PNA/Influenza Flashcards
Pneumonia definition + main types
- infection of the lung parenchyma
- community acquired pneumonia (CAP) = infection outside of health-care system
- health-care associated pneumonia (HCAP) = infections relating to health-care system
- hospital-acquired
- ventilator associated
Pathogenesis of Pneumonia
- **inhalation of infectious particles ==> CAP
- inhalation of oropharyngeal/gastric contents
- hematogenous spread
- infectious from adjacent structures
- direct inoculation
- reactivation
Pneumonia symptoms
- fever, chills
- pleuritic chest pain
- dyspnea
- cough
- productive ==> bacterial
- non-productive ==> viral/atypical
- anorexia, nausea, vomiting, diarrhea
- mental status changes
Pneumonia signs
- tachypnea
- tachycardia
- lungs ==> crackles, rhonchi
- egophany
- dullness to percussion
- bronchial breath sounds
Historical features ==> infectious differential diagnosis
- COPD ==> S. pneumo, H. influenzae, M. catarrhalis, Legionella sp.
- HIV ==> M. tuberculosis
- Postinfluenza ==> S. pneumo, S. aureus, Strep pyogenes, H. influenzae
- Aspiration ==> mixed aerobic, anaerobic
Common radiographic reatures of pneumonia
- lboar consolidation
- interstitial infiltrates
- cavitation
Differential dx of radiographic abnormalities on CXR
- pneumonia
- pulmonary edema
- pulmonary/diffuse alveolar hemorrhage
- pulmonary embolism
- malignancy
- drug-induced lung disease
- inflammation
Radiographic patterns ==> infections differential dx
Pneumonia Severity Index definition
- risk scale developed by PORT (patient outcome research team) study
- divides pts into risk classes (I ==> V) based on risk factors and helps provide indications for admission
Tests recommended for all suspected pneumonias
- CXR
- CBC
- metabolic profile
- blood gas or pulse ox
Advanced dx testing for pneumonia
- sputum sample + staining
- gram-staining ==> gram + or - bacteria
- acid fast stain ==> mycobacteria
- bronchoalveolar lavage or pleural fluid analysis for organisms
- sputum culture ==> tailor therapy
- blood cultures
- fiberoptic bronchoscopy
- biopsy: transbronchial or open lung
Serologic testing in pneumonia
- high IgG titers in blood can indicate infection w/:
- Legionella
- Mycoplasma
- C. pneumonia
Molecular techniques used to dx pneumonia
- DNA probes detect bacteria in sputum:
- Legionella
- M. pneumoniae
- M. tubuerculosis
- PCR assay of sputum:
- atypical bacteria
- viruss
- mycobacteria
- procalcitonin in blood:
- elevated levels indicate inflammation/bacterial infections
Possible substances that can fill alveoli
- Poor Funny Boy Cant Piss For Crap
Poor - Pus
Funny - Fluid
Boy - Blood
Can’t - Cells/Cancer
Piss - Protein
For - Fat (Lipid)
Crap - Calcium
Pneumonia DDX: airway diseases
- •Cryptogenic Organizing Pneumonia (COP)
- •Allergic Bronchopulmonary Aspergillosus (ABPA)
- •Bronchiectasis
- •Bronchopulmonary sequestration
- •Bronchocentric granulomatosis
Pneumonia DDx: vascular diseases
•Alveolar Hemorrhage Syndromes •Eosinophilic lung diseases •Pulmonary infarction •Fat emboli •Vasculitis •Collagen Vascular Diseases •Vascular tumors •Acute chest syndrome in sickle cell crisis
Pneumonia DDx: parenchyma diseases
- •Hypersensitivity pneumonitis
- •Drug reaction
- •Transfusion reaction
- •Alveolar proteinosis
- •Granulomatous lung diseases
- •Lipoid pneumonia
- •Pulmonary edema
- •Neoplasms
- •ARDS
- •Radiation pneumonitis
- •Idiopathic interstitial pneumonias
Common causes of CAP
- Typical Organisms
- •Streptococcus pneumoniae - 30 - 60% of CAP
- •Haemophilus influenzae
- •Moraxella Catarrhalis
- •Staphylococcus aureus
- •Group A Streptococci
- •Anaerobes
- •Aerobic Gram Negatives
- –Atypical Organisms - 10 - 20% of CAP
- •Legionella species
- •Mycoplasma pneumoniae
- •Chlamydia pneumoniae
Outpatient tx of CAP
–Macrolide or Doxycyline
–Respiratory Fluoroquinolone
–Beta-lactam + Macrolide
Inpatient tx of CAP
- –Non - Intensive Care Unit (ICU)
- •Respiratory Fluoroquinolone
- •Beta-lactam + Macrolide
- –Intensive Care Unit (ICU)
- •Beta-lactam + Macrolide
- •Beta-lactam + Respiratory Fluoroquinolone
Antiobiotic tx of HCAP
- •Antipseudomonal Agent:
- •Cephalosporin
- •Carbopenem
- •Plus 1 of the Following:
- •Anti-pseudomonal Fluoroquinolone
- •Anti-Gram Negative Aminoglycoside
- •Plus 1 Anti-MRSA Medication:
- •Linezolid
- •Vancomycin
Common community-acquired respiratory viruses
- •Orthomyxovirus
- •Paramyoviruses
- •Picornaviruses
- •Enteroviruses
- •Herpes Viruses
- •Adenovirus
- •Coronavirus
- •Papilloma Virus
- •Hantavirus
Pathogenesis of influenza
- •IFN Hemagglutinin surface glycoprotein binds to sialic acid residues on respiratory epithelial cell surface glycoproteins - Infection Initiation.
- • After viral replication, progeny virions are also bound to the host cell membrane.
- Neurominidase cleaves these links to liberate new virons and spread infection.
Clinical features of influenza infection
- signs/sx:
- fever
- lethargy
- runny nose, sore throagt
- coughing, wheezing
- anorexia, nausea, vomiting, diarrhea
- ==> primary viral pneumonia and/or secondary bacterial pneumonia
Influenza prevention
- vaccines developed every year
- targeted groups:
- 6-18 yo + >50yo
- chronic care facility pts
- adults w/chornic diseases
- pregnant women
- healthcare workers
Treatment of influenza
- Antiviral drugs:
- Adamantanes - Active only against IFN A
- -Amantadine and Rimantidine - Neurominidase Inhibitors - Active against IFN A and B
- Oseltamivir and Zanamivir
- Benefits of Treatment
- Can shorten duration and severity of symptoms
- Greatest Benefit if given within the first 24 - 30 Hrs
