Diabetes Pt 6 - Chronic Complications Flashcards
?
- Damage to blood vessels 2° chronic hyperglycemia
- Leading cause of DM-related death
- Macro- or microvascular
- Tight glucose control (in type 1 - DCCT study; type 2 - UKPDS) can prevent or minimize complications
Angiopathy
?
Diseases of large & medium-sized blood vessels
- Greater freq & earlier onset in pts w/DM
- cerebrovascular, cardiovascular, & peripheral vascular dz
Macrovascular angiopathy
- Decrease risk factors (yearly screening)
- Obesity
! Smoking (esp injurious to those w/DM & sig inc risk for blood vessel & CVD, CVA, & lower extrem amputation) - HTN
- High fat intake
- Sedentary lifestyle
A target BP of 130/80 is recommended for all pts w/DM
- Screen for & treat hyperlipidemia
ADA recommends (target values):
LDL <100 mg/dL
TG’s <150 mg/dL
HDL >40 mg/dL (M) & >50 mg/dL (F) - Rx’s (primarily statins) are rec for people who do not reach lipid goals w/lifestyle modifications & for people older than 40 yrs w/other CVD risk factors, regardless of baseline lipid lvls
?
Thickening of vessel membranes in capillaries & arterioles
Specific to DM & includes
- Retinopathy
- Nephropathy
- Dermopathy
- Clinical manifestations usually appear 10-20 years >dx (w/type 2 @ time of dx)
Microvascular angiopathy
?
Microvascular damage to the retina as a result of chronic hyperglycemia, presence of nephropathy, & HTN in pts w/DM
- Most common cause of new cases of adult blindness
- Nonproliferative: more common
- Proliferative: more severe
Diabetic retinopathy
?
- Involves retina & vitreous humor
- New blood vessels formed (neovascularization); very fragile & bleed easily
- Can cause retinal detachment
Proliferative (most severe)
?
Partial occlusion of small blood vessels in retina causes microaneurysms to develop in capillary walls
- Vision may be affected if macula is involved
Nonproliferative (most common)
Persons w/DM are also prone to other visual problems
- Glaucoma occurs as a result of the occlusion of the outflow channels 2° to neovascularization; this type of glaucoma is difficult to treat & often results in blindness
- Cataracts develop @ an earlier stage & progress more rapidly in people w/DM
- Initially no changes in vision
- Annual eye exams w/dilation to monitor
- Maintain glycemic control & manage HTN
Treatment
- Laser photocoagulation
- Most common
→ to reduce risk of vision loss in pts w/proliferative retinopathy or macular edema & in some cases of nonproliferative retinopathy - Laser destroys ischemic areas of retina
> Vitrectomy
- Aspiration of blood, membrane, & fibers from inside the eye through a small incision behind the cornea
- Drugs to block action of vascular endothelial growth factor (VEGF)
?
Damage to small blood vessels that supply the glomeruli of kidney
Leading cause of ESRD
Risk factors
- HTN
- Genetics
- Smoking
- Chronic hyperglycemia
Diabetic nephropathy
> Annual screening
- Check for albuminuria w/measuring albumin-to-creatinine ratio in a random spot urine collection; also serum creatinine as an est of GFR & ° of kidney function
> If albuminuria is present, drugs to delay progression
- ACE inhibitors (e.g., lisinopril [Prinivil, Zestril])
- Angiotensin II receptor antagonists (e.g., losartan [Cozaar])
- Control of HTN & tight BG control imperative
?
Nerve damage d/t metabolic derangements of DM
Of pts w/DM, 60-70% have some ° of ___
- Reduced nerve conduction & demyelinization
- Sensory or autonomic
Diabetic neuropathy
- The pathophysiologic processes of diabetic neuropathy are not well understood
- Several theories exist, including metabolic, vascular, & autoimmune factors
- Prevailing theory is that persistent hyperglycemia leads to an accumulation of sorbitol & fructose in the nerves that causes damage by an unknown mechanism
- Result is reduced nerve conduction & demyelinization
- Ischemia in blood vessels damaged by chronic hyperglycemia that supply the peripheral nerves is also implicated in the development of diabetic neuropathy
- Neuropathy can precede, accompany, or follow the dx of DM
The 2 major categories of diabetic neuropathy are ___ neuropathy, which affects the peripheral nervous system, & ___ neuropathy
- Each of these types can take several forms
sensory; autonomic
___ neuropathy
- Loss of protective sensation in lower extremities
! Major risk for lower limb amputation
Sensory
___ ___ ___
- Most common form of sensory neuropathy
- Affects hands and/or feet bilaterally
- loss of sensation [complete or partial loss of sensitivity to touch & temp]
- abn sensations [pt reports walking on pillows or numb feet; sensitive skin to the point of light pressure from bed sheets is intolerable]
- pain [burning, cramping, crushing, or tearing; worse @ night]
- paresthesias [tingling, burning, itching sensations]
Distal symmetric polyneuropathy (aka stocking-glove neuropathy)
Neuropathy: Neurotrophic Ulceration
- Foot injury & ulcerations can happen w/o pt’s ever having pain
- Neuropathy can also cause atrophy of the small muscles of the hands & feet, causing deformity & limiting fine movement
Treatment for sensory neuropathy
- Tight BG control
- Drug therapy
- Topical creams (e.g., capsaicin [Zostrix])
- Tricyclic antidepressants (e.g., amitriptyline [Elavil])
- SSRIs, SNRIs (e.g., duloxetine [Cymbalta])
- Anti-seizure rx’s (e.g., gabapentin [Neurontin], pregabalin [Lyrica])
?
- Can affect nearly all body systems & lead to hypoglycemic unawareness, bowel incontinence & diarrhea, & urinary retention
- Gastroparesis
- Delayed gastric emptying
→ anorexia, n/v, GERD, & persistent feelings of fullness
! can trigger hypoglycemia by delaying food absorption - Cardiovascular abnormalities
- Postural hypotension, resting tachycardia, painless MI
Autonomic neuropathy
Sexual function
- ED
- Decreased libido
- Vaginal infections
Neurogenic bladder → urinary retention
* Empty frequently, use Crede’s maneuver
Rx’s
- Cholinergic agonist rx’s like bethanechol (Urecholine)
- Self-catheterization
Foot Complications
- Microvascular & macrovascular diseases increases risk for injury & infection
- Sensory neuropathy & PAD are major risk factors for amputation
- Also clotting abnormalities, impaired immune function, autonomic neuropathy
- Smoking is deleterious to health of lower extremity blood vessels & increases risk for amputation
- Sensory neuropathy → loss of protective sensation (LOPS) → unawareness of injury
- Monofilament screening
- Peripheral artery disease
- ↓ blood flow, ↓ wound healing, ↑ risk for infection
! intermittent claudication, pain @ rest, cold feet, loss of hair, delayed capillary filling, & dependent rubor (redness of skin that happens when extremity is in a dependent position)
Patient teaching to prevent foot ulcers
- Proper footwear
- Avoidance of foot injury
- Skin & nail care
- Daily inspection of feet
- Prompt treatment of small problems
- Diligent wound care for foot ulcers
- Neuropathic arthropathy (Charcot’s foot)
> Results in ankle & foot changes that ultimately lead to joint dysfunction & footdrop; abn distribution of wt over the foot
