Ch 34: Diabetes Mellitus Flashcards
How to AACE and ADA define hyperglycemia in hospitalized patients?
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
What is the diagnostic criteria for OGTT in DM, pre DM, and normoglycemia?
DM: > 200 mg/dL
Pre DM: 140-199 mg/dL
Nomral: < 140 mg/dL
OGTT should use a 75 g glucose load
What is the diagnostic criteria for fasting BG in DM, pre DM, and normoglycemia?
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
Why is use of sliding scale not recommended by AACE and ADA for prolonged use as sole approach to insulin therapy?
It may put patient at risk for wide fluctuations in glucose
How does Metformin work?
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
For non-critically ill patient, what is the preferred approach for subq insulin administration?
Basal bolus dosing; this mimic normal physiological insulin patterns of basal and meal related insulin secretion in humans
What is the diagnostic criteria for A1c in DM, pre DM, and normoglycemia?
DM: > 6.5%
Pre-DM: 5.7-6.4%
Normal: < 5.7%
Hyperglycemia during hospitalization increases risk of what?
Infection, sepsis, poor healing, CHF, stroke, MI renal failure, transplant rejection, prolonged mech ventilation and ICU LOS
What are A1c goals per the ADA?
What are A1c goals per the AACE/ACE?
• 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
What diagnostic factors are related to metabolic syndrome?
Metabolic syndrome consists of factors related to including resistance including abdominal obesity, dyslipidemia, elevated glucose level, elevated BP, and systemic inflammation
What does A1c measure and what is it correlated with?
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
During PN advancement, dextrose should not be increased in PN until blood glucose concentrates are consistently less than what?
less than 200 mg/dL; regular glucose monitoring with correction insulin is required
In a conscious patient, how is hypoglycemia treated?
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
What symptoms characterized Hyperglycemic Hyperosmolar state?
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
What are some medications that may cuase hyperglycemia?
include steroids, catecholamines, thiazide diuretics, immunosuppressants, atypical antipsychotics and protease inhibitors
Use of PN with GIR greater than what promotes hyperglycemia in critically ill patients
> 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
During first week of PN, why is hypocaloric feeding recommended for critically ill patients?
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
What is the treatment for metabolic syndome?
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
High fasting glucose levels contribute to A1c of what?
A1c of 8.5% or more
Post prandial glucose elevations have greater influence on A1c when DM is better controlled (A1c < 7.3%)
What type of insulin is NPH, glargine, detemir, degludec, and human regular U 500?
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
For hospitalized patients receiving EN, how often is POC (point of care) glucose checks recommended?
Every 4-6 hours and more frequently checks every 1-2 hours when using IV insulin infusion or w/ sudden cessation of EN
Per the ADA, what is the initial therapy for patients with newly diagnosed DM2?
The ADA recommends metformin and combo with lifestyle modifications (diet, exercise, weight loss) as initial therapy for patients with newly diagnosed DM2
In patients with hyperglycemia or refeeding, dextrose should be limited to____ g of dextrose per 24 hours in first bag of PN
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
Short acting insulin has onset, peak, and duration of what?
Onset in 30 to 60 minutes, peak of 2-4 hours, and duration of 5-8 hours
What is type 1 DM?
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
In patients who are NPO, insulin infusion is primarily acting on what?
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
For continuous IV insulin infusion method in critically ill patients, which kind of insulin is typically used?
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)
For critically ill patient w/ hyperglycemia, continuous IV insulin therapy should initiate for glucose values of what?
> 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
What is the max dextrose infusion rec’d for critically ill patients with DM?
4 mg/kg/minute
What are the dietary fat recommendations for patients with DM?
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
women not previously known to have DM or risk factors, when should testing for GDM occur?
During weeks 24-28
How is hypoglycemia defined?
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
What is the minimum CHO recommendation for DM patients?
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
How is the 1500 rule calculated?
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
AACE/ACE includes presence of what as a diagnosis for pre-DM?
Metabolic syndrome
What is the formula for corrected serum glucose considering serum sodium?
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
Rapid acting insulins (lispro, aspart, and glulisine) have an onset, peak, and duration of what?
Onset in 5 to 15 minutes, peak at 30 to 90 minutes, and duration of approximately 4 hours
What is the minimum glucose oxidation rate for glucose for patient on PN?
• Minimum requires for CHO delivery are 1 mg per kg/minute; max requirements of 4-7 mg/kg/min are individualized for the patient
What is the 1500 and 1800 rule?
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
Which type of insulin should be used when initiating enteral nutrition in a hospitalized diabetic patient?
Regular insulin; When initiating enteral nutrition, use of short-acting insulin (regular insulin) is typically used as tolerance and titration may be unpredictable.
Hyperglycemia in a patient receiving PN is associated primarily with what type of sodium/fluid imbalance?
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.
