Melissa O’Donovan Lark Hunter-Bonnah

Insulin is a protein in the human body that plays a major role in decreasing the levels of glucose in the blood and regulating the metabolism of glucose, fats, and proteins.

The human body wants blood glucose (blood sugar) maintained in a very narrow range. The main function of the pancreas is to produce insulin, glucagon, digestive enzymes, and other hormones. Both insulin and glucagon are referred to as pancreatic endocrine hormones. Insulin is synthesized in the beta cells of the pancreas in the Islets of Langerhans through a glucose transporter by means of facilitated diffusion.

The secretion of insulin is controlled by the glucose concentrations in the blood stream. As the level of glucose rises in the blood, the insulin levels also increase. Following a meal, the carbohydrates or sugars are absorbed by the intestines during digestion and enter the bloodstream, which raise blood glucose levels. The beta cells in the islets of Langerhans of the Pancreas respond to this increase in blood glucose levels.

When the levels of glucose in the blood rise, membrane depolarization of the beta cells occurs, causing extracellular calcium to rush into the cell. This influx of extracellular calcium stimulates the export of secretory granules, which contain insulin, out of the cell and into the blood stream. The insulin is circulated through out the body where it enables the glucose to be taken up and used by cells as an energy source and this causes the blood glucose levels to decrease.

Diagram of the insulin and glucose regulation model

 Most cells through out the body have insulin receptors to which insulin binds, and these cells in turn activate other receptors designed to absorb the glucose from the blood stream.  To elevate the glucose levels in the beta cells, calcium- independent pathways are triggered by these receptors.  When glucose levels fall below normal range due to a lack of insulin, glycogen synthesis in the liver ceases and the enzymes responsible for the breakdown of glycogen become active.  Without insulin, many of the cells in the body would not be able to take up glucose and would have to resort to alternative fuel sources such as fatty acids for energy.

 Analogue - A man-made substance resembling insulin in which the molecular structure has been altered for a more desirable effect.  Basal – insulin that controls blood glucose levels between meals and over night.  Bolus - a burst of insulin that is delivered by the pancreas, injection or by insulin pump  Prandial – insulin pertaining to before or during a meal or a snack

 Rapid acting  Short acting  Intermediate acting  Long acting

Insulin Type/Action (Appearance) Brand names (Generic Name) Basal or BolusDosing Schedule Rapid acting analogue (clear) Onset: minutes Peak:1-2 hours Duration: 3-5 hours Apidra (insulin glulisine) Humalog (insulin lispro) NovoRapid (insulin aspart) Bolus Usually taken right before eating or to lower high blood glucose levels Short-acting (clear) Onset: 30 minutes Peak: 2-3 hours Duration: 6.5 hours Humulin-R Novolin ge (Toronto) Bolus Taken about 30 minute before eating or to lower high blood glucose levels Intermediate –Acting (cloudy) Onset: 1-3 hours Peak: 5-8hours Duration: up to 18 hours Humulin-N Novolin ge NPH Basal Often taken at bedtime or twice a day (morning and bedtime) Long-acting basal insulin analogues Onset: 90 minutes Peak: not applicable Duration: up to 24 hours (Lantus 24 hours, Levemir hours) Lantus (insulin glargine) Levemir (insulin detemir) Basal Usually taken once or twice a day Premixed (cloud) A single vial contains a fixed ratio of insulin (the numbers refer to the ratio of rapid or short-acting to intermediate acting insulin in a vial) Humalog Mix 25 Humalog Mix 25, 50 NovoMix 30 Humulin (30/70) Novolin ge (30/70, 40/60, 50/50)

 Insulin delivery refers the routes that insulin is introduced into the body when insulin cannot be produced by the pancreas, as with most people with Type 1 Diabetes.  Examples of Insulin delivery are:  Subcutaneous Injections  Insulin Pens  Insulin Pumps  Inhaled Insulin (Just Recently approved by the FDA in the US)

Resemble a large pen which makes them portable and easy to handle Replace vials and syringes, which is helpful to people with poor eyesight, and also helps avoid over- or under-dosing. Use insulin cartridges and disposable needles. Can select (dial) the proper dose, which is displayed in the pen’s window. Some models allow you to reselect the dose if a mistake is made. Needles simply screw into place and are easily removed

 Insulin pumps are becoming more widely used and are a good therapy option for people with diabetes who have difficulty controlling blood glucose by other means (by using a syringe or pen)  Some insulin pumps are computerized / motorized and can even be flexible use devices, while there are others that serve as a glucose monitor and insulin pump combined.  The pump is filled with rapid or short-acting insulin which is administered into the body before each meal, and there is also a small amount of insulin delivered for 24 hours.  The patient calculates how much insulin is needed based on the carbohydrate content (grams) of the meal or snack. Since it is programed into the pump it helps to prevent overdosing.  The catheter is implanted in the patient’s abdomen beneath skin and fatty layers and the pump is attached to the catheter when needed.  The pump can be attached to different areas of the body, but is most commonly placed on the waist.

 Mrs. Smith has orders for her insulin to be administered at The doctors orders state that she is to receive 5 units Regular and 10 units NPH before breakfast.  How do you mix both types of insulin in one syringe?

AIR DRAW CloudyClear Cloudy NRRN Use the RN Mnemonic Regular then NPH Cloudy Clear Clear Cloudy

1.First, Wash your hands and make sure to follow the 6 R’s 2.Mix insulin (roll vials upright between palms) 3.Clean tops of both vials with alcohol swab 4.Open syringe and needle (Assemble if necessary) 5.Draw air into syringe equivalent to the Total dose (units) of insulin to be given (both kinds) 6.Insert needle into N vial and express air equal to only the required dose of N insulin into the N vial and remove. 7.Insert needle into the R vial and express remaining air left in the syringe into the vial. This should equal the amount of R insulin to be given 8.Leave needle inside the R vial and turn the R vial upside down with the needle still inserted. Check for bubbles. 9.Withdraw required amount of insulin from the R vial and remove needle. 10. Put needle into N vial and turn vial upside down 11. Withdraw the required amount of N insulin and remove needle. 12.Total insulin in syringe should be equal to the total amount of air placed in both vials. 13.Replace cap on needle for transport to patient bedside using the scoop method (scoop cap up with needle tip not with fingers to prevent stick injury) 14. Wash your hands when entering room 15. Administer insulin to patient 16. Wash your hands when leaving the room 17. Document

Mr. G. is a 50 year old gentleman who was admitted to the floor last night at 1900 for an infection in his right big toe. He has type 1 diabetes and hypertension. You are just beginning your shift and it is Meals are 08, 12, 17 with HS The doctors orders for Mr. G are as follows: Vitals (protocol), Amoxicillin 500 mg IV q8h, CBC, Chem. 1 CBG AC, AM, and HS, 10 units NPH SC, Regular insulin SC Sliding Scale (dose based on blood glucose) If CBG = >24 =32 u =28 u =24 u =20 u =16 u =12 u = 8 u = 4 u

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