community acquired Pneumonia

Question 1

Epidemiology on Community acquired Pneumonia?

Answer 1

• 4 million cases/year1 • 800,000 patients require hospitalization/year1 • Increasingly common among older patients and those with coexisting illness • Expanding spectrum of causative organisms – Streptococcus pneumoniae is the most common – No causative agent identified in • 50% of patients • Increasing resistance of pathogens to older antimicrobial agents2

Question 2

Who is at risk for CAP?

Answer 2

• Elderly and the very young • Immunocompromised • Persons with specific comorbidities – Diabetes Mellitus – Chronic obstructive pulmonary disease (COPD) – Chronic renal failure – Splenectomy or functional asplenia

Question 3

Effect of age on CAP?

Answer 3

• Incidence: Proportion requiring hospitalization from CAP – 35/100,000 adults age 20-24 years – 1200/100,000 adults > age 75 years • ICU Admissions – 10% 0f patients with CAP

Question 4

Explain the chart of which etiologies of pneumonia different ages get? Newborns, children, young adults, middle age, and elderly

Answer 4

Question 5

Common pathogens for alcoholism?

Answer 5

Oral anaerobes, gram-negative bacilli, Streptococcus pneumonia

Question 6

Nursing home residents common pathogens?

Answer 6

Streptococcus pnuemoniae, gram-negative bacilli, Haemophilus influenzae, Staphylococcus aureus, including methicillin –resistant Staphylococcus aureus (MRSA)

Question 7

COPD common pathogens?

Answer 7

Haemophilus influenzae, Streptococcus pneumoniae, Moraxella (Branhamella) catarrhalis

Question 8

Common pathogens during an influenza outbreak?

Answer 8

Influenza virus, Streptococcus pnuemoniae, Staphylococcus aureus, Haemophilus influenzae

Question 9

Common pathogens seen with poor dental hygeine?

Answer 9

Oral anaerobes

Question 10

Explain the changing etiology of CAP?

Answer 10

• Causative pathogen unknown in 1/3 to 1/2 of all cases of CAP
• Increase in antimicrobial resistant strains

Question 11

When the pathogen is documented in CAP which are common ones? and atypical?

Answer 11

• Traditional pathogens Streptococcus pneumoniae

Haemophilus influenzae

Moraxella catarrhalis

Staphylococcus aureus

Gram negative bacteria

Acinetobacter

Anaerobic bacteria (Peptostreptococci, Bacteroides sp., Prevotella)

• Viruses

Atypical pathogens: Mycoplasma pneumonia, chlamydia pneumonia, legionella sp.

Question 12

What are the routes of pneumonia infection?

Answer 12

• Inhalation • Aspiration • Hematogenous (rare)

Question 13

List the Major defenses against pulmonary infection and the things that impair them?

Answer 13

Gag reflex: Alcohol, Stroke, Coma

Mucociliary Elevator: Alcohol, Viral infection, Smoking, Kartegener Syndrome

Alveolar Macrophages: Alcohol, Viral infection, Smoking, Pulmonary edema, Steroids

Specific Ig: deficiency

CMI :Steroids, Viral infection

Question 14

Explain what things we do for the diagnosis of CAP?

Answer 14

• Patient history and physical examination findings
• Confirmation by chest radiograph
• Gram stain and culture of sputum*
• Blood culture
• Serologic tests
• Special tests
• Invasive techniques

Question 15

CAP symptomology?

Answer 15

• Cough associated with fever +/- sputum, dyspnea, pleurisy, malaise, GI symptoms
• Acute confusion or deterioration of baseline function (elderly or debilitated patients) – Advanced illness
• Difficult to differentiate between typical/atypical pathogens on clinical presentation

Question 16

Symptoms indicative of Pneumococcal Pneumonia?

Answer 16

– Abrupt onset of single shaking chill

– Fever, cough productive of rust-colored sputum

– Pleuritic chest pain

Question 17

Symptoms indicative of H.Influenza pneumonia?

Answer 17

– Insidious worsening of baseline cough and sputum production

Question 18

Symptoms indicative of Chlamydia Pneumonia?

Answer 18

– URI, bronchitis or laryngitis, subacute in onset, progression to pneumonia in a minority of patients

Question 19

Symptoms indicitive of Mycoplasma Pneumonia?

Answer 19

– Flu-like illness with headache, malaise, and fever – Cough may produce mucoid sputum – Pharyngeal erythema, cervical adenopathy, scattered rales and rhonchi

Question 20

What are the traditional tests for CAP? Evolving tests?

Answer 20

Chest radiogaphy

Expectorated sputum, with gram stain and culture

Blood culture

Evolving: Biochemical, immunologic, molecular

Question 21

Explain the localized alveolar infiltrates of common pneumonia types?

Answer 21

• Pneumococcal pneumonia – most common
• Klebsiella pneumonia – lobar enlargement evidenced by bowing or bulging of a fissure favors Klebsiella or pneumococcal Type III pneumonia
• Staphylococcal pneumonia – empyema common
• Anaerobic pneumonia – favored if posterior segment right upper lobe or superior right lower lobe with cavitation
• Tuberculosis pneumonia
• Histoplasmosis – acute pneumonia form
• Legionnaire’s disease

Question 22

ddx of multiple nodular lesions?

Answer 22

• Metastases
• Granulomas (e.g., histoplasmosis, tuberculosis, blastomycosis, coccidioidomycosis)
• Hamartomas
• Arteriorvenous malformations
• Septic emboli with abscess
• Rheumatoid nodules
• Wegener’s granulomatosis
• Sarcoidosis
• Pulmonary infarcts

Question 23

Explain the advantages and disadvantages of expectoration of sputum, endotrachial aspiration, trantracheal aspiration, fiberoptic brochoscopy, Transthoracic lung aspiration?

Answer 23

Question 24

Laboratory Analysis for CAP includes? how are the specimins collected?

Answer 24

Laboratory Analysis

Culture (2 days)- Nasopharynx wash/swab or throat culture

Rapid antigen detection methods (2-3 hours) - same as above

ELISA: Immunofluorescent, antigen detection- bronchoalveolar lavage.

PCR (investigational) - sputum

Histopathology (2-3 days)- lung tissue

Question 25

Differential Diagnosis of CAP?

Answer 25

* Direct staining of sputum can differentiate pulmonary infections due to the following organisms: – Mycobacterium spp – Endemic fungi (Histoplasma, Blastomyces, Coccidioides, Cryptococcus) – Legionella spp (requires direct fluorescent antibody staining) – Pneumocystis carinii * Chest radiographic findings may suggest tuberculosis or Pneumocystis carinii pneumonia; multilobular involvement indicates severe illness * Atypical pneumonias (Chlamydia pneumoniae, mycoplasma pneumoniae, Legionella spp) are unresponsive to conventional antibiotic therapy (penicillins, cephalosporins, trimethoprim/sulfamethoxazole) or present with extrapulmonary features

Question 26

Indications for Hospitalization in community acquired pneumonia?

Answer 26

* Age \>65 years * Coexisting illness or other findings – COPD - Congestive heart failure – Diabetes mellitus - Chronic liver disease – Chronic renal failure - Hospitalization during previous year * Physical findings – RR \>30 per minute – Systolic/diastolic BP ”90/”60 mm Hg – T \>38.3C/101F * Laboratory findings – WBC \<4,000/L or \> 30,000/L or - PaCO2 \>50 mm Hg absolute neutrophil count \<1,000/ - HCT \<30% – PaO2 \<60 mm Hg - Hb \<9 g/dL * Absence of competent caregiver in stable home situation

Question 27

Streptococus pneumonia Frequency? Hospitalizations? Lethality? Most frequent in? Clinical features? treatment?

Answer 27

* Frequency of pathogen identification – 1930-1937: 81% – 1950-1985: 35%-76% – 1985-present: 10%-20% * Hospitalized CAP patients with etiologic diagnosis: 66%\* * Identified pathogen in lethal cases of CAP with an etiologic diagnoses: 67% * Bacteremic pneumonia: 66% * Most frequent pathogen in elderly * Most common bacterial pathogen in AIDS patients * Clinical features: Single shaking chill, fever, cough with rust-colored sputum, pleuritic chest pain * Treatment: Amoxicillin, cefotaxime, ceftriaxone, fluoroquinolones (levofloxacin, trovafloxacin, grepafloxacin, sparfloxacin), vancomycin, macrolides, clindacycim

Question 28

Incidence of Mycoplasma Pneumonia? Incubation? Clinical features? Extrapulmonary consequences or symptoms? Diagnosis? Treatment?

Answer 28

* Incidence: ~12% patients hospitalized for CAP * Incubation period: 2-4 weeks * Clinical features: Prodrome ĺ tracheobronchitis with cough for 3-4 weeks 㼼 pneumonitis (3%) * Extrapulmonary consequences or symptoms: GI rash, subclinical anemia, neurologic symptoms, myocarditis * Diagnosis: Culture, serology for IgG or IgM, enzymelinked immunosorbent assay (ELISA) or complement fixation (CF) or PCR Cold agglutinins \>1:64 * Treatment: Tetracycline or doxycycline, macrolide, fluoroquinolones

Question 29

Chlamydia pneumonia incidence? Epidemiology? Clinical Features? Diagnosis? MIF criteria? Treatment?

Answer 29

* Incidence: 5%-15% of CAP * Epidemiology: Sporadic and epidemic * Clinical features: Pharyngitis, laryngitis, tracheobronchitis, and may precipitate asthma * Diagnosis: Serology microimmunofluorescence (MIF) preferably with confirmation by polymerase chain reaction (PCR) or culture * MIF Criteria: 4-fold increase IgG or IgG\> 1:512 or IgM\> 1:16 * Treatment: Doxycycline, macrolide, fluoroquinolones

Question 30

Legionella Pneumophila incidence, epi, clinical features? Diagnosis? Treatment?

Answer 30

* Incidence: 2%-6% of patients hospitalized for CAP * Epidemiology: Epidemics (summer) or sporadic (not seasonal) * Clinical features: Non-distinctive • Host susceptibility factors: Age \>40, compromised cell-mediated immunity (non-AIDS), and smoking • Mortality: 15%-25% of patients hospitalized with Legionella pneumonia * Diagnosis: Urinary Ag (for L. pneumophila serogroup 1) and culture on selective media * Treatment: Macrolide (azithromycin, erthromycin, clarithromycin), fluoroquniolones, doxycycline

Question 31

What are the respiratory viruses that can cause Pneumonia?

Answer 31

influenza A and B Respiratory Synticial Virus (RSV) Parainfluenza virus 1, 2, and 3 Adenovirus Coronovirus Rhinovirus

Question 32

What are the non-respiratory viruses that can cause pneumonia?

Answer 32

Herpes simplex virus type 1 Varicella zoster CMV EBV Human herpes virus 6 measels Virus hantavirus

Question 33

What are the two treatment styles in CAP?

Answer 33

Empirical: 1993 guidelines Therapy to be based on likely spectrum of pathogens. Prescence of advanced age or underlying illness, Severity of illness on presentation, inpatient versus outpatient management. Etiologic or pathogen-derived guidelines 1998 Therapy to emphasize the identification of causitive pathogen with pathogen specific therapy. Minimize polypharmacy, reduce resistance, reduce adverse drug reactions, reduce cost.

Question 34

Who should receive the pneumococcal polysaccharide vacine?

Answer 34