Diabetic complications Flashcards
State the major cardiovascular risk factors
Modifiable: Diabetes mellitus Smoking Hypertension Hyperlipidaemia Obesity Physical inactivity
Non-modifiable: Age Male Ethnicity FHx
What are the main complications of diabetes mellitus?
Microvascular: Nephropathy, retinopathy, neuropathy
Macrovascular: MI (4x), stroke (2x), PVD
PVD includes acute limb ischaemia, intermittent claudication, critical limb ischaemia, and erectile dysfunction
What are the targets for HbA1c, BP, total cholesterol, and LDLs in DM?
HbA1c: T1DM <7.0%, T2DM 6.5-7.5%
BP <140/90 or <130/80 if end organ damage present
Total cholesterol <4 mmol/L
LDL <2 mmol/L
What are the types of diabetic retinopathy?
Background Pre-proliferative Proliferative Advanced retinopathy Maculopathy
What changes are seen with diabetic background retinopathy?
Microaneurysms
Blot haemorrhage
Hard lipid exudates
*Background retinopathy is usually the first finding in uncontrolled DM
What changes are seen with diabetic pre-proliferative retinopathy?
Cotton-wool spots (infarcts)
Venous beading
Venous loops
Haemorrhage
What changes are seen with diabetic proliferative retinopathy?
New vessel formation
Vitreous haemorrhage
Pre-retinal haemorrhage
Requires urgent referral due to sudden loss of vision
What changes are seen with diabetic advanced retinopathy?
Retinal fibrosis
Traction retinal detachment
What changes are seen with diabetic maculopathy? When should this be suspected?
Hard exudate
Microaneurysms
Retinal haemorrhage
Macular oedema
Suspect when there is decreased visual acuity
Besides retinopathy, name 2 other visual complications of diabetes mellitus
Cataracts: presents as fluctuating difficulty in reading
Rubeosis iridis: neovascularisation of iris, may cause glaucoma
How is diabetic retinopathy treated?
Laser treatment: Stabilises new vessels to prevent haemorrhage and increase flow. Preserves central vision, but can impact night vision.
Anti-VEGF injections
Intravitreal steroid implants
Vitrectomy: indicated for vitreous haemorrhage, retinal detachment, or severe fibrosis
Outline the impact of diabetic retinopathy on driving, and appropriate patient advice
Background retinopathy - safe to drive, may notice a little glare
Must be able to read number plates at 20m
Must inform DVLA of laser eye treatment
Maculopathy, pre-proliferative, and proliferative retinopathy may have difficulty with glare. Use sunglasses to reduce glare. Severe glare should stop driving.
Severe central visual loss - stop driving
Poor night vision after laser treatment - stop driving at night
What are the 3 main ways diabetes damages the kidney?
Glomerular damage
Ischaemia due to hypertrophy of arterioles
Ascending infection -> Pyelonephritis
How is diabetic nephropathy diagnosed?
Annual urinalysis for microalbuminuria (early, reversible) and proteinuria (late, irreversible).
Microalbuminuria defined as;
albumin:creatinine ratio >2.5 mg/mmol (men), or
albumin:creatinine ratio >3.5 mg/mmol (women), or
albumin concentration >20 mg/L
Once proteinuria is present, there is inevitable progression to end-stage renal disease.
Outline the management of diabetic nephropathy
Microalbuminuria: ACEi or ARBs with target <130/80 mmHg
Avoid oral hypoglycaemic agents with renal excretion (e.g. Metformin and glibenclamide)
Frequent eye checks for associated retinopathy (progresses rapidly)
State one histological change seen with diabetic nephropathy
Kimmelstiel-Wilson lesion: Nodular glomerulosclerosis with hyaline deposition. Occurs late.
What is the commonest presentation of uncontrolled diabetes mellitus?
Diabetic peripheral neuropathy
What is the earliest complication of uncontrolled diabetes mellitus?
Diabetic background retinopathy
What is the distribution of sensory loss in diabetic neuropathy?
Stocking distribution
What are the features of diabetic foot?
Ulceration
Infection (cellulitis, abscess, osteomyelitis)
Sensory neuropathy
Failure to heal trivial injuries
Name 4 risk factors for ulceration in diabetic
Previous ulceration Neuropathy (stocking distribution and Charcot foot) Peripheral arterial disease (highly calcified arteries) Altered foot shape Callus - indicate high foot pressures Visual impairment Living alone Renal impairment
What are the causes of ulceration in diabetic foot?
Neuropathy (45%)
Ischaemia of large or small vessels (10%)
Mixed neuropathic-ischaemic origin (45%)
Describe the presentation of diabetic foot with pure neuropathic ulceration
Warm foot with palpable pulses
Evidence of sensory loss -> unrecognised repeated trauma
Normal or high duplex USS flow
Describe the presentation of diabetic foot with ischaemic or mixed ulceration
Foot may be cool
Absent foot pulses
Ulcers commonly on toes, heel, metatarsal
Secondary infection with minimal pus and mild cellulitis
ABPI may be misleadingly high due to calcification of vessels
Low duplex USS flow
What investigations can be used to differentiate the causes of diabetic foot ulceration?
Ankle/brachial pressure index
Duplex USS
Angiography - suspected critical limb ischaemia
Outline prophylactic management of ulceration in diabetic foot
Specialist diabetic foot clinic with MDT Regular foot inspection Wide-fitting footwear Nail care with chiropody Debridement of calluses Keep foot cool Avoid walking barefoot
Outline the management of infection in established ischaemic ulceration
Treat local or systemic infection following trust ABX guidelines
Debride/amputate any necrotic tissue
Drain pus
X-ray for osteomyelitis
What surgical options are available for diabetic foot?
Angioplasty
Femoro-distal bypass graft
Amputation
What is Charcot’s foot?
A bone deformity that occurs in severe neuropathy. Altered osteoclast activity and vasculature softens bone. Repeated fracture and dislocation deforms the foot, resulting in ulceration (early) and loss of arch (late).
How is Charcot’s foot managed?
Relieve pressure
Plaster cast
Osteotomy if bone is prominent
Outline the management of diabetic neuropathic pain
1st line: Amitriptyline, duloxetine, gabapentin, or pregabalin
Tramadol as rescue medication for exacerbation
Pain management clinic for refractory pain
