How do you prepare an insulin drip?

How to Prepare an Insulin Drip

Prepare a continuous insulin infusion at a standardized concentration of 1 unit/mL using regular human insulin in 0.9% normal saline, and prime the tubing with a 20-mL waste volume before connecting to the patient. 1

Standard Preparation Protocol

Concentration and Solution

• Use regular human insulin at a concentration of 1 unit/mL for all continuous infusions in critically ill patients 1
• Mix the insulin in 0.9% normal saline solution as the standard diluent 1, 2
• For example: Add 100 units of regular insulin to 100 mL of normal saline to achieve 1 unit/mL concentration 1

Tubing Preparation (Critical Step)

• Prime new IV tubing with at least 20 mL of the insulin solution as waste before initiating therapy 1
• This priming step is essential because insulin adsorbs to polyvinylchloride (PVC) surfaces of IV tubing 3
• After the initial 50 mL wash-out, at least 75% of expected insulin is delivered in the first 50 mL, and 100% thereafter 3
• An insulin concentration of at least 25 units per 500 mL (0.05 units/mL) with 50 mL tubing flush eliminates the need for albumin additives 3

Special Considerations for Concentrated Preparations

Higher Concentration Options

• For patients requiring high-dose insulin (such as calcium channel blocker or beta blocker overdose), concentrated insulin at 16 units/mL in 0.9% saline is stable for 14 days both refrigerated and at room temperature 2
• This higher concentration prevents fluid volume overload in patients requiring large insulin doses 2
• Concentrated preparations ranging from 2-fold to 5-fold (U-200 to U-500) are available but primarily for subcutaneous use 4, 5

Visual Inspection Before Use

Quality Check

• Inspect the insulin vial before each use for clumping, frosting, precipitation, or changes in clarity or color 1, 6
• Regular insulin and rapid-acting insulins should appear clear 1
• Any visual changes may indicate loss of potency and the vial should be replaced 1

Storage Guidelines

Before Preparation

• Unopened insulin vials should be refrigerated at 36-46°F (2-8°C) 6
• Avoid extreme temperatures (<36°F or >86°F) and excess agitation to prevent loss of potency 1, 6
• Insulin in use may be kept at room temperature 1

Common Pitfalls to Avoid

• Failing to prime the tubing adequately: This results in significant insulin loss to PVC surfaces and unpredictable dosing in the initial hours 3
• Using the wrong insulin type: Only regular human insulin should be used for IV infusions; do not use rapid-acting analogs, NPH, or long-acting insulins intravenously 1
• Mixing with incompatible solutions: No other medication should be mixed with insulin unless specifically approved 1
• Not inspecting for visual changes: Using insulin that has changed appearance can result in inadequate glycemic control 1, 6

When to Use IV Insulin Infusion

• Preferred for hemodynamically unstable patients with hyperglycemia 1
• Essential for patients with type 1 diabetes in critical care settings 1
• Required when rapid titration and immediate flexibility are needed for tight glycemic control 1
• Should not be initiated in patients with hypothermia, significant edema, or frequent interruptions of dextrose intake 1