Question

Calculate the IV flow rate in \(\mathrm{gtt} / \mathrm{min}\) for the following IV administrations, unless another unit of measure is stated. Infuse albumin \(250 \mathrm{~mL}\) over \(2 \mathrm{hr}\). Drop factor: \(15 \mathrm{gtt} / \mathrm{mL}\)

Short answer

The IV flow rate is approximately 31 gtt/min.

Step-by-step solution

Determine the Total Volume of IV Solution

Identify the total volume of IV fluid to be administered. In this exercise, the total volume is given as 250 mL.

Convert Hours to Minutes for Infusion Time

Since IV rates are often calculated in minutes, convert the infusion time from hours to minutes. Here, \(2 \text{ hr} = 120 \text{ min}\).

Calculate the Volume Per Minute

Divide the total volume by the total time in minutes to determine the flow rate in mL/min: \[ \text{Flow Rate (mL/min)} = \frac{250 \text{ mL}}{120 \text{ min}} \approx 2.083 \text{ mL/min}. \]

Determine the IV Flow Rate in Drops Per Minute

Use the drop factor to convert the flow rate from mL/min to drops/min \(\text{gtt/min}\). Multiply the flow rate by the drop factor: \[ \text{Flow Rate (gtt/min)} = 2.083 \text{ mL/min} \times 15 \text{ gtt/mL} \approx 31.245 \text{ gtt/min}. \]

Round to the Nearest Whole Number

Round the calculated flow rate to the nearest whole number since flow rates in gtt/min must be whole numbers. Thus, the IV flow rate is approximately 31 gtt/min.

Key concepts

Drop Factor

The drop factor is an important component of calculating the IV flow rate. It represents how many drops (gtt) of IV fluid make up 1 milliliter (mL) of solution. In this case, the drop factor is 15 gtt/mL. The manufacturer typically provides the drop factor, and it is essential for converting mL into drops per minute when you're determining the flow rate. Having a higher or lower drop factor means you'll need more or fewer drops to deliver the same amount of fluid.

Total Volume of IV Solution

Knowing the total volume of IV solution is crucial in calculating how fast the fluid must be administered. Here, the total volume is 250 mL of albumin. This volume is the total amount of liquid the patient will receive. The higher the volume, the longer it might take to administer, depending on the prescribed time. Keeping track of the volume ensures the patient receives the precise amount necessary for their therapy.

Infusion Time

Infusion time refers to the total duration over which the IV fluid is administered. The exercise states an infusion time of 2 hours. Often, you will need to convert hours into minutes (e.g., 2 hours = 120 minutes) since most IV calculations work with time in minutes. Precise infusion time is key to ensure the therapy's efficacy and patient's safety, avoiding under or overdosing caused by incorrect timing.

Flow Rate

Flow rate defines how quickly the IV fluid is being administered to the patient. It can be in units of mL/min or gtt/min. To find the flow rate, you divide the total mL by the total minutes to get mL/min. Afterward, multiply by the drop factor to convert to gtt/min. This exercise calculates it to about 31 gtt/min after rounding. Accurately determining the flow rate ensures that the patient receives the prescribed fluid amount at the correct pace.