the diabetic foot

Question 1

what are the factors that predispose the diabetic foot

*

Answer 1

neuropathy - damage to the nerves - ssensory, motor and autonomic effected

peripheral vascualr disease

Question 2

what is the epidemiology of diabetic foot disease

Answer 2

prevalence in england and wales - 2-3%

prev of foot ulceration in dm is 5-7%

risk of amputation is 60x - poor subsequent prognosis - long term effects

10% hospital beds taken by dm problems - people have to stay in hospital becasue they cant bear weight for a long time

Question 3

how can you assess sensory neuropathy *

Answer 3

use a monofilament - nylon wire that gives specific weight when it bends

see whether the pt feels light touch

Question 4

describe the pathway to diabetic foot ulceration *

Answer 4

1. sensory neruopathy - important for the vitality of tissue - predicts nater ulceration
2. motor neuropathy = clawing of toes - imbalance of teh long extensor and plantar flexors to foot so lose shape of foot = knuckles scrape across surface of toe, need the motor sense to walk without it you put more weight on great toe metatarsal head = ulcerations
3. limited joint mobility - tendons are glycosylated (sugar sticks to collagen) = stop flexibility working - feet dont bend when walking
4. autonomic neuropathy - dry feet, control if the sweat gland that gives moisture is lost = lose integrity of the skin - have to use cream
5. peripheral vascular disease - lost arteries which is disasterous - no bloodd supply to feet
6. trauma - repeated minor/ddiscrete episodes
7. reduced resistance to infection - eg get fungi infection becasue they like the sugar = weaken our biome - lead way to more infection
8. other dm complicaations eg retinopathy - mean more likely to knock feet

Question 5

how can pvd be treated *

Answer 5

surgery

put in angioplasty - balloon blow up in blocked bit - increase diameter

or sew in vein to go around block

these aim to increase flow further down

Question 6

what is the neuropathic foot *

Answer 6

numb - bad because dont feel pain so get injuries

warm

dry - no autonomic supply

palpable foot pulses

ulcers at point of high pressure loading eg great metatarsal head

Question 7

what is the ischemic foot *

Answer 7

cold

pulseless

ulcer at extremity when blood supply is worse

Question 8

what is the neuro-ischemic foot *

Answer 8

numb

cold

pulseless

ulcers at points of high pressure loading and at margins

Question 9

describe a foot ulcer *

Answer 9

hard skin there first - bare weight incorrectly

then ulcer forms

thick skin around it prevents healing

Question 10

can only diabetics get gangrenous toes (eg from arterial problems)*

Answer 10

no - eg smokers can

Question 11

what are the steps if a pt has a gangrenous toe *

Answer 11

tissue dead so surgically amputate or allow to auto-amputate ie drop off - as long as not wet otherwise gangrene will spread

Question 12

what do you look for when you are assessing a diabetic foot *

Answer 12

appearance - is there a deformity/callus

feel - hot/cold are they dry - sweat is a good thing

foot pulses - dorsalis pedis and posterior tibial pulse

neuropathy - is there vibration sensation, temperature sensation, ankle jerk reflex, fine touch sensation - fine touch best way to predict future problems

Question 13

how do you manage a diabetic foot *

Answer 13

reduce bp - prevent macrovascualr disease

stop smoking

educate to look after feet - cut nails straight not close to the skin oterwise might cut skin and cause an ulcer

treat the dyslipidaemia

Question 14

how do you prevent a diabetic foot *

Answer 14

control the dm

inspect feet daily

have feet measured when buying shoes

buy shoes with laces and square toe box

inspect inside of shoes for foreign object

attend chiropodist

cut nails straight

never walk barefoot

Question 15

who is involved in an mdt for diabetic feet *

Answer 15

diabetes nurse

diabetologist

chiropodist

orthotist - get better fitting shoes

limb fitting centre

orthopedic surgeon

vascular surgeon

Question 16

how do you manage foot ulceration *

Answer 16

relieve the pressure - put on bed rest - however this has risk of dvt and heel ulceration. Redistribute pressure/total contact cast - avoid pressure on the ulcerated area

AB - treat osteomyelitis whihc is infection in bone, need ab for 3 months

debridement - remove the gangrenous area

revascularisation - angiography/arterial bypass surgery

amputation

Question 17

describe the charcot foot *

Answer 17

bottom of foot is like a rocker

bare weight in middle of foot

bones are in the wrong place

no pain because of neuropathy so people carry on walking

cause ulceration in middle of foot

Question 18

what is the difficulty in managing charcot foot *

Answer 18

need to know if fluid seen on x ray is from infection/inflammation

Question 19

what is the difference between osteomyelitis and active charcot *

Answer 19

both have hot red feeet

osteomyelitis has ulcer, charcot doesnt

in charcot mri - marrow oedema is in midfoot, on osteom it is in the forefoot and hindfoot near the ulcer

Question 20

is prevention or risk prediction better for managing diabetic foot - what could we use to predict risk *

Answer 20

prevention - on individual basis risk prediction not that effective

yrs since diagnosis, smoking, ethnicity, deprivaation, hba1c, sbp, cholesterol ratio, cardiac failur, af, cvd, renal, ra, retiopathy