Intraop Insulin Infusion Rate Calculator

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Intraoperative Insulin Infusion Rate Calculator

Typical range: 0.01 to 0.05 depending on patient insulin resistance.

Recommended Infusion Rate:

0.0 Units/hr

function calculateInsulinRate() { var bg = parseFloat(document.getElementById('bgLevel').value); var mult = parseFloat(document.getElementById('sensitivityFactor').value); var resultDiv = document.getElementById('resultArea'); var output = document.getElementById('rateOutput'); var note = document.getElementById('safetyNote'); if (isNaN(bg) || bg <= 0) { alert("Please enter a valid Blood Glucose level."); return; } var rate = 0; var color = "#28a745"; // Green if (bg < 70) { rate = 0; output.innerHTML = "0.0 Units/hr"; note.innerHTML = "CRITICAL: Blood glucose is low. Stop infusion and follow hypoglycemia protocol (D50 administration)."; color = "#dc3545"; // Red } else if (bg < 120) { rate = 0; output.innerHTML = "0.0 Units/hr"; note.innerHTML = "Glucose is within target range for many protocols. Continue monitoring."; color = "#17a2b8"; // Blue } else { // Common Formula: Rate = (BG – 60) * Multiplier rate = (bg – 60) * mult; if (rate < 0) rate = 0; output.innerHTML = rate.toFixed(1) + " Units/hr"; note.innerHTML = "Formula used: (BG – 60) × " + mult; color = "#d9534f"; // Red/Orange for insulin delivery } resultDiv.style.backgroundColor = color + "10"; resultDiv.style.border = "1px solid " + color; output.style.color = color; resultDiv.style.display = "block"; }

Understanding Intraoperative Insulin Management

Maintaining tight glycemic control during the perioperative period is a critical component of modern anesthesia care. Surgical stress triggers a neuroendocrine response characterized by the release of catecholamines, cortisol, and glucagon, which collectively induce a state of insulin resistance and hyperglycemia, even in patients without a history of diabetes.

The Role of Continuous Insulin Infusion (CII)

Intraoperative insulin infusion is often preferred over intermittent bolus dosing because it allows for more precise control and rapid adjustments to the patient's changing metabolic needs. The "Portland Protocol" and similar linear algorithms are commonly used in cardiac and general surgery to keep blood glucose levels between 120 and 180 mg/dL (or tighter, depending on institutional guidelines).

How the Calculation Works

The calculator above utilizes a common linear titration formula used in many surgical centers:

Insulin Rate (U/hr) = (Current Blood Glucose – 60) × Multiplier

The multiplier (often starting at 0.02) represents the patient's sensitivity to insulin. This factor may need to be increased (e.g., to 0.04 or 0.06) for patients with significant insulin resistance, high BMI, or those undergoing procedures involving cardiopulmonary bypass.

Practical Example

  • Patient BG: 210 mg/dL
  • Standard Multiplier: 0.02
  • Calculation: (210 – 60) = 150
  • Final Rate: 150 × 0.02 = 3.0 Units/hour

Safety and Monitoring

When utilizing a continuous insulin infusion in the OR, consider the following safety measures:

  • Frequent Monitoring: Blood glucose should be checked every 30 to 60 minutes.
  • Potassium Management: Insulin shifts potassium intracellularly. Monitor serum potassium levels to prevent hypokalemia.
  • Priming the Tubing: Insulin adheres to plastic; ensure the IV tubing is primed with at least 20mL of the insulin solution before starting the infusion.
  • Standard Concentrations: Use standardized concentrations (e.g., 1 unit/mL in Normal Saline) to prevent calculation errors.

Disclaimer: This tool is for educational purposes only and should not replace clinical judgment or institutional protocols. Always verify dosages and rates according to your specific hospital guidelines.

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