18 - Chronic Disease + Infections Flashcards
In general, how do chronic conditions lead to a predisposition to infections?
- Disease causes a change in the structure or function of tissues, e.g less mucous
- Consequences of treatment, e.g antibiotics and streroids
Therefore, need successful management to prevent
Outline a brief pathophysiology of cystic fibrosis.
What are some complications of CF?
Due to thicker secretions of mucous and blocking secretion in pancreas
Why do patients with CF get infections?
Their innate immunity is compromised e.g dehydrated, thick mucus so mucociliary escalation cannot occur and there is airway remodelling due to chronic inflammation from infections
What are some lung infections that patients with CF are more susceptible to?
What is pseudomonas aeruginosa?
- Gram negative bacilli
- Aerobe with flagella
Why is pseudomonas aerunginosa difficult to treat and how would you identify it?
Sputum culture to find out what antibiotics sensitive to and what organism
How can you prevent patients with CF from developing pseudomonas aerungiosa?
- Try to manage the CF
- Difficult to prevent colonisation
How can you treat pseudomonas infections?
- Need combination of antibiotics as develops resistance quickly
- Ciprofloxacin, tazocin, gentamycin, ceftazidime
Why do patients with diabetes mellitus become susceptible to infections?
- Hyperglycaemia affects humoral immunity and interferes with neutrophils and lymphocytes
- Micro/macrovascular complications with DM results in poor tissue perfusion so increase risk as no WBC in the area
- Neuropathy causes decrease in sensation so cuts and ulcers go unnoticed, issue with innate immunity as loss of pain
What infections are diabetics more susceptible to?
- Cellulitis
- UTI
- Malignant otitis externa
- Respiratory infections
Why do patients with DM get cellulitis and what organisms cause this?
The patient below has diabetes, what investigations should you carry out once you see this.
How can you treat diabetic cellulitis and how can you prevent it?
Treat infection with antibiotics depending on the causative microorganism, e.g flucloxacillin
Why do patients with DM get UTIs and what bacteria can cause this?
How would you investigate and treat UTIs in a diabetic patient
What is a major issue if a patient with type 1 diabetes acquires an infection?
At risk of DKA
What is malignant otitis externa and what causes it?
- External ear infection that starts in external auditory canal
- Can spread to soft tissue, cartilage and bone
- Severe ear pain, otorrhoea
- Pseudomonas aerungiosa
Why are diabetic patients susceptible to respiratory infections and what are the organisms typicaly causing this?
- Hyperglycaemia interfering with neutrophil function
- Altered perfusion due to vascular disease cause inflammatory damage
- Can give influenza vaccines to these patients
Why do patients with COPD get infections?
- Increased mucus production
- Local overreactivity causing inflammation and damage to airways
- Airway remodelling due to damage to the cilia
What infections are patients with COPD susceptible to?
- Pneumonia
- Common organisms: atypical community acquired, e.g H.Influenzae, Ps.aeruginosa
- Rare organisms: S.pneumoniae, moraxella cararrhalis, E.coli
Where is pseudomonas aeruginosa normally found?
Soil, water, plants and animals and normally doesn’t cause disease when in human, apart from if human is immunocompromised
What diseases can P.aerungiosa cause?
Nosocomial UTI, pneumonia, surgical site infections, severe burn infections, chemotherapy patients infection
What is the pathogenesis of P.aeruginosa?
- Mucoid capsule containing alginate that allows resistance to phagocytosis and clearing in CF lung
- Host tissue damage allows bacteria to adhere so it releases numerous toxins that promote local invasion
What localised infections can P.aeruginosa cause?
- Keratitis in eye
- Ear, e.g swimmers ear and external otitis
- Skin rashes in contaminated hot tubs
- Diarrheoa
- Abscesses
What is the FEVER pain score?
Helps you to decide whether or not to prescribe antibiotics in a case of pharyngitis
