SFP: respiratory infections Flashcards
Describe bacteria seen in bacterial pneumonias
Lots of pyogenic bacteria (neutrophils present, not lymphocytes), potentially mycobacteria (TB), sometimes actinomyces but unusual
Why do lung infections cause a large proportion of death?
The large alveolar surface area is exposed to contaminated air, we can aspirate nasopharyngeal flora, and the lungs are often involved in multisystem and systemic issues causing vulnerability
What are physical defenses to infection?
Cilia/mucus, surfactant, and cough reflex
What are immunological or humoral defenses to infection?
IgA/G/M, cytokines IL1 and TNF, and complement or fibronectin
What are cell mediated defenses to infection?
Neutrophils, eosinophils, macrophages, and lymphocytes
Neutrophils indicate ___ infection, while lymphocytes indicate ___ infection.
Bacterial, viral
Describe lobar pneumonia.
Impacts only one lobe of the lung and can be seen on CXR
Describe bronchopneumonia.
Patchy pattern seen throughout the lung, seen on CXR
What does ‘ground glass’ infiltrate tend to indicate?
Bronchopneumonia
What are the different etiological classifications of pneumonia?
- Community acquired
- Nosocomial (hospital acquired)
- Aspiration pneumonia (aspiration of gastric contents resulting in bacterial and chemical pneumonia)
What type of pneumonia is community acquired?
Bacterial
What type of pneumonia is community acquired atypical pneumonia?
Usually viral but may be bacterial
What type of pneumonia is nosocomial pneumonia?
Bacterial
What type of pneumonia is aspiration pneumonia?
Chemical and bacterial
What is necrotizing pneumonia?
A pneumonia in which bacteria collect and lung abscesses form; the tissue is damaged
What is the most common cause of bacterial pneumonia?
Strep pneumonia
What is the clinical presentation of bacterial pneumonia?
High fever, chills, productive cough, pleuritic chest pain
How do we diagnose bacterial pneumonia?
Blood culture
What is organizing pneumonia?
The infiltrate can organize, and fibrin can develop into fibrosis in the alveolar spaces
What are some complications of bacterial pneumonias?
Abscess, empyema (pus in pleural space), organization and fibrosis, bacteremia, pleuritis, pleural effusion
Describe lung abscess.
They often evolve from necrotizing pneumonia and are a localized suppurative process that involves necrosis of lung tissue. They vary, almost always rupture into airways, and may have a fibrous wall in chronic cases
What are the common organisms associated with lung abscess?
Staph aureus/MRSA, gram-negatives (pseudomonas), mixed infection
Why can abscesses be harder to treat than infection in alveolar spaces?
They tend to wall themselves off and do not allow the antibiotic into the abscess, while the alveolar spaces are highly vascularized and allow antibiotic in
Describe the clinical presentation of lung abscess.
Cough, fever, weight loss, chest pain; the course is variable and most resolve with antibiotic, but 10% die from sepsis.
What are complications of lung abscess?
Empyema, pneumothorax, hemorrhage, brain abscess
What is empyema?
Prurulent debris in the pleural space
Describe who gets aspiration pneumonia.
Often seen in debilitated patients, including those who are unconscious or have abnormal swallowing/gag reflex.