From the Guidelines
Insulin infusion (gtt) is recommended after orthopedic surgery to maintain blood glucose levels below 180 mg/dL, as indicated by the most recent and highest quality study 1. The typical approach involves starting an insulin infusion when glucose exceeds 180 mg/dL, using regular insulin at an initial rate of 1-2 units/hour, with adjustments based on hourly glucose measurements. For implementation, a standard insulin infusion protocol should be followed, with glucose checks every 1-2 hours initially, then every 4 hours once stable. This glucose control is important because hyperglycemia increases the risk of surgical site infections, impairs wound healing, and prolongs hospital stays after orthopedic procedures. The stress response to surgery naturally elevates blood glucose through increased cortisol and catecholamines, making insulin necessary to counteract these effects. Some key points to consider in the management of blood glucose after orthopedic surgery include:
- Withholding oral glucose-lowering agents the morning of surgery and giving half of NPH dose or 60–80% doses of long-acting analog or pump basal insulin, as recommended by 1.
- Monitoring blood glucose at least every 4–6 h while patient is taking nothing by mouth and dosing with short- or rapid-acting insulin as needed, as suggested by 1. Once the patient resumes eating, transition to subcutaneous insulin is appropriate. Non-diabetic patients can usually discontinue insulin once glucose normalizes, while diabetic patients will need to resume their home regimen with possible adjustments. It's worth noting that the target range for blood glucose in the perioperative period should be 80–180 mg/dL, as indicated by 1. Overall, the use of insulin infusion to control blood glucose after orthopedic surgery is a crucial aspect of patient care, and should be guided by the most recent and highest quality evidence, such as 1.
From the Research
Insulin Therapy in Orthopedic Surgery
- The use of insulin therapy in orthopedic surgery is crucial for managing hyperglycemia and preventing postoperative complications 2, 3.
- Studies have shown that elevated blood glucose levels can increase the risk of complications in orthopedic patients, and therefore, intraoperative and postoperative glycemic management is essential to maintain glucose at safe levels 2.
- However, there is no specific recommendation for insulin gtt (intravenous insulin therapy) in orthopedic surgery to keep glucose less than 200 mg/dL in the provided studies.
Glycemic Control Targets
- A study on gastroenterological surgery recommends a target blood glucose level of ≤150 mg/dL to reduce the risk of surgical site infections in non-diabetic patients 4.
- The American Diabetes Association recommends a target blood glucose level of <140-180 mg/dL for critically ill patients, but the optimal target for orthopedic surgery patients is not specified in the provided studies.
- The EADSG guidelines recommend individualized insulin regimens to achieve glycemic goals, but do not provide specific targets for orthopedic surgery patients 5.
Insulin Therapy in Hyperglycemia Management
- Insulin therapy is effective in managing hyperglycemia in hospitalized patients, and basal insulin analogues such as glargine and detemir can be used to achieve glycemic control 6.
- However, the choice of insulin therapy and the target blood glucose level should be individualized based on the patient's specific needs and medical history.