GTT, which stands for “drops per minute,” or “gtt per min,” is a medical term used to describe the drip rate of intravenous (IV) fluids. Knowing how to calculate this drip rate is critical for healthcare professionals. This article will provide a step-by-step guide on how to calculate gtt.

Step 1: Determine the Doctor’s Order

The first step in calculating gtt is to determine the doctor’s order concerning the patient’s IV therapy. The doctor’s order typically includes the amount of fluid to be administered over a specific period.

Step 2: Identify the IV Tubing Drip Factor

The next step is to determine the drop factor (drip rate) of the IV tubing being used. The drop factor indicates how many drops make up one milliliter (mL) of fluid. This information can usually be found on the tubing packaging or from the manufacturer.

Step 3: Convert Units (if necessary)

Before performing calculations, ensure that all units are in milliliters (mL). If the doctor’s order is in units other than mL, convert it accordingly, as follows:

1 teaspoon = 5 mL

1 tablespoon = 15 mL

1 ounce = 30 mL

1 liter = 1000 mL

Step 4: Calculate GTT per Minute

To calculate the gtt per minute, follow this simple formula:

GTT per minute = (amount of fluid in mL / time in minutes) x drop factor

Example:

If a doctor orders a patient to receive 1000 mL of fluid in eight hours and the tubing has a drop factor of 20 gtt/mL, here’s how you would calculate gtt per minute:

First, determine time in minutes: 8 hours x 60 minutes/hour = 480 minutes

Next, use the formula:

GTT per minute = (1000 mL / 480 minutes) x 20 gtt/mL

GTT per minute ≈ 41.67

In this example, the IV drip rate would be set to approximately 42 gtt per minute.

Conclusion

Calculating gtt is an essential skill for healthcare professionals dealing with IV administration. By understanding the doctor’s order, determining the drop factor, and following the necessary calculations, you can accurately calculate gtt and ensure patients receive the appropriate IV therapy.