Transcript Pneumonia - doc meg's hideout

Pneumonia
Dr. Meg-angela Christi Amores
Definition
• infection of the pulmonary parenchyma
• often misdiagnosed, mistreated, and
underestimated
• community-acquired pneumonia (CAP) or
health care–associated pneumonia (HCAP)
– hospital-acquired pneumonia (HAP) and
ventilator-associated pneumonia (VAP)
Pathophysiology
• proliferation of microbial pathogens at the
alveolar level and the host's response
• aspiration from the oropharynx
• inhaled as contaminated droplets
• hematogenous spread
Pathophysiology
• Host defense:
– hairs and turbinates of the nares
– branching architecture of the tracheobronchial tree
traps particles on the airway lining
– gag reflex and the cough mechanism
– normal flora adhering to mucosal cells of the oropharynx
– resident alveolar macrophages
• host inflammatory response, rather than the
proliferation of microorganisms, triggers the
clinical syndrome of pneumonia
• inflammatory mediators, such as interleukin
(IL) 1 and tumor necrosis factor (TNF), results
in fever
Pathology
• Edema
– presence of a proteinaceous exudate
• Red hepatization
– erythrocytes in the cellular intraalveolar exudate
• Gray hepatization
– neutrophil is the predominant cell, fibrin
deposition is abundant, and bacteria have
disappeared
• Resolution
Etiology
• Typical:
– S. pneumoniae, Haemophilus influenzae, S. aureus
and gram-negative bacilli such as Klebsiella
pneumoniae and Pseudomonas aeruginosa
• Atypical:
– Mycoplasma pneumoniae, Chlamydophila
pneumoniae, and Legionella spp. as well as
respiratory viruses such as influenza viruses,
adenoviruses, and respiratory syncytial viruses
(RSVs
Risk factors
• CAP:alcoholism, asthma, immunosuppression,
institutionalization, and an age of 70 years
versus 60–69 years
Clinical Manifestations
• frequently febrile, with a tachycardic
response, and may have chills and/or sweats
and cough
• pleura is involved, the patient may experience
pleuritic chest pain
• fatigue, headache, myalgias, and arthralgias
• Crackles, bronchial breath sounds
Management
• Diagnosis
– CLINICAL
– XRAY – suggests etiology
• pneumatoceles suggest infection with S. Aureus
• upper-lobe cavitating lesion suggests tuberculosis
– Sputum Gram stain and culture
– Blood culture
Management
• Treatment : CAP
– Site of Care
• Home
• Hospital
– Antibiotics
• Empiric
• Previously healthy and no antibiotics in past 3 months
• A macrolide [clarithromycin (500 mg PO bid) or
azithromycin (500 mg PO once, then 250 mg od)] or
Doxycycline (100 mg PO bid)