This document discusses community-acquired pneumonia (CAP). It defines CAP and outlines its epidemiology, noting risk factors like increasing age and winter season. Diagnosis involves clinical evaluation, chest imaging, and ruling out other causes if imaging is abnormal but symptoms aren't. Severity is assessed using scores like CURB-65 to determine appropriate treatment setting. Most ambulatory patients receive 5 days of antibiotics while hospitalized patients get broader empiric coverage. Adjunctive steroids may benefit severe cases. Proper follow up and prevention through vaccination and smoking cessation are also discussed.

1. COMMUNITY - ACQUIRED
PNEUMONIA
ANH LUONG.T.N MD

2. CONTENT
1. DEFINITION
2. EPIDEMIOLOGY
3. DIAGNOSTIC APPROACH TO COMMUNITY- ACCUIRED PNEUMNIA
(CAP)
4. ASSESSING SEVERITY AND DERTERMINING THE APPROPRIATE SITE
OF CARE
5. TREATMENT OF CAP IN THE OUTPATIENT SETTING
6. TREATMENT OF CAP WHO REQUIRE HOSPITALIZATION

3. 1. DEFINITION
• Community-acquired pneumonia (CAP)
is defined as an acute infection of the
pulmonary parenchyma in a patient
who has acquired the infection in the
community, as distinguished from
hospital-acquired (nosocomial)
pneumonia (HAP).

4. 2. EPIDERMIOLOGY
• The incidence of CAP is approximately 5.16 to 6.11 cases per 1000 persons
per year in US. The rate of CAP increases with increasing age. [1]
• More cases occurring during the winter months
• Men > women; black persons > Caucasians
• The etiology of CAP varies by geographic region; however, Streptococcus
pneumoniae is the most commonly identified bacterial cause of CAP
worldwide. Viruses are common causes of CAP as well [2], [3]
• All-cause mortality in patients with CAP is as high as 28 percent within one
year.

5. US deaths due to pneumonia by patient age
• DOI: 10.3810/pgm.2010.03.2130

6. The overall mortality due to CAP
doi.org/10.1016/j.rmed.2013.04.003

7. 3. DIAGNOSTIC APPROACH TO CAP
The diagnosis of CAP generally requires 2 factors:
• The demonstration of an infiltrate on chest
radiograph
•Clinically compatible syndrome (eg, fever, dyspnea,
cough, and sputum production).

8. Clinical evaluation
Marrie TJ. Community-acquired pneumonia. Clin Infect Dis 1994; 18:501.
SYMTOM RATE OF APPERANCE
Chest pain 30 %
Chills 40 - 50 %
Rigors 15%
Febrile 80%
A respiratory rate above 24 breaths/minute 45- 70 %
Audible crackles most patients
Decreased or bronchial breath sounds, dullness to
percussion, tactile fremitus, and egophony
33%

9. Metlay JP, Kapoor WN, Fine MJ. Does this patient have community-acquired pneumonia? Diagnosing pneumonia by history and
physical examination. JAMA 1997; 278:1440
• No clear constellation of symptoms and signs has been found to
accurately predict whether or not the patient has pneumonia.
• As an example, the sensitivity of the combination of fever, cough,
tachycardia, and crackles was less than 50 percent when chest
radiograph was used as a reference standard.

10. Radiographic evaluation
• The gold standard for diagnosing pneumonia
• Include lobar consolidation, interstitial infiltrates, and/or cavitation

11. Cases to argue (1)
• Clinical manifestations => normal
• X- ray => abnormal

12. Cases to argue (2)
• Clinical manifestations => abnormal
• X- ray => normal

13. • Case 1: other causes for the radiographic abnormalities must be
considered, such as malignancy, hemorrhage, pulmonary edema,
pulmonary embolism, and inflammation secondary to noninfectious
causes.
• Case 2: the radiograph may represent a false-negative result. In some
cases, this can be clarified with a CT scan which has higher sensitivity
and accuracy than chest radiographs for detecting CAP

14. High-resolution CT scan in pneumonia
Viruses, Mycoplasma, and Chlamydia. In: Imaging of Pulmonary Infections, Müller NL, Franquet T, Lee KS (Eds), Lippincott
Williams & Wilkins, Philadelphia 2007. Copyright © 2007 Lippincott Williams & Wilkins

15. Why is X- ray false-negative?

16. => Volume depletion may produce an initially negative
radiograph, which "blossoms" into infiltrates following
rehydration.
=> The ability of the absence of infiltrate at 24 hours
after onset of symptom.

17. Some notices
• Lung ultrasound to diagnose pneumonia with the
sensitivity of lung ultrasound was approximately 80 to
90 percent and the specificity approximately 70 to 90
percent. [4], [5]

18. Normal lung surface: bat sign, seashore sign
DOI: 10.1186/2110-5820-4-1

19. Pleural effusion: the quad sign, sinusoid sign
DOI: 10.1186/2110-5820-4-1

20. Lung consolidation
DOI: 10.1186/2110-5820-4-1

21. Lung consolidation

22. Interstitial syndrome and the lung rockets
DOI: 10.1186/2110-5820-4-1

23. Pneumothorax and the stratosphere sign
DOI: 10.1186/2110-5820-4-1

24. Pneumothorax and the lung point
DOI: 10.1186/2110-5820-4-1

25. Clinical indications for diagnostic testing for community-acquired pneumonia
Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of
Community-Acquired Pneumonia in Adults. Clin Infect Dis 2007; 44:S27.

26. Laboratory test
• Procalcitonin is not routinely used to aid in the diagnosis of CAP. It can
help determine the appropriate duration of antibiotics.
• CRP has shown more limited utility, due in part to the paucity of
studies.
• One study showed a CRP >40 mg/L had a sensitivity and specificity for
bacterial pneumonia of 70 and 90 percent, respectively. Another study that
included 364 patients with respiratory infection showed a sensitivity of 73
percent and specificity of 65 percent

27. 4. ASSESSING SEVERITY AND DERTERMINING
THE APPROPRIATE SITE OF CARE

29. PSI

30. CURB-65 pneumonia severity score
Lim WS, van der Eerden MM, Laing R, et al. Defining community acquired pneumonia severity on presentation to hospital: an
international derivation and validation study. Thorax 2003; 58:377. Lim WS, Baudouin SV, George RC, et al. BTS guidelines for the
management of community acquired pneumonia in adults: update 2009. Thorax 2009; 64 Suppl 3:iii1. Qureshi KN, Hodkinson HM.
Evaluation of a ten-question mental test in the institutionalized elderly. Age Ageing 1974; 3:152.

31. IDSA/ATS severity criteria- minor criteria for ICU admission
• Altered mental status
• Hypotension requiring fluid support
• Temperature <36°C (96.8°F)
• Respiratory rate ≥30 breaths/minute
• PaO2/FiO2 ratio ≤250
• Blood urea nitrogen ≥20 mg/dL (blood urea 7 mmol/L)
• Leukocyte count <4000 cells/microL
• Platelet count <100,000/mL
• Multilobar infiltrates
=> recommend ICU care for patients with at least three criteria.

32. 5. TREATMENT OF CAP IN THE OUTPATIENT
SETTING
the 2007 recommendations of the Infectious Diseases Society of America and the American Thoracic Society

33. Initial empirical treatment regimens for CAP
the 2009 guideline
recommendations
of the British
Thoracic Society

34. Treatment duration
• Most ambulatory patients with CAP should be treated for five days.
• Patients should be afebrile for ≥48 hours and clinically stable before
therapy is discontinued

35. Usual duration of findings in treated community-acquired
pneumonia
Marrie TJ, Beecroft MD, Herman-Gnjidic Z. Resolution of symptoms in patients with community-acquired pneumonia treated on
an ambulatory basis. J Infect 2004; 49:302. Metlay JP, Atlas SJ, Borowsky LH, Singer DE. Time course of symptom resolution in
patients with community-acquired pneumonia. Respir Med 1998; 92:1137. Fine MJ, Stone RA, Singer DE, et al. Processes and
outcomes of care for patients with community-acquired pneumonia: results from the Pneumonia Patient Outcomes Research
Team (PORT) cohort study. Arch Intern Med 1999; 159:970.

36. Folow- up
• Clinical follow-up: within 24 to 48 hours after being diagnosed and a
later visit is often indicated to assess for resolution of pneumonia.
• Follow-up chest radiograph:
• All CAP patients who are responding clinically is unnecessary
• Radiographs are performed 7 to 12 weeks following treatment to document
resolution of the pneumonia and exclude underlying diseases, such as
malignancy.
• Follow-up chest radiograph is particularly important for males and smokers in
> 50 years of age group

37. The nonresponding patient
• 6 to 15 percent
• require hospitalization

38. 6. TREATMENT OF CAP WHO REQUIRE
HOSPITALIZATION

39. INITIAL EMPIRIC THERAPY
the 2007 recommendations of the Infectious Diseases Society of America and the American Thoracic Society
Treatment of community-acquired pneumonia in
adults who require hospitalization

40. Risk factors for Pseudomonas or drug-resistant
pathogens
• Gram-negative bacilli (including Pseudomonas) :
• Previous antibiotic therapy
• Recent hospitalization
• Immunosuppression
• Pulmonary comorbidity (eg, cystic fibrosis, bronchiectasis, or repeated
exacerbations of chronic obstructive pulmonary disease that require frequent
glucocorticoid and/or antibiotic use)
• Probable aspiration
• Multiple medical comorbidities (eg, diabetes mellitus, alcoholism)

41. • Methicillin-resistant Staphylococcus aureus:
• Gram-positive cocci in clusters seen on sputum Gram stain
• End-stage renal disease
• Contact sport participants
• Injection drug users
• Those living in crowded conditions
• Men who have sex with men, prisoners
• Recent influenza-like illness
• Antimicrobial therapy (particularly with a fluoroquinolone) in the prior three
months
• Necrotizing or cavitary pneumonia, and presence of empyema

42. • Streptococcus pneumoniae :
• Age >65 years
• Beta-lactam, macrolide, or fluoroquinolone therapy within the past three to
six months
• Alcoholism
• Medical comorbidities
• Immunosuppressive illness or therapy
• Exposure to a child in a daycare center

43. • Timing of antimicrobial initiation — We recommend that
antimicrobials be administered as soon as possible after diagnosing
CAP and before leaving the emergency department or clinic

44. Adjunctive glucocorticoids
• Controversial between reducing the inflammatory response to
pneumonia and contributing to its morbidity and mortality.
• The decision of using steroid on a case-by-case basis.

45. Giving adjunctive glucocorticoids
• The patients are at high risk of mortality and are likely to benefit the
most. Such patients who have evidence of an exaggerated or
dysregulated host inflammatory response.
• It defined as sepsis or respiratory failure with
• an FiO2 requirement of >50 percent
• plus one or more of the following features (metabolic acidosis with an arterial
pH of <7.3, lactate >4 mmol/L, or a C-reactive protein >150 mg/L)

46. Reasons to avoid glucocorticoids:
• Severe adverse events such as recent gastrointestinal bleeding, poorly
controlled diabetes, or severe immunocompromise.
• Avoid glucocorticoids in patients with CAP known to be caused by a viral
pathogen such as influenza or a fungal pathogen such as Aspergillus.
• Generally find that the potential for harm outweighs the potential for
benefit in patients who are at low risk for mortality.

47. Using adjunctive glucocorticoids
• Five days
• For patients who are unable to take oral medications, using
methylprednisone 0.5 mg/kg IV every 12 hours.
• For patients who can take oral medications, we use prednisone 50 mg
orally daily
Corticosteroid Therapy for Patients Hospitalized With Community-Acquired Pneumonia: A Systematic Review and Meta-analysis;
Siemieniuk RA, Meade MO, Alonso-Coello P, Briel M, Evaniew N, Prasad M, Alexander PE, Fei Y, Vandvik PO, Loeb M, Guyatt GH ;
Ann Intern Med. 2015;163(7):519
Adjunctive Systemic Corticosteroids for Hospitalized Community-Acquired Pneumonia: Systematic Review and Meta-Analysis
2015 Update; Horita N, Otsuka T, Haranaga S, Namkoong H, Miki M, Miyashita N, Higa F, Takahashi H, Yoshida M, Kohno S,
Kaneko T ; Sci Rep. 2015;5:14061.

48. Influenza therapy
• Antiviral treatment is recommended as soon as possible for all
persons with suspected or confirmed influenza requiring
hospitalization or who have progressive, severe, or complicated
influenza infection, regardless of previous health or vaccination status
Antiviral agents for the treatment and chemoprophylaxis of influenza --- recommendations of the Advisory Committee
on Immunization Practices (ACIP); Fiore AE, Fry A, Shay D, Gubareva L, Bresee JS, Uyeki TM, Centers for Disease Control
and Prevention (CDC) ; MMWR Recomm Rep. 2011;60(1):1.

49. Clinical response to therapy
• With appropriate antibiotic therapy, some improvement in the patient's
clinical course is usually seen within 48 to 72 hours. Patients who do not
demonstrate some clinical improvement within 72 hours are considered
nonresponders

50. Patients who respond to therapy
• Narrowing therapy
• Switching to oral therapy

52. Duration of hospitalization
• Hospital discharge when:
• clinically stable from the pneumonia
• Can take oral medication
• no other active medical problems
• Has a safe environment for continued care
• Patients do not need to be kept overnight for observation following
the switch.

53. Duration of therapy
Graphic 89823
Version 1.0,
Uptodate

54. Clinical follow-up after discharge
• Usually within one week.
• A later visit is often indicated to assess for resolution of pneumonia.

55. Risk factors for rehospitalization
• initial treatment failure
• one or more instability factors (eg, vital signs or oxygenation) on
discharge
• risk factors for non-pneumonia-related readmissions were age ≥65
and decompensated comorbidities (most commonly cardiac or
pulmonary).

56. Prevention
• Vaccination
• Screening for influenza vaccination status is warranted during influenza
season (eg, from October through March in the northern hemisphere) in all
patients.
• Screening for pneumococcal vaccination status is warranted in patients age 65
or older or with other indications for vaccination
• Vaccination can be performed during outpatient treatment

57. Smoking cessation
• Smoking cessation should be a goal for patients with CAP who smoke

58. Reference
• [1] Marrie TJ, Huang JQ. Epidemiology of community-acquired pneumonia in Edmonton, Alberta: an emergency department-based
study. Can Respir J 2005; 12:139.
• [2] Gadsby NJ, Russell CD, McHugh MP, et al. Comprehensive Molecular Testing for Respiratory Pathogens in Community-Acquired
Pneumonia. Clin Infect Dis 2016; 62:817.
• [3] Jain S, Self WH, Wunderink RG, et al. Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults. N Engl J
Med 2015; 373:415.
• [4] Long L, Zhao HT, Zhang ZY, et al. Lung ultrasound for the diagnosis of pneumonia in adults: A meta-analysis. Medicine
(Baltimore) 2017; 96:e5713.
• [5] Llamas-Álvarez AM, Tenza-Lozano EM, Latour-Pérez J. Accuracy of Lung Ultrasonography in the Diagnosis of Pneumonia in
Adults: Systematic Review and Meta-Analysis. Chest 2017; 151:374.

59. [6] Treatment of community-acquired pneumonia in adults who require hospitalization, Thomas M File, Jr, MD
[7] Community-acquired pneumonia in adults: Assessing severity and determining the appropriate site of care,
Donald M Yealy, MD, FACEP, Michael J Fine, MD, MSc
[8] Diagnostic approach to community-acquired pneumonia in adults, John G Bartlett, MD
[9] Epidemiology, pathogenesis, and microbiology of community-acquired pneumonia in adults, Thomas J
Marrie, MD, Thomas M File, Jr, MD
[10] Treatment of community-acquired pneumonia in adults in the outpatient setting, Thomas M File, Jr, MD