Bacterial Infections of Lung

Bacterial Pneumonia

Patchy exudative consolidation

Bronchopneumonoia

Strep Pneumo (90-95%)

Lobar pneumonia

Elderly smoker, Cl- resistant, Cooling system

Legionnaire's Disease

Gram negative enterics, anaerobes, gag reflex

Aspiration pneumonia

r

Location depends on patient's position:Lying on back --> apical segment of Right lower lobe

High mortality

Gastric acid

Hyper/Hypotonic fluids

Large particulate matter

Low mortality

Isotonic fluids

Variable

Oropharyngeal

r

Onset: < 24 h (Others are relatively immediate)

Foamy macrophages

Lipoid pneumonia

Mineral Oil (Laxative)

Exogenous

Obstruction

Endogenous

Lung Abscess

r

Localized suppurative process with necrosis of lung tissueyoung adults60% anaerobic organismsCopious foul-smelling sputumchest pain

Sx

Cough

Fever

Copious foul-smelling sputum

Chest pain

CXR

Cavitary mass w/ Air-fluid level

Morphology

Gross

Necrotic, cavitary mass

Micro

Neutrophil destruction w/ necrosis

r

Suppurative process (neutrophil destruction) w/ cavitation (necrosis)

"Atypical" Pneumonias

RNA

RSV

Less than 1 year old

MGCs

Human metapneumovirus

Influenza A

Sx

Fever

Muscle pain

Headache

Cough

Hemagglutinin

r

Prevent future infection

Neuraminidase

r

Ameliorate future infection

SARS-CoV

DNA

Adenovirus

Military recruits

Smudge cells

HSV

Forms of Infxn

Ulcerative tracheobronchitis

Hemorrhagic parenchymal nodules

Micro

Intranuclear inclusion surrounded by halo

Ground glass nuclei

MGCs

VZV

Pregnant women

r

Mortality Rate = 42%

CMV

Immunocomp

Neonates

Predisposing Factors

Loss or suppression of cough reflex

Mucociliary apparatus dysfunction

Distrubance of the phagocytic actions

Hypogammaglobulinemia

How Infections Develop

Routes

Inhalation

Hematogenous spread

Nosocomial

Intubation

I.V. Lines

Bacteria

P. aeruginosa

S. aureus

Mycoplasma Pneumonia

r

"Walking Pneumonia" = Asymptomatic pneumonia, but CXR looks bad"Primary atypical pneumonia"

Community-acquired pneumonia

Cold agglutinins (50%)

r

Serum agglutinates group O blood at freezing point (0 deg C)

PCP

T cell count < 200

CXR

Perihilar shadow

Silver methenamine stain

Honeycomb appearance