#16 – Pneumonia



 

Classifications of Pneumonia

  • Community-Acquired (CAP)
  • Healthcare-Associated (HAP)
    • Any IV therapy, wound care, or chemotherapy within 20 days
    • Resident of nursing home or other long term care facility
    • Hospitalization for ≥ 2 days within 90 days
    • Visit to outpatient clinic or hemodialysis within 30 days
  • Ventilator-Associated (VAP)
    • Currently or previously intubated during current hospitalization

Epidemiology

  • 6 cases per 1000 persons per year (~ 5 million cases per year)
  • Top 10 in mortality in US (~60,000 deaths/year)
  • 12% 30-day mortality in patients requiring admission
  • 28% all-cause mortality within one year

 

Pathogenesis

4 phases of development

  • Edema
    • Proteinaceous exudate in the alveoli
    • Bacteria accumulation
  • Red hepatization
    • Erythrocyte extravasation
  • Grey hepatization
    • Neutrophil extravasation with bacterial clearance
  • Resolution
    • Macrophage proliferation with inflammatory response

 

Picture1

Murthy SV. Pathology of Pneumonia. SlideShare.

Risk Factors

  • Age
  • Winter months
  • Increased risk of aspiration (AMS, CVA, intoxication, seizures)
  • Smoking
  • Underlying pulmonary disease (Asthma, COPD, cancer)
  • Immunosupression
  • Viral URI
  • Decreased host defenses (impaired ciliary clearance)
  • Acid-reducing medications
  • Malnutrition
  • Inhalation exposures
2

Up To Date. 2016.

 

Pathogens

  • Viral (most common)
    • Rhinovirus (most common)
    • Influenza
    • Adenovirus
    • Respiratory Syncytial Virus (RSV)
  • Bacterial
    • S. pneumoniae (most common CAP)
    • H. influenza
    • M. pneumoniae (most common atypical)
    • K. pneumoniae (tends to be more severe)
    • Legionella
    • ESKAPE bugs (>80% of VAP)
      • Enterococcus
      • Staphylococcus
      • Klebsiella
      • Acinetobacter
      • Pseudomonas
      • Enterobacter
  • Fungal (immunocompromised)
    • Histoplasmosis
    • Cryptococcus
    • Coccidioides
    • Blastomycosis
    • Aspergillus

Signs and Symptoms

  • Productive cough
  • Fever
  • Chills and/or rigors
  • Dyspnea
  • Pleuritic chest pain
  • Nausea/vomiting
  • Altered mental status

 

Physical Exam Findings

  • Vital signs
    • Febrile (elderly may not mount a response)
    • Tachycardic
    • Tachypnic
  • Pulmonary
    • Rales and/or rhonchi
    • Signs of consolidation
      • Decreased breath sounds
      • Dullness to percussion
      • Increased tactile fremitus
      • Egophany
      • Whispered pectoriliquoy

 

Radiographic Evaluation

  • Bacterial
    • Unilateral, lobar, air bronchograms

3

  • Viral
    • Diffuse or perihilar, bilateral

4

Laboratory Evaluation

  • CBC with differential
  • Blood cultures
  • Sputum culture and gram stain
    • Good sample = PMNs with < 10 squamous cells per LPF
  • Urine antigen (pneumococcal and Legionella)
  • Multiplex PCR
5

Up To Date. 2016.

Should They Stay or Should They Go Now????

  • Pneumonia Severity Index (PSI)
    • Step 1
      • If none of the following, then Class I and outpatient treatment
        • Age > 50 years
        • Neoplastic disease
        • Heart failure
        • Cerebrovascular disease
        • Renal disease
        • Liver disease
        • Altered mental status
        • HR ≥ 125/min
        • RR ≥ 30/min
        • SBP ≤ 90 mmHg
        • Temperature ≤ 35oC or ≥ 40oC
    • Step II
Screen Shot 2016-07-12 at 7.45.22 AM

Step II of PSI/PORT Score for Risk Stratification

  • CURB-65 Score
    • 5 variables
      • Confusion
      • Urea (BUN ≥ 20 mg/dL)
      • Respiratory rate ≥ 30/min
      • Blood pressure (SBP < 90 mmHg or DBP < 60 mmHg)
      • Age ≥ 65 years
    • Interpretation
      • Score 0-1 = Outpatient management
      • Score 2-3 = Inpatient management
      • Score 4-5 = ICU management
  • SMART-COP Score
    • Used to predict need for respiratory or vasopressor support

6

 

Treatment

  • Care should be taken to think about patients with risk factors for drug-resistant S. pneumoniae:
    • Age > 65 years
    • Beta-lactam, macrolide, or fluouroquinolone in the past 3-6 months
    • Alcoholism
    • Medical comorbidities
    • Immunosuppression
    • Exposure to child in daycare
  • Community-Acquired
7

Treatment for Community-Acquired Pneumonia. IDSA/ATS 2007 Guidelines.

  • Healthcare-Associated
8

Treatment of Healthcare-Associated Pneumonia. IDSA/ATS 2007 Guidelines.


Cottage Physician

CottageMD

Cottage Physician. 1893.


References

  1. Mandell LA, Wunderink RG. Pneumonia. In: Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J. eds. Harrison’s Principles of Internal Medicine, 19e. New York, NY: McGraw-Hill; 2015. http://accessmedicine.mhmedical.com/content.aspx?bookid=1130&Sectionid=79733578. Accessed July 11, 2016.
  2. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. American journal of respiratory and critical care medicine. 171(4):388-416. 2005. [pubmed]
  3. File TM, Marrie TJ. Burden of community-acquired pneumonia in North American adults. Postgraduate medicine. 122(2):130-41. 2010. [pubmed]
  4. Murthy SV. Pathology of Pneumonia.    http://www.slideshare.net/vmshashi/pathology-of-pneumonia.  Accessed on July 11,  2016.
  5. Almirall J, Bolíbar I, Balanzó X, González CA. Risk factors for community-acquired pneumonia in adults: a population-based case-control study. The European respiratory journal. 13(2):349-55. 1999. [pubmed]
  6. Mandell LA, Wunderink RG, Anzueto A. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 44 Suppl 2:S27-72. 2007. [pubmed]
  7. Musher DM, Thorner AR. Community-acquired pneumonia. The New England journal of medicine. 371(17):1619-28. 2014. [pubmed]
  8. Jain S, Self WH, Wunderink RG. Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults. The New England journal of medicine. 373(5):415-27. 2015. [pubmed]
  9. Metlay JP, Kapoor WN, Fine MJ. Does this patient have community-acquired pneumonia? Diagnosing pneumonia by history and physical examination. JAMA. 278(17):1440-5. 1997. [pubmed]
  10. Fine MJ, Auble TE, Yealy DM. A prediction rule to identify low-risk patients with community-acquired pneumonia. The New England journal of medicine. 336(4):243-50. 1997. [pubmed]
  11. Lim WS, van der Eerden MM, Laing R. Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study. Thorax. 58(5):377-82. 2003. [pubmed]
  12. Charles PG, Wolfe R, Whitby M. SMART-COP: a tool for predicting the need for intensive respiratory or vasopressor support in community-acquired pneumonia. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 47(3):375-84. 2008. [pubmed]
  13. Pugh R, Grant C, Cooke RP, Dempsey G. Short-course versus prolonged-course antibiotic therapy for hospital-acquired pneumonia in critically ill adults. The Cochrane database of systematic reviews. 2015. [pubmed]

One thought on “#16 – Pneumonia

  1. Pingback: Update to Pneumonia Podcast | PAINE Podcast and Medical Blog

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s