SSTI Flashcards
what are the normal protecting factors in skin
- dry - inhibits growth fatty acids acidic ph renewal of epidermis - bact removed low temp - inhibit growth
what causes ssti
pathophysiology
injury diseases - lead to disruption of normal host defences
= normal skin bact penetrates depper
= other bact introduces
= excessive bact growth
risk factors of ssti
- innocula with high bact eg dirty knife
- excessive moisture
- red blood supply ( dec wbc , inc infection risk )
bacterial nutrients eg diabetic
poor hygiene
sharing personal items
4 categories for classification of ssti
severity - mild mod severe
depth - superficial or deep uncomp or comp
presence of absence of discharge - purulent or non purulent
microbiology
- single pathogen ( pri ) or polymicrobial ( secondary )
impetigo and ecthyma category
mild, uncomplicated, purulent or non , primary epidermic or up to the dermal epidermal junction
impetigo treatment for mild
mupirocin bd 5 days topical
severe impetigo ( not common ) or all ecthyma treatment
empiric w no allergy OR MSSA CULTURE DIRECTED cephalexin or cloxacillin if pen allergy use clindamycin culture directed for s.pyogenes use penicillin vk
7 days for all
hair follicles which 3 types
think of the clue related to hair
furuncles
carbuncles
cutaneous abscesses
furuncles /boils
carbuncles
cutaneous abscess
differeniate btwn them
furuncles - 1 hair follicle
carbuncles - few adjacent hair follicles
- small abscess
cutaneous abscess
- pus collection
- not necessary near foliccle
mainstay treatment for fur carb cute
incision and drainage
when to use ab for fur carb cute
- if cant drain fully
- no response to draining
- extensive and alot of sites involved
- v old or v young
- immunosuppressed
- sirs critera
what are the sirs critera
1. fever > 38 deg or temp < 36 2. rr > 24 breaths / min 3. HR > 90 bpm 4. WBC < 4x 10^9/L or > 12x10^9/L
AB treatment for fur carb cute
and duration
mssa only
= cloxacillin, cephalexin or cefazolin
mssa, mrsa
- clindamycin
- trimethoprim/sulfamethoxazole
- doxycycline
outpatinet 5-7 days
inpatient 7-14 days
cellulitis affect what and purulence
dermis to fascia
can be purulent or non purulent
erysipelas affect what and purulence
superficial dermis
non purulent
cellulitis and erysipelas complications 7
- bacteremia
- endocarditis
- toxic shock
- glomerulonephritis
- lymphedema
- osteomyolitis
- necrotising soft-tissue infections eg necrotisng fasciitis
types of microbio cultures
- cultaneous aspirates
- tissue samples from bipsies
- blood
- peripheral skin swab but may not be causation organism
MRSA risk factors
- immunosuppression
- failed treatment priot without mrsa coverage
- critically ill - hypotensive
cellulitis and erysipelas
categorise severity
and what to cover
mild - no sirs - cover strep spp
mod - 2 or more sirs
- cover s.aureus also
severe - more than 2 sirs + hypo <100, rapid prog, immunosuppression, comorb = cover p.aureg also ( gram neg )
treatment for mild non purulent cellulitis/erysipelas
and treatment for mild PURULENT cellulitis/erysipelas
po pen vk - narrowest cloxacillin cephalexin ^ broader clindamycin for allergy
if purulent must cover s.aureus also cefalexin cloxacillin clindamycin and if mrsa risk factors add any one of the 3 mild ones
treatment for moderate non purulent cellulitis/erysipelas
if only 1 sirs treat for same as mild
pen v, cloxacillin, cephalexin, clindamycin
preferably cloxacillin and cephalexin bc broader
if 2 sirs or above fails
then use
IV - cefazolin, penicillin G
or clindamycin ( allergy )
treatment for severe non purulent cellulitis /erysipelas
iv -
piptazo
cefepime
meropenem
if mrsa risk factors add iv vanco daptomycin or linezolid ^ last 2 more ex and broader , vanco common
3 abs for coverage of mrsa in milder cases
clindamycin
trimethoprim, sulfamethoxazole
doxycycline
3bs for coverage of mrsa in more SEVERE cases
vancomycin
daptomycin
linezolid
diff between cefalexin and cefazolin
both cover strep and staph
cefazolin only iv
alternative for anti staph penicillins in patients allergic to penicillins
diff between pen g and pen v
pen v is oral ( vomit )
pen g is parental
treatment for moderate PURULENT cellulitis/erysipelas
cover for staph aureus also if only 1 sirs criteria - cefalexin - cloxacillin - clindamycin
2 sirs criteria or if above fails
iv cefazolin
cloxacillin
clindamycin
if mrsa risk factor add any one of the severe ones
treatment for severe purulent cellulitis/erysipelas
same as non purulent
iv piptazo
cefepime
meropenem
and if mrsa risk factor then add one of the 3 severe ones
cellulitis from bite wounds organisms
s.aureus strep spp animal - pasteurella multocida human - eikenella corrodens oral anerobes eg prevotella spp, peptostreptococcus spp
treatment for bite cellulitis
what to cover then whats the treatment
augmentin ( gram neg )
ceftriaxone/cefuroxime
or
cipro/levo for pen allergy
add clindamycin or metronidazole if need anaerobic coverage
po or iv depends on severity
monitoring for cellulutis and erysipelas
when to look for changes
when t o switch to oral
duration of ab
what if no culture results
2-3 days response
switch to po if afebrile 48 hrs and clinical improvement
- if no culture then choose oral agent w similar coverage as initial iv agent
ab for 5 days at least
if immunocompromsed 7-14 days
3 pathophysiology paths for dfi
- neuropathy
peripheral - dec pain sensation and altered pain response
motor - muscle imbalance
autonomic - inc dryness cracks and fissures - vasculopathy
- early atherosclerosis
- peripheral vascular disease
- worsened by hyperglycemia and hyperlipidemia - immunopathy
impaired immune response
- inc susceptibility to infections
- worsened by hyperglycemia
all these cause ulcer formation or wounds
- bacterial colonisation, penetration, proliferation
= dfi
dfi and PU
diagnosis criteria
purulent discharge or at least 2 signs of inflammation
erythema warmth tenderness pain induration ( localised hardening of the sst)
dfi and Pu microbio
when gram neg present
when anaerobes present
strep and staph aureus most common
gram neg when chronic or prev treated w ab
- ecoli, klebsiella, proteus spp
anaerobic when ishchaemic or necrotic
- peptostreptococcus, veillonella , bacteriodes
when to culture for dfi and pui
dont culture if not infected - dont culture
how deep is not related to whether infected
mod to severe
- use tissue culture after cleansing and before starting ab
- dont use skin swab
when to empirically cover pseudomonas aeruginosa
severe
prev treatment failure when not active against p.aerug
dfi and pui mild classification and what to treat and treatment
duration
classification
- no sirs
- erythema 2 cm orless around the ulcer
- skin and sc infection
cover strep and staph po cloxacillin cephalexin clindamycin
if mrsa risk factor add one of 3 mild one po
( trimethoprim, sulfomethoxazole
doxycycline , clindamycin)
duration 1-2 weeks
dfi and pui moderate classification
what to treat and
treatment
duration
classification
- no sirs
- infection of deeper tissues like bone or joints
- erythema >2cm around ulcer
cover
strep, staph , gram neg , anaerobes
treatment IV amox/clav ertapenem( reserved for esbl) ceftriaxone + metronidazole/clindamycin ( for anaerobic coverage )
if mrsa risk factor add one of 3 iv severe options
vanco, dapto, linezolid
and strep down to po if improvement
duration 1-3 weeks
dfi and pui severe classification
what to cover
and treatment
and duration
classification - as long as 1 sirs criteria present
cover strep, staph,
gram neg including p.aerug and anaerobes
treatment
iv piptazo
meropenem
cefepime + metronidazole/clindamycin for anaerobic coverage
if mrsa risk factor add one of 3 iv severe options
vanco, dapto, linezolid
can step down to po if patient improves
duration 2-4 weeks
duration of dfi and pui treatment for bone involved
surgery amputated
2-5 days
surgery w infected tissue left
1-3 weeks
surgery w residual viable bone - 4-6 weeks
no surgery or surgery w residual dead bone
- at least 3 months
for dfi and pui do we continue ab until complete wound healing
no
ab may resolve th einfection but ulcer or wound may take longer to heal, not necessary to continue ab til wound healing ocurs
dfi wound care
and foot care
wound care
- debridement - procedure to remove infected tissue
- offloading - supporitive shoes
- dressing for healing environemnt and control excess exudation
foot care
- daily inspection
- prevent wound and ulcers
4 factors causing pressure ulcers
moisture
pressure
shearing force
friction
risk factors for pressure ulcers ( PU ) 6
red mobility debilitated red consciousness sensory and autonomic impairment eg incontinence extreme age malnutriiton
pui adjuctive measures
what kind of liquid to use
debridement
local wound care
- normal saline and avodi harsh chemicals
relief of pressure
turn every 2 hrs
for prevention
antibiotic dosing
Amoxicillin/clavulanate 625mg PO BD-TDS*; 1.2g IV Q8H* Cefepime 2g IV Q8H* Cefazolin 1-2g IV Q8H* Cefepime 2g IV Q8H* Cephalexin 250-500mg PO QDS* Cloxacillin 250-500mg PO QDS; 1-2g IV Q4-6H Penicillin G 2-4 million units Q4-6H* Penicillin VK 250-500mg PO QDS Piperacillin/tazobactam 4.5g IV Q6-8H*
Trimethoprim/sulfamethoxazole 800/160mg PO BD*
Vancomycin 15mg/kg Q8-12H
Clindamycin 300mg PO QDS; 600mg IV Q8H
Metronidazole 500mg PO/IV TDS
is nausea and vomitting an allergy
and whats considered true allergy
no
its side effect
anaphylaxis , hives
diff between ertapenem and meropenem/imipenem
mero and imipenem covers p.aureg - used for severe dfi/pui
erta dosent - use for moderate dfi/pui but we like to reserve this class for esbls !
diff between augmentin and piptazo
piptao covers p.aerug -severe dfi/pui
augmentin dosent - used for moderate dfi/pui
diff between cefepime and ceftriaxone
cefepime - 4th gen covers p.aureg used for severe dfi/pui
ceftriaxone -3rd gen - dosent cover so used for moderate dfi/pui
