This document provides information on community-acquired pneumonia (CAP), including epidemiology, risk factors, presentation, diagnosis, treatment recommendations, and prevention strategies. It notes that CAP is one of the most common infectious diseases worldwide, with higher rates among the elderly. Common bacterial causes are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Clinical assessment and chest imaging are important for diagnosis and management. Antibiotic treatment should be based on likely pathogens and severity of illness. Immunization can help prevent CAP in high-risk groups.

1. Community
acquired
pneumonia
DR MD ABDULLAH SALEEM
MBBS, MD (PULMONOLOGY)

2. Epidemiology
One study, in which 46,237 elderly patients were monitored over a 3-
year period, showed the rate of CAP among those aged 65-69 years to
be 18.2 cases per 1000 person-years
. Among person older than age 85 years, the rate was 52.3 cases per
1000 person-years.
Estimates based on this data suggested that annually, 1 of 20 persons
older than 85 years develop CAP.
The investigators also estimated that approximately 915,900 cases of
CAP occur among the elderly population annually in the United States.[3

3. ◦ one of the most common infectious
diseases
◦ an important cause of mortality and
morbidity worldwide
◦ Typical bacterial pathogens that
cause the condition
include Streptococcus
pneumoniae(penicillin-sensitive and -
resistant strains), Haemophilus
influenza (ampicillin-sensitive and -
resistant strains), and Moraxella
catarrhalis (all strains penicillin-
resistant)..

4. Definition
Inflammation and consolidation of lung due
to an infectious agent
Developing outside the hospital

5. Risk factors
Obstruction: When part of the airway (bronchus) leading to the alveoli is obstructed, the lung cannot eliminate
fluid; this can lead to pneumonia. One cause of obstruction, especially in young children, is inhalation of a foreign
object such as a marble or toy. The object lodges in a small airway, and pneumonia develops in the obstructed area
of the lung. Another cause of obstruction is lung cancer, which can block the flow of air.
Lung disease: Patients with underlying lung disease are more likely to develop pneumonia. Diseases such as
emphysema and habits such as smoking result in more-frequent and more-severe bouts of pneumonia. In
children, recurrent pneumonia may indicate cystic fibrosis or pulmonary sequestration.
Immune problems: Immune-deficient patients, such as those with HIV/AIDS, are more likely to develop
pneumonia. Other immune problems range from severe childhood immune deficiencies, such as Wiskott–Aldrich
syndrome, to the less-severe common variable immunodeficiency

6. Presentation to the doctor
Patients with community-acquired pneumonia (CAP) due to typical
bacterial CAP pathogens present with pulmonary symptoms, while
patients with CAP due to atypical CAP pathogens present with a variety
of pulmonary and extrapulmonary findings (eg, CAP plus diarrhea).
Patients with bacterial CAP typically present with fever, usually with a
productive cough and often with pleuritic chest pain.

7. clinical findings
Physical findings are confined to the lungs in patients with typical
bacterial community-acquired pneumonia (CAP).
Purulent sputum is characteristic of pneumonia caused by typical
bacterial CAP pathogens and is not usually a feature of that caused by
atypical pathogens, with the exception of Legionnaires disease. Blood-
tinged sputum may be found in patients with pneumococcal
pneumonia, Klebsiella pneumonia, or Legionellapneumonia.
Rales are heard over the involved lobe or segment. If consolidation is
present, an increase in tactile fremitus, bronchial breathing, and E to A
change may be present.

12. Differential diagnosis
Acute bronchitis
AECB
Myocardial infarction
Congestive heart failure and pulmonary edema
Pulmonary fibrosis
Sarcoidosis
SLE pneumonitis
Pulmonary drug hypersensitivity reactions (nitrofuranto

13. Bronchogenic carcinoma
Radiation pneumonitis
Vasculitis
Tracheobronchitis

15. Complications
Sepsis,
Respiratory failure
Pleural effusion
Empyema
Abscess

16. HIV and pneumonia
Determined by assessing the CD4 count and the chest radiographic
appearance.
Patients with HIV infection and a normal or slightly decreased CD4 count with
focal infiltrates have approximately the same pathogen distribution as
otherwise healthy hosts (eg, S pneumoniae)
Patients with nonfocal infiltrates and hypoxemia may
have Pneumocystis (carinii) jiroveci pneumonia (PCP).
Patients with HIV infection and focal infiltrates may have tuberculosis, which is
easily diagnosed using acid-fast bacillus (AFB) smears of sputum.
In patients with HIV infection in whom S pneumoniae CAP is suspected, urinary
antigen testing may be useful.

20. Pneumonia Severity
Index
Age in years
Men
Women -10
Nursing home resident
+10

21. Co existing illness
Neoplastic diseases +30
Liver diseases +10
Congestive Heart disease +10
Cardiovascular disease +10
Renal disease +10

22. Findings on Physical
Exam
Altered mental status +20
Respiratory rate +20
Syatolic BP <90 +20
Temperature <35 or >40 +15
Pulse >125 +10

23. Lab/radiographic findingsArterial pH<7.35
Blood urea >30 +20
Serum sodium < 130 +20
Serum glucose >250 +10
Hematocrit <30 +10
paO2 <60 +10
Pleural effusion +10

24. Risk Stratification
Low <70
Moderate 91-130
High >130

25. Role of Chest
Radiograph
Wherever feasible a chest radiograph must (I A)
Where not possible,treat on basis of clinical suspicion
Should be repeated when not improving

26. Role of CT Scan
Not recommended routinely
Indicated for non resolving pneumonia
For assessment of complications

27. Microbiological
investigations
Blood cultures in all hospitalized patients
Not required in routine outpatient
management of CAP
Initial sputum sample for all hospitalized
patients
Quality of sample should be ensured
Sputum for AFB as per RNTCP guidelines

28. Pneumococcal antigen detection not required
routinely
Pneumococcal PCR not required routinely
Legionella urinary antigen test desirable in
patients with severe CAP
Other atypical pathogen testing for
Mycoplasma,Chlamydia need not be done

29. General investigations
No investigations are routinely required
Pulse oximetry is desirable
Pulse oximetry as early as possilble
aBG in those saturation<90%,chronic lung
disease
Blood urea,glucose,electrolytes in all
hospitalized patients
Blood count/LFT

30. Role of Bio markers
Procalcitonin and CRP need not be performed routinely

31. Risk stratification
Whether admission is required or not
Managed in ward or ICU
Initial assessment CRB – 65,if more than 1,consider admission(1A)
Clinical judgement may be used
Pulse oximetry to admit hypoxaemic patients (SpO2 < or 92% for age < 50
or 90% for patients>50years
If any major criterion or >3_minor criteria to be admitted to ICU

32. Antibiotic Use
Most likely pathogen
Knowledge of local susceptibility patterns
Pharmacokinetic/Pharmacodynamics of antibiotics
Compliance,safety,cost of drugs
Recently administered drugs

33. Recommendations for
antibiotics
Therapy for common organism namely Streptococcus pneumonia
Outpatients should be stratified as those with or without co-morbidities
Oral macrolides or Beta lactums for Ops with co – morbidities
Beta lactums plus macrolides for Ops with co-morbidities
Flouroquinolones not to be used for empiric therapy

34. Hospitalised non ICU setting (beta lactum like
cephtriaxone,cefotaxim,amoxyclav) plus a
macrolide
If hypersensitive to beta lactums then choose
flouroquinolones
Route of administration to be decided clinically

35. ?Cover of Atypical
organisms
Monotherapy suffices for patients treated on OP Basis
Oral macrolides to be used with caution in elderly as their use has been
associated with increased cardiovascular mortality

36. Role of
Flouroquinolones
Have been recommended in various guidelines for empiric treatment of
CAP
Studies for use have been in low prevalence settings of TB
Enough evidence to suggest that use is associated with masking of
tubercular infection and increased risk of drug resistance

37. Time of first
antibiotic use
In severe CAP as soon as possible after the diagnosis(preferably within !
Hour)
In non severeCAP,a diagnosis should be established before starting
antibiotics

38. In the ICU
Beta lactum+macrolide (without risk for pseudomonas)
If risk for pseudomonas – cefepime,ceftazidime,cefaperazone,Piperacillin-
tazobactum,imipenem,meropenem
Diagnostic interventions should be done wherever indicated
If no response within 48-72 hours evaluate again

39. Discharge plan
When the patient is afebrile
Accepting orally
Haemodynamically stable
In the OP for 5days treatment
IP patient treated for 7days

40. Adjunctive therapies
Steroids not recommended for non severe CAP
Should be used for septic shock or ARDS
ARDS,Sepsis,Septic shock to be managed according to standard
management protocol
NIV in patients with acute respiratory failure

41. Role of
immunisation
Routine use of pneumococcal vaccine in healthy immune competent adults
not recommended(1A)
To be used for special population who are at for invasive pneumococcal
disease
Influenza vaccination for all adults
Smoking cessation should be advised