DR M A IDRIS

AIMS OF INVESTIGATION IN DMFS  Risk factors /Aetiology  Comorbidities  Complication(s)  Monitoring of treatment  Prognostication

APPROACH  General Investigations  Specific Investigations I. Infections I. Ischemia II. Neuropathy

GENERAL INVESTIGATIONS  Fasting or Random Blood Glucose  Glycoheamoglobin (HbA1c)  E/U/Cr  Urinalysis.

GENERAL INVESTIGATIONS  FBC+ Diff  ESR+CRP  Fasting Lipids Profile .

INVESTIGATIONS OF DMFS INFECTIONS  M/C/S : samples in order of clinical utility  Wound swab: Least clinical utility  Tissue scrapings from base of debrided ulcer:  Deep space pus aspirate : Most accurate  Bone biopsy: Gold standard in osteomyelitis  Imaging

WOUND CULTURES  Serious infections are usually caused by 3 to 5 bacterial species  Gram positive aerobes: most important pathogens in diabetic foot -Staph Aureus (40%) -Streptococci-30%  Gram negative aerobes – Enterobacteriaciae – chronic or previously treated wounds(40%),Pseudomonas – often in wounds treated with wet dressings  Anaerobes  Fungi

PLAIN RADIOGRAPH  First line Imaging modality  View: Anterior posterior, lateral and oblique views.  Osteomyelitis  Fractures,  Dislocations seen in neuropathic osteoarthropathy.  Medial arterial calcification  Soft tissue gas  Foreign bodies

DIAGNOSING OSTEOMYELITIS  Larger (>2cm)  Deeper (>3mm)  ESR > 70 mm/hr  If you can touch bone 90% correlation with osteomyelitis  Bone biopsy and culture(Gold standard).  X-ray – changes take 2 weeks to occur Sensitivity 55 %, specificity 75% Focal osteopenia, cortical erosions, periosteal reaction

PLAIN RADIOGRAPH IN OSTEOMYELITIS

OTHER IMAGING IN OSTEOMYELITIS  MRI - Sensitivity > 90%, specificity > 80 % -Osteomyelitis hyperintense on T2  CT: less sensitive than MRI but better than Plain radiograph.  USS: 85% sensitive, 45% specific

MRI IN OSTEOMYELITIS

OTHER IMAGING IN OSTEOMYELITIS  Nuclear imaging(Tc-99-MDP,HMPAO, Indium-111) 85% sensitive, 45% specific  Leukocyte Scans  PET :Most accurate with sensitivity of 96% and spec of 91%

INVESTIGATION OF ISCHAEMIA Ankle-Brachial Index (ABI)/Segmental Pressures/Toe Pressures - Assess pressure at multiple levels on the limb or digit Arterial Duplex Ultrasound - Duplex ultrasonography of the arteries Transcutaneous Oximetry (TcPO 2 ) – measures the oxygenation of the tissues around the ulcer

TOE BRACHIAL INDEX(TBI)  Toe systolic pressure/Brachial systolic pressure  Less prone to falsely elevated values Vs ABI  Normal >0.7  Mild  Moderate  Severe <0.35 INVESTIGATION OF ISCHAEMIA

 Laser Doppler velocimetry and measurement of SPP  Arteriography : Detailed imaging of the vessels.. INVESTIGATION OF ISCHAEMIA

NEUROPATHY INVESTIGATIONS  Semmes-Weinstein monofilament test.  Measurement of Vibration perception threshold using biothesiometer  Nerve conduction studies

NEUROPATHY INVESTIGATIONS  Plantar pressure assessment using - Harris Mat -Pressure stat

NEUROPATHY INVESTIGATIONS PressureStat®

INVESTIGATIONS IN CHARCOT FOOT  X-Ray  bone scan Tc99 sulphur colloid:  Labeled leucocytes scan  MRI:

CONCLUSION  Investigation is aimed at detecting risk factors, aetiology, comorbidities, complications & prognostication.  Interpret with caution.  Proceed from non invasive to invasive investigations  Investigation should start immediately after diagnosis of DM.  PREVENTIVE MEDICINE IS THE WAY TO GO!!!

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