GI/GU: Monitoring fluid intake and output

Normally, the amount of total body water should be balanced through the ingestion and elimination of water: ins and out. To ensure this balance, as a nursing assistant, you may need to track and record all fluid intake and output on an intake and output sheet, commonly known as I&O sheet.

This is particularly important for certain groups of clients, like those on special fluid orders, including “encourage fluids” and “restrict fluids;” those who are at risk of developing dehydration, or losing too much body fluid, which impairs normal body functions; or those who might develop edema where swelling occurs in tissues due to excess fluid build up.

High risk of dehydration exists for those who may not be drinking an adequate amount of fluids throughout the day or those who might be losing too much due to receiving certain medications, like diuretics, or through vomiting, diarrhea, bleeding, burns, excessive sweating, fever, or vigorous exercise. Common signs include dry mouth, excessive thirst, and dark urine.

Likewise, clients at risk of developing edema include those receiving intravenous fluids or those with heart or kidney disease, where the body has trouble eliminating excess fluid. The fluid builds up and causes swelling, especially in the lower extremities.

Nursing assistants should check with nurses in charge of the client and the nursing plan of care to find out if the client's intake and output should be monitored. So, every time one of these clients receives or loses fluids in any way, the exact volume can be recorded. These volumes are then totaled at the end of every shift and then at the end of a 24-hour period.

Okay, so for fluid intake, you’ll need to count anything the client drinks, including water and beverages as well as all foods that are liquid at room temperature, like ice cream, gelatin, sherbert, pudding, custard, ice chips, and popsicles. The nurse will also measure the fluids provided through intravenous therapy, enteral, or total parenteral nutrition.

Now, the unit typically used to measure fluid intake is 1 milliliter, or mL for short. But some containers use different units, so you may need to be able to make the appropriate conversions. 1 milliliter equals 1 cubic centimeter, or cc for short, and 0.001 liters, or L for short. 1 fluid ounce can get converted into 30 milliliters. And 1 pint is approximately 500 milliliters, whereas 1 quart is about 1,000 milliliters.

It’s also important to know the usual serving sizes in your facility. As a rule of thumb, 1 teaspoon typically contains 5 milliliters; 1 tablespoon, 15 milliliters; and 1 cup, 250 milliliters. But for the rest of them, like mugs, glasses, or bowls, the volume of fluid contained may vary.

So, keeping in mind any necessary conversions, gather the supplies you’ll need, including gloves and a graduated measuring container. You can then add all fluid volumes served to that client.

For example, during your shift, the client could have been served with 200 milliliters of water, 360 milliliters of soda, and 140 milliliters of milk. All together, these equal 700 milliliters. But it’s possible that the client hasn’t finished all of them. So, you now need to wear your gloves and transfer whatever has remained from each liquid into a graduated measuring container.

Remember to keep the graduate even and at eye level to ensure precise measurements. So, if the volume left in the graduate is 80 milliliters, this has to be subtracted from the full serving amount of 700 milliliters, giving us a total fluid intake of 620 milliliters. Finally, remove your gloves and practice hand hygiene.

Now, when it comes to fluid output, this includes urine, vomitus, wound drainage, diarrhea, and blood. Special precautions are required for certain clients, like those undergoing chemotherapy since their urine, stool, and vomit can contain the chemotherapy agent.

Once again, your supplies include gloves and a graduated container. If there’s a possibility of splashing, make sure to also include personal protective equipment, such as a gown, goggles or face shield, and a mask.