What are the preoperative insulin dose reductions for basal and bolus insulin in patients with Type 2 (Type II) diabetes mellitus?

From the Guidelines

For patients with type II diabetes undergoing surgery, preoperative insulin adjustments should include reducing basal insulin to one-half of the dose, as recommended for NPH insulin or long-acting basal insulin analogs, and holding bolus insulin on the day of surgery. This approach is supported by the latest guidelines from the Diabetes Care journal, which emphasizes the importance of careful glucose management in the perioperative period 1. The goal is to maintain blood glucose levels between 100-180 mg/dL (5.6-10.0 mmol/L) within 4 hours of surgery, while minimizing the risk of hypoglycemia.

Key considerations for preoperative insulin adjustments include:

• Reducing NPH insulin to one-half of the dose or long-acting basal insulin analogs, such as Lantus (glargine), Levemir (detemir), or Tresiba (degludec), to 50% of the usual dose on the morning of surgery
• Holding all rapid-acting bolus insulins, such as Humalog (lispro), NovoLog (aspart), Apidra (glulisine), or regular insulin, entirely on the day of surgery
• Monitoring blood glucose closely before, during, and after surgery to adjust insulin doses as needed
• Considering the patient's individual factors, such as glycemic control, surgery type, expected duration of fasting, and timing of the procedure, when determining the exact reduction percentage.

It is essential to note that metformin should be held on the day of surgery, and SGLT2 inhibitors should be discontinued 3-4 days before surgery, as recommended by the guidelines 1. By following these guidelines and adjusting insulin doses accordingly, healthcare providers can help minimize the risks associated with surgery in patients with type II diabetes and ensure optimal glycemic control.

From the Research

Preoperative Insulin Reductions for Basal and Bolus in Type II Diabetes

• The management of type 2 diabetes, especially in the context of surgery, is crucial for preventing complications and ensuring optimal outcomes 2, 3.
• Studies have shown that basal-bolus insulin therapy can be effective in achieving glycemic control in patients with type 2 diabetes, with some research indicating it may be superior to sliding scale insulin therapy in terms of reducing hypoglycemic events and weight gain 3, 4.
• The "basal plus strategy" is an approach that involves adding prandial insulin to basal insulin, starting with the meal that has the most significant impact on postprandial glucose values, and can be an effective way to manage type 2 diabetes 2.
• Research has also explored the efficacy of different basal insulins, such as insulin detemir and insulin glargine, in basal-bolus regimens, finding them to be effective and safe for glycemic control in type 2 diabetes, with some differences in terms of weight gain and hypoglycemia risk 5.
• In the context of hospitalized patients with type 2 diabetes, basal-bolus insulin therapy has been shown to result in significantly lower mean daily blood glucose levels compared to sliding scale insulin therapy, although it may be associated with an increased risk of mild hypoglycemia 6, 4.

Key Considerations for Preoperative Insulin Reductions

• When considering preoperative insulin reductions for basal and bolus in type 2 diabetes, it is essential to take into account the individual patient's glycemic control, insulin regimen, and medical history 3, 5.
• The goal of preoperative insulin management is to achieve optimal glycemic control while minimizing the risk of hypoglycemia and other complications 2, 6.
• Healthcare providers should carefully evaluate the patient's current insulin regimen and adjust it as needed to ensure safe and effective glycemic control in the preoperative period 4.