A Nurse’s Guide to Insulin Therapy

• Nursing processes and patient education are crucial for achieving optimal glycemic control, minimizing risks, and managing complications associated with insulin therapy. 
• Insulin is a hormone regulating storage and utilization of glucose, amino acids, and fatty acids, with various types such as rapid-acting, short-acting, intermediate-acting, and long-acting. 
• Insulin therapy is used in diabetes management, hyperkalemia, and other clinical conditions; proper administration, drug interactions, and adverse reactions are important considerations.
  

Insulin is a vital hormone that regulates the storage and utilization of glucose, amino acids, and fatty acids in the body. It is synthesized and secreted by beta cells of the islets of Langerhans in the pancreas and is instrumental in maintaining blood glucose levels within a healthy range.

Insulin therapy is a cornerstone of diabetes management, and it is also used in other clinical conditions such as hyperkalemia. This blog post will provide an in-depth look at the different types of insulin, their indications, and essential information on their administration, drug interactions, adverse reactions, and nursing processes related to insulin therapy. 

Indication and Types of Insulin

Insulin lowers blood glucose by: 

• inhibiting glycogenolysis and gluconeogenesis in the liver 
• stimulating glucose uptake by muscle and adipose tissue. 
  

The indications of insulin are: 

• Type I diabetes 
• Type II diabetes 
• Pregnant women in whom blood glucose levels are not getting controlled with dietary restrictions 
• When the body is too stressed, such as myocardial infarction or after surgery 
• Patient taking corticosteroids for long-term chemotherapy (because they affect your blood glucose levels) 
• For the management of hyperkalemia
  

Insulins are of various types, such as: 

• Rapid-acting 
• Glulisine, Lispro, Aspart 
• Short-acting 
• Insulin 
• Intermediate-acting 
•  NPH or Neutral Protamine Hagedorn 
• Long-acting  
• Glargine, Detemir, Degludec 

Let’s break down each of these types of insulin.

A Closer Look at the Types of Insulin

Rapid-Acting Insulin

Glulisine  

• It comes under the brand name Apidra 
• The onset of action occurs in 10 to 15 minutes 
• Achieves peak in 1 to 1.5 hours 
• The duration of action 3 to 5 hours 
• Stable at room temperature for 28 days after opening 
• Can be mixed with NPH 
• Do not freeze 
• Refrigerate unopened and opened vials
  

Lispro  

• It comes under the brand name Humalog 
• The onset of action occurs in 15 to 30 minutes 
• Achieves peak in 0.5 to 2.5 hours 
• The duration of action is 6 to 8 hours 
• Stable at room temperature for 28 days after opening 
• Can be mixed with NPH 
• Do not freeze 
• Refrigerate unopened and opened vials
  

Aspart  

• It comes under the brand name Novolog 
• The onset of action is 10 to 20 minutes 
• Achieves peak in 1 to 3 hours 
• The duration of action is 3 to 5 hours 
• Stable at room temperature for 28 days after opening 
• Can be mixed with NPH 
• Do not freeze 
• Refrigerate unopened and opened vials 

Short-Acting Insulin

Regular Insulin  

• It comes under the brand name Humulin R and Novolin R 
• The onset of action is 30 to 60 minutes 
• Achieves peak in 1 to 5 hours 
• The duration of action is 6 to 10 hours 
• Stable at room temperature for 28 days after opening 
• Can be mixed with NPH 
• Do not freeze 
• Refrigerate unopened and opened vials 

Intermediate-Acting Insulin

NPH or Neutral Protamine Hagedorn 

• It comes under the brand name Novolin N or Humulin N 
• The onset of action is 1 to 2 hours 
• Achieves peak in 6 to 14 hours 
• The duration of action is 16 to 24 hours 
• Stable at room temperature for 31 days after opening (Pen 14 days) 
• Can be mixed with Aspart, Lispro, Glulisine 
• Do not freeze 
• Refrigerate unopened and opened vials 

Long-Acting Insulin

Glargine  

• It comes under the brand names Lantus and Basaglar  
• The onset of action 1 to 4 hours  
• No significant peak occurs  
• The duration of action is 24 hours 
• Do NOT mix with other insulins 
• Refrigerate unopened and opened vials 
• Do not freeze 
• Stable at room temperature for 28 days after opening
  

Detemir  

• It comes under the brand name Levemir  
• The onset of action is 0.8 to 2 hours 
• No significant peak occurs 
• The duration of action is 12 to 24 hours (dose-dependent) 
• Do NOT mix with other insulins 
• Refrigerate unopened and opened vials 
• Do not freeze 
• Stable at room temperature for 42 days after opening 

Degludec  

• It comes under the brand name Tresiba  
• The onset of action in 0.5 to 1.5 hours 
• Achieves peak in 12 hours  
• The duration of action is 42 hours  
• Do NOT mix with other insulins 
• Refrigerate unopened and opened vials 
• Do not freeze 
• Stable at room temperature for 56 days after opening
  

Administering Insulin

Insulin is not given through the oral route because they are made up of protein, hence broken down by the gastric fluid in the gastrointestinal tract. Therefore they are not absorbed.  

Insulin can be given through intramuscular, subcutaneous, and IV routes. You can administer all insulins through a subcutaneous route. But only REGULAR insulin is given intravenously. It can also be administered in the dialysate fluid infused into the peritoneal cavity for patients on peritoneal dialysis therapy. 

Insulin does not affect urination frequency, but it can correct the symptoms of hyperglycemia such as polyuria and polydipsia. It also facilitates the movement of potassium from the extracellular fluid into the cell, therefore given to correct hyperkalemia.  

Insulin is also used to treat complications associated with diabetes such as diabetic ketoacidosis (DKA), which is more common with type 1 diabetes, and hyperosmolar hyperglycemic nonketotic (HHNK) syndrome, which is more common with type 2 diabetes.

Insulin Drug Interactions

The following drug interactions can occur with insulin therapy: 

• Anabolic steroids, salicylates, alcohol, sulfa drugs, angiotensin-converting enzyme inhibitors, propranolol, guanethidine, and monoamine oxidase (MAO) inhibitors might increase the hypoglycemic effects of insulin. Therefore if you administer any of these drugs with insulin, keep an eye on blood glucose levels and adjust the insulin dose accordingly.  
• Corticosteroids, sympathomimetic drugs, isoniazid, thyroid hormones, niacin, furosemide, and thiazide diuretics may reduce the effects of insulin, resulting in hypoglycemia. Therefore you need to increase the insulin dose with any of these drugs.  
• Beta-adrenergic blockers such as propranolol, atenolol, bisoprolol, and others may prolong the hypoglycemic effect of insulin and mask signs and symptoms of hypoglycemia.  

Adverse Reactions

The most common adverse reaction of insulin is hyperglycemia. To prevent it, you strictly need to monitor the patient’s blood glucose levels frequently and check them for any signs of hypoglycemia. It is essential to educate them about it.  

The other adverse reactions of insulin are: 

• Somogyi effect- hypoglycemia followed by rebound hyperglycemia 
• Hypersensitivity reactions 
• Lipodystrophy- disturbance in fat deposition. It occurs when insulin is administered repeatedly at the same time and can affect glycemic control as well.
• Insulin resistance
  

The Nursing Processes With Insulin Therapy

With insulin therapy, follow these nursing processes: 

Assessment

• Before starting the therapy, check the patient’s glucose levels and, frequently, after administration too.  
• In patients with the following conditions, monitor blood glucose levels more frequently than usual: 
• Under stress 
• Unstable 
• Pregnant 
• Recently diagnosed with diabetes 
• Undergoing dietary changes 
• Under orders to have nothing by mouth 
• Experiencing nausea and vomiting 
• Taking drugs that can interact with insulin 
• Keep a regular check on the patient’s glycosylated hemoglobin. It indicates glycemic control over months.  
• When blood glucose levels are elevated, check the patient’s urine ketone levels.  
• Check the patient for any adverse drug reactions or drug interactions.  
• Monitor the injection sites for local reactions such as swelling, redness, or erythema.  
• Assess the patient’s and the family member’s knowledge about insulin therapy.  

Key Nursing Diagnoses

• Ineffective health maintenance and poor glycemic control 
• Risk for injury related to drug-induced hypoglycemia 
• Deficient knowledge related to drug therapy 

Planning Outcome Goals

• The blood glucose levels will remain within normal limits.  
• The risk of injury to the patient will be minimized.  
• The patient and his family will verbalize their understanding of the drug therapy.

Implementations

Facilities that need healthcare providers will typically begin a partnership with a staffing agency in order to have ‘more hands-on deck.’  

• For emergency situations like circulatory collapse, diabetic ketoacidosis, or hyperkalemia, use regular insulin. However, avoid using it at a concentration of 500 units/mL when administered intravenously. 
• Do not use intermediate-acting or long-acting insulin for coma or other emergencies requiring rapid relief. 
• In cases of insulin resistance, large doses of insulin may be needed for effective glycemic control. U-500 insulin can be used as concentrated regular insulin. Notify the pharmacy in advance, as they may need to make arrangements. Store its vial separately from other insulins to prevent accidental overdose. Be cautious to avoid mixing insulin vials. 
• To mix insulin suspension, gently swirl the vial and rotate it between your palms or palm and thigh. Avoid vigorous shaking, as it can cause bubbles and air in the syringe. 
• Lispro insulin acts rapidly and should be administered only 15 minutes before a meal. 
• Never mix or dilute insulin glargine with other insulins, and do not administer it intravenously. 
• Regular insulin can be mixed with NPH or Lente insulins in any proportion. When combining regular insulin with NPH insulin, draw up the regular insulin first. Changing from separate injection sites to a mixture may alter the patient’s response, so be cautious. 
• Administer mixtures of NPH or Lente with regular insulin promptly to prevent potency loss. 
• Do not administer insulin that appears clumped, discolored, or granular. 
• Check the vial’s expiration date before use. 
• For intravenous administration, use only regular insulin at prescribed doses. For continuous infusion, it can be combined with normal saline. 
• To administer insulin subcutaneously, pinch a skin fold between two fingers, starting at least 3 inches away, and insert the needle at a 45 to 90-degree angle. Press the injection site after administering but do not rub it. Chart and rotate injection sites to avoid overuse and achieve better glycemic control. 
• Hospitalization and treatment with intravenous regular insulin may be necessary for ketosis-prone type 1 patients, severely ill individuals, and newly diagnosed diabetic patients with very high glucose levels. 
• Inform the prescriber of excessively high or low blood glucose levels, ketosis, and whether effective glycemic control is being achieved. 
• Be prepared to provide supportive treatment for diabetic ketoacidosis or hyperglycemic hyperosmolar nonketotic coma. 
• If a conscious patient experiences hypoglycemia, give them an oral glucose drink or candy to raise blood glucose levels, followed by a complex carbohydrate meal. If the patient is unconscious, treat hypoglycemia with glucagon or IV glucose. 
• Discuss patient noncompliance with medication or insulin administration with the prescriber. 
• Ensure the patient adheres to dietary restrictions and exercise programs. Insulin dosage adjustments may be needed with other changes, such as increased physical activity. 
• Educate the patient and their family members on checking blood glucose levels and administering insulin. 

Patient Teaching

With insulin therapy, teach the following points to the patient and his caregivers: 

• Diabetes is a lifelong condition. Insulin can help lower elevated blood glucose levels but can not treat the disease.  
• You must learn how to check your blood glucose levels because it is an essential guide to the success and dose of insulin therapy.  
• Follow this regimen to prevent complications of diabetes: 
• Adhere to a specific diet 
• Reduce excess weight 
• Maintain a daily routine of exercise 
• Maintain personal hygiene, such as daily foot inspection and cleaning the oral cavity 
• Consult with the prescriber about ways to avoid infection 
• Discuss your meal timings and injection timings with the prescriber. And do not skip the meal.  
• With insulin therapy, drug measurement and accuracy is crucial, especially with regular insulin. Therefore check with a magnifying glass or seek someone’s help to recheck if the dose is correct or not. Moreover, review with the prescriber or an expert about insulin measurement and administration.  
• Do not alter the order in which insulin types are mixed or change the model or brand of the syringe or needle used.  
• Know the symptoms of hypoglycemia or hyperglycemia and what to do when they occur.  
• For emergencies, keep a sweet candy always with you.  
• Carry or wear medical identification at all times.  

The Bottom Line

Understanding the various types of insulin, their indications, and proper administration is crucial for effective diabetes management and treatment of other conditions that necessitate insulin therapy.

As a healthcare professional, it is essential to educate patients and their caregivers on the importance of insulin therapy, proper blood glucose monitoring, and maintaining a healthy lifestyle to achieve optimal glycemic control. By following the appropriate nursing processes and providing patient education, healthcare professionals can help patients achieve better outcomes and minimize the risk of complications associated with insulin therapy.

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