FOOT PROBLEMS IN DIABETIC PATIENTS Diagnosis and management

Objectives: Clarify the amplitude of the problem of diabetic foot Clarify the amplitude of the problem of diabetic foot Recognize the different patho-physiologic mechanisms leading to diabetic foot problems Recognize the different patho-physiologic mechanisms leading to diabetic foot problems Clarify the overall management of different problems related to the diabetic foot Clarify the overall management of different problems related to the diabetic foot

Amplitude of the problem: Diabetes mellitus is a rather very common systemic disease Diabetes mellitus is a rather very common systemic disease million people are diabetics in the US million people are diabetics in the US. 20% of these patients will be hospitalized at least once in their life time with foot problems 20% of these patients will be hospitalized at least once in their life time with foot problems Diabetic patients account for more than two thirds of patients undergoing non-traumatic limb amputation annually Diabetic patients account for more than two thirds of patients undergoing non-traumatic limb amputation annually This will cost a BILLION dollars every year This will cost a BILLION dollars every year Grunfeld et al

Patho-physiology NEOUROPATHYISCHAEMIAINFECTION

Neuropathy: One of the triad of the pathological conditions characteristic of this disease (neuropathy, nephropathy and retinopathy) One of the triad of the pathological conditions characteristic of this disease (neuropathy, nephropathy and retinopathy) Pathogenesis: Pathogenesis: Changes in the vasa nervosa Changes in the vasa nervosa Metabolic disorders with release of nerve toxic substance

Neuropathy affects: Motor Nerves resulting in: Motor Nerves resulting in: wasting of small muscles of the foot and foot deformities (claw foot) wasting of small muscles of the foot and foot deformities (claw foot)

Autonomic nerves resulting in: Autonomic nerves resulting in: Dryness of the skin and loss of sweat and oil secretion which leads to excessive callus formation and skin cracks Loss of neurogenic component of inflammatory response which leads to plunting of inflammatory response and less severe signs of a severe infections

Sensory nerves: Sensory nerves: sensory loss of superficial and deep sensation is the most important part of sensory affection Patients are unaware of trauma to the foot and usually result in pressure sores over weight bearing points of the foot

Neuropathic arthropathy: Neuropathic arthropathy: Joints can be affected by neuropathy resulting in the so called Charcot foot It is relatively painless progressive degenerative arthropathy of single or multiple joints caused by loss of proprioceptive and pain sensation leads to foot deformity and abnormal pressure points

Infection: Patho-physiology: Patho-physiology: peripheral neuropathy: Sensory and autonomic neouropathy provides site of entry of organisms and blunt neurogenic immune response Sensory and autonomic neouropathy provides site of entry of organisms and blunt neurogenic immune response Metabolic state: Hyperglycaemia an manifest protienurea causes a state of immuno-suppression

Infection causes increased metabolic and oxygen demands of tissues and inability to meet with this demand will increase tissue damage and necrosis

Microbiology: Microbiology: Usually in limb threatening diabetic foot infections there is polymicrobial bacterial infection with gram positive, gram negative, and anaerobic bacterial infection. sometimes with very severe life threatening infections fungus infection is also present

Ischemia: Diabetes mellitus is an independent risk factor for atherosclerosis (coronary, cerebral and peripheral) Usually atherosclerosis affects crural vessel (anterior tibial, posterior tibial and peroneal) with sparing of aortoiliac and femoral segments Ankle vessels runoff are usually patent (posterior tibial and dorsalis pedis),but they may lead to a diseased foot arches (distal vessel disease) Medial calcification affects all vessels but the vessels remain patent in spite heavy calcification

DIAGNOSIS Clinical examination: Clinical examination: Careful history taking and thorough general examination is essential Careful inspection and palpation of the foot lesion (look and feel in all aspects of the foot and between toes). Probing any foot ulcer or sinus to detect bone affection Palpation of peripheral pulses is essential to exclude ischaemia

Imaging studies: Imaging studies: Plain X ray: it is the basic study in all patients with diabetic foot it can show: osteomylitis, bone fractures, joint dislocations, foreign bodies, gas due to gas forming infections, soft tissue inflammatory hypertrophy MRI scan: very sensitive in detecting the extent of soft tissue infection and bone and joint involvement Bone scan and radio-active labeled leukocyte scan are of low clinical importance Pedobarography: computerized method to detect points of high pressure in patients with neuropathic ulcers

Vascular studies: Vascular studies: Ankle brachial pressure index (ABPI): is usually of no value in diabetic patients because of calcified pedal vessels Ankle brachial pressure index (ABPI): is usually of no value in diabetic patients because of calcified pedal vessels toe pressure is usually used in diabetics (toe pressure of 30 mm gH indicates good vascularity) Duplex scan: can be done to evaluate blood vessels in non limb threatening infections and in follow up Angiography: It is done when planning for vascular reconstruction in case of ischemic diabetic infections MRA: Is used in case of severe renal impairment and severe dye hypersensitivity which is not uncommon in diabetics

Treatment Treatment of neuropathic ulcers: Treatment of neuropathic ulcers: Avoid pressure over the ulcer Non weight bearing using crutches, wheel chairs and sometimes applying slabs and casts. Wearing a specially designed shoes specially prepared by foot care persons Topical applications on the ulcers trimming of the surrounding callus. Antibiotic ointments and gels. Applying saline soaked gauze pads Proper treatment of infection and ischaemia if present

Treatment of infection: Treatment of infection: Severe limb threatening diabetic foot infection should be treated as an emergency. Some of theses infection will require major limb amputation or may turn to a life threatening infections if not treated properly Treatment consists of: Surgical drainage and debridement Surgical drainage and debridement Antibiotic therapy Antibiotic therapy Care of general condition and blood sugar control Care of general condition and blood sugar control

Antibiotic therapy: Antibiotic therapy: In limb threatening diabetic foot infections the patient should be hospitalized and IV antibiotics administered to reach an efficient plasma concentration It should cover gram positive and negative bacteria and anaerobes as well It should be started as empiric treatment and soon be changed according to culture and sensitivity

Surgical drainage: Surgical drainage: It is the corner stone in treatment of diabetic foot infection. It should be done as soon as possible. It should aim at draining all pus pockets and debriding all infected tissues including bone and joints

Some hints: 1. Skin incision should be longitudinal and further than infected subcutaneous tissue which is further opened further than the deeper infected planes so no pockets will remain 2. Cartilage and cortical bone do not heal well and should be removed 3. Tendons are avascular and should be removed as hi as possible 4. Never attempt to close a diabetic foot infection wound the role is OPEN drainage

5. When planning your incisions and amputations be aware that the sole of the foot will be covered by sole skin and any remaining ulcer will not be in a pressure point ( long posterior flaps )

6. The best dressing is dressings which maintain a humid environment. Avoid irritant applications which are in common use like hydrogen peroxide 7. Remaining row clean areas can be covered later by flabs or split thickness skin grafts

Diabetic foot infection with ischaemia: Diabetic foot infection with ischaemia: Ischaemia with diabetic foot infection is diagnosed when there is inability to feel the pedal pulses It’s a dangerous condition which is usually a limb threatening and sometimes turn up to be a life threatening The patient should be referred to a vascular surgeon consultation as soon as possible Urgent vascular reconstruction may be needed for limb salvage

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