Ch 34: Diabetes Mellitus

Question 1

How to AACE and ADA define hyperglycemia in hospitalized patients?

Answer 1

BG concentrations > 140 mg/dL

Can occur without previous diagnosis of DM; glucose usually returns to normal after resolution of critical illness in those without preadmission DM diagnosis

Seems to be caused by interactions between counterregulatory hormones and cytokines during illness or injury

Question 2

What is the diagnostic criteria for OGTT in DM, pre DM, and normoglycemia?

Answer 2

DM: > 200 mg/dL
Pre DM: 140-199 mg/dL
Nomral: < 140 mg/dL

OGTT should use a 75 g glucose load

Question 3

What is the diagnostic criteria for fasting BG in DM, pre DM, and normoglycemia?

Answer 3

DM: > 126 mg/dL
Pre-DM: 100-125 mg/dL
Normal: < 100 mg/dL

Fasting glucose should be done after patient has gone at least 8 hours w/out energy intake

Question 4

Why is use of sliding scale not recommended by AACE and ADA for prolonged use as sole approach to insulin therapy?

Answer 4

It may put patient at risk for wide fluctuations in glucose

Question 5

How does Metformin work?

Answer 5

Metformin decreases hepatic glucose production, increases insulin sensitivity by increasing peripheral glucose uptake and utilization and decreases intestinal absorption of glucose

ADA recommends Metformin be combined with other therapy if A1c target not attained w/in 3 months of metformin monotherapy

Question 6

For non-critically ill patient, what is the preferred approach for subq insulin administration?

Answer 6

Basal bolus dosing; this mimic normal physiological insulin patterns of basal and meal related insulin secretion in humans

Question 7

What is the diagnostic criteria for A1c in DM, pre DM, and normoglycemia?

Answer 7

DM: > 6.5%
Pre-DM: 5.7-6.4%
Normal: < 5.7%

Question 8

Hyperglycemia during hospitalization increases risk of what?

Answer 8

Infection, sepsis, poor healing, CHF, stroke, MI renal failure, transplant rejection, prolonged mech ventilation and ICU LOS

Question 9

What are A1c goals per the ADA?

What are A1c goals per the AACE/ACE?

Answer 9

• ADA generally recommends target of A1c < 7%; more or less stringent target depends on other factors (long v limited life expectancy, h/o severe hypoglycemia, advanced complications, etc)

AACE/ACE established A1c goal of 6.5% or less for those without concurrent illness and not at risk for hypoglycemia and A1c greater than 6.5% for those with concurrent illness and at risk for hypoglycemia

Question 10

What diagnostic factors are related to metabolic syndrome?

Answer 10

Metabolic syndrome consists of factors related to including resistance including abdominal obesity, dyslipidemia, elevated glucose level, elevated BP, and systemic inflammation

Question 11

What does A1c measure and what is it correlated with?

Answer 11

Measure of glucose levels during 3-month period. Highly correlated w/ development of microvascular (retinopathy, nephropathy, and neuropathy) disease and most useful indicator of treatment efficacy

Question 12

During PN advancement, dextrose should not be increased in PN until blood glucose concentrates are consistently less than what?

Answer 12

less than 200 mg/dL; regular glucose monitoring with correction insulin is required

Question 13

In a conscious patient, how is hypoglycemia treated?

Answer 13

15-20 g of rapid acting CHO should be administered with repeat CHO administration in 15 minutes of glucose values continue to show hypoglycemia. In addition, a small meal/snack should be provided

Question 14

What symptoms characterized Hyperglycemic Hyperosmolar state?

Answer 14

D|Can result when glucose levels rise above 600 mg/dL and are accompanied by severe dehydration and hyperosmolality w/out development of pronounced ketoacidosis

Question 15

What are some medications that may cuase hyperglycemia?

Answer 15

include steroids, catecholamines, thiazide diuretics, immunosuppressants, atypical antipsychotics and protease inhibitors

Question 16

Use of PN with GIR greater than what promotes hyperglycemia in critically ill patients

Answer 16

> 5 mg/kg/minute

Limiting energy intake while providing adequate protein is recommended to limit hyperglycemia and insulin resistance during the first week of ICU admit

Question 17

During first week of PN, why is hypocaloric feeding recommended for critically ill patients?

Answer 17

To reduce potential of hyperglycemia and refeeding; rates are less than 20 kcal/kg/day or 80% of estimated energy needs and at least 1.2 g protein/day

Question 18

What is the treatment for metabolic syndome?

Answer 18

Lifestyle modification, including diet/exercise w/ goal of 5-10% weight loss to prevent or delay dx of DM and reduce CV risk.

Oral medications may potentially be used

Question 19

High fasting glucose levels contribute to A1c of what?

Answer 19

A1c of 8.5% or more

Post prandial glucose elevations have greater influence on A1c when DM is better controlled (A1c < 7.3%)

Question 20

What type of insulin is NPH, glargine, detemir, degludec, and human regular U 500?

Answer 20

Basal insulin

Usually injected once or twice a day and intended to achieve a steady state of insulin with main purpose of controlling hepatic glucose output

B/c liver continuously produces glucose under fasting condition, patients who are not eating or receiving nutrition support need to have basal insulin administered

Question 21

For hospitalized patients receiving EN, how often is POC (point of care) glucose checks recommended?

Answer 21

Every 4-6 hours and more frequently checks every 1-2 hours when using IV insulin infusion or w/ sudden cessation of EN

Question 22

Per the ADA, what is the initial therapy for patients with newly diagnosed DM2?

Answer 22

The ADA recommends metformin and combo with lifestyle modifications (diet, exercise, weight loss) as initial therapy for patients with newly diagnosed DM2

Question 23

In patients with hyperglycemia or refeeding, dextrose should be limited to____ g of dextrose per 24 hours in first bag of PN

Answer 23

100 g per 24 hours in first bag of PN and should not be advanced until BG is well controlled and within target range.

At that time, PN may be advanced over the next 1-3 days toward nutrition goal while focusing on maintaining glycemic control and lyte balance

Question 24

Short acting insulin has onset, peak, and duration of what?

Answer 24

Onset in 30 to 60 minutes, peak of 2-4 hours, and duration of 5-8 hours

Question 25

What is type 1 DM?

Answer 25

Caused by autoimmune destruction of pancreatic beta cells leading to absolute insulin deficiency; rate of beta cell destruction is variable

Requires insulin to sustain life and prevent development of DKA

Question 26

In patients who are NPO, insulin infusion is primarily acting on what?

Answer 26

To restrain hepatic glucose production at a level that maintains the targeted glucose range and is analogous to basal insulin

When PN or EN is initiated the insulin infusion should be increased to manage both hepatic glucose output and glucose from nutrition

Question 27

For continuous IV insulin infusion method in critically ill patients, which kind of insulin is typically used?

Answer 27

Human regular U-100

B/c of very short half-life of circulating insulin, continuous IV infusion allows for rapid dose adjustments based on patient status

In general, continuous IV insulin infusion may be initiated at 05.-1 units/h based on patient characteristics and hospital protocol.Patients experiencing insulin resistance may require higher initial dose (2 or more units/h)

Question 28

For critically ill patient w/ hyperglycemia, continuous IV insulin therapy should initiate for glucose values of what?

Answer 28

> 180 mg/dL; more stringent goals of 110-140 mL/dL may be appropriate for some ICU patients if these goals can be accomplished w/out hypoglycemia

Question 29

What is the max dextrose infusion rec’d for critically ill patients with DM?

Answer 29

4 mg/kg/minute

Question 30

What are the dietary fat recommendations for patients with DM?

Answer 30

Limited research on ideal fat intake in DM; emphasize type of fat rather then amount

Saturated fat should not exceed 10% of total energy; trans fat should be avoided altogether

Recommendations and dietary guidelines no longer include cholesterol

Question 31

women not previously known to have DM or risk factors, when should testing for GDM occur?

Answer 31

During weeks 24-28

Question 32

How is hypoglycemia defined?

Answer 32

Any blood glucose value less than 70 mg/dL

Severe hypoglycemia is defined as blood glucose value less than 40 mg/dL

Risk factors include DM1, advanced age, malnutrition, increased severity of illness, renal impairment, liver failure, HF, previous h/o severe hypoglycemic episodes and autonomic neuropathy

Question 33

What is the minimum CHO recommendation for DM patients?

Answer 33

130 g/d; optimal CHO intake as a percentage is undefined

Glycemic index has not been beneficial in reducing A1C levels for those with DM2

Question 34

How is the 1500 rule calculated?

Answer 34

Divide 1500 by the total daily insulin dose.

For example, if total daily insulin requirement is 60 units, the sensitivity factors is 25 (1500/60 = 25), predicting the blood glucose level with decrease by 25 mg/dL for each unit of regular insulin given. If premeal glucose is 195 mg/dL and target is 140 ml/dL, glucose needs to decreased by 75 mg/dL to reach the target level; therefore, 3 units of regular insulin are needed.

The 3 units of regular insulin should be added to the scheduled insulin dose for that meal to bring the glucose into an acceptable range leading up to next meal

To use 1800 rule, steps are similar to 1500 rule above

Question 35

AACE/ACE includes presence of what as a diagnosis for pre-DM?

Answer 35

Metabolic syndrome

Question 36

What is the formula for corrected serum glucose considering serum sodium?

Answer 36

Corrected serum glucose = measured serum sodium + (0.016 x serum glucose – 100)}

Hyperosmolarity from hyperglycemia shifts fluid from intracellular to extracellular compartments resulting in dilution decrease in sodium levels

Intervention to correct sodium levels r/t hyperglycemia are unwarranted; sodium levels will return to normal as hyperglycemia is corrected and insulin shifts glucose and water back into the intracellular compartment

Question 37

Rapid acting insulins (lispro, aspart, and glulisine) have an onset, peak, and duration of what?

Answer 37

Onset in 5 to 15 minutes, peak at 30 to 90 minutes, and duration of approximately 4 hours

Question 38

What is the minimum glucose oxidation rate for glucose for patient on PN?

Answer 38

• Minimum requires for CHO delivery are 1 mg per kg/minute; max requirements of 4-7 mg/kg/min are individualized for the patient

Question 39

What is the 1500 and 1800 rule?

Answer 39

The 1500 rule estimates the sensitivity factor or the point drop in glucose for every 1 unit of regular insulin

The 1800 rule estimates the sensitivity factor or the point drop in glucose for every 1 unit of rapid acting insulin

Question 40

Which type of insulin should be used when initiating enteral nutrition in a hospitalized diabetic patient?

Answer 40

Regular insulin; When initiating enteral nutrition, use of short-acting insulin (regular insulin) is typically used as tolerance and titration may be unpredictable.

Question 41

Hyperglycemia in a patient receiving PN is associated primarily with what type of sodium/fluid imbalance?

Answer 41

Hypertonic hyponatremia

Hypertonic hyponatremia may result from hyperglycemia or administration of hypertonic sodium free solutions. Hyperglycemia causes a shift of water out of cells into the extracellular space, resulting in dilution of serum sodium. For every 100 mg/dL increase in serum glucose concentration above 100 mg/dL, the serum sodium would be expected to decrease by approximately 1.6 mEq/L. Treatment should consist of correction of the underlying hyperglycemia, not changes in sodium and water administration, as this is not a true sodium or water imbalance.