema • brain abscess • endocarditis • splenic abscess • Osteomyelitis ?
Since most patients are elderly & havemultiple comorbid conditions, complicationsduring hospital stay are not uncommonThe most common complications are:
1. Acute type I respiratory failure2. Congestive heart failure3. Septicemia & shock
• Leading to multiorgan failure
4. Dysrhythmias (arrhythmias) due to • hypoxia• dyselectrolytemia
5. Gastrointestinal bleeding• Stress or Curling’s ulcers
6. Renal insufficiency
Due to severe/uncontrolled infection: 7. lung abscess
• Not a common complication of CAP• may occur in association with
aspiration with Klebsiella & staphylococcal infections
8. Complicated pleural effusion leading to empyema
9. Metastatic infection brain abscess endocarditis
• Requires immediate attention & proper treatment
10. Retention of sputum causing lobar collapse
11. Super infection with gram-negative organisms
12. Acute respiratory distress syndrome 13. Of all complicationsDeath
Findings predicting severe disease
1. WBC count <4000/μL or >30,000/μL,2. Absolute neutrophil count <1000/μL 3. Abnormal renal function - serum creatinine
>1.2 mg/dL or blood urea> 45 mg/d
4. ABG determinations- • PaO2 of <60 mm Hg • PaCO2 > 50 mm Hg on room air
5. Evidence of sepsis or organ dysfunction as manifested by • Metabolic acidosis• Increased prothrombin time• Picture of disseminate intravascular
coagulation • Increased partial thromboplastin time, • Decreased platelets
X ray findings for: multilobar involvement presence of a cavity rapid radiographic progressionpresence of a pleural effusion
Influenza and pneumococcal vaccination
smoking cessation
attention to oral hygiene in patient prone to aspiration
Hospital
acquired
Hospital acquired (nosocomial) Pneumonia
• Pneumonia acquired during or after hospitalization for another illness or procedure with onset at least 72 hrs after admission
• causes, microbiology, treatment and prognosis
are different from Community acquired pneumonia
• Up to 5% of patients admitted to hospital for
other causes subsequently develop pneumonia
FACTORS PREDISPOSING TO NOSOCOMIAL PNEUMONIA
Reduced host defences against bacteria
•Reduced immune defences (e.g. corticosteroid treatment, diabetes, malignancy) •Reduced cough reflex (e.g. post-operative) •Disordered mucociliary clearance (e.g. anaesthetic agents) •Bulbar or vocal cord palsy
Aspiration of nasopharyngeal or gastric secretions
•Immobility or reduced conscious level •Vomiting, dysphagia, achalasia or severe reflux •Nasogastric intubation
Bacteria introduced into lower respiratory tract•Endotracheal intubation/tracheostomy •Infected ventilators/nebulisers/bronchoscopes •Dental or sinus infection
Bacteraemia
•Abdominal sepsis •Intravenous cannula infection •Infected emboli
.
• The microorganisms a person is exposed to in a hospital are often different from those at home
• Hospital-acquired microorganisms include resistant bacteria • Escheresia• Pseudomonas• Klebsiella• MRSA (Multidrug Resistant Staphylococcusaureus)• Anaerobic organism
• Ventilator-associated pneumonia (VAP) a subset of hospital-acquired pneumonia. • pneumonia which occurs after at least 48
hours of intubation and mechanical ventilation
Treatment
Started empirically till the investigation reports
Are availableInitial therapy determined by
• severity of illness• risk factors• length of hospitalization• day of onset- latter is more severe
Patients With Mild-to-Moderate Hospital-Acquired Bacterial Pneumonia With Risk Factors, Onset Any Time
Anaerobes recent abdominalsurgery, witnessed
aspiration
Clindamycin or beta-lactam/beta-lactamase inhibitor
S aureus coma, head trauma,
diabetes mellitus, renal failure
+/-vancomycin (until methicillin-resistant S aureus is excluded
Legionella high-dose steroids Erythromycin +/- rifampin
P.Aeruginosa prolonged ICU staySteroidsantibioticsstructural lungdisease
Aminoglycoside or ciprofloxacin +
Anti pseudomonal penicillinBeta-lactam/beta-lactamase
inhibitorCeftazidime or cefoperazone
Atypical pneumonia
Pneumonia caused by Atypical pathogens:
caused by one or a combination of the following organis
Legionella pneumophila • Causes a severe form of pneumonia with a relatively high
mortality rate, known as legionellosis or Legionnaires' disease
Mycoplasma pneumoniae • Usually occurs in younger age groups and may be associated
with neurological and systemic (e.g. rashes) symptoms Chlamydophila pneumoniae
Atypical clinical features: In general few physical signs Patient looks worse than the
symptoms suggest No signs and symptoms of lobar
consolidation, • affection is restricted to small areas,
rather than involving a whole lobe
Absence of leukocytosis Extrapulmonary symptoms, related to
causative organism
Atypical therpeutic response: No response to common antibiotics as
sulfonamide and beta-lactams like penicillin