Pneumonia Flashcards
What is pneumonia?
Pneumonia is the infection and inflammation of the lung parenchyma.
Describe the pathophysiology of pneumonia.
Debatable methods of invasion include:
- damage to muco-ciliary escalator by prior infection or smoking.
- inhibition of cough reflex e.g. because of neurodegenerative disorder or opioid drug use.
- inhibition of IgA.
- damage to alveolar macrophages.
can all cause pathogens to accumulate in the lungs.
What are symptoms of typical pneumonia?
Fever
Cough with purulent sputum
Dyspnoea
Pleuritic pain
Fatigue
What are clinical signs of typical pneumonia?
- Tachypnoea (and accessory muscle use, intercostal retraction).
- Unilateral decrease in chest expansion (lobar pneumonia).
- Increase tactile fremitus (vibration when saying ‘ninety-nine).
- Percussion: dullness (signifies fluid).
- Ausculation: bronchial breath sounds and crackles.
- Tachycardia.
- Septicaemia: rigors.
What are the complications of pneumonia?
Respiratory failure by causing acute respiratory distress syndrome (ARDS).
Septic shock: the causative agent enters the patients bloodstream, releasing cytokines.
Pleural effusion.
Emphysema.
Lung abscess.
Hypotension: sepsis or dehydration is usually the underlying cause.
What are the causative organisms in children and younger individuals?
Viruses (e.g., RSV, influenza).
Pneumococcus.
Mycoplasma (atypical pneumonia).
Which bacteria are the most common cause of community acquired pneumonia?
Streptococcus pneumoniae.
Haemophilus influenzae.
Moraxella catarrhalis.
Influenza virus.
Which bacteria are the most common cause of hospital acquired pneumonia?
Gram-negative bacteria.
Staphylococcus aureus (MRSA).
Streptococcus pneumoniae.
Pseudomonas.
Discuss pneumonia treatment (Hint: BAPP).
Breathing: maintain oxygen saturation levels.
Antibiotics: treat the underlying cause (check hospital guidelines).
Pain: give analgesics.
Pneumococcal vaccines for those at risk, e.g., diabetics, the immunosuppresed and those over 65.
What are the causes of recurrent pneumonia?
Recurrent pneumonia most commonly occurs in patients with underlying lung disease such as COPD or bronchiectasis, immunocompromised patients, and those with local obstructive processes such as a tumour.
What is the difference between bronchopneumonia and lobar pneumonia?
In bronchopneumonia, the infection can be spread throughout the lungs, involving the bronchioles as well as the alveoli. A CXR will show patchy areas spread throughout the lungs.
In lobar pneumonia, the infection causes complete consolidation of a whole lobe of the lung, meaning the entire region is filled with fluid.
Define the mechanisms of defence in the respiratory system.
Macrophage mucociliary escalator > alveolar macrophages > mucociliary escalator > cough reflex.
General immune system: humoral and cellular immunity.
Respiratory tract secretions.
Upper respiratory tract acts as a filter.
What investigations can be performed?
CXR: look for infiltrates.
Sputum sample: identify causative organsim.
Monitor oxygen sats.
Bloods: Raised WCC and inflammatory markers (CRP).
Urinary antigen test: for pneumococcal or legionella antigen.
Arterial blood gas (ABG).
How is the severity of pneumonia assessed (CURB-65)?
Confusion.
Urea > 7 mmol/L.
Respiratory rate > 30/min.
BP <90/60 mmHg.
>65 years old.
What are the ways in which pneumonia can be acquired?
- inhalation of a pathogen.
- aspiration of food and fluids.
- haemotogenous spread e.g. IV drug users.
