Gastroenteritis, Cellulitis, Infective Endocarditis Flashcards
Clinical features of gastroenteritis?
Short history
Diarrhoea (a lot)
Vomiting
Fever
Malaise, myalgia
Dehydration: thirst, dry mucous membranes, dizziness, weakness
If a patient with type 2 diabetes presents with diarrhoea and generally unwell, what should you make sure you check?
BMs
He could have hyperglycaemic hyperosmolar non-ketotic state
A condition that is precipitated by infection, MI etc.
Results in hyperosmolality, hypernatraemia, decreased consciousness
What is HONK?
Clinical features?
Management?
Hyperglycaemic hyperosmolar non-ketotic state
A condition that affects people with type 2 diabetes
Precipitated by MI, infection
Causes hyperosmolality and hypernatraemia
Decreased conscious level
Management: fluid replacement, stop metformin, insulin
Which drugs put a dehydrated patient at more risk of AKI?
Metformin PPI (lanzoprazole) ACEi NSAIDs Diuretics Aminoglycosides (gentamicin)
Investigations of gastroenteritis?
Bedside:
- BM
- Obs
- ABG, VBG
Routine:
- Bloods: FBC, UE, LFTs, TFTs, Clotting, CRP
- Cultures: blood, stool
- AXR
Specialist:
- MRI
- CT
- Scopes
List some pathogens that cause diarrhoea.
What would you see in the history with these pathogens?
Salmonella
Shigella: bloody diarrhoea
Campylobacter: commonly from chicken
E. coli: salads
Hep A: shellfish
Hep E: pork
(these usually have longer incubation period)
What should you worry about in an E. coli GI infection?
Explain it!
E. coli 0157
Can lead to haemolytic uraemic syndrome
Triad of:
- anaemia
- uraemia (AKI)
- thrombocytopenia
A toxin released by the bacteria binds to receptors in renal and CNS tissue and causes damage
Management of gastroenteritis?
Supportive
Oral rehydration solution
Anti-emetics and anti-diarrhoeals
You only give antibiotics if:
- bacteraemia
- severe infection
- immunocompromised
- C. diff
Which antibiotics do you give in these situations?
Bacteraemia:
- amoxicillin to cover salmonella
- azithromycin to cover campylobacter
C. diff: metronidazole, 2nd line PO vanc
What are the public health rules associated with infective gastroenteritis?
Notify public health England
If they work in food handling, hospitals, with vulnerable people wait 48hrs after last episode
Trace back to the cause of infection, like if its a shop or restaurant
List some skin infections and say which part of the skin is involved.
Cellulitis: dermis and subcutaneous tissue
Erysipelas: dermis and upper subcutaneous tissues
Folliculitis: hair follicle, leading to a boil
Impetigo: superficial
Necrotising fasciitis: skin and deeper fascia
Clinical features of cellulitis?
Erysipelas?
Cellulitis:
- poorly demarcated
- blisters and bullae
- systemic unwell
Erysipelas:
- well demarcated
- red, tense, shiny, bullae
- systemic unwell
Which bugs usually cause:
- folliculitis
- impetigo?
Folliculitis: s. aureus
Impetigo: s. aureus or s. pyogenes
Differential diagnosis of cellulitis?
Erysipelas DVT Septic arthritis or osteomyelitis Dermatitis Vasculitis Gout Chronic venous insufficiency
Why are diabetic patients predisposed to cellulitis?
Type 1 diabetics have a weakened immune system
Peripheral neuropathy: may not feel an injury so high chance it could get infection
Sugary blood = good for bacterial growth
Chronic hyperglycaemia can affect activity of immune system (neutrophils, phagocytes etc.)
What are some risk factors for cellulitis?
Previous cellulitis or erysipelas Venous insufficiency Diabetes Alcohol excess IVDU Lymphoedema Obesity Pregnancy Athletes foot
Investigations of cellulitis?
Bedside:
- BM
- Obs
- urinalysis (if they’re diabetic and unwell, high chance of DKA)
Routine:
- Bloods: FBC, UE, LFTs, CRP, Clotting, ketones
- Cultures: blood, swab of wound, between toes
- XR
Specialist:
- fine needle aspiration of leading edge of lesion
- MRI
- CT
Which pathogens cause cellulitis?
Bugs that colonise the skin
Strep: beta-haemolytic - group A (pyogenes) and group C and G
Staph aureus
Anaerobes can too but these arrive by haematogenous spread
Others
- Klebsiella
- moraxella
- psuedomonas
- clostridium perfringens
Management of cellulitis?
Flucloxacillin: covers B-haemolytic strep and s. aureus
PO or IV
Supportive: analgesia
NSAIDs and corticosteroids reduce recovery time
When should you refer a case of cellulitis to hospital?
If you suspect nec fasc Severe or rapidly worsening Systemically unwell Complications Facial infection Immunocompromised Diabetic Child under 1 Frail Lymphoedema
Clinical features of necroitising fasciitis?
Which bug?
Infection of skin and deep fascia
Cuts of blood supply leading to necrosis
Severe systemic toxicity
Rapidly spreading
Crepitus if organisms produce gas
S. pyogenes
Clinical features of infective endocarditis?
FEVER AND NEW MURMUR
Often mitral regurgitation, early diastolic murmur
Fever and chills Malaise Myalgia Anorexia Weight loss Abdominal pain Nausea and vomiting
CCF: SOB, orthopnoea, PND
Splinter haemorrhages
Roth’s spots (retinal haemorrhages)
Emboli to brain, lung, spleen
What is the most common murmur in IE patients?
Aortic regurgitation
Which is an early diastolic murmur
What are some signs in the hands of IE?
Splinter haemorrhages
Osler’s nodes: small nodules on pulp of phalanges
Janeway’s lesions: painless erythematous macules on the thenar and hypothenar eminence
What might you find on examination of a patient with IE?
A new murmur: often early diastolic (A. regurg)
Petechiae: conjuctiva, hands and feet, chest, abdo, oral mucosae
Splinter haemorrhages
Osler’s nodes
Janeway lesions
Arthritis
Splenomegaly
Meningism / meningitis
Investigations of IE?
Bedside:
- Obs
- BM
- ABG, VBG
- Trans thoracic echo
- Urinalysis
Routine:
- Bloods: FBC, UE, CRP, LFT, Clotting
- Blood cultures
- CXR
Specialist:
- trans-oesophageal echo
- CT, MRI
Risk factors for IE?
Valvular heart disease
Valve replacement
Structural congenital heart disease
Previous IE
Hypertrophic cardiomyopathy
IVDU
Invasive vascular procedures
Pathogenesis of IE?
Starts off with a sterile fibrin-platelet vegetation (thrombus)
Which then gets infected
Which valves are most commonly affected in IE?
Mitral valve
Aortic valve
Both
Which organisms cause IE?
Staph. aureus (most common)
Strep:
- viridans
- group A, B, C, G
- intermedius
Psuedomonas
Kingella kingae, Haemophilus species, cardiobacterium species
Fungi
What complications can IE cause?
Meningitis
Emboli in brain: middle cerebral artery, causing hemiplegia
Renal infarcts - painless haematuria
Nephritis
AKI
Splenic infarct - pain
MI
CCF
Pericarditis
Retinal artery occlusion - blindness
Pulmonary emboli
Synovitis
Back pain: immune complex deposition in disc spaces
What’s the antibiotic management of IE?
IV abx for 4 weeks (6 weeks if prosthetic valve)
Staph confirmed:
- Fluclox for non-MRSA
- Vancomycin and rifampicin for MRSA
Strep confirmed:
- BenPen
- Ceftriaxone
- Gentamicin
Management of IE?
Antibiotic therapy
- IV, 4 weeks, 6 weeks for prosthetic
Surgical: if prosthetic valve or if severe IE with CCF in native valve
