wk11- diabetic foot infections

Question 1

what is neuropathy

Answer 1

caused by damage to peripheral nerves

Question 2

types of diabetic neuropathy

Answer 2

1. sensory neuropathy- burning, tingling or paraesthesia in a stocking and glove distribution or numbness
2. motor neuropathy- atrophy in the intrinsic muscles of the foot, resulting in toe clawing and changes to the architecture of the mid foot leading to pressure redistribution over the metatarsal heads
3. autonomic neuropathy results in increased skin atrophy, dry or overly moist skin, hair loss to legs and brittle toe nails

Question 3

what happens with the blood vessels and nerves in the foot of a diabetic?

Answer 3

reduced blood flow and as a result a damaged nerve

Question 4

the main bacteria on the foot is?

Answer 4

Staphylococcus species account for 70% of the normal skin microbiome on the plantar zone of the foot.

Question 5

unregulated inflammation results in which of the following symptoms/conditions

Answer 5

tissue damage
pain
oedema

Question 6

how do infectious agents persist in wounds 6

Answer 6

-change in gene expression (change in virulence factors)
-altered microbial growth (reduced metabolic rate/reproduction)
-resistance caused by impaired host immune defenses
-resistance caused by antimicrobial resistance
-resistance caused by resistance to disinfection
-impaired wound healing dur to biofilm formation

Question 7

why do diabetics have delayed wound healing

Answer 7

sub-optimal blood flow to peripheral limbs, and impaired nutrient supply required to support the healing process.

Question 8

the most common diabetic foot infections?

Answer 8

Staphylococci or streptococci- as the depth and severity of the infection increases, these infections become polymicrobial and include with Gram-negative and anaerobic infectious agents.

Question 9

as resistance increases and species number also increases the infection goes from neuropathic to?

Answer 9

neuroischemic

Question 10

traits of neuropathic infections

Answer 10

warm
well perfused
palpable pulses
sweating is diminished
skin dry and prone to fissuring

Question 11

traits of neuriischemic infections

Answer 11

cool
poorly perfused
pulseless
skin thin, shiny and hairless

Question 12

when should foot infection be suspected and treated?

Answer 12

when 2 of the following are present
local swelling or induration
erythema extending more than 0.5 cm in any direction from the wound
local tenderness or pain
local warmth
purulent discharge.

Question 13

wound assessment involves 3

Answer 13

Careful inspection to identify signs of infection
Debridement to remove necrotic tissue
Probing to assess wound depth

Question 14

medical imaging is useful when the wound extends beyond what layer?

Answer 14

superficial fascia

Question 15

when shouldn’t microbial investigations and antimicrobial therapy be used

Answer 15

when theres no clinical signs and symptoms of infection

Question 16

swabbing wounds how to

Answer 16

Swabbing dry crusted areas is unlikely to yield the causative pathogen
Remove debris (debride) and surface exudate and clean with sterile saline prior to specimen collection
Pass the sterile collection swab deep into lesion and firmly sample the leading (advancing) edge of the wound

Question 17

why should uninfected wounds/ulcers not be processed in the diagnostic microbiology laboratory

Answer 17

all wounds are contaminated with infectious agents and ulcers are not meant to be sterile

Question 18

interventions for wound management 5

Answer 18

-wound management (dressing, removal of biofilm and debridement)
-glycaemic monitoring and control
-pressure area care
-management of ischemia via vascularization
-treatment of infected wounds (antimicrobial therapy and antisepsis)

Question 19

antimicrobial therapy for mild diabetic foot infections
-what level of infection, infectious agents, treatment duration and route

Answer 19

Involves only the skin and subcutaneous tissue
Erythema extends no more than 2 cm from the wound margin and there are no systemic features of infection

Gram-positive cocci (staphylococci, streptococci) with or without MRSA

1-2 weeks

orally

Question 20

antimicrobial therapy for moderate diabetic foot infections
-what level of infection, infectious agents, treatment duration and route

Answer 20

Involves structures deeper than the skin or subcutaneous tissues (eg muscle, bone, joint, tendon)
Erythema that extends more than 2 cm from the wound margin.

Gram-positive cocci; gram-negative rods; anaerobes with or without multidrug-resistant organisms (e.g., MRSA, extended-spectrum beta-lactamase–producing strains (ESBLs), vancomycin-resistant enterococcus (VRE))

2-4 weeks

orally or parenterally followed by orally

Question 21

antimicrobial therapy for severe diabetic foot infections
-what level of infection, infectious agents, treatment duration and route

Answer 21

Infection associated with systemic inflammatory response syndrome (SIRS)
Two or more of:
-abnormal temperature [more than 38°C or less than 36°C]
-heart rate more than 90 beats/minute
-respiratory rate more than 20 breaths/minute
-white cell count more than 12 × 109/L or less than 4 × 109/L, or more than 10% immature [band] forms

Gram-positive cocci; gram-negative rods; anaerobes with or without multidrug-resistant organisms (e.g., MRSA, ESBLs, VRE)

minimum 6 weeks

administer parentally then switch to orally

Question 22

do adults or children have better blood supply?

Answer 22

children