By Matthew Newton, DNP, CRNA
Patients with type 1 diabetes mellitus (T1DM) present unique challenges in the perioperative setting, where optimization of blood glucose (BG) is essential to patient safety and surgical success. Poor glycemic control has been linked to increased rates of surgical site infection, delayed wound healing, and prolonged hospital stays (Duggan, Carlson, & Umpierrez, 2017). For anesthesia providers, understanding and applying evidence-based recommendations for insulin management is critical not only for patient safety but also for efficiency, operating room flow, and outcomes. The following is intended as a refresher on the topic and to add some additional considerations the clinician may utilize when advising T1DM patients in the perioperative period.
Current Challenges in Perioperative Glycemic Management
Despite the growing body of evidence, perioperative insulin recommendations remain inconsistent across institutions. Much of this variability stems from differences in provider training, clinical comfort, and the lack of standardized, evidence-based protocols. In practice, T1DM patients often arrive at the preoperative area with blood glucose levels out of target, primarily due to improper basal insulin management in the fasting period before surgery.
First, it’s important to understand the difference between basal and bolus insulin. Think of basal insulin as your body’s idle metabolic pace, responsible for managing your blood glucose between meals and throughout the night. Basal insulins are mostly your long-acting insulins. Bolus insulin is designed to manage glucose spikes in association with food and correct BG when levels are undesirably high. This is typically done with short or rapid-acting insulins. Basal insulin, unlike bolus insulin, is necessary even in the absence of food intake to suppress hepatic glucose production and maintain metabolic homeostasis. Some old-school methodologies and teachings recommend dramatic reductions or complete withholding of basal insulin in the perioperative period. This is outdated information. Withholding or excessively reducing basal insulin doses increases the risk of hyperglycemia and diabetic ketoacidosis (DKA), both of which can increase perioperative complications, morbidity, and cause delays in care at the procedural site. Joshi et al. (2010) emphasized in their consensus statement that inappropriate perioperative insulin instructions contribute significantly to patient safety risks in ambulatory surgery.
Current Recommendations for Anesthesia Providers
To promote consistent, safe practices, anesthesia providers should follow evidence-based protocols for T1DM patients in the perioperative period. Of course, there is no one-size-fits-all protocol since each patient is unique and their comorbidities and personal history should be considered. Key recommendations to consider include:
- Continue basal insulin:
- Do not withhold basal insulin, even when fasting.
- Administer 75–100% of the patient’s usual basal insulin dose the evening before or morning of surgery (ADA, 2023; Duggan et al., 2017).
- For patients on insulin pumps, continue the basal rate; reduce to 75–80% if concern for hypoglycemia.
- Hold or reduce prandial (bolus) insulin:
- Consider withholding short-acting or rapid-acting insulin while the patient is NPO.
- Resume with meals postoperatively.
- Monitor blood glucose frequently:
- Check BG on arrival to pre-op, intraoperatively every hour, and in the immediate PACU period.
- Maintain target perioperative BG between 140–180 mg/dL (ADA, 2023).
- Avoid prolonged fasting without insulin coverage:
- Patients with T1DM require insulin at all times; IV insulin infusions may be necessary for longer cases or unstable glucose trends.
- Individualized care based on surgical setting and patient history:
- Ambulatory cases may tolerate subcutaneous basal insulin continuation, while inpatient or complex cases may benefit from IV insulin protocols combined with close monitoring.
- Ensure clear communication across teams in the perioperative period:
- Standardized pre-op instructions should come from anesthesia or endocrinology, not from multiple specialties with variable expertise.
Educational and System-Level Interventions
Establishing and revising a standardized insulin protocol is only the first step. Reinforcement through ongoing provider education and institutional support is essential. Recommended strategies, such as EHR prompts, order sets, and multidisciplinary collaboration, should be encouraged to take care of the T1DM population. Resistance to new protocols is common, but repeated reinforcement and leadership support can reduce variability and improve adherence. The benefits can be substantial: better glycemic control, fewer perioperative complications, and more efficient surgical flow.
Implications for Clinical Practice
For anesthesia providers, perioperative glucose management in T1DM requires vigilance, precision, and teamwork. Protocol-driven care reduces the risk of DKA and hyperglycemia, minimizes cancellations or delays due to out-of-range BG, and improves patient satisfaction. As Joshi et al. (2010) emphasized, consensus-driven protocols are key to safe ambulatory surgery for diabetic patients, while Duggan et al. (2017) underscored the risks of inconsistent insulin management.
Patients with T1DM depend on their providers to safeguard against the dangers of poor insulin management in the perioperative period. Evidence supports the continuation of basal insulin, reduction or withholding of prandial insulin when NPO, and close glucose monitoring throughout the perioperative course. By implementing standardized protocols, providing ongoing education, and reinforcing evidence-based practices, anesthesia providers can reduce complications, improve efficiency, and deliver safer care to this vulnerable patient population.
References
• American Diabetes Association. Standards of Medical Care in Diabetes—2023. Diabetes Care. 2023;46(Suppl 1):S1–S291.
• Duggan EW, Carlson K, Umpierrez GE. Perioperative Hyperglycemia Management: An Update. Anesthesiology. 2017;126(3):547–560.
• Joshi GP, Chung F, Vann MA, et al. Society for Ambulatory Anesthesia Consensus Statement on Perioperative Blood Glucose Management in Diabetic Patients Undergoing Ambulatory Surgery. Anesth Analg. 2010;111(6):1378–1387.
