Diabetes, Pt. 3 Flashcards
What is the time of onset on a glucose curve? Nadir? Duration of effect? Glucose differential?
amount of time until apparent effect
lowest glucose value, ideally midway in dosing interval
how long the insulin lasts - amount of time the BG is in the ideal range when the nadir is acceptable
difference between highest and lowest glucose values, preferrable < 100
What is the ideal glucose range in a diabetic patient’s glucose curve? What in the main goal of therapy?
- DOGS: 80-200 mg/dL for 24 hours
- CATS: 80-300 mg/dL for 24 hours
eliminate clinical signs
What is the ideal nadir? When should it occur?
80-150 mg/dL
approximately halfway through dosing interval - time of nadir indicated peak insulin action
How should insulin dosages be altered if the nadir is too high or low? If it occurs too soon or late?
TOO HIGH = increase dose of insulin by 10-25%
TOO LOW = decrease dose of insulin by 10-25%
TOO SOON = change to a longer acting insulin
TOO LATE = change to a shorter duration
What is happening in this glucose curve?
nadir occurred too soon - change to longer acting insulin
What is happening in this glucose curve?
no response to insulin
- increase dose
- insulin resistance!
What is happening in this glucose curve?
nadir is too low and too soon
- likely rebound hyperglycemia
- decrease dose first
What is the Somogyi effect? What should be done when this is seen?
rebound hyperglycemia in response to severe hypoglycemia, due to the low levels of glucose causing catecholamine release —> glycosuria, severe hyperglycemia on spot BG measurements
decrease insulin by 25% and repeat the curve in a week
Unregulated diabetic:
When is insulin resistance expected?
- very difficult to regulate a patient on what should be adequate levels of insulin
- > 1.5 U/kg in dog or cat to get BG <300 mg/dL
What are some causes of insulin resistance?
- administration of drugs that antagonize insulin - corticosteroids commonly found in eye and ear meds
- heat cycle, diestrus, pregnancy
- bacterial infection - UTI, dental disease
- hypothyroidism
- hyperadrenocorticism
- acromegaly
- hyperthyroidism
- chronic pancreatitis
How can it be determined if it is truly insulin resistance or owners not giving insulin properly?
- observe owners’ administration
- discuss insulin handling and storage
- check for proper syringe
- check expiration dates
- double-check type of insulin and dose
- switch to non-diluted
What are the most common causes of hypoglycemia in response to insulin therapy?
- incorrect use of syringe
- concentrated insulin
- overlap of insulin action (long-acting)
- anorexia, vomiting
- maldigestion, malabsorption
- transient diabetes
- insulin dose too high
- aging, remission
What are common signs of hypoglycemia caused by insulin administration?
- behavioral changes
- ataxia
- depression
- ptyalism
- weakness, seizures
- stupor, coma
What are 3 potential long-term complications of hypoglycemia?
- cerebral edema
- temporary blindness
- behavior change
How long might a patient need to be on a dextrose drip after ecoming hypoglycemic on insulin therapy?
up to 3 days
After hypoglycemia, when should insulin be reinitiated?
when BG is in the diabetic range at a 50% reduced dosage
What are some signs of complicated diabetes?
- PU/PD
- lethargy, weakness
- inappetence
- vomiting, diarrhea
- emaciation
- dehydration, shock
- acetone odor on breath (DKA)
- neurologic abnormalities
What should be looked for in a patient that is no longer regulated on insulin therapy and has become sick? What should always be done in this case?
- pancreatitis
- UTIs
- renal disease
- metabolic disease
- Cushing’s
- hypothyroidism
- ketosis
- obesity
- acromegaly
(a diabetic dog should always be hungry!)
urine culture
What is hyperosmolar hyperglycemic state?
relative lack of insulin where hyperlgycemia causes osmotic diuresis and decreased fluid intake —> hyperglycemia + hypernatremia = hyperosmolarity
- most common in the peripheral tissues of cats with Type 2 diabetes
What is diabetic ketoacidosis?
insulin deficiency allows for the production of ketones from impaired fatty acid metabolism and their buildup in adipose tissue
What biochemical triad is present in diabetic ketoacidosis?
- hyperglycemia
- ketonemia/ketonuria
- metabolic acidosis
cane have ketosis without ketoacidosis = ketones present, but not at high enough concentration to cause acidosis
When is diabetic ketoacidosis most common? What causes this? What clinical signs are associated?
dogs and cats previously diagnosed with BM
inadequate insulin and concurrent infection, inflammation, or insulin resistant disorders
- dehydration
- depression, weakness
- tachypnea
- vomiting, abdominal pain
- acetone odor on breath
- slow and deep breathing
What are the 5 steps to the pathophysiology of DKA?
- glucose in unable to go into cells to be used as a fuel source = perceived starvation
- liver makes a huge amount of glucose and when cells cannot use it, the body starts using adipose tissue for energy (fat —> ketones)
- initial formation of ketone bodies are a protective mechanism against cellular starvation, but organs need insulin to use it
- utilization of ketones decreases, allowing for their accumulation
- increased amounts cause metbolic acidosis
How does DKA cause dehydration and hypovolemia? Nauseous signs? What electrolyte abnormalities are seen?
ketonuria and osmotic diuresis from glucosuria
ketonemia and hyperglycemia stimulate CTZ
hypernatremia, low K
What are the 4 most common signs of DKA?
- dehydration
- shock
- scidosis
- hyperosmolarity
What concurrent disease processes are most common in dogs and cats with DKA? Why?
- DOGS: acute pancreatitis, UTIs, hyperadrenocorticism
- CATS: hepatic lipidosis, CKD, acute pantreatitis, infections, neoplasia
increased stress hormones (glucagon, cortisol) counteract the effects of insulin = ketone prodcution
What is the goal to treating DKA?
- correct fluid deficits, acid-base balance, electrolyte imbalances
- reduced blood glucose and ketonuria
- being insulin therapy
- treat concurrent disease
What insulin is recommended for treating DKA? How does ketonemia and hyperglycemia affect this?
rapid acting - Regular —> lowers hyperglycemia and ketonemia —> once BG are lowered and maintained at 200-250 and clinical signs stop, longer acting ones can be used
with significant ketonemia, insulin must be given even if blood sugars are normalizing —> this means glucose needs to be added to fluids so that the insulin does not cause hypoglycemia - once ketones are normalized, glucose is weaned off
What is euglycemic ketoacidosis? What is critical in these patients?
DKA that occurs despite normal blood glucose almost exclusively in patients on SGLT2 inhibitors
insulin administration despite normoglycemia —> administer dextrose to maintain normal values!
What are common signs of diabetic hyperosmolar (nonketotic) syndrome?
DM symptoms and….
- dehydration
- lethargy
- depression, comatose
(most common in cats)
What is seen on serum biochemistry in patients wtih diabetic hyperosmolar (nonketotic) syndrome? Why?
- BG > 600
- minimal to no ketones
- serum osmolality > 350 mOsm/kg (glucose, sodium, BUN!)
relative lack of insulin + hyperglycemic osmotic diuresis + hypernatremia (lack of fluid intake) = hyperosmolarity
How should the hypoosmolar state seen in diabetic hyperosmolar (nonketotic) syndrome be corrected? Why? How is insulin therapy altered?
slow correction with a balance of fluids, BG, and electrolytes by reduceing BG at 50 mg/dL/hr, or else cerebral edema occurs
delayed 4-6 hours until fluids have improved the condition by correcting dehydration and improving urine production, hyperglycemia, hyperosmolarity, and electrolytes
What are the most common causes of death in diabetic patients?
- hypoglycemia
- euthanasia (exasperated owners by imperfect control) —> SGLT2 inhibitors will likely decrease this!
What are some considerations for diabetics that need to undergo surgery?
- ensure good glycemic control
- not allowed food in the morning, give half a dose of insulin
- schedule as first procedure
- monitor frequently
- 5% dextrose in fluids
- can use Regular insulin until awake enough to eat
