N101 Unit 10 Chapter 18

Key Points

1. Children are particularly prone to adverse drug reactions because of the immaturity of their organs. 2. Body weight is a quick and convenient method for calculating drug dosages, but it may not accurately reflect age-related variation in drug absorption, distribution, metabolism, excretion, or serum drug levels. 3. Some drugs prescribed for children, such as some anti-infectives or chemotherapy agents, may be prescribed based on body surface area instead of weight. 4. Pediatric-only IV pumps, microtubing, and volume control sets are devices that can help safeguard against accidentally overhydrating children during IV therapy. 5. Many physiological changes occur during pregnancy and place the fetus at risk for the development of birth defects or injury. The fetus is at highest risk of developing injuries from medications during the first trimester. 6. Breastfeeding mothers should take medications right before or right after breastfeeding to reduce the amount of medication that may be transferred to the infant. 7. Aging adults are at risk for adverse drug reactions because of deteriorating organ function and polypharmacy.

Objectives

1. Describe general considerations when administering medications to children, pregnant or lactating women, and aging adults. 2. Calculate drug dosages for children based on body weight. 3. Calculate drug dosages for children based on body surface area. 4. Describe two methods of safe IV administration in children. 5. Calculate daily fluid maintenance needs for children.

General Considerations for Children

2002 Best Pharmaceuticals for Children Act -Law established a process for studying medications used in the pediatric population 2003 Pediatric Research Equity -amended the federal Food, Drug, and Cosmetic Act -Authorized the FDA to require pharmaceutical companies to conduct pediatric studies of drugs if the drug might be used for children -These laws have improved product labeling, identification of adverse drug events, and the development of new formulations specific to the pediatric population. 2016 FDA Report -Over 600 drugs had pediatric labeling, and inclusion of children in clinical drug studies were becoming a regular part of drug development by manufacturers

ALERT!

Certain medications are toxic to infants and children such as chemotherapy drugs and certain antibiotics. You may need to round your answer to the nearest hundredth place instead of the nearest tenth to provide the most accurate dose. Consult the prescribing provider, facility pharmacist, or drug manufacturer for recommendations.

Burette

A chamber used to ensure precise measurement of small amounts of IV fluids; part of a volume control set.

Volume control set

A device that contains a burette; designed to hold a small volume of IV solution from a larger container to avoid accidental fluid overload.

General Considerations for Pregnant and Lactating Women

A woman taking medications during pregnancy or breastfeeding must consider the impact that the drug has on her body, the fetus, or the nursing infant. Very few drugs are considered completely safe for use during pregnancy and lactation.

PSI

Abbreviation for pounds per square inch; a measure of pressure.

Calculating Dosages for Infants and Children Using Body Surface Area

Calculating drug dosages using body surface area (BSA) is thought to be more accurate than body weight alone. BSA is proportional to an individual's metabolic rate, reflecting a drug's metabolism rate. BSA also correlates well to organ size and fluid compartments within the body, making BSA better than body weight at predicting the effects of drugs

Comorbid

Coexisting with another unrelated disease process; for example, having diabetes, high blood pressure, depression, and chronic kidney disease at the same time.

Controlling Intravenous Infusions for Children

Extra care must be taken when initiating and monitoring IV therapy in infants and children to avoid accidental fluid overload.

Calculating Maintenance IV Fluids for Children

Fluid balance is monitored very carefully in children to avoid overhydration. Accurately monitoring and recording fluid intake and output is a crucial responsibility of a pediatric nurse. The volume of fluid that a child needs over 24 hours is referred to as daily maintenance fluid needs and depends upon the child's weight and current hydration status. For an adequately hydrated child, daily maintenance fluid needs are based on weight (see Table 18-2). Calculating the fluid needs of a dehydrated child is beyond the scope of this book.

Infiltration

Fluid or medication that leaks from the blood vessel into the surrounding tissues.

Infusion Pumps

Infusion pumps specifically designated for pediatric use should be used to infuse IV fluids. Pediatric infusion pumps deliver fluids at a PSI that is lower than that needed for adults, which reduces the risk of rapid infiltration and volume overload. Electronic drip controllers are not appropriate for pediatric IV therapy nor should fluids be infused under manual control.

Free drug

Medication that is not bound to plasma proteins in the blood.

Microdrip tubing

Microdrip tubing is specially calibrated to deliver 60 drops per milliliter. Its small diameter will not allow large volumes of fluid to be delivered to the patient unless great pressure is applied (such as from squeezing the IV bag).

Until all medication used by children can be studied to determine the appropriate doses:

Providers should calculate drug dosages and nurses should verify the accuracy of prescribed dosages. All dosage calculations should be double-checked by another nurse or pharmacist before administration.

Intake and output

The measurement of all fluid intake and output during a 24-hour period.

Metabolism

The process by which a medication is changed by the body.

Absorption

The process by which a medication moves from its site of administration into the blood.

Excretion

The removal of medications from the body through the kidney, lungs, GI tract, or glands.

Distribution

The transportation of medications throughout the body after having been absorbed.

Polypharmacy

The use of many medications

33. The purpose of a volume control set is to: a. prevent accidental dehydration in children. b. limit the volume of fluid the child will receive if the infusion pump malfunctions. c. decrease the pressure needed by the infusion pump to overcome venous resistance. d. increase the volume of fluid available for infusion.

b. limit the volume of fluid the child will receive if the infusion pump malfunctions.

Volume Control Sets

Volumes control sets—sold under the brand names Volutrol, Buretrol, Metriset, and Soluset—are infusion devices that hold small volumes of fluid (up to 150 mL) in a chamber called a burette. See Figure 18-1. The purpose of the volume control set is to limit the amount of fluid that the child receives if the infusion pump malfunctions. To prevent children from receiving an accidental fluid bolus, the burette is filled with no more than two or three times the prescribed hourly flow rate. For example, if the prescribed IV flow rate is 12 mL/hr, the nurse should ensure that no more than 24 to 36 mL of fluid is in the volume control chamber.

NOTE

Weight-based pediatric dosages may be prescribed in total daily amounts divided into specific time frames, such as every 4 hours or every 8 hours. The doses should be equal in amount.

34. The nurse is teaching a patient about taking medications during pregnancy and breastfeeding. Which statement by the patient indicates that she understands the teaching? a. "The greatest risk of injury to my baby is in the first trimester of pregnancy." b. "The placenta protects my baby from the medications I am taking." c. "I should never take any medications during my pregnancy, no matter what the problem." d. "My baby is not affected by any drugs I take while breastfeeding."

a. "The greatest risk of injury to my baby is in the first trimester of pregnancy."

35. The elderly are more likely to experience adverse drug reactions because: a. They tend to have a higher body mass index than younger adults. b. They have an increased amount of body water that affects how medications are distributed throughout the body. c. Declining organ function affects how medications are absorbed, distributed, metabolized, and excreted. d. They tend to have a decreased amount of body fat compared to younger adults.

c. Declining organ function affects how medications are absorbed, distributed, metabolized, and excreted.

32. The nurse is preparing to administer medication to a 6-month old infant. Which statement regarding immature kidney function in infants is true? a. Medications are metabolized faster. b. Medications are absorbed slowly. c. Medications are excreted slowly. d. Medications are excreted rapidly.

c. Medications are excreted slowly.

Drug Use During Pregnancy

many medications can cross the placenta and be distributed throughout the fetus's body, adversely affecting fragile developing organs.