Infection/Wound & Dressings

Wendy McInnes ; Vascular Nurse Practitioner

The Lyell McEwin Hospital, Adelaide, South Australia

wendy.mcinnes@sa,gov.au 0447 051 036

WIFi – Foot Infection

Clinical Manifestation of Infection PEDIS Grade

Infection Severity

No local or systemic signs of infection 0 Uninfected

Infection present, as defined by the

presence of at least 2 of the following:

• Local swelling or induration

• Erythema > 0.5 to < 2 cm around the ulcer

• Local tenderness or pain

• Local warmth or purulent discharge (thick, opaque to white or sanguineous secretion)

1 Mild

Infection involving structures deeper than

skin and subcutaneous tissues (e.g. bone,

joint, tendon, muscle) or erythema > 2 cm

around ulcer margin and NO altered infection parameters (see below)

2 Moderate

Evidence of local infection with 2 or more of

the following altered parameters:

• Temperature >38° or <36°C

• Heart Rate >90 beats/min

• Respiratory rate >20 breaths/min or PaCO2

<32 mmHg • White cell count < 4 or > 12 x 109/L

3 Severe

Foot Infection: IDSA/PEDIS System of Infection Severity

Infection Local swelling or Induration

Purulent discharge

Odour

Friable tissue – bleeds easily

Abscess formation

Delayed Healing

Infection

Don’t always show signs of infection

Infection

Investigations Complete blood counts, HbA1c, liver function, serum creatinine

C-reactive protein, erythrocyte sedimentation rate (ESR) (markedly high markers are suggestive of osteomyelitis)

X ray for all patients with suspected non superficial Diabetic foot infection; particularly if ulcer present for over 2 weeks (assess deformity, bone destruction, soft tissue gas and foreign bodies)

MRI if abscess, OM or Charcot is suspected especially if ulcer is chronic, deep or overlying bony prominence

Bone scan or labelled white cell scan – if MRI is contraindicated/not possible

ABI/ Toe pressures

CT angiogram or MR angiogram – consider when ulcer doesn’t heal in 6 weeks despite optimal management OR urgent imaging and revascularisation if ankle pressure , 50 mmHg/ABI <0.5 Toe pressure <30mmHg

Deep tissue histology and microscopy, culture and sensitivities – punch biopsy or curette after cleaning/debridement – aspirate purelent secretions with sterile needle/syringe

Do not obtain repeat cultures unless evaluating non response or for infection control surveillance

Considerations

– Sepsis

– Perfusion

– Functionality / offloading

– Bone Involvement

– Age/Lifestyle

– Co-morbidities/ Risk factors

Infection

Infection – delayed closure

Infection Impiric Antibiotic Therapy – according to severity of infection (CALHN)

Likely pathogens - Methicillin sensitive Staphylococcus aureus & Beta-haemolytic streptococci

High Risk MRSA – add vancomycin

and seek ID advice

High Risk Psueodomonas spp.

Replace IV amoxicillin/clavulanic acid with

Piperacillin/tazobactam 4.5g IV 6hrly

Central Adelaide Local Health Network : Infectious Diseases 2017

Diabetic Foot Infection Assessment, Management & Treatment Guideline

Severity of Infection

(refer to Appendix

1

Table 3) for

classification

No Penicillin or Cephalosporin

Allergy

Penicillin Allergy (Delayed rash

which is NOT urticarial or

DRESS/SJS/TEN)

High Risk Penicillin / Cephalosporin

allergy (e.g. anaphylaxis, urticaria,

bronchospasm, angioedema,

DRESS/SJS/TEN)

For antibiotic allergies not listed above, consult ID for advice

Ulceration

(no infection) Antibiotics not recommended

Mild Infection Dicloxacillin 1 gram

PO QID*

If patient has received

antibiotic therapy in the past

month instead give

Amoxicillin/ Clavulanate

875/125mg PO BD* (for additional

Gram negative & anaerobic cover)

Cefalexin 1 gram PO QID*

Clindamycin 450 mg PO TDS

Moderate Infection

(if patient has

received antibiotic

therapy in past

month – treat as for

severe infection

below)

Flucloxacillin 2 gram IV

6-hourly*

PLUS

Metronidazole 400 mg

PO BD

Followed by:

Dicloxacillin 500mg

PO QID*

PLUS

Metronidazole 400 mg PO BD

Cefazolin

2 gram IV 8-hourly*

PLUS

Metronidazole

400 mg PO BD

Followed by:

Cefalexin 500mg PO QID*

PLUS

Metronidazole 400 mg PO BD

Clindamycin 450 mg PO TDS

Severe Infection

Amoxicillin / Clavulanic acid

1.2 g IV 8-hourly*♠

Cefepime 2 gram IV

8-hourly*#

PLUS Metronidazole 400mg PO BD

Clindamycin 900 mg IV

8-hourly (slow infusion)

PLUS

Ciprofloxacin*# 400mg IV

12-hourly OR Ciprofloxacin*# 750 mg PO BD

Once systemically improved, switch to oral therapy according sensitivity results (seek advice from ID)

Infection

Antimicrobial Stewardship

Oral antibiotics

IV antibiotics

May require long term antibiotics

PICC /24 hr infusion

Antimicrobials

Wound Ulcer Classifications Wagner

– ulcer depth, gangrene, loss of perfusion

– 6 grades

– does not take into account infection& ischaemia

University of Texas

– Two part score, grade & stage

WIFi –

– Wound, Ischaemia, Foot infection

World Union of Wound Healing Societies 2016 “Local Management of Diabetic Foot Ulcers – A position Document” Wounds International

WIFi – Wound Grading Classification

Grade Ulcer Gangrene

0 None No

1 - Small shallow ulcer, no bone exposure

unless limited to distal phalanx

- Minor tissue loss, salvageable with 1-2 digital amputations

No

2 - Deeper with bone exposure not

involving heel /shallow heel ulcer,

without calcaneal involvement

- Major tissue loss, salvageable with > 3 digital amputations/standard TMA

Digits only

3 - Extensive deep ulcer involving forefoot

and/or midfoot/ deep full thickness

heel +/- calcaneal involvement

- Extensive tissue loss, salvageable only

with complex foot reconstruction/non-

traditional proximal TMA/flap coverage

or complex wound management needed for soft tissue defect

Extensive/Heal

Wound Grading Classification

*TMA, Trans-metatarsal amputation

The Wound T: tissue viability Location

I: infection / inflammation Pain

M: moisture imbalance Odour

E: edge of wound Education

Debridement

Reduce Bioburden and biofilm reformation

Reduce Callous

PERFUSION ? Promote eschar

IS IT SAFE????

Wound Management Moisture Balance

Low Exudate

May require increased moisture if perfusion ok

May require slough removal

Consider gel (PHMB/ Superoxidized )

High exudate

Slough & high levels of exudate

Maceration

Excoriation

Wound Management

Dry Necrotic Tissue

Keep Dry – can paint with betadine

Prevent Infection (always cover even in shower)

Low adherent dressing or gauze between toes

Keep covered so as not to induce infection – demarcated areas can allow bacteria in

Oedema Management

Risk of skin damage from adhesives

Venous insufficiency, cardiac, renal issues

Consider compression if perfusion intact

Cleansing Normal saline or sterile water

Antiseptic Solutions

– Povidone Iodine (promotes eschar – dry gangrene)

– PHMB (surfactant lifts debri)

– Super-oxidised solutions – (disrupts biofim & planktonic bacteria)

International Wound Infection Institute 2016 “Wound Infection in Clinical Practice International consensus update 2016

Note – antimicrobial effect on biofilm increases with exposure time – washes/soaks for smaller time periods may not see the same effects as studies reporting 24 hour exposure time

Edwards-Jones, V 2017 “Wound Biofilms: What makes them stick? Wound Essentials, Vol 12, No.1

Bjarnsholt T, Eberlein T, Malone M, &Schultz G 2017 Management of Biofilm Made Easy” Wounds International, May 2017

Wound Management

NO EVIDENCE

Absorb excess exudate

Maintain moist environment

Protect surrounding skin

Barrier to bacterial contamination

Cost effective

Not require frequent changes

Gas and water vapour permeable – no films

Comfortable

Not too bulky – added pressure - footwear

Dry Moist Exuding Heavily Exuding

Hydrogels Films Foams/Absorbent pads Extra Absorbent Pads

Gel sheets Hydrocolloids Absorbent Films Hydrofibre

Non adherent nets/dressings Alginates Negative Pressure

Wound

Hydration/

Debridement

Moisture

Retentive

Exudate

Management

Infected

Heavily Colonised Antimicrobials

Silver

Iodine based dressings

Disinfectant Solutions/Gels

Never debride legs

or feet if decreased

blood supply

Protect the Skin Odour

Control Offload Pressure

First Aid Kit

Povidone Iodine

– Betadine (promote gangrene)

– Inadine (decrease bacterial load)

Gel - consider PHMB or Super-oxidized Solution

Absorbent – reflect exudate level

– Foam – expensive option

– Absorbent pads (cheap option) – some better than others

– Calcium Alginates (stop bleeding)

– Fibre dressings (+/- silver)

Non adherent contact layers (some much more expensive than others

Primary/secondary dressing (not films)

Tubular compression – oedema reduction if perfusion ok