Staph aureus bacteraemia Flashcards
Initial management of suspected SAB is basic management for sepsis.
What are potential sites S aureus likes to infect
Skin Bone - need MRI IE Prosthesis - cannula, haemodialysis, urinary catheter/ ICD IVDU - abscess/ septic DVT
Rarer sources:
Pneumonia
UTI
Consider recent hospitalisation as increased risk factor
What will initial examination involve?
Check skin - cellulitis/ ulcers/ abscess
Check joints/ spinal tenderness
Heart murmurs/ peripheral stigmata IE
Devices - cannula/ catheter
Which patients recommended to have TTE in SAB?
If focus cannot be identified, then should all have ECHO.
Many patients may need ECHO if not improving, as SAB can seed to valves
Which patients should have TOE?
If high risk IE, source unknown, TTE negative
Persistent bacteraemia >4 days
Permanent cardiac device
Before starting treatment, we should assess for risk of MRSA. What are risk factors?
MRSA is not more likely to infect than MSSA, just harder to treat
Check MRSA swab results previous admission
Recent history of hospitalisation 3 months
Regular hospital visits - e.g dialysis
Indwelling prosthesis - Hickman line
Care home resident
Chronic ulcers
IVDU
What is initial empirical therapy for SAB?
MSSA - flucloxacillin 2g QDS
MRSA - vancomycin/ teicoplanin/ daptomycin/ tigecycline
If high risk MRSA, treat with vancomycin
Empirical treatment also involves removing infected device/ draining abscess/ joint washout
What is treatment duration for SAB?
2 weeks IV if uncomplicated. Uncomplicated includes no IE, negative repeat cultures, cannula removed
Septic arthritis - 4 weeks total (min 2 weeks IV)
IE/ osteomyelitis - 6 weeks total (min 2 weeks IV)
Vancomycin for MRSA - what are target levels?
15-20mg/L for MRSA/ deep seated infection
Normal uses of vancomycin have acceptable levels between 10-20mg/L
If not responding to vancomycin, what are next steps?
If levels OK, do not increase dose
Switch agent e.g teicoplanin
Perform vancomycin resistance testing with E-test
Search/ remove source
Referral phones asking for advice about SAB - what do you tell them to do
Examine for source
Investigate/ source control -
- MRI - spine/ joints
- ECHO
- doppler USS
Treat antibiotics
Repeat blood cultures after 72 hours
MRSA skin infection (no bacteraemia) - what are treatment options
MRSA UTI (no bacteraemia) - what are treatment options
Skin - Co-trimoxazole Clindamicin Doxycycline Linezolid
UTI -
trimethoprim
nitrofurantoin
If not improving - Vancomycin Teicoplanin Daptomycin Tigecycline
Why are quinolones avoided if suspecting staph aureus infection?
ciprofloxacin/ levofloxacin are to be avoided because rates of MRSA infection are increased in hospitalized patients treated with quinolones
When treating cellulitis, and you are suspecting staph aureus, what other organisms should you be vary of?
Group A Strep
Co-trimoxazole/ doxycycline you may use for staph skin infection, are less effective against GAS
clindamicin is effective against GAS/ S aureus
SAB does not need isolated. But if patient MRSA swab is positive, then they need isolated. Those with open wounds/ devices have higher risk of spreading MRSA.
All admissions are screened for MRSA
What is decolonisation treatment?
Bactroban - mupirocin 2% - nasal BD for 5 days. Must be limited to two courses, as shown to develop resistance after this.
Chlorhexidine wash 4% - OD body wash 5 days,
Day 1/ day 5 hair wash
Re-screen two days after treatment
Re-screen five days after treatment
No longer considered colonised if 2 repeat screens negative
If MRSA decolonisation fails, what are options?
octenisan daily wash
neomycin nasal cream (naseptin) for 5 days. Avoid if nut allergy
When isolated in side room, what precautions should be taken?
PPE
5 moments hand hygiene
Only essential staff entering
MSSA/ MRSA can produce a toxin called PVL (Panton Valentine Leucocidin). <2% of Staph aureus infections are PVL
What effect does it have?
Toxin forms pores on neutrophil membranes, lysing them
What are clinical features of PVL-SA?
Boils - particularly recurrent/ more than one household member
Folliculitis
Necrotic skin lesions
Necrotising fasciitis
Necrotising pneumonia - commonly have flu-like illness preceeding it
Osteomyelitis
Failure on treatment for MSSA
What are risk factors for PVL-SA?
CDC 5Cs
Cleanliness Close contact Crowding Cleanliness Cuts
Nursing home
Military camps
IVDU
Close contact sport - rugby, judo
What is treatment for
PVL-MSSA - SSTI
PVL-MRSA - SSTI
PVL-MSSA - flucloxacillin doxycycline clindamicin co-trimoxazole
PVL-MRSA - doxycycline clindamicin rifampicin + fusidic acid rifampicin + trimethoprim
Incision and drainage of boils is optimal treatment
What is treatment for severe PVL-SA infection?
MSSA + MRSA
Toxic shock
Necrotising pneumonia
Purpura fulminans
Clindamicin + linezolid
Urgent surgical debridement is key
What is treatment for deep seated infections
PVL-MSSA
PVL-MRSA
PVL-MSSA -
Clindamicin + linezolid
Clindamicin + rifampicin
PVL-MRSA
Vancomycin + sodium fusidate
Vancomycin + gentamicin
Vancomycin + rifampicin
All patients with PVL-SA should be isolated.
If have PVL pneumonia, what precautions must be taken?
What is decolonisation procedure?
Respiratory precautions
Same as for MRSA
