ssti 2

Question 1

Diabetic foot infection

Answer 1

Softtissueorboneinfectionsbelowthemalleoli AreasofDFIs –Skinulceration(peripheralneuropathy) –Wound(trauma) Leadingcauseofhospitalizationsandamputations amongdiabetics

Question 2

DFIs:Pathophysiology

Answer 2

1)Neuropathy
Peripheral:↓pain sensationandaltered painresponse
Motor:muscleimbalance
Autonomic:↑dryness, cracksandfissures

2) 2)Vasculopathy
Earlyatherosclerosis
↓lowerextremity circulation
Worsenedby hyperglycemiaand hyperlipidemia

3)Immunopathy
Impairedimmune response
↑suscepbilityto infections
Worsenedby hyperglycemia

Leads to ulcer formation or wounds
–> bacterial colonization, penetration, proliferation –> DFI

Question 3

DFI definiton

Answer 3

DFIs:Definition
Bacterialcolonizationofulcersorwoundsiscommon
–Notalwaysinfected

Definitionofinfection
–(___Purulent discharge_______);or
–≥2signsorsymptomsof(__inflammation___)

• Warmth
• Erythema
• Tenderness
• Pain
• Induration

Question 4

Classification of DFIs

Answer 4

1) Uninfected
- No signs orsymptomsofinfection

2) Mild
- Local infectionofskinandSCtissue -
Iferythema,≤2cmaroundulcer

3) Moderate
- Localinfection witherythema>2cm
- Involvesdeeperstructuresortissues, e.g.osteomyelitis,fasciitis
- NoSIRS

4) Severe
- Local infectionwithsignsofSIRS

Question 5

DFI clinical presentation

Answer 5

1) superficial ulcer , mild erthema
2) Deep tissue infection, extensive erythema
3) infection of bone and fascia, purulent discharge
4) localized gangrene

Question 6

Causative organsim DFI

Answer 6

Causativeorganisms
–Typically(__POLYMICROBIAL____)
–(__S.aureus_____)and(___STREPTO___)mostcommon
–(____GRAM -ve ____) •E.coli,Klebsiellaspp.,Proteusspp.,etc

•Pseudomonasaeruginosa
RISKFACTOR
o Warmclimate
o Frequentexposureoffoottowater

–(___ANAEROBE___) •Peptostreptococcusspp.,Veillonellaspp.,Bacteriodesspp.

Question 7

DFI CULTURES

Answer 7

Cultures
– Donotcultureuninfectedwounds
– MildDFIs
•Optional

– Moderate– severeDFIs
•Deeptissueculturesaftercleansingandbeforestarting
antibiotics (ifpossible)
•Avoidskinswabs

moderate can wait for result to be out before tx
severe enuf just start first

Question 8

DFIs:Treatment principle

Answer 8

Empiricantibiotic androute selectiondependon
–(__SEVERITY OF DFI__)
–(___MRSA__)riskfactors
–(__PSEUDOMONAS_)riskfactors

Totalantibioticduration dependson 
– SeverityofDFI 
– ExtentofDFI 
     •E.g.osteomyelitis? 
     •Surgicalintervention?

Question 9

DFIs:Treatment MILD

Answer 9

IDSA infection severity 
1) MILD
Presentation 
- Local infectionof skinandSC tissue 
- Iferythema, ≤2cm aroundulcer

Organism

• s aureus
• strepto

Empiric 
MSSA + strepto 
- Cloxacillin PO 250-500mg QDS
- Cephalexin PO 250-500mg QDS
- amo/clav PO 625 BD-TDS

MRSA + MSSA + Strepto

• Clindamycin PO 300mg QDS
• TMP/SMX PO 960-1920mg BD*
• Doxycyclin PO 100mg BD*
• = limited strepto activity

Duration = 1-2 weeks

Question 10

DFIs:Treatment Moderate

Answer 10

MODERATE
Erythema >2cm
Involves deeper tissues(e.g. bone,joints) NoSIRS

ROA
= Maybe POorIV initiallythen switchedtoPO

organisms
S.aureus 
Streptococci 
Gram‐negative bacilli 
Anaerobes

NoPseudomonas coverage 
Ampicillin/sulbactam (IV 1.5-3g q6-8h)
Ceftriaxone* (1-2g IV q24h) 
Ertapenem ( 1g IV q24h)
Moxifloxacin (400mg IV/PO q24h) 

Pseudomonal coverage
Meropenem (IV 1g q8h)
Piperacillin/tazobactam (IV 3.375g q6h)
Ceftazidime* (IV 1-2g q8h)
Cefepime* (IV 1-2g q8h)
Levofloxacin* (500-750mg IV/PO q24h)
Ciprofloxacin* (400mg IV q12h / 500-750mg PO BD)

IfMRSAcoverageneeded,add
Vancomycin (IV 15-20mg/kg q8-12h)
Daptomycin (IV 4mg/kg q24h)
Linezolid (IV/PO 600mg BD

*Add metronidazole or clindamycin (300mg PO QDS / 600mg IV q8h) if antibiotic does not cover anaerobes

Duration = 1-3 weeks

Question 11

DFIs:Treatment severe

Answer 11

SEVERE
signs of SIRS

ROA
= IV initiallythen switchedtoPO

organisms
S.aureus 
Streptococci 
Gram‐negative bacilli 
Anaerobes

NoPseudomonas coverage 
Ampicillin/sulbactam (IV 1.5-3g q6-8h)
Ceftriaxone* (1-2g IV q24h) 
Ertapenem ( 1g IV q24h)
Moxifloxacin (400mg IV/PO q24h) 

Pseudomonal coverage
Meropenem (IV 1g q8h)
Piperacillin/tazobactam (IV 3.375g q6h)
Ceftazidime* (IV 1-2g q8h)
Cefepime* (IV 1-2g q8h)
Levofloxacin* (500-750mg IV/PO q24h)
Ciprofloxacin* (400mg IV q12h / 500-750mg PO BD)

IfMRSAcoverageneeded,add
Vancomycin (IV 15-20mg/kg q8-12h)
Daptomycin (IV 4mg/kg q24h)
Linezolid (IV/PO 600mg BD

*Add metronidazole or clindamycin (300mg PO QDS / 600mg IV q8h) if antibiotic does not cover anaerobes

Duration = 2-4 weeks

Question 12

DFI Duration of therapy

Answer 12

Bone and or joint involved

Surgery–allinfectedtissueremoved (e.g.amputation)
2‐5days

Surgery–Residualinfectedsofttissue
1‐3weeks

Surgery–Residualviablebone
4‐6weeks

Nosurgeryor Surgery–residualdeadbone
≥3months

DO NOT continue antibiotics until complete wound healing

Question 13

DFIs:AdjunctiveMeasures

Answer 13

Woundcare 
–Debridement 
–“Off‐loading” 
–Applydressingsthatpromoteamoisthealingenvironment
and controlexcessexudation 

Footcare
–Promotehealing
–Preventwoundsandulcers

Question 14

12TipsofFootCare

Answer 14

Wash your feet daily, especially between toes –Avoid harsh chemicals
Avoid direct heat to the feet, e.g. heating pads –If cold, wear loose fitting socks
Never walk barefooted
Donotsmoke
Askyourpodiatristaboutorthoticsandinsoleoptions

Checkyourfeetdailyforinjuries
Wearcomfortableclosedtoeshoes
–Avoidslipperswithoutsupport
Keepyoufeetwarmanddry

Controlyourdiabetes
Moisturizeyourfeet,ankleandlegsdaily
–Donotmoisturizebetweentoes Cuttoenailsstraightacrosstopreventingrownnails

Wearlight‐coloredsockswithnoseams

Question 15

Pressure ulcers

Answer 15

Pressureulcers=decubitusulcers=bedsores Synergisticinteractionbetween4factors 
–Moisture 
–Pressure(amountandduration) 
–Shearingforce 
–Friction

Question 16

PressureUlcers:RiskFactors

Answer 16

Reducedconsciousness
Extremesofage Debilitatedbyseverechronicdiseases
–E.g.multiplesclerosis,stroke,cancer

Reducedmobility
–E.g.spinalcordinjuries,paraplegic Sensoryandautonomicimpairment
–Incontinence
Malnutrition

Question 17

PressureUlcers:ClinicalPresentation

Answer 17

Stage1
Abrasionofepidermis Irregularareaoftissueswelling
Noopenwound

Stage2
Extendsthroughthedermis
Openwound

Stage3
Extendsdeepintosubcutaneousfat Opensoreorulcer

Stage4
Involvesmuscleandbone
Deepsoreorulcer

Question 18

pressure ulcer s microbiology

Answer 18

SimilartoDFIs
–Polymicrobial
–Recommenddeeptissueculturesorbiopsyspecimens
–Avoidskinswabs

Question 19

Pressure ulcer tx

Answer 19

Antibioticsselection,dosingandduration
–RefertoDFIs

Adjunctivemeasures
–Localwoundcare
•Reliefofpressure
o Turnorrepositionevery2hours
o Alsoimportantforprevention
•Debridementofnecrotictissue
•Woundcleansinganddressing
oNormalsalinepreferred
oAvoidharshchemicals
oAvoidocclusivedressings