This CE activity is approved by EMS World Magazine, an organization accredited by the Continuing Education Coordinating Board for Emergency Medical Services (CECBEMS) for 1 CEU. To take the CE test that accompanies this article, go to www.rapidce.com to take the test and immediately receive your CE credit. Questions? E-mail editor@EMSWorld.com.
- Review anatomical and physiological features of pediatric patients that influence drug administration
- Discuss pediatric pain management
As you prepare to leave a community event where you've been on standby, a mother hurries to your tent with her 3-year-old daughter, who has a wheezy cry and is drooling. The mother tells you the child is allergic to bee stings and was just stung by three bees. Your partner alerts dispatch for a paramedic squad while you do a quick exam and find three sting sites on the girl's right arm, hives rapidly spreading across her chest and face, and audible wheezes. Oxygen is applied and, as you reach for an epinephrine auto-injector, your partner asks if you need the pediatric auto-injector. Looking at the adult auto-injector in your hand, you remember that young children like your patient need special doses of medication.
Why does a child need a special dose? How is their body different from an adult's? Are there other types of patients who should also be given special consideration? This article discusses special considerations for pediatric drug administration.
Children's bodies are a world apart from adults'. One of the easiest ways to understand why drugs may have different actions and different effects in children is to take a system-by-system approach to pediatric anatomy.
An incredible amount of blood circulates oxygen, nutrients and other chemicals into the brain. Because our brain cells are very sensitive to harmful substances and cannot be reproduced, it is important to keep harmful chemicals out of brain matter. As a result, the epithelial cells, or outermost brain cells that connect with circulating blood at the capillary level, have grown very tightly together. This layer of tightly packed epithelial cells, which is called the blood-brain barrier, prevents most proteins and polarized molecules from entering the brain. While lipid-soluble molecules can pass through the blood-brain barrier easily, most other chemicals are kept out.1
The protective blood-brain barrier in adults is not well developed in children, and is underdeveloped in premature infants, as their bodies' connective tissues have not yet been strongly formed. While the blood-brain barrier normally keeps potentially harmful drugs and other toxins from entering the brain, these same toxins and drugs can easily enter a child's brain. Extreme caution is required when administering drugs to these young patients. When the blood-brain barrier is weakened, certain drugs can potentially harm the neonatal infant's brain.
Drugs with known side effects that include neurological impairment require careful administration. These side effects are more common in the pediatric patient. For example, morphine is known to cause respiratory depression and sedation by slowing responses in the central nervous system. This effect can be seen more dramatically and at lower doses in children.
A child's cardiovascular system is not as strong as an adult's, and cardiac output is significantly lower. The heart is less developed and cannot increase the strength of contraction as well as an adult heart.2 As a result, the pediatric heart compensates best by increasing its rate instead of its contractile force. Peripheral vasoconstriction occurs earlier in pediatric patients and is less effective at increasing circulating blood volume. Tachycardia, or rapid pulse rate, needs to be recognized as a compensation mechanism. It is usually OK if it persists until the underlying problem can be corrected.