Insulin Therapy In-Depth Practice Manual: From Injection Site Selection to Standardized Application of Pen Injectors

12. Who should choose insulin therapy? (1) Patients with type 1 diabetes. (2) Patients with type 2 diabetes whose diabetes cannot be controlled by diet and oral hypoglycemic agents. (3) Patients with diabetes complicated by ketoacidosis, nonketotic hyperosmolar coma, lactic acidosis, severe infection, high fever and wasting diseases, or acute stress conditions such as myocardial infarction. (4) Before and after surgery. (5) Pregnant women. (6) Patients with chronic complications such as diabetic retinopathy, nephropathy, neuropathy, and gangrene of the lower extremities. (7) Patients with severe liver disease (hepatitis, cirrhosis) or kidney disease complicated by renal failure.

13. What are the precautions for insulin therapy? When using insulin therapy, the following points should be noted: (1) Type 1 diabetic patients are more prone to hypoglycemia than type 2 diabetic patients. (2) Elderly type 2 diabetic patients are also prone to hypoglycemia because the elderly often have irregular eating habits, making it difficult to cooperate with insulin therapy, and their renal function is generally declining, which easily leads to insulin accumulation in the body. (3) In insulin therapy, it is necessary to understand the types, duration of action, and timing of use of short-acting, intermediate-acting, and long-acting insulins. (4) Injecting short-acting insulin before meals is likely to cause hypoglycemia 2-3 hours after meals; injecting intermediate- or long-acting insulin before breakfast often causes hypoglycemia in the afternoon or at night. (5) Regardless of the degree of hyperglycemia, insulin therapy should start with a small dose, and blood glucose monitoring should be carried out at the same time to adjust the insulin dose and injection frequency in a timely manner in order to achieve satisfactory blood glucose control without hypoglycemia. (6) When type 2 diabetic patients use oral hypoglycemic agents and insulin in combination, after blood glucose is satisfactorily controlled, the insulin dose should be reduced or discontinued in a timely manner to prevent hypoglycemia.

14. What are the precautions for insulin injection? (1) Prepare the necessary equipment and supplies. Insulin preparation, 70% alcohol, sterile cotton and insulin syringe (1 ml glass or disposable plastic syringe, insulin pen syringe, etc. can be used). (2) Check whether the insulin preparation is within the expiration date and whether it is sealed and undamaged. Short-acting insulin should be clear in appearance. If it is cloudy, it should not be used, while medium- and long-acting insulin is normal if it is cloudy. (3) When using medium- and long-acting insulin, the insulin should be mixed well. It can be rubbed slowly between the hands. Do not shake it vigorously up and down. (4) Selection of insulin injection site. The choice of injection site is not only related to the absorption of the drug and the occurrence of complications, but also to the reduction of pain and the benefit of long-term treatment. The best sites for subcutaneous injection in the human body are: the anterolateral aspect of the upper buttock, the anterolateral aspect of the lower limb bone, the upper outer 1/4 area of ​​the buttock (i.e., the intramuscular injection site), and the abdomen (around the navel and waist). Abdominal absorption is the fastest. If you exercise immediately after injection, you should avoid injection in the upper and lower limbs to avoid hypoglycemia caused by rapid absorption. (5) Alternating injection sites. Divide each injection site into a small square of 2 cm × 2 cm. Select one small square for each injection. The two injection points should be 2 cm apart. Inject in this way, alternating between left and right. Be sure to avoid injecting continuously in the same small square. (6) Method of drawing insulin. After washing your hands, disinfect the cap with alcohol. After disinfecting the syringe, draw an appropriate amount of air. Push the plunger to the desired insulin volume mark. First, turn the insulin bottle mouth upwards, insert the syringe into the bottle mouth, and push in air. Then, turn the insulin bottle mouth downwards and gently pull out the plunger to the accurate mark of the required insulin dose. If mixing two types of insulin, be sure to draw the short-acting insulin first, and then the intermediate and long-acting insulin. Otherwise, the short-acting insulin mixed with the intermediate and long-acting insulin will appear cloudy and the efficacy will be poor. Take the syringe out of the insulin bottle. If there are air bubbles inside, turn the needle upwards, gently tap the syringe to make the air bubbles rise to the neck of the syringe, and then gently push the plunger to expel them. (7) Method of injecting insulin. Select a suitable injection site and disinfect it from the center outwards with 70% alcohol (iodine is not necessary), then allow it to air dry.

15. What is an insulin pen? An insulin pen is an insulin injection device, slightly larger than a pen. Insulin is contained in the pen vial, making it portable. To use it, simply remove the cap to inject insulin; it's very convenient. The insulin used is a special cartridge-type insulin with a concentration different from regular insulin: U-100, or 100 units/mL (regular insulin has a concentration of U-40, 40 units/mL, with each cartridge containing 400 units). Cartridge insulin typically contains 300 units or 150 units per cartridge. After use, the cartridge is replaced for continued use. Pen injectors are convenient to carry, simple to operate, provide accurate dosage, and are virtually painless, making them worthy of widespread adoption.

16. What are the advantages of insulin pens? (1) Convenience: It eliminates the tedious process of drawing insulin from an insulin vial with a syringe. Patients no longer need to carry a lot of items such as syringes, insulin vials, and sterile cotton swabs when going out; they only need to carry a small "pen." (2) The insulin injection process is simpler and more discreet, avoiding the embarrassment of injecting insulin in public. Some people even inject insulin with one hand under the table. (3) It makes it easier for patients with poor vision or even blindness to inject insulin. It is difficult to draw insulin with a syringe and inject it if one has poor vision. Because insulin pens are easy to operate and have a clear "click" sound when setting the dose, even those with poor vision can inject insulin with an insulin pen after training. (4) The insulin dose is more precise, and the insulin dose can be adjusted in units of 1 unit. Insulin syringes are generally accurate to a minimum of 2 units. (5) It is basically painless. Its needle is finer than that of a dedicated insulin injector, and some patients have found that there is basically no pain after using it.

17. What are the disadvantages of insulin pens? (1) The initial investment is relatively large, and special cartridges need to be purchased. The insulin pen itself costs more than 200 yuan, and special insulin cartridges are required. Regular insulin cannot be used in the pen. At present, only foreign-made insulin cartridges are available in my country, and insulin cartridges are more expensive than regular insulin. (However, when considering the cost, it should also be considered that using an insulin pen will save the cost of purchasing plastic syringes for life). (2) When two types of insulin need to be mixed for injection (such as NovoMix R + NovoMix N or Humulin R + Humulin N), the insulin pen cannot be used in one injection. This requires two pens to be used for injection separately. In this case, premixed insulin NovoMix 30R or Humulin 30R can be used, and your doctor can help adjust your treatment plan to use only one type of insulin, such as premixed insulin 30R or 50R, because premixed insulin contains both short-acting insulin R and intermediate-acting insulin N. (3) This type of insulin pen and cartridge is not yet widely available in our country. Therefore, you may not be able to buy insulin cartridges in some areas, so you may need to carry enough insulin cartridges when you are away for a long time.

18. Precautions for using insulin pens: (1) Insulin pens are personal property and should never be shared with others. (2) It is recommended to remove the needle after injection to prevent contamination of the insulin in the bottle and to avoid insulin leaking from the needle when the temperature rises. However, it is also acceptable not to remove the needle after use. (3) Although the needle is disposable, it can be reused. It is recommended to use it 5-6 times. If it is properly sterilized, it is also acceptable to use it for 1 week before discarding it. (4) The best insulin for pen treatment is premixed insulin 30R and 50R. (6) After injection, be sure to leave the needle in the pen for 2-3 seconds before pulling it out of the skin, otherwise a drop of insulin may remain on the needle and be carried out. (7) It is best to use different insulin pens for different insulins. Therefore, ask your doctor to adjust your insulin to use only one type of insulin. If this is not possible, you will need to buy two insulin pens to inject short-acting and intermediate-acting insulin respectively. (8) The insulin pen cartridge is imported insulin U-100, with 300 units per bottle. Pay attention when purchasing. (9) The dosage range for each insulin pen injection is 1 to 70 units. (10) After use, insulin pens do not need to be placed in a refrigerator at 4 to 8 degrees Celsius. Insulin can be stored at room temperature for more than one month.