Diabetes

Question 1

What is a predictor of risk in a diabet pt?

Answer 1

• Degree of end organ dysfunction
• degree of glucose control
• Impact seen on microvascular and macrovascular levels

Question 2

How is diabetes diagnosed?

normal?

pre-diabetic?

Answer 2

• Fasting plasma glucose (FPG) > 126 mg/dl
  
  • normal <100
  • Prediabetic 100-125
• A1C- measures average blood glucose for the past 2-3 months
  
  • normal <5.7%
  • Prediabetes 5.7-6.4%
  • diabetes >6.5%
• Oral glucose tolerance test- drink glucose, check bs 2 hrs after
  
  • normal <140
  • prediabetic 140-199
  • diabetic >200
• Random glucose >200

Question 3

What are treatments for type 2 diabetes?

Answer 3

• Dietary adjustments
• weight loss
• exercise
• 4 classes of oral anti-diabetic drugs
  
  • Secretagogues
  • Biguanides
  • Glitazones
  • A-Glucosidase inhibitors

Question 4

Who uses insulin?

What are the different types?

Answer 4

• All type 1 diabetics and 30% of type 2
• Long acting (Ultra-lente, glargine, detemir)
• Intermediate acting (NPH, Lente)
• Short acting (regular)- what we use in OR
• Ultra short acting (Lispro, aspart)

Question 5

What is considered hypoglycemia?

symptoms?

Treatment?

Answer 5

• Plasma glucose <50 mg/dl
• Symptoms: (may be masked by anesthesia)
  
  • sweating
  • tachycardia
  • restelss
  • pallor
  • fatigue
  • confusion
• Treatment- glucose
  
  • If unconscious:
    
    • glucose 0.5 g/kg IV or
    • glucagon 0.5-1 mg IV or IM

Question 6

Ketoacidosis:

Plasma glucose > _____

volume status?

What will you see on ABG?

Answer 6

• Plasma glucose >250 mg/dl
• High glucose osmotic diuresis, causing hypovolemia
• Ketoacids produced by breakdown of fat and proteins
• ABG:
  
  • anion gap develops
  • acidosis: pH<7.3, bicarb <18, K normal or elevated

Question 7

How is Ketoacidosis treated?

Answer 7

• Restore volume
• Insulin:
  
  • 0.1 unit/kg loading dose then 0.1 unit/kg/hour infusion
  • Sodium bicarb if pH <7.1
• *Cancel case and stabilize patient first

Question 8

What are some complications you would expect to see in a pt with diabetes?

Answer 8

• renal disease
• peripheral neuropathy
• gastroparesis
• autonomic neuropathy
• infections
• HTN
• cardiac disease

Question 9

What should you include in your assessment of a pt with diabetes?

Answer 9

• Type of diabetes and duration of disease
• Daily therapy- type of insulin/medications, diet, normal blood sugar range for them
• Pre-op EKG
• electrolytes
• HgbA1C
• Check bs in pre-op, cancel case if >300
• target range 80-180

Question 10

What is stiff joing syndrome?

How do you check for it

what should you be concerned about?

Answer 10

• Increase glucose levels over time cause fibrosis of joints and sclerodermic skin
  
  • Glycosylation of tissue proteins leads to limited atlanto-occipital mobility and laryngeal rigidity
  • check by having pt put hands in prayer pose, if palms cant touch, this correlates to difficult intubation (31%)
• 30-40% of pts with IDDM show evidence of limited joint mobility

Question 11

What else should you assess in the physical assessment of a diabetic patient?

Why?

Answer 11

• Thyroid gland size
• Pts with type 1 dm have a 15% association of other autoimmune diseases, such as:
  
  • hashimoto thyroiditis
  • graves disease

Question 12

Autonomic neuropathy:

prevalence?

What does it affect?

Anesthetic considerations?

Answer 12

• Autonomic nervous dysfunction results from diabetes
• present in 20-40% of all diabetics
• mostly affects the cardiovascular and GI system
• Anesthetic considerations:
  
  • orthostatic hypotension
  • resting tachycardia
  • loss of HR variability- if brady, atropine will not work, go straight to epi
  • cardiac dysrhythmias
  • altered regulation of breathing
  • sudden death
  • peripheral neuropathy
  • gastroparesis

Question 13

How do you manage insulin pre-operatively?

Answer 13

• Depends on type and dose
  
  • NPH: 2/3 dose night before and 1/2 am dose
  • Regular: 2/3 dose night before and no am dose
  • Insulin pump: overnight cut to 30%, d/c in am
• ***Double and triple check that the insulin pump is turned OFF

Question 14

Oral hypoglycemics should be discontinued ______ hours preop

Answer 14

24-48 hours

Question 15

What fluid should you avoid administering to a diabetic pt?

What should you consider for fluid status?

Answer 15

lactate because it converts to glucose

• Pt may be hypovolemic if they are diaresing d/t high osmolarity from excess glucose in plasma
  
  • look for fluid deficit and electrolyte abnormalities

Question 16

What do you need to consider regarding the anesthetic management of a diabetic pt?

Answer 16

• Schedule early in the day
• monitors depend of condition and surgical procedure
• possibility of difficult intubation
• consider aspiration precautions for gastroparesis (RSI)
• Oxygenation (50-100%) b/c they probably have cardiac disease
• check frequent bs
• avoid nephrotoxic agents
• may be more sensitive to cardiorespiratory depressants
• aggressively treat bradycardia with epi if you suspect autonomic neuropathy
• Position carefully to avoid ulcers d/t decreased tissue perfusion

Question 17

General vs regional in the diabetic patient

Answer 17

• Both can be safe to use
• GA
  
  • induces hormonal changes causing glycogenolysis and gluconeogenesis
• Regional
  
  • concern with neuropathy/compensatory mechanisms to vasodilation may be impaired
  • be prepared to use vasoactive drugs for BP control
  • Local will not be effective if injected into an infective site, inject above

Question 18

What questions do you need to have answered to decide how to manage the blood sugar in the OR?

Answer 18

• Need to determine how “tight” control needs to be
  
  • Did the pt take insulin or oral hypoglycemic on day of surgery?
  • How often should the blood glucose be monitored?
  • Will the pt require an insulin drig?
  • Will pt require a glucose containing solution?
  • How should they be managed postoperatively?

Question 19

What are the benefits of tight control?

Answer 19

• Tight control reduces risk of chronic complications in type 1
• may affect surgical outcome!
  
  • increased wound healing
  • decreased infection
  • decreased osmotic diuresis
  • decreased incidence of DKA
  • decreased risk of neurologic insult

Question 20

What are the goals of anesthetic management?

Answer 20

• AVOID hypoglycemia!!
  
  • frequent bs checks!!!
• minimize metabolic derangements
• There are different protocols

Question 21

How much does 1 unit of insulin lower blood glucose?

Answer 21

20-40 mg/dl

Question 22

How do we like a diabetic pts bs to be during anesthesia?

What do you do if hypoglycemia occurs?

Answer 22

• mild transient hyperglycemia to avoid hypoglycemia
• If hypoglycemia occurs:
  
  • 50 ml of 50% dextrose in water will increase 100 mg/dl

Question 23

What is an example of a non-tight method?

Answer 23

• check BS before surgery
• IV 5% dextrose 100-150 ml/hr
• administer 1/2 normal insulin dose SQ
• Have 2nd IV for fluid and anesthetic drug administration
• check bs q 1 hour
• BS>180 administer Regular insulin on sliding scale

Question 24

What are the disadvantages of non-tight method?

Answer 24

• SQ absorption unpredictable- depends on BP, blood flow, and temp changes
• Onset and peak subq insulin may not correspond with surgical stress and length
• 1/2 life of Regular insulin is short, causing rollercoaster glucose profile

Question 25

How can tight management be done?

Answer 25

• Insulin infusion- mix 100 units regular insulin in 100 ml NS
• check fasting BS
• IV with D5W 100 ml/hour and 2nd IV for fluids
• Insulin infusion started- to determine rate: BS/150 = units/hour
  
  • run insulin gtt on a pump!
• check bs q 1 hour and monitor K
• administer 20 mEq KCl added to D5W if K is low

Question 26

What are the risks and advantages to tight control?

Answer 26

• risk: hypoglycemia
• advantage: can continue into post-op care to maintain BS 140-180 mg/dl