lab measures in diabetic foot mumbai

1. LABORATORY MEASURES INLABORATORY MEASURES IN
DIABETIC FOOTDIABETIC FOOT
Dr. Ghanshyam GoyalDr. Ghanshyam Goyal
ILS Multispeciality ClinicILS Multispeciality Clinic
S. K. Diabetes & Research Centre,S. K. Diabetes & Research Centre,
KolkataKolkata

2. Logic of Foot ExaminationLogic of Foot Examination
 DFU are expensive, potentially limb/life threatening butDFU are expensive, potentially limb/life threatening but
Highly PreventableHighly Preventable
 DFU affect 15% of all Diabetic SubjectsDFU affect 15% of all Diabetic Subjects
 Pts. DPN have annual incidence of DFU 7.2%Pts. DPN have annual incidence of DFU 7.2%
 DFU account for 20% of Diabetes-related hospitalDFU account for 20% of Diabetes-related hospital
admission (USA)admission (USA)
 Cause of DFU : 45 – 60 % Neuropathic, 25 – 45% areCause of DFU : 45 – 60 % Neuropathic, 25 – 45% are
neuro-ischemic, ~10% ischemicneuro-ischemic, ~10% ischemic

3. Priorities of Physical ExaminationPriorities of Physical Examination
 Non-Diabetic Subject – English –Non-Diabetic Subject – English –
Head – to – Foot ExaminationHead – to – Foot Examination
 Diabetic Subject - Sanskrit -Diabetic Subject - Sanskrit -
ApadaMastakApadaMastak
( Foot – to – head )( Foot – to – head )
Foot Examination is a priority in a DiabeticFoot Examination is a priority in a Diabetic
SubjectSubject

4. High Risk PatientsHigh Risk Patients
 Duration of Diabetes > 10 yearsDuration of Diabetes > 10 years
 Male > FemaleMale > Female
 Poor Blood Glucose ControlPoor Blood Glucose Control
 Patients with Cardiovascular, Renal or, RetinalPatients with Cardiovascular, Renal or, Retinal
ComplicationsComplications
John A. Colwell : Diabetes, p.38., 2003John A. Colwell : Diabetes, p.38., 2003

5. High Risk Foot - CausesHigh Risk Foot - Causes
 NeuropathiesNeuropathies
 VasculopathiesVasculopathies
 Foot Architecture – Congenital / AcquiredFoot Architecture – Congenital / Acquired
 Mechanical – Overweight, Shoes, CallusMechanical – Overweight, Shoes, Callus
 Others – Poor vision, elderly, ChronicOthers – Poor vision, elderly, Chronic
HyperglycemiaHyperglycemia
Examination and approach should address theseExamination and approach should address these
issues.issues.

6. Sensory Neurons – Fibers TypeSensory Neurons – Fibers Type
Fiber TypeFiber Type SizeSize ModalityModality
A-alphaA-alpha 13-20 microns13-20 microns
myelinatedmyelinated
Limb propioceptionLimb propioception
A-betaA-beta 6 – 12 microns6 – 12 microns
myelinatedmyelinated
L.P., vibration &L.P., vibration &
pressurepressure
A – deltaA – delta 1 5 microns1 5 microns Mechanical sharpMechanical sharp
painpain
CC 0.2-1.5 microns0.2-1.5 microns
unmyelinatedunmyelinated
Thermal, burningThermal, burning
painpain

7.  InspectionInspection
– Skin, nailsSkin, nails
– Architecture – pes planus, claw toeArchitecture – pes planus, claw toe
 Palpation – ADP & Post. Tibial, BonesPalpation – ADP & Post. Tibial, Bones
 Auscultation – bruitAuscultation – bruit
 SpecialSpecial
– MonofilamentMonofilament
– Tuning forkTuning fork
– Biothesiometry (VPT > 25)Biothesiometry (VPT > 25)
– Hand-held DopplerHand-held Doppler

8.  Sensorimotor nerve functions investigated bySensorimotor nerve functions investigated by
four bedside testsfour bedside tests
 MonofilamentMonofilament
 Achilles Tendon reflexesAchilles Tendon reflexes
 VPTVPT
– Tuning forkTuning fork
– BiothesiometerBiothesiometer

9. Lab MeasuresLab Measures
AA SensationSensation Large fibre: Tuning fork; monofilament &Large fibre: Tuning fork; monofilament &
biothesiometer’biothesiometer’
Small fibre: Pain, TemperatureSmall fibre: Pain, Temperature
BB VascularityVascularity Exam. Of pulses;Exam. Of pulses;
A/B index.A/B index.
CC PressuresPressures
(Planter)(Planter)
Movement – big toeMovement – big toe
Harris matHarris mat
Foot scanFoot scan
DD RadiologyRadiology X-ray; USG; Nuclear scan; MRIX-ray; USG; Nuclear scan; MRI
EE MetabolicMetabolic Hemogram, Sugar, Hba1c, RenalHemogram, Sugar, Hba1c, Renal
parameters, Serum albuminparameters, Serum albumin
FF MIcrobiologyMIcrobiology Wound C/S, Blood C/SWound C/S, Blood C/S

10. Semmes-Weinstein MonofilamentSemmes-Weinstein Monofilament
 5 g,5 g, 10 g10 g, 75 g, 75 g
 Sites – not standardized (RecommendedSites – not standardized (Recommended
sites : Great toe, heels & MT heads)sites : Great toe, heels & MT heads)
 Gently touch skin and apply pressure untilGently touch skin and apply pressure until
filament buckles – ask patientfilament buckles – ask patient
 DO NOT apply on ulcersDO NOT apply on ulcers
 Corns & Calluses are usually insensitiveCorns & Calluses are usually insensitive
 Sensitivity 95%, specificity 87% (10g)Sensitivity 95%, specificity 87% (10g)

12. Vibration PerceptionVibration Perception
 128 Hz Tuning Fork128 Hz Tuning Fork
 Large diameter fibersLarge diameter fibers
 Sensitivity > 80 %Sensitivity > 80 %
 Specificity ~ 60 – 70 %Specificity ~ 60 – 70 %
 Site not Standardized – base of great-toeSite not Standardized – base of great-toe
nail and on medial malleolusnail and on medial malleolus

13. BiothesiometerBiothesiometer

14. Temperature SensationTemperature Sensation
 Warmth -- Smallest, unmyelinated CWarmth -- Smallest, unmyelinated C
fibersfibers
 Cold – Small, myelinated ACold – Small, myelinated Aδδ fibersfibers
 Heating / Cooling detector uses theHeating / Cooling detector uses the
Peltier principle (metal element is heatedPeltier principle (metal element is heated
or, cooled according to the direction ofor, cooled according to the direction of
electric currentelectric current

15. NeurotipsNeurotips
 Disposable, made up of plastic with aDisposable, made up of plastic with a
sharp metal end and a blunt endsharp metal end and a blunt end
 Marketed by Owen Mumford, Oxford, UKMarketed by Owen Mumford, Oxford, UK
 Detects loss of touch sensation (superiorDetects loss of touch sensation (superior
to safety pins, needles or, hat-pins)to safety pins, needles or, hat-pins)

16. HCP SensitometerHCP Sensitometer
..
 Assessment ofAssessment of Thermal (Hot/cold) perceptionThermal (Hot/cold) perception
thresholdthreshold

17. Hand-held DopplerHand-held Doppler
 Excellent tool for vascular assessment at bed-Excellent tool for vascular assessment at bed-
sideside
 Normal sound Biphasic or TriphasicNormal sound Biphasic or Triphasic
 Atherosclerotic vessels – monophasicAtherosclerotic vessels – monophasic
 Ankle Brachial Index : < 0.9 usually indicatesAnkle Brachial Index : < 0.9 usually indicates
angiogram positive disease (falsely highangiogram positive disease (falsely high
because of high S.P. in atherosclerotic vessels).because of high S.P. in atherosclerotic vessels).

19. Ankle / Brachial PressureAnkle / Brachial Pressure
Index (ABI)Index (ABI)
 Normal ABI = 1Normal ABI = 1
 Ischemia < 0.85Ischemia < 0.85
Ankle / Brachial PressureAnkle / Brachial Pressure
Index (ABI)Index (ABI)

20. VASCULAR DOPPLER REPORTVASCULAR DOPPLER REPORT

21. Ankle/Brachial IndexAnkle/Brachial Index
 > 1.0> 1.0 NormalNormal
 0.9-1.00.9-1.0 Minimal diseaseMinimal disease
 0.5-0.90.5-0.9 ClaudicationClaudication
 <0.5<0.5 Rest pain, Severe arterialRest pain, Severe arterial
diseasedisease

22. Who Undergoes Vascular EvaluationWho Undergoes Vascular Evaluation
 All patients with foot lesionsAll patients with foot lesions
 Examination of pulsesExamination of pulses
 ABPIABPI
 Duplex scanDuplex scan
 AngiographyAngiography

24. Foot Pressure studies in DNFoot Pressure studies in DN
 Semi QuantitativeSemi Quantitative
– Pressure statPressure stat
– Harris matHarris mat
 QuantitativeQuantitative
– Foot ScanFoot Scan
– In shoe techniqueIn shoe technique
– Bare foot techniqueBare foot technique

25. Pressure StatPressure Stat Harris matHarris mat

26. ParomedParomed
 Static weight bearingStatic weight bearing
 Dynamic Gait patternDynamic Gait pattern
 Dynamic ImpulsesDynamic Impulses
 Quantum valuesQuantum values
 3-D analysis of peak3-D analysis of peak
plantar pressuresplantar pressures
during the ambulationduring the ambulation
periodperiod
0 N/cm2
to 19 N/cm2
20 N/cm2
onwards

29. X-ray FootX-ray Foot
 Soft tissue swellingSoft tissue swelling
 Foreign bodyForeign body
 Gas gangreneGas gangrene
 Vascular calcificationVascular calcification
 Loss of foot archLoss of foot arch
 Charcot’s arthropathyCharcot’s arthropathy
 AmputationsAmputations
 OsteomyelitisOsteomyelitis

33. Foot: MR ImagingFoot: MR Imaging
 Anatomical detailsAnatomical details
 Osteomyelitis (Abnormal marrowOsteomyelitis (Abnormal marrow
signal, soft tissue mass and corticalsignal, soft tissue mass and cortical
destruction)destruction)
 Neuropathic jointNeuropathic joint
-- Disorganised destruction, dislocation,Disorganised destruction, dislocation,
marrow edema, effusion, loss of jointmarrow edema, effusion, loss of joint
definitiondefinition

34. Charcots FootCharcots Foot

35. Selected Antibiotics Regimens for Initial Empiric Therapy of FootSelected Antibiotics Regimens for Initial Empiric Therapy of Foot
Infections in Patients with Diabetes MellitusInfections in Patients with Diabetes Mellitus
InfectionInfection Antimicrobial regimenAntimicrobial regimen
Non-limbNon-limb
threateningthreatening
Cephalexin 500mg p.o. q6hCephalexin 500mg p.o. q6h
Clindamycin 300 mg p.o. q8hClindamycin 300 mg p.o. q8h
Amoxicillin-clavulanate (875/125 mg) one q12hAmoxicillin-clavulanate (875/125 mg) one q12h
Dicloxacillin 500 mg p.o. q6hDicloxacillin 500 mg p.o. q6h
Levofloxacin 500-750 mg qdLevofloxacin 500-750 mg qd
Limb threateningLimb threatening Ceftriaxone 1 g IV daily plus clindamycin 450-600 mg IVCeftriaxone 1 g IV daily plus clindamycin 450-600 mg IV
q8hq8h
Ciprofloxacin 400 mg IV q12h plus clindamycin 450-600 mgCiprofloxacin 400 mg IV q12h plus clindamycin 450-600 mg
IV q8hIV q8h
Ampicillin / sulbactam 3 g IV q4-6hAmpicillin / sulbactam 3 g IV q4-6h
Piperacillin / tazobactam 3.375 g IV q4h or 4.5 g IV q6hPiperacillin / tazobactam 3.375 g IV q4h or 4.5 g IV q6h
Fluoroquinolone IV plus metronidazole 500 mg IV q6hFluoroquinolone IV plus metronidazole 500 mg IV q6h
Life threateningLife threatening Impenem cilastatin 500 mg IV q6hImpenem cilastatin 500 mg IV q6h
Piperacillin / tazobactam 4.5 g IV q6h plus gentamicin 1.5Piperacillin / tazobactam 4.5 g IV q6h plus gentamicin 1.5
mg/kg IV q8hmg/kg IV q8h
Vancomycin 1 g IV q12h plus gentamicin plusVancomycin 1 g IV q12h plus gentamicin plus
metronidazolemetronidazole

36. SummarySummary
 Periodic Examination of Foot is Mandatory in allPeriodic Examination of Foot is Mandatory in all
Diabetic PatientsDiabetic Patients
 Identification of Early foot problems canIdentification of Early foot problems can
prevent major events &prevent major events & CostCost
 Identification of High Risk Foot is possible atIdentification of High Risk Foot is possible at
Primary Care SettingPrimary Care Setting
 Education of Physician AND Patient is importantEducation of Physician AND Patient is important
for Prevention of Foot Complicationsfor Prevention of Foot Complications