What is the Vellore regimen for intraoperative blood sugar monitoring?

Vellore Regimen for Intraoperative Blood Sugar Monitoring

The Vellore regimen is a simple glucose-insulin protocol where for every 1-50 mg/dL increase in blood glucose above 100 mg/dL, you add 1 unit of insulin to the injection port of a 100-mL measured volume set containing 5% dextrose in water, with hourly blood glucose monitoring throughout the operative period. 1

Core Protocol Components

Insulin and Glucose Administration

• Add 1 unit of regular insulin to the injection port of a 100-mL measured volume set containing 5% dextrose in water for every 1-50 mg/dL increase in blood glucose concentration above 100 mg/dL 1
• This combines both glucose-insulin infusion and variable rate adjustment in a single, easily implemented system 1
• The regimen maintains blood glucose in the target range of 100-200 mg/dL 1

Monitoring Frequency

• Measure blood glucose hourly during the intraoperative period 1
• Use arterial or venous blood samples (taken from the opposite side to glucose infusion) rather than capillary blood, as capillary measurements overestimate blood glucose levels, especially during vasoconstriction and hypoglycemia 2
• A capillary glucose reading of 70 mg/dL (3.8 mmol/L) should be considered hypoglycemia and requires immediate verification by laboratory measurement 2

Clinical Effectiveness

Glycemic Control Outcomes

• The Vellore regimen achieved mean blood glucose of 156 ± 36 mg/dL compared to 189 ± 63 mg/dL in control groups using various other techniques (P = 0.003) 1
• Poorly controlled patients (outside 100-200 mg/dL range) decreased from 51% to 28% with no patients experiencing glucose <60 mg/dL, compared to control groups where poor control increased from 49% to 72% with 10 patients experiencing glucose <60 mg/dL (P = 0.0013) 1

Integration with Current Guidelines

Target Blood Glucose Range

• While the Vellore regimen targets 100-200 mg/dL 1, current perioperative guidelines recommend a broader target of 90-180 mg/dL (5-10 mmol/L) to balance morbidity reduction without excessive hypoglycemia risk 2
• Maintain blood glucose below 180 mg/dL (10 mmol/L) to reduce perioperative morbidity and mortality, particularly infection risk 2

Insulin Type Considerations

• Modern guidelines recommend ultra-rapid short-acting insulin analogues diluted to 1 IU/mL concentration 2
• Always provide simultaneous glucose infusion (100-150 g/day or equivalent to 4 g/hour) except during hyperglycemia 2

Critical Pitfalls to Avoid

Hypoglycemia Management

• If blood glucose drops below 60 mg/dL (3.3 mmol/L), stop insulin infusion immediately and administer 2 ampules (6 g) of 30% dextrose 2
• Resume insulin at half the previous rate only when blood glucose reaches 100 mg/dL 2
• Recheck blood glucose at 15 and 30 minutes after hypoglycemia treatment 2

Monitoring Method Selection

• Never rely solely on capillary glucose measurements using bedside glucometers, as these overestimate blood glucose levels during vasoconstriction and underestimate during hypoglycemia 2
• Use blood gas analyzers when available for more accurate intraoperative glucose measurement 2

Electrolyte Monitoring

• Monitor potassium concentration every 4 hours during insulin infusion, targeting 4-4.5 mmol/L, as insulin therapy can induce dangerous hypokalemia 2
• Measure potassium hourly after any change in insulin infusion rate 2

Advantages of the Vellore Regimen

• Simple to implement without requiring complex computer algorithms or intensive calculations 1
• Combines both glucose and insulin delivery in a single system, reducing complexity 1
• Effective for maintaining intraoperative glycemic control with minimal hypoglycemia risk 1
• Requires only hourly monitoring rather than more frequent checks needed with other protocols 1