Intravenous Fluid Regulation
Intravenous (IV) fluid regulation refers to the manual or automatic pump control of the rate of flow of IV fluids as they are delivered to a patient through a vein.
The purpose of intravenous fluid regulation is to control the amount of fluid that a patient is receiving, usually within a given hour of IV therapy. Without fluid regulation, the IV would run in by gravity at a rapid rate and could cause fluid or drug overload.
There are varied types of IV administration sets, and they deliver fluid at different amounts per drop. Nurses should always determine the type of drip chamber that they are using and calculate the IV flow per minute based upon the amount of fluid that the administration set delivers per drop.
There are varied types of IV pumps and IV tubing used to deliver IV fluids. Nurses should be sure to use the correct tubing for the pump selected. The specific directions for the use of each individual pump should be followed.
Manual regulation of IV fluids is performed by adjusting the roller adaptor on the IV tubing until it reaches the appropriate drip rate per minute. To manually regulate the IV rate, the nurse looks at her watch and times the number of drops that fall into the drip chamber over one full minute. If the rate is too slow, the adapter should be rolled to a looser position to speed the dripping of the IV. If the rate is too fast, the roller adapter should be tightened to decrease the dripping of the IV. Nurses should adjust the roller until the IV rate is set at the correct amount of drops per minute to deliver the IV fluids as ordered. The IV rate must be checked every hour or more often according to the policy of the medical setting to be certain that the rate remains accurate.
To regulate the IV fluid to be delivered by an IV pump, the tubing should be threaded into the machine correctly. Nurses should dial in the hourly IV rate (cc to be delivered over an hour) and start the pump following the manufacturers guidelines. IVs must be checked hourly when on a pump to be sure that the rate remains accurate and that the correct amount of fluid is delivered. Most pumps have a reading that shows how much fluid has been delivered over the past hour.
The physicians order for IV therapy should be reviewed. An IV therapy order will include the type of IV fluid to be delivered over a specific amount of time. Some physicians will order IV therapy in terms of an hourly rate. (Example: Lactated Ringers IV, run at 125 cc/hour.) More commonly the physician will order IV therapy in terms of eight, 12, or 24 hour time periods. (Example: One liter of D5W IV over the next eight hours.)
If the fluid is ordered by the shift (every eight hours) or for a 24-hour period, the first calculation must be to
Phlebitis—An inflammation of a vein.
Tachycardia—A condition where the heart rate is faster than normal, usually over 100 beats a minute in an adult.
determine how much fluid is ordered per hour. This can be determined by dividing the total amount of fluid by the total time ordered for delivery. For example, if the doctor ordered 1000 cc to be given over eight hours, divide the 1000 cc by the time (eight hours) to obtain the rate per hour. The hourly rate for the IV would be 125 cc for each hour. Another example would be that the doctor orders 3 liters of IV fluid to be given over 24 hours. Divide 3 liters (3000 cc) by the time (24 hours) to obtain the hourly rate of 125 cc per hour. When using an IV pump, the only calculation needed is the rate per hour because IV pumps when set will deliver an hourly rate of IV fluid automatically. The machine does the calculation and drip control. Nurses should be sure to select the specific tubing that the manufacturer recommends for use with each pump.
When not using an automatic IV pump, an administration set should be selected, and the nurse should look on the packaging for the calibration of the drip rate. Standard IV administration sets have a drip factor of 10, 15, or 20 drops/cc. A microdrip or minidrip administration set has a drip factor of 60 drops/cc and is used primarily for low IV rates, such as those used for pediatric clients. The calibration of the administration set must be known in order to calculate the flow of the IV fluids correctly.
The next step is to convert the drops per hour into drops per minute so that the nurse can literally count the drops delivered each minute to set the IV flow. To calculate the drops per minute, the drip factor of the administration set must be used. The nurse should divide the number of ccs to be delivered per hour by the number of minutes in an hour (60) and multiply by the drip factor of the IV administration set to find the drops per minute. For example, if the patient should receive 125 cc per hour using a set that delivers 10 drops/cc, the nurse would multiply the fraction 125/60 times 10 to get a drip rate per minute of 20.8 drops/minute. The number should be rounded to 21 drops per minute. Another example would be if the patient should receive 150 cc per hour using a set that delivers 20 drops/cc, the nurse would multiply the fraction 150/60 times 20 to get a drip rate of 50 drops per minute. The easiest calculation is using an administration set that delivers 60 drops/cc, because the drops and the minutes cancel each other out. For example, to give 50 cc/hr using a 60 drops/cc administration set, the fraction 50/60 should be multiplied by 60 to get a drip rate per minute of 50. Once the drip rate per minute is determined, the flow of the IV is ready to be regulated according to the doctor's order.
Regulating IV fluid is an ongoing process from the time that an IV is started until it is completed. Hourly checks of an IV should include assessing the client's response to the IV, the rate of the IV flow, how much fluid has infused, how much fluid remains to be infused, and the condition of the IV insertion site. Adjust the rate if the IV is not flowing at the rate that was ordered. If IV fluid is flowing in slowly, the nurse should check for a kink in the tubing or a positional problem. In addition, the IV could be out of the vein, or a small clot, phlebitis, or infection at the site could be slowing the IV down. If an IV is flowing too rapidly, it may be leaking out around the IV insertion site or may run faster when the patient extends the extremity. The whole system, from the insertion site to the IV bag, should be examined. The physician will assess IV fluid needs and reorder IV therapy daily according to client needs.
Circulatory overload can occur if an IV is not regulated and IV fluids infuse too rapidly for the patient's body to handle. Signs of fluid overload include tachycardia, elevated blood pressure, headache, anxiety, wheezing or other signs of respiratory distress, diaphoresis, restlessness, distended neck veins, or chest pain. If these signs occur, slow the IV rate and contact the physician.
Sluggish IV flow or mechanical failure can also occur, which results in the IV fluid not being delivered as ordered. The sign of sluggish IV flow is an IV rate that is persistently behind in spite of constant regulation. Sluggish IV flow can be caused by kinked tubing; small clots, phlebitis, or infection at the site; infiltration of the IV cannula; or a problem with the needle leaning against the wall of the vessel and cutting off IV flow. If the problem is not positional or equipment related, the IV will need to be restarted in a new vein in order to deliver the IV therapy safely and effectively.
IV fluids when regulated to flow according to the physicians orders have positive therapeutic effects such
Health care team roles
IV fluid regulation is delegated to registered nurses in most medical settings. Paramedics, LPNs, and IV team technicians who have received special IV training may regulate IV flow rates according to the policies in some medical settings. Patients and their families can be trained to use IV therapy in the home setting. The equipment for home IV therapy, however, will usually include a pump that automatically controls the IV rate. This setting is usually locked so that it cannot be accidentally altered. Patients are taught the signs of complications and learn to trouble-shoot IV alarms. IV nurses visit daily or every few days to change the IV tubing and are on-call to assist the patients and their families 24 hours a day when problems arise.
"Intravenous Administration." In Medication Administration. Nurse's Clinical Guide. Pennsylvania: Springhouse Corporation, 2000.
"Basics of IV Therapy." Baxter Online. Baxter, Inc. June 1999. <http://www.baxter.com/doctors/iv_therapies/index. html/>.
"Calculating IV Flow Rates." Medical CEUs Online. 2001. <http://www.medceu.com/tests/ivflow.htm>.
Clark, B., R.N., M.S. and Houser, C. "IV Flow Rates." Dosage Calculations for Nurses Online. 200l. <http://home.sc.rr.com/nurdosagecal/IV%20Flow%20 Rates%20and%20Duration.htm/>.
"IV Therapy." Chapter 6. Lippincott Manual of Nursing Practice. Books at Ovid Online. 2001. <http://pco.ovid.com/lrppco/>.
Mary Elizabeth Martelli, R.N., B.S.