PNEUMONIA

1. PNEUMONIA Dr.M.Shahparianpour

3. Mr. P • 92 yo male w/ h/o fall 3 days prior to admission, came to ER with c/o mental status changes (per NH staff), and 1 day h/o vomiting and dyspnea. • Pmhx of alzheimers, emphysema, glaucoma. • Meds included 5 different eye drops and donepezil. No drug allergies. • Shx: nursing home resident, no recent etoh or tobacco. Daughter involved. • Pneumovax 2001, flu vaccine 2002.

4. PE: T 97.9, rr 22, bp 109/65, p 77, 70% RA oxygen saturation. • Confused, non-rebreather in place. Heent wnl. Lungs: coarse crackles bilaterally. CV: reg, s1s2, no mrg. Abd: wnl. Ext: +2 ankle edema. Neuro: non-focal, not oriented, following some commands. • Labs remarkable for wbc 12.6 w/ 90% n, chem 7 wnl, po2 on ABG of 38 mm Hg (ph 7.44) • CXR w/ ? small RLL infiltrate, but portable film, final read by radiology negative.

9. Does this patient have pneumonia?In other words, how do youdefine pneumonia?Why is diagnosing pneumonia important?And if he has pneumonia, what kind, and how do you investigate possible causes further?How do you triage the patient?How do you treat him?When do you send him home?Could it have been prevented?

10. Pneumonia is defined as inflammation and consolidation of the lung tissue due to an infectious agent. • Pneumonia that develops outside the hospital setting is considered community-acquired pneumonia • Pneumonia developing48 hours or moreafter admission to the hospital is termed nosocomial or hospital-acquired pneumonia. • Community-acquired pneumonia is caused most commonly by bacteria that traditionally have been divided into 2 groups, typical and atypical. • Typical organisms include S pneumoniae (pneumococcus) and Haemophilus and Staphylococcus species. • Atypical refers to pneumonia caused by Legionella, Mycoplasma, and Chlamydia species.

12. Definition (per IDSA) Acute infection of the pulmonary parenchyma accompanied by: • Acute infiltrate on CXR or auscultatory findings consistent with pneumonia • And usually two of the following: fever or hypothermia, rigors, sweats, new cough with or without sputum (or change in color), chest discomfort, dyspnea. • In the elderly, more common to be afebrile/hypothermic, and altered mental status sometimes is the ONLY complaint.

14. Pneumonia • Community • Nosocomial • Eldery house • Immunocompromised host • Immunocompromised host

15. Community-acquired pneumonia remains a common illness. • pneumonia is reported to be 170 cases per 100,000 persons. • Estimates of incidence of nosocomialpneumonia range from 4-7 episodes per 1000 hospitalizations. • Approximately25%of patients in intensive care units (ICUs) develop pneumonia.

16. 20% result in hospitalization • Withadvancing age, the incidence increases3 folds in patients( aged 44 years to 65 years) • Pneumonia as a cause of hospitalization increasedfrom 36 to 48 cases per 100,000 persons between 1984 and 1995.

17. Pneumonia is thesixth leading cause of death • the most common infectious causes of death. • Themortality rateis reported to be 1% in the outpatient setting but may increase to up to 25% in those requiring hospital admission. • In a patient with preexisting respiratory disease, onset of bacterial pneumonia may result in deterioration of respiratory status, leading to respiratory failure and death.

18. Nosocomial pneumonia is the leading causeof death among hospital-acquired infections. • Recent studies have shown that nosocomial pneumonia causes excessive risk of death, and the mortality rates range from 20-50%.

19. Although less common in the antibiotic era, bacterial pneumonia may lead to bronchiectasis. • However, lower respiratory infection with pneumococci, staphylococci, and Klebsiella speciesmay result in bronchiectasis, especially if treatment is delayed.

20. Incidence is greater in males than in females. • Advanced ageincreases the incidence of pneumonia and the mortality from pneumonia. • Elderly persons have • weaker immune responses, • higher risk of aspiration, • comorbidities.

21. Resistant bacteriaare becoming an increasing problem, which affects treatment. • We have an increasing population with immunosuppression or chronic diseases (which impacts cause and mortality)

22. Pathogenesis of typical pneumonia • S pneumoniae generally resides in the nasopharynxand is carried asymptomatically in approximately 50% of healthy individuals. • Invasive disease may occur upon acquisition of a new epithelium serotype. • A strong association exists with viral illnesses, such as influenza. • Viral infections increase pneumococcal attachment to the receptors on activated respiratory epithelium.

23. Once aspirated from the nasopharynx to the alveolus, pneumococci infect type II alveolar cells. • The pneumonic lesion progresses as pneumococci multiply in the alveolus and invade alveolar epithelium. • Pneumococci spread from alveolus to alveolus through the pores of Kohn, thereby producinginflammation and consolidation along lobar compartments.

24. Pathogenesis of atypical infection • After inhalation, the atypical organisms attach to the respiratory epithelial cells by a variety of mechanisms. • The presence of pili on the surface of Legionella speciesfacilitates attachment. • Once adhered, the organisms cause injury to the epithelial cells and their associated cilia.

25. Many of the pathogenetic mechanisms may be immune-mediatedrather than due to direct injury by the bacteria. • A host defense is mounted via cell-mediated and humoral immunity. • Infection caused by atypical organisms often spreads beyond the lobar boundaries and frequently is bilateral.

26. Pathogenesis of nosocomial pneumonia • Aspirationplays a central role in the pathogenesis of nosocomial pneumonia . • Approximately 45% of healthy subjectsaspirate during sleep, and an even higher proportion of severely ill patients aspirate routinely. • Depending on the number and virulenceof the pathogenic organismsreachingthe lower respiratory tract and on the host defense factors, pneumonia may develop.

27. The oropharynx of hospitalized patients may become colonized with aerobic gram-negative bacteria within a few days of admission. • Therefore, nosocomial pneumonia is caused predominantly by the gram-negative bacilli. • However, the incidence of Staphylococcus aureuslower respiratory tract infection is increasingly common in the hospitalized and institutionalized patient and must now be considered a possible pathogen for nosocomial pneumonia.

29. PneumoniaDecisions • PORT • Microbiology • Empiric Therapy

30. PneumoniaRoutes of Transmission • Inhalation • Aspiration • Blood-borne

34. Community Acquired Pneumoniaetiology S.pneumoniae H.influenzae Other Anaerobes L.pneumophilia M.pneumoniae C.pneumoniae

35. Community - Acquired • Bacteria % Cases • Streptococcus pneumoniae 50-70 • Hemophilusinfluenzae 10-15 • Staphylococcus aureus 5 • “Atypical” • Mycoplasmapneumoniae 10-30 • Chlamydia pneumoniae 10-20 • Virus • Influenzae Epidemic • Adenovirus

36. Community PneumoniaMicrobiology • Unusual / Don’Miss • PCP • Tb • Moraxella • Legionella • Very Unusual • Hantavirus • Fungi (cocchisto) • Anthrax, SARS

37. Different categories of pneumonia and common pathogens • Patients w/ minimal co-morbidities (cause identified only 50% of the time): • S. pneumoniae (most common overall) • M. pneumoniae/C. pneumoniae • Viruses • Chronic pulmonary/cardiovascular disease: • Drug resistant S. pneumoniae • H. influenza • M. catarrhalis • Legionella

38. Nosocomial (hospitalized or nursing home patients): • Resistant GNR’s • Pseudomonas aeruginosa • S. aureus (MRSA) • Aspergillosis • Anaerobes (aspiration) • In alcoholics: • Klebsiella pneumoniae, anaerobes, TB • IVDU: • S. aureus, PCP, anaerobes

39. Post-splenectomy: • S. pneumoniae, H. influenza • HIV/AIDs: • PCP, S. pneumonia, TB, fungal • Leukemic patients/bone marrow transplant: • Aspergillosis, legionella, CMV, other fungal. • Post influenza: • S. pneumoniae, S. aureus • Cystic fibrosis: • Pseudomonas aeruginosa, S. aureus

40. In patients who have received solid organ transplants, pneumonia from S pneumoniae may occur more than 3 months after the transplant. • Other organisms include Legionella species, Pneumocystis carinii, and cytomegalovirus. • Sickle cell disease may indicate S pneumoniae or H influenzaeinfection. • Diabetic ketoacidosis may lead to S pneumoniae or S aureusinfection

41. Animal exposure: • C. psittaci, Cryptococcus neoformans, Histoplasmosis capsulatum(birds) • Tularemia(rabbit),plague(rat), hantavirus (deer mouse), H. capsulatum(bat). • Q fever (C. burnetii)– farm animals • Travel: • SARS (Asia), coccidiomycoses, (SW USA), Legionella (endemic/epidemic areas).

42. This sputum smear shows staphylococcus bacteria using Gram stain technique in a patient with staphylococcal pneumonia.

43. A photomicrograph of Streptococcus spp. bacteria using Gram stain technique.

44. Scanning electron micrograph of S. pneumoniae

45. Photomicrograph of Streptococcus pneumoniae bacteria revealing capsular swelling using the Neufeld-Quellung test.

46. Pneumocystis carinii, now called P. jiroveci, is present in this lung impression smear, using Giemsa stain.

47. A photomicrograph of Pseudomonas aeruginosa bacteria.

48. Photomicrograph of Haemophilus influenzae as seen using a Gram stain technique.

49. MYCOPLASMA

50. History • Clinical presentation in patients with pneumonia varies from a mildly ill ambulatory patient to a critically ill patient with respiratory failure or septic shock. • The character of sputum produced may suggest a particular pathogen. • Patients with pneumococcal pneumonia may produce bloody or rust-colored sputum. • Infections with Pseudomonas, Haemophilus, and pneumococcal species are known to expectorate green sputum. • Anaerobic infections characteristically produce foul-smelling and bad-tasting sputum. • Currant-jelly sputum suggests pneumonia from Klebsiella or pneumococcal species.