Meet the Expert: Diabetic Foot

Transcription

1 Meet the Expert: Diabetic Foot AACE, Austin, May 2017 Andrew J M Boulton, MD, DSc, FACP, FRCP Universities of Manchester, UK and Miami, FL, USA

2 The art of medicine consists of amusing the patient while nature cures the disease Voltaire

3 Who is at risk of Foot Neuropathy Ulceration? Peripheral Vascular Disease Past history of foot ulceration Microvascular Complications (especially nephropathy) Poor glycemic control Cigarette smoking Foot deformity Amputation

4 How to assess for Neuropathy? Monofilaments Vibration Pin prick Ankle Reflexes Composite Score (eg., modified NDS) QST (eg., Biothesiometer) Electrophysiology

5 Monofilaments Advantages Cheap No specialist training No power source needed Up to 91% sensitivity Disadvantages Accuracy is the MF buckling at 10g? How many sites? How many sites missed to define abnormal? Time consuming Durability?

6 Bed-Side Instruments

7 The Ipswich Touch Test (IpTT) 265 diabetic patients assessed in three clinics VPT > 25 gold standard of risk 10g Monofilament tested on 4 sites/foot IpTT on 3 or 4 sites/foot: Neuropathy defined as >= 2 insensate sites in total IpTT also compared with 10g MF Rayman et al, Diabetes Care 2011:epub

8 Do not push, poke, prod or rub

9 N=265 VPT 25 V indicative of 'at-risk' feet 2/6 contact sites insensate MF ITT Sensitivity(%) Specificity(%)

10 Sensitivity ROC at 6 Contact points VPT>25V indicative of 'at-risk' feet insensate 2 insensate 3 insensate 4 insensate 5 insensate 6 insensate Specificity MF6 ITT 6

11 The Ipswich Touch Test (IpTT) IpTT and 10g MF showed almost perfect agreement. Both showed approximately 80% sensitivity and 90% specificity in identifying at-risk feet. Excellent PPV (c. 90%) and NPV (c 80%) IpTT a useful screening test for the at-risk foot requiring no equipment Rayman et al, Diabetes Care 2011:epub

12 The Ipswich Touch Test ticks all the boxes Rapid, Reliable Equipment that is readily at hand Safe and sterile Carried out by any member of the healthcare team with little training. Has no cost

13 Vibratip a pocket-sized, wipe-clean, battery operated disposable device for checking vibration sensation Study of 80 patients with varying severity of neuropathy Comparison with VPT (biothesiometer), 10 g monofilaments, modified NDS and IpTT. Bowling et al, 2011

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17 Vibratip a pocket-sized, wipe-clean, battery operated disposable device for checking vibration sensation Study of 80 patients with varying severity of neuropathy Comparison with VPT (biothesiometer), 10 g monofilaments, modified NDS and IpTT. Bowling et al, 2011

18 Spearman s Correlation of Vibratip with: Touch Test VPT VPT Cutoff NDS NDS Cutoff R value P Value < < < < < Sample size = 62.

19 Neuropad A simple visual indicator test to evaluate sympathetic autonomic neuropathy (sweating) in the feet. Correlates with NSS, NDS, QST and autonomic function testing as well as ith IENFD. Predicts risk of foot ulceration Quattrini et al, Diabetologia 2008;51:1046 Tentolouris et al, Diabetes Care 20110;33:1112

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23 The trouble with most doctors is not that they don t know enough but that they do not see enough Dominic Corrigan

24 At risk foot

25 Do not walk barefoot Burn to sole of foot Need footwear for protection

26 Foot Ulcer in developing country Rat Bite Dr. Abbas

27 Loss of proprioception

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29 Any patient with a plantar ulcer who walks into the clinic without a limp must have neuropathy Paul Brand

30 Elevated plantar pressure

31 Cases from the Diabetic Foot Clinic 1. Don t forget

32 Cases from the Diabetic Foot clinic 39y obese white male no known DM 2010 diet and fitness regimen Dec 2010 injured L foot at home trod on glass: treated with local antiseptic 14/01/11: presented to walk-in centre with L foot infection. RBG 324 mg%. 21/01/11: seen in diabetic foot clinic: normal pulses, NDS 7: VPT 32/20. Infected R 1 st mtp/hallux ulcer sausage shaped hallux

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38 Cases from the Diabetic Foot clinic Admitted 1 st ray amputation Diabetes controlled on diet and metformin Fundal examination - maculopathy Normal renal function 16/03/2011: post-op wound granulating well: HBGM mg%. Referred to retinopathy clinic.?? Foot eye syndrome (Walsh CH et al, Lancet 1975;1: ).

39 Don t forget: Motto of story Type 2 Diabetes can present with a foot ulcer.

40 Cases from the Diabetic Foot Clinic 2. Atypical ulcer

41 Case 2 TN, 27 yr Male T2DM diagnosed in 2009 Diet HBA1C - 10% July 2010 Metformin FH Father has T2DM Currently unemployed (Taxi driver) Smokes 10/day Alcohol - Nil

42 History of presenting illness 23/11/10 Admitted under surgeons Severe pain & swelling in Rt heel Generally unwell No h/o injury GP Rx antibiotics No effect Similar swelling in Lt heel 1/12 ago Not as severe Spontaneously discharged whitish pus Pain completely resolved

43 Examination Height 5 8 Weight 114 Kg BMI 38.5 Apyrexial Systemic examination unremarkable Rt heel Erythematous, tender and fluctuant swelling Necrotic skin overlying

44 Diagnosis & Treatment Diagnosis Abscess Treatment Incision & drainage Purulent material drained Necrotic overlying skin debrided Loculi broken & cavity curetted Saline washout Packed with aquacel ribbon IV Antibiotics

45 Post-operative period Culture & sensitivity Staph. Aureus - Fluclox Abscess cavity Sloughy ulcer discharging thick whitish secretions Developed multiple whitish nodular swellings over both plantar surfaces

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50 Oct 2008 Further history Admitted with severe pain in Lt Knee O/E Tender, hot, erythematous, swollen knee Diagnosis Septic arthritis Joint aspirated straw coloured fluid Microscopy No organisms C/S No growth Fluid sent to Prof Freemont NEGATIVELY BIREFRINGENT CRYSTALS

51 Diagnosis Acute Gout Treated with Colchicine & discharged No acute attacks since then Mild joint pains recently GP referred to Rheumatologists A/W OP appt

52 Referred to Prof Boulton CBGs around 180mg% MF dose increased Feet 24 x 28 mm Grade 2B ulcer over Rt heel Prominent metatarsal heads Sensations Normal All pulses palpable. Doppler biphasic. ABPI 1.0

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58 Diagnosis Foot ulcer secondary to tophaeceous gout Management Flucloxacillin Debridement as necessary Cleaning & dressing Off loading Scotch Cast Boot Further investigations Swab for C/S, Punch Biopsy, Crystal analysis

59 Swab c/s Staph. aureus sensitive to Fluclox Polarized light microscopy No crystals Histopathology Necrotic superficial squamous epithelium No dermis available for assessment Hyperkeratosis Fibrinous keratinous debris containing neutrophils Eosinophilic globule within fibrinous material Despite lacking foreign body giant cell reaction, suspicious of gouty tophus

60 Treatment for gouty ulcer in T2DM General life style modification i.e diet/wt/alcohol Good glycaemic control Urate lowering therapy Antibiotics if infected Cleaning & dressing Off loading Gentle debridement as necessary Surgical debulking of infected tophi

61 Cases from the Diabetic Foot Clinic 3. Multiple pathologies

62 Cases from the Diabetic Foot clinic 52y Type 1 DM 28yrs: painless DPN, retinopathy, proteinuria 1g/24 hr, egfr >90 ml/min Christmas Disease: factor IX conc <1%: Factor IX inhibitor, previous Hepatitis C 2002 L Charcot ankle 03/2011: swelling but no discomfort R ankle: O/E: dense DPN: VPT>50v. L ankle 36ºC, R 28ºC Diagnosis: Acute Charcot foot in area of multiple previous bleeds

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65 Right ankle

66 Left Ankle

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69 Cases from the Diabetic Foot clinic: Charcot in Christmas Disease - management Offloading with Aircast boot previously successful. Dangers of TCC Provided with Aircast 18/03/11 Returned after 4 days -

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71 Cases from the Diabetic Foot Clinic 4. A case of FUO?

72 A Case of FUO? 63 yr old male Type 2 DM 15y: insulin Maculopathy multiple laser, partially sighted Known peripheral neuropathy 18 months on CAPD diabetic nephropathy Admitted last Friday in May - FUO

73 A Case of FUO? Temp 38.3C. Tachycardia, normotensive CVS/RS nad Abdomen no tenderness exit site slight discharge. Legs moderate oedema bandage over R hallux CNS grossly inact

74 A Case of FUO? Hb 10.9g%, wbc 15.5 platelets normal Urea 34, Creat 766, K 5.0 Blood cultures negative CXR, ECG - unremarkable PD fluid culture negative Exit site culture skin commensals U/S and CT abdomen - unremarkable

75 A Case of FUO? Started on broad spectrum antibiotics No improvement after holiday weekend Diabetes team referral Tuesday Feet examined, dressing removed

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77 A Case of FUO: Motto of story In diabetes, ALWAYS examine the feet: lack of symptoms lack of Neuropathy

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