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Perioperative Diabetes Management. Dr. Ken Locke March 2007. Objectives. At the end of the seminar, you will be able to: Describe the problems created by inadequate perioperative glycemic control Develop a series of goals in the perioperative management of diabetes, and prioritize them
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Perioperative Diabetes Management Dr. Ken Locke March 2007
Objectives At the end of the seminar, you will be able to: • Describe the problems created by inadequate perioperative glycemic control • Develop a series of goals in the perioperative management of diabetes, and prioritize them • Explain strategies for managing diabetes, and apply them to clinical cases
Outline • Clinical cases • Background on perioperative hyperglycemia • Principles of perioperative diabetes management • Recommendations • Cases revisited
Clinical Cases • A 25 year old type 1 diabetic woman is scheduled for hysteroscopy for infertility • What are the important considerations in her periop management? • What strategies could be used?
Clinical cases cont. • A 72 year old man with type 2 diabetes on 150 units of insulin/day is scheduled for cataract extraction • What are the important considerations in his periop management? • What strategies could be used?
Clinical cases cont. • A 58 year old type 2 diabetic woman on glyburide and metformin is scheduled for AAA resection • What are the important considerations in her periop management? • What strategies could be used?
Why is perioperative glycemic control important? • Improvement in wound healing parameters (tissue level data) • Improvement in infection parameters (tissue level and case series) • Improved mortality seen in critical illness, post CV surgery, and post AMI with STRICT glycemic control (RCT level data)
Why is perioperative glycemic control difficult? • Altered glucose inputs • NPO, changes in motility, enteral feeds, TPN • Altered hypoglycemic therapy • Cannot use OHAs • SC insulin may have different absorption profile • Altered glucose homeostasis • Increased counter-regulation in perioperative environment • Decreased ambulation • Increased tissue consumption after larger surgeries
Principles of Perioperative DM Management • 1st Goal: Avoid intra-operative hypoglycemia • 2nd Goal: Avoid acute complications of hyperglycemia • 3rd Goal: Maintain optimum glycemic control
Avoid Intraoperative Hypoglycemia • Hypoglycemia is potentially damaging at any time • Intraoperative hypoglycemia is impossible to detect clinically • Sympathetic responses are ablated by anaesthesia • Hypoglycemia is more likely intraoperatively • Increased glucose consumption in response to surgery
Avoid Intraoperative Hypoglycemia • Solution: Support patients with IV D5W who take any pharmacologic DM therapy • Remember, yesterday’s evening doses are peaking during this morning’s OR! • Minimum is 5g of glucose/hour = 100 cc/hour • Also prevents catabolism
Avoid Acute Complications of DM • Type 1 patients are prone to ketoacidosis • But Type 2 patients can develop it with great stress • Type 2 patients are at risk of hyperosmolarity • Risk of both of these increases with duration and complexity of surgery • Direct effects of counter-regulation and fluid balance
Avoid Acute Complications of DM • Solution: • Ensure adequate insulin is present during surgery and afterward • Remember that insulin resistance in Type 2 patients may require dose increases • Monitor glucose before, during and after OR • Ensure appropriate fluids are being given to assist in glucose clearance
Maintain Optimum Glucose Levels • Range of 8-11 typically used • Avoids hypoglycemia but not beyond range of control • Choose the strategy that fits: • type of surgery (metabolic stress) • duration of surgery • availability of resources
Options • Rely exclusively on residual insulin from previous day’s therapy (oral or SC insulin) • Best for short procedures where risk of acute hyperglycemia is very low • SC long acting insulin (adjusted dose) • May not be adequate for longer procedures • IV insulin infusion with frequent monitoring of glucose level • Requires time/personnel to monitor and adjust
Best Practices • All patients hold their usual doses on day of surgery while NPO • No agreement on anything beyond this! • IV insulin preferred to achieve optimum glucose control • Use for Type 1&2 DM, longer procedures, especially with significant insulin resistance • SC insulin when IV insulin not necessary • Can be more liberal with Type 2 than Type 1 • “Yesterday’s insulin” – never for Type 1
Postoperative Management • When patients resume eating, can usually resume usual therapy • Alterations (NPO, reduced diet, enteral feeds etc.) require altered management • Oral agents should wait until reliable diet • IV insulin easiest to titrate/achieve control • Remember to anticipate rather than react to abnormal glucose
Back to the Cases • Develop a plan for each case: • A 25 year old type 1 diabetic woman is scheduled for hysteroscopy for infertility • A 72 year old man with type 2 diabetes on 150 units of insulin/day is scheduled for cataract extraction • A 58 year old type 2 diabetic woman on glyburide and metformin is scheduled for AAA resection