Wk4 Flashcards
what is insulin
• Considered the body’s main fuel storage hormone.
• Secreted by pancreatic beta cells in response to raised levels of glucose in the blood.
Overall function:
1)Ensure tissues have adequate chemical substrates for energy
2)Storage
3)Anabolism and repair
• It is synthesised in the beta cells from a larger protein known as proinsulin (the storage form of the hormone)
normal insulin glucose metabolism
- Insulin binds to insulin receptor on cell surface
- Generation of intracellular signal
- Glucose transporter moves from inactive site to cell wall
- Glucose transported across cell wall.
release and circulation of insulin
• Insulin released via capillaries into portal circulation to the liver
• Pulses every 30 -60 minutes, increased release with extra stimuli
– most important of which is raised blood glucose.
• Initial release of insulin happens within 30 – 60 seconds.
Slower release over the next 60 – 90 minutes
• Insulin facilitates removal of glucose from the blood and promotes storage of metabolic fuels
• It affects uptake, utilization and storage of carbohydrates, fats and proteins in the liver, adipose and muscle cells, so that nutrients are stored as:
– Glycogen, triglycerides, fatty acids and proteins.
ultra-rapid acting insulin and example
analog of human insulin, 5-15min onset, last 3-6hrs
Lispro(Humalog) immediately B4 eating, Aspart (Novolog) eat straight after
short duration/slow acting insulin and example
unmodified crystalline insulin, 30-60min onset, 7hr duration, clear soln. given as SC
actrapid
intermediate insulin and example
humulin neutral protamine Hagedorn, 60-180min onset, 16-24hr duration, prepared by conjugating regular insulin with a Lg protein = decreases solubility of NPH insulin = slows absorption
Lente insulin – regular insulin with zinc = reduces solubility, no proteins added therefore less allergic than above, 60-180min onset, 16-24hr duration
humulin N, Novolin N, insuvet Lente
long duration insulin and example
reduced solubility 240-360min onset, 24-28hr duration or glargine (modified human insulin with 70 min onset 24hr duration, one day SC injection at bedtime
Ultralente (humulin U), glarigine (Lantus)
premixed biphasic insulin
both short and intermediate forms
30/70 – 2-12hrs peak – 24hr duration
20/80 – 2-8hrs peak – 24hr duration
50/50 – 4-8hrs peak – 24hr duration
nursing considerations of insulin
Insulin release inhibited by somatostatin and adrenaline
Deficiencies of release occur in pancreatic disorder: DM, pancreatitis, cushings, acromegaly
what is the treatment of diabetes
replace insulin to physiological levels; to obtain metabolic control with insulin, oral hypoglycaemic drugs, or exercise and dietary regimens.
Typical dose = 0.7 IU/kg per day
Normal pancreatic production = 50 IU per day
fixed dose insulin therapy
The amount of insulin taken at each meal does not vary
You can be on any injection regimens and on a fixed dose therapy
• Can help to simplify the understanding of blood glucose
• Does not offer the flexibility
flexible insulin therapy
Choose how much insulin to inject at each meal. Flexible insulin therapy is particularly common for basal-bolus insulin regimen
basal bolus regimen
dose of short-acting insulin is given before each meal plus some intermediate or long-acting insulin at bedtime. Mimics bodies natural release rhythms
split mixed regimen
The total daily dose in units is estimated. This is split between 1⁄3 short-acting and 2⁄3 intermediate or long-acting insulins, 2⁄3 of the total mixture given before breakfast and the other 1⁄3 before the evening meal
once daily regimen
Involves taking a single dose of insulin each day
• The regimen is suitable for people with type 2 diabetes who are unable to produce enough of their own insulin to control their diabetes
• People on this regimen will need to take tablets in addition to the insulin
• A once daily regimen can either involve taking a long acting peakless insulin or an intermediate NPH insulin
• A long acting peakless insulin for people with hyperglycemia through the day and night
• An intermediate insulin dose is suitable for people who experience high blood glucose overnight and in the morning but better during the day.
• In this case, the insulin dose will be taken before bed.