A nurse is caring for a diabetic client who is scheduled for major abdominal surgery in the morning. The client's preoperative blood glucose is 180 mg/dL, and the anesthesiologist has ordered to hold all oral hypoglycemic medications. What is the most appropriate nursing intervention to ensure optimal perioperative glucose management?

Continuous insulin infusion provides the most precise and flexible glucose control during the perioperative period, allowing for real-time adjustments based on blood glucose levels and surgical stress response.

Perioperative blood glucose management in diabetic patients undergoing surgery requires careful consideration of multiple physiological factors. The surgical stress response promotes the secretion of counter-regulatory hormones such as cortisol, epinephrine, and growth hormone, which significantly raise blood glucose through gluconeogenesis and glycogenolysis. Additionally, the inflammatory response to surgical trauma further exacerbates hyperglycemia.

The patient's preoperative blood glucose of 180 mg/dL is already elevated, indicating that glucose control has not been optimized. Major abdominal surgery is highly likely to cause further blood glucose elevation due to surgical stress, anesthetic effects, and potential complications. Oral hypoglycemic agents are appropriately discontinued before surgery because of the risk of hypoglycemia during fasting and potential drug interactions with anesthetics.

A continuous insulin infusion protocol provides the most accurate perioperative glucose control because it allows real-time dose adjustments based on frequent blood glucose monitoring (typically every 1–2 hours). This approach can maintain blood glucose levels within the target range of 140–180 mg/dL, which has been shown to reduce surgical complications including wound infections, delayed healing, and cardiovascular events. The infusion rate can be easily increased or decreased according to the patient's response to surgical stress, fluid administration, and nutritional status.

This intervention requires close collaboration between nursing staff and the medical team to ensure safe implementation and monitoring throughout the perioperative period.

Understanding the Clinical Scenario
The client has a preoperative blood glucose of 180 mg/dL, indicating hyperglycemia. Major abdominal surgery imposes significant physiological stress, triggering the release of counter-regulatory hormones like cortisol and catecholamines. This creates a state of relative insulin resistance and increased hepatic glucose production, making perioperative glycemic control challenging. The order to hold oral hypoglycemics is standard to prevent intraoperative hypoglycemia, but it leaves the hyperglycemia unaddressed, which is a proven risk factor for poor surgical outcomes.

Analyzing the Options
- Option 1: Administering metformin with a sip of water is incorrect and dangerous. Metformin is held for surgery due to the risk of lactic acidosis, particularly in the context of potential intraoperative hemodynamic instability, contrast dye exposure, or altered renal function. Continuing it violates a direct order and a core safety principle.
- Option 2: Requesting an order for sliding scale regular insulin (SSI) alone is a reactive, suboptimal strategy. SSI treats hyperglycemia after it occurs, leading to peaks and valleys in glucose levels. Evidence from critical care and perioperative literature emphasizes that proactive, continuous insulin delivery is superior for maintaining stable euglycemia and reducing glucose variability, a factor linked to complications ^[3].
- Option 4: Monitoring blood glucose every 4 hours and documenting is a passive action. While monitoring is essential, it does not constitute an intervention to manage the existing 180 mg/dL hyperglycemia. The time interval is also too long for the dynamic intraoperative and immediate postoperative period, where hourly or more frequent checks are standard during an insulin infusion ^[3].

Why Option 3 is the Best Intervention
Collaborating with the physician to initiate a continuous insulin infusion protocol is the gold standard for managing hyperglycemia in patients undergoing major surgery. This approach directly aligns with the principles of enhanced perioperative glucose management.

The rationale is rooted in the concept of metabolic vulnerability. A preoperative glucose of 180 mg/dL signals a high-risk metabolic state. Research on the hemoglobin glycation index (HGI) demonstrates that discordance between chronic and acute glycemic measures can identify patients at greater risk for postoperative complications, independent of a single glucose value . This highlights that a proactive, tightly controlled strategy is not just about correcting a number, but about stabilizing a complex, dysregulated metabolic system under surgical stress.

A continuous intravenous insulin infusion allows for minute-to-minute titration, matching the rapidly changing insulin requirements during anesthesia and surgery. This method is the foundation of effective glycemic control models. An endocrinologist-led glucose management model, which utilizes real-time continuous glucose monitoring (RT-CGM) paired with a continuous insulin infusion, has been shown to be a safe and effective strategy in critically ill patients . The nurse, as the coordinator of care, is pivotal in advocating for and implementing such a protocol. The nurse's role involves ensuring the protocol is ordered, preparing the infusion, and performing the frequent blood glucose monitoring required to titrate the infusion safely, a key nursing responsibility detailed in glycemic control practices ^[3]. While automated insulin delivery systems are an emerging area of study for perioperative patients, the established, readily available intervention for a hyperglycemic patient undergoing major surgery today is an intravenous insulin infusion . This collaborative intervention directly mitigates the risk of postoperative infection, poor wound healing, and fluid/electrolyte imbalances associated with uncontrolled hyperglycemia.