Pneumonia lecture,Describe the common pathogenesis and pathogens of pneumonia Discuss diagnosis and initial management of community acquired pneumonia (CAP) Understand features of the Pneumonia PORT Severity Index Discuss the IDSA/ATS guidelines and recommendations for final antibiotic choice Understand issues in basic management for pneumonia in children, nursing home patients, and immunocompromised patients.

1. Pneumonia
Desalew Mekonnen, MD
Internal medicine
4th year lecture
University of Gondar

2. Objectives
• Describe the common pathogenesis and pathogens o
f pneumonia
• Discuss diagnosis and initial management of commu
nity acquired pneumonia (CAP)
• Understand features of the Pneumonia PORT Severit
y Index
• Discuss the IDSA/ATS guidelines and recommendatio
ns for final antibiotic choice
• Understand issues in basic management for pneumo
nia in children, nursing home patients, and immunoc
ompromised patients.

3. Epidemiology
• Unclear! Few population-based statistics on the cond
ition alone
• CDC combines PNA with influenza for morbidity & m
ortality data
– PNA & influenza = 7th leading causes of death in the US (2
001)
– Age-adjusted death rate = 21.8 per 100,000
– Mortality rate: 1-5% out-Pt, 12% In-Pt, 40% ICU
– Death rates increase with comorbidity and age
– Affects race and sex equally

6. Community Acquired Pneumonia
• Infection of the lung parenchyma in a person
who is not hospitalized or living in a long-ter
m care facility for ≥ 2 weeks
• 5.6 million cases annually in the U.S.
• Estimated total annual cost of health care = $8
.4 billion
• Most common pathogen = S. pneumo (60-70%
of CAP cases)

7. “Nosocomial” Pneumonia
• Hospital-acquired pneumonia (HAP)
– Occurs 48 hours or more after admission, which w
as not incubating at the time of admission
• Ventilator-associated pneumonia (VAP)
– Arises more than 48-72 hours after endotracheal i
ntubation

8. “Nosocomial” Pneumonia
• Healthcare-associated pneumonia (HCAP)
– Patients who were hospitalized in an acute care hospital fo
r two or more days within 90 days of the infection; resided
in a nursing home or LTC facility; received recent IV abx, ch
emotherapy, or wound care within the past 30 days of the
current infection; or attended a hospital or hemodialysis cli
nic
• Guidelines for the Management of Adults with HAP, V
AP, and HCAP. American Thoracic Society, 2005

9. Pathogenesis
• Inhalation, aspiration and hematogenous spre
ad are the 3 main mechanisms by which bacte
ria reaches the lungs
• Primary inhalation: when organisms bypass n
ormal respiratory defense mechanisms or whe
n the Pt inhales aerobic GN organisms that col
onize the upper respiratory tract or respiratory
support equipment

10. Pathogenesis
• Aspiration: occurs when the Pt aspirates colon
ized upper respiratory tract secretions
– Stomach: reservoir of GNR that can ascend, coloni
zing the respiratory tract.
• Hematogenous: originate from a distant sourc
e and reach the lungs via the blood stream.

11. Pathogens
• CAP usually caused by a single organism
• Even with extensive diagnostic testing, most in
vestigators cannot identify a specific etiology f
or CAP in ≥ 50% of patients.
• In those identified, S. pneumo is causative pat
hogen 60-70% of the time

12. Streptococcus pneumonia
• Most common cause of CAP
• Gram positive diplococci
• “Typical” symptoms (e.g. malaise, shaking chill
s, fever, rusty sputum, pleuritic chest pain, cou
gh)
• Lobar infiltrate on CXR
• Suppressed host
• 25% bacteremic

13. Atypical Pneumonia
• #2 cause (especially in younger population)
• Commonly associated with milder Sx’s: subacute ons
et, non-productive cough, no focal infiltrate on CXR
• Mycoplasma: younger Pts, extra-pulm Sx’s (anemia,
rashes), headache, sore throat
• Chlamydia: year round, URI Sx, sore throat
• Legionella: higher mortality rate, water-borne outbre
aks, hyponatremia, diarrhea

14. Viral Pneumonia
• More common cause in children
– RSV, influenza, parainfluenza
• Influenza most important viral cause in adults,
especially during winter months
• Post-influenza pneumonia (secondary bacteria
l infection)
– S. pneumo, Staph aureus

15. Other bacteria
• Anaerobes
– Aspiration-prone Pt, putrid sputum, dental disease
• Gram negative
– Klebsiella - alcoholics
– Branhamella catarrhalis - sinus disease, otitis, COPD
– H. influenza
• Staphylococcus aureus
– IVDU, skin disease, foreign bodies (catheters, prosthetic joi
nts) prior viral pneumonia

16. Diagnosis and Management

17. Guidelines
• American Thoracic Society
– Guidelines for the Management of Adults with CA (2001)
• Infectious Diseases Society of America
– Update of Practice Guidelines for the Management of CAP
in Immunocompetent adults (2003)
• ATS and IDSA joint effort
– IDSA/ATS Consensus Guidelines on the Management of CA
P in Adults (March 2007)

18. Clinical Diagnosis
• Suggestive signs and symptoms
• CXR or other imaging technique
• Microbiologic testing

19. Signs and Symptoms
• Fever or hypothermia
• Cough with or without sputum, hemoptysis
• Pleuritic chest pain
• Myalgia, malaise, fatigue
• GI symptoms
• Dyspnea
• Rales, rhonchi, wheezing
• Egophony, bronchial breath sounds
• Dullness to percussion
• Atypical Sx’s in older patients

20. Clinical Diagnosis: CXR
• Demonstrable infiltrate by CXR or other imagi
ng technique
– Establish Dx and presence of complications (pleur
al effusion, multilobar disease)
– May not be possible in some outpatient settings
– CXR: classically thought of as the gold standard

21. Infiltrate Patterns
Pattern Possible Diagnosis
Lobar S. pneumo, Kleb, H. flu,
GN
Patchy Atypicals, viral, Legionell
a
Interstitial Viral, PCP, Legionella
Cavitary Anaerobes, Kleb, TB, S.
aureus, fungi
Large effusion Staph, anaerobes, Kleb

22. Clinical Diagnosis: Recommended testi
ng
• Outpatient: CXR, sputum Cx and Gram stain n
ot required
• Inpatient: CXR, Pox or ABG, chemistry, CBC, tw
o sets of blood Cx’s
– If suspect drug-resistant pathogen or organism no
t covered by usual empiric abx, obtain sputum Cx
and Gram stain.
– Severe CAP: Legionella urinary antigen, consider b
ronchoscopy to identify pathogen

23. Clinical Diagnosis
• Assess overall clinical picture
• PORT Pneumonia Severity Index (PSI)
– Aids in assessment of mortality risk and dispositio
n
– Age, gender, NH, co-morbidities, physical exam lab
/radiographic findings

24. Severity assessment
• There are currently two sets of criteria:
– the Pneumonia Severity Index (PSI), a prognostic
model used to identify patients at low risk of dying
; and
– the CURB-65 criteria, a severity-of-illness score.

25. PSI
• points are given for 20 variables, including age
, coexisting illness, and abnormal physical and
laboratory findings.
• On the basis of the resulting score, patients ar
e assigned to one of five classes with the follo
wing mortality rates: class 1, 0.1%; class 2, 0.6
%; class 3, 2.8%; class 4, 8.2%; and class 5, 29.
2%.

26. • Clinical trials have demonstrated that routine
use of the PSI results in lower admission rates
for class 1 and class 2 patients. Patients in clas
ses 4 and 5 should be admitted to the hospital
, while those in class 3 should ideally be admit
ted to an observation unit until a further decis
ion can be made.

27. CURB-65
• 5 variables:
– confusion (C);
– urea >7 mmol/L (U);
– respiratory rate 30/min (R);
– blood pressure, systolic 90 mmHg or diastolic 60
mmHg (B); and
– age 65 years (65).

28. • Patients with a score of 0, among whom the 3
0-day mortality rate is 1.5%, can be treated ou
tside the hospital.
• With a score of 2, the 30-day mortality rate is
9.2%, and patients should be admitted to the
hospital.
• Among patients with scores of 3, mortality rat
es are 22% overall; these patients may require
admission to an ICU.

29. IDSA: Outpt Management in Previously
Healthy Pt
• Organisms: S. pneumo, Mycoplasma, viral, Chlamydia
pneumo, H. flu
• Recommended abx:
– Advanced generation macrolide (azithro or clarithro) or do
xycycline
• If abx within past 3 months:
– Respiratory quinolone (moxi-, levo-, gemi-), OR
– Advanced macrolide + amoxicillin, OR
– Advanced macrolide + amoxicillin-clavulanate

30. IDSA: Outpt Management in Pt with co
morbidities
• Comorbidities: cardiopulmonary dz or immunocompr
omised state
• Organisms: S. pneumo, viral, H. flu, aerobic GN rods,
S. aureus
• Recommended Abx:
– Respiratory quinolone, OR advanced macrolide
• Recent Abx:
– Respiratory quinolone OR
– Advanced macrolide + beta-lactam

31. IDSA: Inpt Management-Medical Ward
• Organisms: all of the above plus polymicrobial infecti
ons (+/- anaerobes), Legionella
• Recommended Parenteral Abx:
– Respiratory fluoroquinolone, OR
– Advanced macrolide plus a beta-lactam
• Recent Abx:
– As above. Regimen selected will depend on nature of rece
nt antibiotic therapy.

32. IDSA: Inpt Management-Severe/ICU
• One of two major criteria:
– Mechanical ventilation
– Septic shock, OR
• Two of three minor criteria:
– SBP≤90mmHg,
– Multilobar disease
– PaO2/FIO2 ratio < 250
• Organisms: S. pneumo, Legionella, GN, Mycopl
asma, viral, ?Pseudomonas

33. IDSA: Inpt Management: Severe/ICU
• No risk for Pseudomonas
– IV beta-lactam plus either
• IV macrolide, OR IV fluoroquinolone
• Risk for Pseudomonas
– Double therapy: selected IV antipseudomonal beta-lactam
(cefepine, imipenem, meropenem, piperacillin/tazobactam
), plus
• IV antipseudomonal quinolone
-OR-
– Triple therapy: selected IV antipseudomonal beta-lactam pl
us
IV aminoglycoside plus either
IV macrolide, OR IV antipseudomonal quinolone

34. Switch to Oral Therapy
• Four criteria:
– Improvement in cough and dyspnea
– Afebrile on two occasions 8 h apart
– WBC decreasing
– Functioning GI tract with adequate oral intake
• If overall clinical picture is otherwise favorable
, can can switch to oral therapy while still febri
le.

35. Management of Poor Responders
• Consider non-infectious illnesses
• Consider less common pathogens
• Consider serologic testing
• Broaden antibiotic therapy
• Consider bronchoscopy

36. Prevention
• Smoking cessation
• Vaccination per ACIP recommendations
– Influenza
• Inactivated vaccine for people >50 yo, those at risk for i
nfluenza compolications, household contacts of high-ris
k persons and healthcare workers
• Intranasal live, attenuated vaccine: 5-49yo without chro
nic underlying dz
– Pneumococcal
• Immunocompetent ≥ 65 yo, chronic illness and immuno
compromised ≤ 64 yo

37. Pneumonia in Children: Dx
• Symptoms
– Infants: non-specific manifestations
• Fever, poor feeding, irritability, vomiting, diarrhea, URI Sx, cough, r
espiratory distress
– Older children: more specific
• Fever, cough, chest pain, tachypnea, tachycardia, grunting, nasal fl
aring, retracting. Cyanosis usually very late.
• Signs/Physical exam
– RR > 60 for all ages
– Hypoxia
– Rales, wheezes, crackles, coarse breath sounds

38. Pneumonia in Children: Pathogens
• 0-4 wks: GBS, GN enterics, Listeria
• 4-12 wks: C. trachomatis, GBS, GN enterics, Lis
teria, viral (RSV/parainfluenza), B. pertussis
• 3 mos-4 yrs: Viral, S. pneumo, H. influenza, M.
catarrhalis, Grp A Strep, Mycoplasma
• > 5yrs: Mycoplasma (5-15yrs), C. pneumo, S. p
neumo, viral

39. Pneumonia in the Elderly
• Prevention important
• Presentation can be subtle
• Antibiotic choice in CAP is same as other adults
• Healthcare associated pneumonia
– Consider S. aureus (skin wounds) and GN bacteria (aspirati
on)
• Pneumonia in Older Residents of Long-term Care Facilities. AFP 20
04; 70: 1495-1500.

40. Pneumonia in Immunocompromised P
ts
• Smokers, alcoholics, bedridden, immuno-compromis
ed, elderly
• Common still common
– S. pneumo
– Mycoplasma
• Pneumocystis Carinii Pneumonia
– P. jirovecii
– Fever, dyspnea, non-prod cough (triad 50%), insidious onse
t in AIDS, acute in other immunocompromised Pts
– CXR: bilateral interstitial infiltrates
– Steroids for hypoxia
– TMP-SMZ still first line

42. Lung abscess
• Localised area of suppuration and tissue necr
osis.
• Causes:
– Aspiration of infected oropharyngeal contents /
vomitus.
– Poor oral hygiene and sepsis.
• Risk of aspiration:
– Loss of consciousness (alcoholic stupor, anaesthe
sia, epilepsy).
– Oesophageal pathology (carcinoma, congenital at
resia / fistula).

43. • Obstruction of bronchus
– carcinoma,
– foreign body.
• Complication of pneumonia
– virulent organisms esp. Klebsiella, Staph.
• Bronchiectasis.
• Septic embolism (infective endocarditis on right-
sided heart valves) or septisaemia.
• Penetrating trauma e.g. stab wound.
• Direct spread of sepsis from other organs (e.g. a
moebic liver abscess).

44. Complications
• Rupture into pleural space ⇒ empyema or br
oncho-pleural fistula (⇒ pyopneumothorax).
• Rupture into pericardium ⇒ pericarditis.
• Septisaemia ⇒ sepsis in other organs e.g. ost
eomyelitis, brain abscess.
• Erosion of blood vessels ⇒ haemoptysis.
• Organisation ⇒ fibrosis.

45. New Guideline

46. IDSA/ATS 2007 Guideline
• Hospital Admission Decision
– CURB-65 criteria (confusion, uremia, RR, low BP, age 65 yrs
or greater) or PSI can be used to ID candidates for outpt m
anagement
• Diagnostic Testing
– Acknowledges the low yield and infrequent positive impact
on clinical care
– Outpt testing for etiologic Dx remain optional
– Inpt testing for etiologic Dx recommended for specific indic
ations
• Antimicrobial therapy: essentially unchanged

47. Summary
• Use overall clinical presentation to guide thera
py
• The admission decision is an “art of medicine”
decision
• Use risk factors and guidelines to assist with cli
nical judgement