A nurse is preparing a 72-year-old client with type 2 diabetes mellitus for a scheduled below-the-knee amputation (BKA). The client has been NPO since midnight, and the 6:00 AM preoperative blood glucose reading is 180 mg/dL. Recognizing the physiological stress associated with the upcoming procedure, which nursing action should be the highest priority during this preoperative period?

Frequent blood glucose monitoring is the highest priority for diabetic clients undergoing surgery due to the multiple factors that can cause dangerous fluctuations in blood glucose levels during the perioperative period.

For diabetic patients undergoing surgery, frequent monitoring of blood glucose levels is the highest-priority nursing intervention during the preoperative period. This priority stems from the complex physiological changes that occur when diabetes, surgical stress, and perioperative management protocols intersect.

The stress response to surgery promotes the secretion of counter-regulatory hormones, including cortisol, epinephrine, and growth hormone. These hormones stimulate gluconeogenesis and glycogenolysis while creating insulin resistance, potentially leading to dangerous hyperglycemia. Additionally, the required fasting state before surgery disrupts the patient's normal eating patterns and medication timing, creating risks for both hyperglycemia and hypoglycemia.

Diabetic patients have a significantly higher risk of perioperative complications. These include delayed wound healing, increased infection rates, cardiovascular events, and metabolic emergencies such as diabetic ketoacidosis. Optimal blood glucose control through frequent monitoring enables early detection of dangerous glucose fluctuations and allows for timely interventions.

The target blood glucose range for diabetic surgical patients is generally 140-180 mg/dL, with some institutions aiming for 110-140 mg/dL. Levels outside this range require immediate intervention—hyperglycemia may necessitate insulin administration, while hypoglycemia requires glucose supplementation. Frequent monitoring also provides essential data on current blood glucose levels to the anesthesia team, who must make informed decisions regarding perioperative management.

This monitoring priority takes precedence over other important but less immediately critical interventions because uncontrolled blood glucose can lead to life-threatening complications during and after surgery.

Understanding the Preoperative Blood Glucose of 180 mg/dL
A preoperative blood glucose of 180 mg/dL in a client with type 2 diabetes who is NPO and facing a below-the-knee amputation (BKA) is a critical finding. While this value is elevated, it reflects the body's physiological stress response. Surgical anticipation triggers the release of counter-regulatory hormones like cortisol and catecholamines, which promote hepatic glucose production and insulin resistance ^[3]. The priority is not to immediately “fix” this number with insulin without further context, but to recognize it as a dynamic marker of metabolic stress that requires close surveillance.

Why Frequent Monitoring is the Highest Priority
The correct action is to monitor blood glucose levels frequently and report abnormal values. In the NPO preoperative state, the risk for both hyperglycemia and hypoglycemia is heightened. Administering insulin without current, trended data and knowledge of the client’s baseline regimen could precipitate dangerous hypoglycemia, which is immediately life-threatening. The consensus statement on perioperative management highlights that both hyperglycemia and hypoglycemia are harmful, and the primary goal is to maintain glycemic stability through vigilant monitoring ^[2][3]. A hospital-wide glycemic management model demonstrated that systematic monitoring and protocol-driven adjustments, rather than isolated one-time interventions, significantly improve perioperative outcomes ^[1]. Therefore, establishing a trend through frequent checks is the foundational safety step before any medication administration.

Analysis of Incorrect Options
- Option 1: Administer the client's usual morning insulin dose as prescribed. This is a high-risk action without first assessing the trend and the client's current clinical status. The client is NPO, and their “usual” dose was prescribed for a state of oral intake. Administering it could cause severe hypoglycemia. Furthermore, if the client is on a sodium-glucose cotransporter 2 inhibitor (SGLT2i), standard insulin protocols may need adjustment due to the risk of euglycemic diabetic ketoacidosis (euDKA), a condition where ketoacidosis occurs with only mildly elevated glucose levels, especially under fasting and surgical stress ^[2]. The nurse must first gather data (monitor) before acting.
- Option 2: Encourage the client to drink clear liquids to prevent dehydration. This action directly violates the NPO order, which is in place to prevent pulmonary aspiration during anesthesia. Maintaining NPO status is a non-negotiable safety requirement, and dehydration must be managed through intravenous fluids as prescribed, not oral intake.
- Option 3: Provide detailed preoperative teaching about the surgical procedure. While preoperative teaching is an essential nursing role, it is not the highest physiological priority at this moment. The immediate concern is the client's metabolic instability. Teaching can be effectively integrated after the acute physiological assessment and intervention are underway, but it does not take precedence over a potentially fluctuating blood glucose level that could lead to a life-threatening event.

Connecting Surgical Stress, Glycemic Control, and Outcomes
The surgical stress of a BKA will exacerbate hyperglycemia, which is directly linked to adverse outcomes, including postoperative infections and increased mortality ^[3]. The nurse’s role is to act as the first line of surveillance, identifying dangerous trends before they culminate in a crisis. This is the core principle behind structured glycemic management teams, which rely on frequent, accurate glucose data to guide therapy and shorten hospital stays ^[1]. By prioritizing monitoring, the nurse generates the essential data that will inform the provider’s decision on whether to administer insulin, dextrose, or intravenous fluids, thereby preventing both hypoglycemic events and the onset of acute hyperglycemic crises, including the often-missed euglycemic DKA in clients who may be taking SGLT2i medications .