What is the Yale protocol for insulin management in inpatients?

Yale Insulin Infusion Protocol for Inpatient Management

Overview of the Yale Protocol

The Yale insulin infusion protocol is a validated computerized or written algorithm for continuous intravenous insulin administration in critically ill patients that targets blood glucose levels of 120-160 mg/dL, achieving target glycemia within approximately 7 hours while maintaining hypoglycemia rates below 0.3%. 1

The protocol was specifically designed for intensive care settings and has been updated to align with current consensus guidelines recommending more conservative glycemic targets compared to earlier tight control strategies. 1

Critical Care Implementation

Target Blood Glucose Range

• The updated Yale protocol targets blood glucose concentrations of 120-160 mg/dL in the ICU setting 1
• This aligns with current American Diabetes Association guidelines recommending targets of 140-180 mg/dL for most ICU patients, with more stringent goals of 110-140 mg/dL appropriate for select patients (cardiac surgery, acute ischemic events) if achievable without significant hypoglycemia 2

Protocol Characteristics

• Uses validated written or computerized protocols that allow predefined adjustments in insulin infusion rate based on glycemic fluctuations and immediate past and current insulin infusion rates 2
• Achieves target blood glucose range within a median of 7 hours from initiation 1
• Maintains mean blood glucose of approximately 155.9 mg/dL (median 150 mg/dL) once target is reached 1
• Requires median insulin infusion rate of 3.5 units/hour to reach and maintain target range 1

Safety Profile

• Hypoglycemia is rare: only 0.3% of blood glucose values fall below 70 mg/dL and 0.02% below 40 mg/dL 1
• When hypoglycemia occurs, it is rapidly corrected with intravenous dextrose without evident adverse outcomes 1
• The protocol has been successfully adapted for different populations, including Japanese patients after cardiac surgery 3

Comparative Effectiveness

• The Yale protocol demonstrates superior performance compared to the Leuven protocol, providing more time in normoglycemia (37% vs 26%), less time in hypoglycemia (0% vs 5%), and reduced glycemic variability 4
• Continuous glucose monitoring studies show the Yale protocol achieves better average glycemia with less variability 4

Transitioning from IV to Subcutaneous Insulin

Timing and Dosing

• Administer subcutaneous basal insulin 2 hours before discontinuing IV infusion to minimize rebound hyperglycemia 2
• Calculate total daily subcutaneous dose based on 60-80% of the insulin infusion rate during the prior 6-8 hours when stable glycemic goals were achieved 2, 5
• For example: if average IV rate is 1.5 units/hour, the 24-hour requirement is 36 units; give 60-80% (22-29 units) as subcutaneous insulin 5

Emerging Transition Strategy

• Consider adding low-dose basal insulin analog (0.15-0.3 units/kg) during IV infusion to reduce duration of insulin infusion, prevent rebound hyperglycemia, and shorten hospital stay without increasing hypoglycemia risk 2

Non-Critical Care Subcutaneous Protocols

For Patients Eating Regular Meals

• Use basal-bolus approach starting at 0.5 units/kg basal insulin (glargine once daily or NPH twice daily) plus 0.1 units/kg rapid-acting analog at each meal 6
• Reduce basal dose by 0.2 units/kg for conditions with high insulin sensitivity: renal/hepatic impairment, thin/normal weight, elderly, frail, hypothyroidism, adrenal insufficiency 6
• Increase basal dose by 0.2 units/kg for insulin resistance states: marked obesity with metabolic syndrome, open wounds, infections 6
• This approach is preferred over sliding scale insulin alone, which is strongly discouraged as it results in poorer glycemic control and increased complications 2, 7

For Continuous Tube Feedings

• Administer the same 24-hour insulin dose (0.6-1.0 units/kg) as divided doses of 70/30 NPH/regular insulin every 8 hours 6
• Alternatively, use NPH insulin every 8-12 hours for continuous feedings 7
• Calculate nutritional insulin as 1 unit per 10-15 grams of carbohydrate in the formula 7

For Type 1 Diabetes

• Always maintain basal insulin even when NPO - never hold basal insulin in type 1 diabetes patients, especially during care transitions 2, 7
• An insulin regimen with basal and correction components is mandatory for all hospitalized type 1 diabetes patients 2

Critical Pitfalls to Avoid

Common Errors

• Never use sliding scale insulin alone as the sole regimen - it increases both hypoglycemia and hyperglycemia risk and worsens hospital complications 2, 7
• Avoid premixed insulin formulations in the hospital - they significantly increase hypoglycemia compared to basal-bolus therapy 2, 7
• Do not use subcutaneous insulin in critically ill patients, particularly during hypotension or shock - IV infusion is required 2

Hypoglycemia Prevention

• Implement a standardized hospital-wide hypoglycemia management protocol as recommended by the Joint Commission 2
• Monitor overnight hours (midnight to 6 AM) when hypoglycemia risk peaks 2, 7
• Review and adjust insulin doses when blood glucose falls below 70 mg/dL - 84% of severe hypoglycemia cases had prior episodes that went unaddressed 2
• Address common causes: improper prescribing, nutrition-insulin mismatch, unexpected interruption of feedings, reduced corticosteroid doses, renal failure 2

Medication Management

• Discontinue SGLT2 inhibitors 3-4 days before surgery and avoid during hospitalization 7
• Withhold metformin on the day of surgery 7
• For patients on concentrated insulin (U-200, U-300, U-500), ensure correct dosing with separate pens/vials per patient and meticulous pharmacy supervision 2