Rapid-acting (lispro, aspart, glulisine) onset is about 15 minutes, so it must be given with food on the tray to prevent hypoglycemia.
Before you read
Test yourself first: 5 questions
Question 1 of 5
A nurse is preparing to administer regular insulin and NPH insulin in the same syringe. Which step ensures safe preparation?
Answer: B. When mixing insulins, the nurse draws up the clear (short-acting regular) insulin before the cloudy (intermediate NPH) insulin: clear before cloudy. Air equal to each dose is injected into each vial first. Drawing cloudy first risks contaminating the regular insulin vial with NPH, which could alter the rapid-acting insulin's action.
Question 2 of 5
A nurse is preparing to administer regular insulin and NPH insulin to a client in the same syringe. Which action should the nurse take?
Answer: B. When mixing insulins, draw up the clear (short-acting regular) insulin before the cloudy (intermediate NPH) insulin. Air is injected into the NPH vial first, then into the regular vial, but the regular insulin is withdrawn first to avoid contaminating the rapid-acting vial with the longer-acting suspension. Drawing NPH first risks contaminating the regular vial.
Question 3 of 5
A nurse is preparing to start an IV regular insulin infusion for a client in DKA. Which insulin is the only type appropriate for IV administration?
Answer: A. Regular (short-acting) insulin is the only insulin formulation approved for IV use. Intermediate and long-acting insulins (NPH, glargine, detemir) and most rapid analogs are not given IV. Regular insulin allows precise titration during DKA management.
Question 4 of 5
A client with type 1 diabetes takes insulin glargine once daily. The nurse teaches that this insulin should not be mixed with other insulins because it:
Answer: A. Insulin glargine is a long-acting basal insulin with a relatively flat action and no pronounced peak. It must not be mixed in the same syringe with other insulins because doing so alters its pH and absorption profile. It is given as a separate injection.
Question 5 of 5
A client with type 1 diabetes uses an insulin pump that delivers rapid-acting insulin. The pump malfunctions and stops delivering insulin for several hours. For which complication should the nurse monitor most closely?
Answer: B. Insulin pumps deliver only rapid-acting insulin with no long-acting basal reserve, so an interruption quickly leads to insulin deficiency, hyperglycemia, and diabetic ketoacidosis. The nurse should monitor blood glucose and ketones. Hypoglycemia would result from too much insulin, not a delivery failure.
Keep the streak going with more questions like these, each with a full rationale.
What is insulin types and timing?
Knowing each insulin's peak is essential because the peak is when hypoglycemia is most likely. Memory aid: rapid-acting lispro/aspart are given with the meal tray, regular insulin is the only insulin given IV, and long-acting glargine has no pronounced peak.
Key points to remember
- Rapid-acting (lispro, aspart, glulisine) onset is about 15 minutes, so it must be given with food on the tray to prevent hypoglycemia.
- Short-acting regular insulin onset is about 30-60 minutes and is the only insulin that can be given intravenously, such as in DKA.
- Intermediate-acting NPH is cloudy, peaks in roughly 4-12 hours, and is the peak most likely to cause overnight or late-morning hypoglycemia.
- Long-acting glargine and detemir last about 24 hours with no pronounced peak and must never be mixed with other insulins.
- When mixing NPH and regular insulin, draw up the clear (regular) before the cloudy (NPH): 'clear before cloudy' or 'RN'.
- The peak time of any insulin is when the nurse must watch most closely for hypoglycemia.
Signs & symptoms
- Hypoglycemia: shaky, sweaty, confused
- Peak time = highest hypo risk
Nursing priorities
- Verify the correct insulin type, dose, and timing relative to meals, and confirm the dose with a second nurse per policy for high-alert insulin.
- Coordinate rapid- and short-acting insulin administration with food being available.
- Rotate injection sites within one anatomic area to prevent lipohypertrophy.
- Monitor blood glucose at appropriate intervals and especially during the insulin's peak.
- Treat hypoglycemia with 15 grams of fast-acting carbohydrate and recheck in 15 minutes.
Labs & values
Patient teaching
- Keep a fast-acting sugar source available and recognize early hypoglycemia symptoms.
- Rotate injection sites and store unopened insulin in the refrigerator.
- Eat your meal right after taking rapid-acting insulin, and do not skip meals.
Red flags: report now
- Signs of hypoglycemia such as shakiness, sweating, confusion, and tachycardia, especially at the insulin's peak.
- Giving rapid-acting insulin without ensuring the patient will eat.
- Mixing glargine or detemir with any other insulin or giving them IV.
- Blood glucose below 70 mg/dL requires immediate carbohydrate treatment.
References
Clinical references for this topic
