Transcript Community Aquired Pneumonia File

COMMUNITY-ACQUIRED
PNEUMONIA (CAP)
Pulmonary Medicine Department
Ain Shams University
http://telemed.shams.edu.eg/moodle5
At the end of this lecture the student
should be able to:
1. Describe the clinical types of pneumonias.
2. Know the definition of community acquired
pneumonia.
3. Know the impact, mortality, epidemiology and
etiology of community acquired pneumonia.
4. Describe the pathogenesis.
5. Discuss the classification of community acquired
pneumonia.
6. Know the clinical presentation.
7. Interpret the investigations for community
acquired pneumonia.
8. Propose the suitable antibiotic therapy.
9. Explain the indications for hospitalization and
icu admission.
10. Know the role of immunization in community
acquired pneumonia.
11. Discuss the non-infectious pneumonitis.
12. Explain the causes of treatment failure.
13. Discuss the causes of recurrent pneumonia.
Clinical types of pneumonia:
• Community- acquired pneumonia (CAP).
• Hospital-acquired (nosocomial) pneumonia (HAP).
• Pneumonia in immunocompromised host including
AIDS patients.
• Aspiration pneumonia.
• Recurrent pneumonia.
Community-Acquired
Pneumonia
Is a parenchymal lung infection
which develops outside the hospital
without
iatrogenic
or
invasive
procedure.
Mortality of Community-acquired pneumonia
Mortality in home-treated patients <1%
Mortality in hospital-treated patients 5-15%.
Mortality in ICU-treated patients 20-50%.
ETIOLOGY OF CAP
 Conventional diagnostic testing for CAP is imperfect
e.g role of sputum isolates in diagnosing aetiology of
LRTI is controversial (colonization)
 No sufficiently rapid and accurate battery of diagnostic
tests for CAP are available presently
 Etiology remains unknown in up to 50% of cases
 However, local knowledge of likely pathogen is
imperative
Carroll KC. J Clin Micro 2002;40:3115-3120
Bartlett et al. NEJM 1995;333:1618-1624
Niederman et al. Am J Respir Crit Care Med 2001;163:1730-1754
Organsims causing CAP:
Streptococcus pneumoniae
Haemophilus influenzae
Respiratory viruses
Mycoplasma pneumoniae
Legionella species
Chlamydia pneumoniae
Gram negative bacilli
Staphylococcus aureus
Moraxella catarrhalis
Mycobacterium tuberculosis
40-60%
10%
10-15%
5-15%
5-10%
5-10%
5%
5%
<5%
<5%
Etiology of communityacquired pneumonia
Other bacteria (12.5%)
Mycoplasma (6.7%)
Viral (12.6%)
H. influenzae
(14.3%)
Legionella (5.2%)
Chlamydia (3.7%)
S. pneumoniae
(44.9%)
Analysis of 16 studies of >3300 hospitalized patients (1960–1987)
LaForce. Clin Infect Dis 1992;14 (Suppl. 2):S233–7
Clinical picture of pneumonia
Respiratory symptoms:
Cough
Sputum
Dyspnea
Chest pain
URT
Haemoptysis
Non-respiratory symptoms:
Vomiting
Confusion Diarrhea
Rash
Abdominal pain
Signs:
Fever
Tachypnea Tachycardia
Consolidation Confusion Hypotension
Differential Diagnosis of
Pneumonia
• Pulmonary infarction.
• Atypical pulmonary oedema.
• Subphrenic abscess or pancreatitis.
• Pulmonary eosinophilia.
• Bronchoalveolar cell carcinoma.
• Primary and secondary lung tumors.
PNEUMONIA
TYPICAL
• Sudden onset
• Productive,purulent or
bloody sputum
• High fever
• Evident local signs
• Myalgia & headache
uncommon
• Focal alveolar or lobar
infiltrates in CXR
• Leucocytosis is common
ATYPICAL
• Gradual onset
• Nonproductive or only
scant mucoid sputum
• Low-grade fever
• Minimal local signs
• Myalgia & headache
common
• Diffuse interstitial
infiltrates in CXR
• Leucocytosis is uncommon
Diagnostic Algorithm for CAP
Office
Emergency Room
History and physical
examination
Consider chest X-ray
Treat empirically
If
necessary
History and physical
examination
Nursing Home
History and physical
examination
If
necessary
Chest X-ray:
CBC and diff; oximetry
chemistry; ABG
Ward
Blood culture
+
Sputum Gram stain and culture
±
Serology
–
Thoracentesis
+
Legionella urinary antigen testing +
ICU
+
+
–
+
+
Consider chest X-ray
Treat empirically
Chest X-ray
• Can help to diagnose pneumonia
• Can’t determine pathogen
• Helps to determine severity
– multilobar
– Cavities
– Pleural effusion.
Consolidation , Focal opacity
S pneumoniae
H influanzae
Atypical
Interstitial / Miliary
Viral
Mycoplasma
M TB
Fungi
Bil. hilar lymphadenopathy and nodular opacities
M TB
Atypical
Viral
Cavity: Staph aureus, Klebsiella, Anaerobes, M TB
Sputum Gram Stain & Culture
• Neither sensitive nor specific
• 30% of patients can’t produce sputum
• With grading—only 25%-40% good quality
• At best 28% are good samples
• Can’t detect atypicals
• Prior antibiotics affect results
Blood Cultures
• Outpatient – < 1%
• Ward patients – 6.6%-17.6%
• ICU patients – 27%
• Recommended for hospitalized patients
• It has a low sensitivity but high specificity
Serology
• Need paired assessments (acute &
convalescent)
• Results not available at time of initial
treatment decision
• Not recommended for routine use
Laboratory diagnosis of C. pneumoniae
infections
Feature
Culture
DFA
PCR
Serology
-------------------------------------------------------------------------------------Detection
Infectious
Antigen
DNA
Antibodies
organism
Specimen
Throat Swab Throat Swab Throat Swab
BAL
BAL
BAL
Sputum
Sputum
? Blood ?
Blood
Sensitivity
50%
20-60%
85-90%
60-80%
Specificity
100%
70-95%
95-100%
90-100%
Diagnostic Tests for Legionella and CAP
Test
Specimen
Sensitivity Specificity
Time to
diagnosis
Culture
Sputum
Blood
< 10-80%
0%-6%
100%
100%
3-7 days
3-7 days
Direct fluorescent
antibody screen
Sputum
33%-68%
>95%
1 hour
Antigen detection
Urine
80%-90%
>99%
< 1 hour
Serology
Serum
60%-80%
>95%
6-10 weeks
Urine/blood
Respiratory
secretions
75%-82%
83%-100%
90%-100%
90%-100%
2-4 hours
2-4 hours
PCR
Waterer GW, et al. Am J Med. 2001;110:41-8; Murdoch DR. CID 2003;36:64-9
Invasive Procedures
• Fulminant course
• Unresponsiveness to standard antimicrobials
• Thoracentesis if effusion > 10 mm on lateral
decubitus
Invasive diagnostic techniques
• Transtracheal aspiration
• Bronchoscopy with a protected brush catheter
• Bronchoalveolar lavage with or without balloon
protection
• Direct needle aspiration of the lung
• Thoracocentesis
Characteristics of Empyema
• Pleural fluid.
• PH < 7.1
• WBC > 10,000 cells / mm3
• Low glucose
• Culture
or
Gram
demonstrating organisms
stain
Criteria for hospitalization
History:
>65 yr, DM, renal failure, heart failure, ch. Lung disease,
alcoholism, malignancy and immunosupression.
Clinically:
RR>30, Systolic BP<90 or Diastolic BP<60, hyperpyrexia,
altered mental state and extrapulmonary site of infection.
Investigation:
WBC<4,000 or >30,000, Pa o2<60mmHg,haematocrit<30
and pleural effusion or multiple lobe or rapid spread in
CXR.
CURB-65
score
Any of:
• Confusion
• Urea >7 mmol/l
• Respiratory rate 30/min
• Blood pressure (SBP <90 mmHg or DBP 60 mmHg)
• Age 65 years
0 or 1
2
3 or more
Group 1
Group 2
Group 3
Mortality low
(1.5%)
Mortality intermediate
(9.2%)
Mortality high
(22%)
(n=324; died = 5)
(n=184; died = 17)
(n=210; died = 47)
Consider hospital
supervised treatment
Options may include
a) short stay inpatient
b) hospital supervised
outpatient
Manage in hospital as
severe pneumonia
Treatment options
Likely suitable for
home treatment
Assess for ICU
admission especially if
CURB-65 score = 4 or 5
Lim et al. Thorax, 2003
Antibiotic Selection for RTI
The micro-organism:
* Possible pathogens.
* Resistant organisms.
The patient:
*Age.
*Allergy to antibiotics.
*Pregnancy.
* Severity of infection.
* Concomitant disease.
The antibiotic:
* Spectrum of activity.
* Penetration to infection site.
* Potential for resistance.
* Drug and food interaction.
* Clinical efficacy.
* Adverse effects.
* Convenience.
* Cost.
CAP — out-patient
therapy/nursing home residents
No risk factors
Modifying factors present
(a)
Macrolide
OR
doxycycline
(b)
2nd generation
macrolide
Respiratory fluoroquinolone
OR
amox/clav  macrolide
doxycycline
OR
OR
2nd generation  macrolide
cephalosporin
(a) COPD but no steroids within 3 months
(b) COPD, oral steroids, antibiotics within 3 months
Canadian guidelines, 2000
CAP — hospitalised, ward
managed
Respiratory fluoroquinolonea
OR
2nd/3rd/4th generation cephalosporin + macrolide
aEither
levofloxacin + clindamycin, or trovafloxacin if aspiration suspected
Canadian guidelines, 2000
CAP — ICU managed
Ciprofloxacina + antipseudomonal b-lactamb
OR
antipseudomonal b-lactam + aminoglycoside
+ macrolide or 4th generation fluoroquinolone
aAdd
clindamycin if aspiration suspected
bCeftazidine, piperacillin/tazobactam, imipenem or meropenem
Canadian guidelines, 2000
Duration of therapy
Total duration of treatment of
CAP , may be 10-14 days or 5
days after disappearance of fever
(2 weeks in legionella or Staph
pneumonia ).
Criteria for Switch Therapy
• No clinical indications for continuing IV
therapy .
• No abnormal GI absorption .
• Patient afebrile .
• Cough & respiratory distress improved .
• WBC returning to normal .
Response to Treatment
• Adequate clinical response:
– Clinical improvement within 48-72 h (ATS, ERS)
– Subjective response within 1-3 days (IDSA) or 3-5 days (CIDS/CTS)
– Fever usually persists for longer than other signs and symptoms
• Clinical resolution can be delayed by:
–
–
–
–
Old age
Comorbidity
Severe infection
Other host factors
• Radiographic deterioration common during first several days of
treatment (reflecting continued inflammatory change in absence of
viable bacteria)
Huchon G, et al. Eur Resp Rev. 1998;8:391-426. Bartlett JG, et al. Clin Infect Dis. 2000;31:347-82. Mandell
LA, et al. Clin Infect Dis. 2000;31:383-421. American Thoracic Society. Am J Respir Crit Care Med.
2001;163:1730-54.
Reasons for Treatment Failure
Patient fails to respond or deteriorates following initial therapy
Incorrect diagnosis
Other conditions
Congestive
heart failure
Embolus
Neoplasm
Sarcoid
Drug reaction
Hemorrhage
Host
Local factors (eg,
obstruction,
foreign body)
Inadequate host
response
Complication (eg,
pulmonary
superinfection,
empyema)
Bartlett JG, et al. Clin Infect Dis. 2000;31:347-82.
Correct diagnosis
Drug
Error in drug
selection
Error in dose or
route
Compliance
Adverse drug
reaction
Pathogen
Drug-resistant
organism
Other pathogen
Causes of recurrent pneumonia
Local bronchial obstruction :
• Intraluminal ( foreign body ). • Intramural (adenoma , carcinoma)
• Extramural (Compression by lymph node )
Local bronchopulmonary disease :
• Pulmonary sequestration
• Localized bronchiectasis
Generalized bronchopulmonary disease :
• Bronchiectasis
• Cystic fibrosis • Chronic bronchitis
• Immotile cilia syndrome
• Chronic sinusitis
Non-respiratory disease :
• Recurrent aspiration ( neuromuscular & oesophageal problems ,
alcoholics , epileptics )
• Immune deficiency states
• Gingival disease .
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