External ventricular drain (EVD)
An external ventricular (ven-TRICK-you-lur) drain is a small, flexible tube that relieves pressure on the brain. This drain is often called an EVD. It may be used for children with brain tumors, a brain abcess, hydrocephalus (hi-drowSEF-uh-luss: fluid build-up in the brain), head injuries, and brain infections due to shunts (permanent, internal drains).
How does an EVD work? Doctors place your child’s EVD during surgery. Your child receives medicines to help him or her sleep during the surgery. A small spot on your child’s head is shaved in the area that will have the EVD. The doctor first makes a small opening in the skin. Then the doctor makes a very small
opening in the skull to insert the tube. The tube reaches into a ventricle in the brain, as shown in the illustration. This allows the extra fluid to be drained, which relieves the pressure. Finally, the doctor stitches the tube under the skin.
A collection system is attached to the drain. This system allows the brain fluid to stay at the correct pressure by allowing the extra fluid to drain into a collection bag. This collection system is hung on an IV pole, and specific pressure levels are set to keep the brain fluid pressure correct. The Zero line (which has a red tip) on the EVD system is adjusted so that it is level with the top of the child’s ear. The slide chamber is placed at a specific level, ordered by the doctor, to keep the brain fluid pressure where it should be. It is very important that the height of the collection system is not changed, or your child’s head is not raised or lowered without a nurse’s help. The settings on the system must stay at the correct height at all times to make sure the right amount of fluid drains. While the drain is in place, your child’s activities should be limited and closely supervised. Your child’s nurse cleans the skin around the site daily. The nurse watches and records the amount of fluid that collects in the bag and empties it often. The nurse also makes sure that your child drinks enough fluid to replace the amount that leaves the body.
Are there any side effects? After an EVD is placed, your child may experience: • New emotions. Your child may be angry, scared, confused, or think the EVD is ugly. Be honest with your child in explaining the need for the EVD. Try to be supportive and sensitive to your child’s fears and self-image. • A headache. Usually headaches are relieved after the EVD is placed. If they continue, they are usually relieved with acetamenophen (Tylenol®). Sometimes stronger pain relievers are used for severe headaches. • Vomiting. Vomiting is common after surgery. If your child is vomiting, his diet will change to clear liquids and slowly progress to solids when foods do not make him vomit.
How is the EVD removed? If your child improves with the EVD, it is removed by your child’s doctor. When the doctor removes the EVD, he or she removes the stitches and then gently pulls the tube out. The doctor uses a staple or stitch to close the opening. The staple or stitch is removed during your follow-up visit.
Call your nurse if. . . • Your child needs to change positions, such as sitting up or laying down. • Your child needs to use the bathroom or wants to go for a walk. • Your child feels sick to his stomach or vomits. • Your child cries more or is fussier than usual. • The drain is pulled out or pulled apart. • The collection system comes apart in any way.
Pediatric Education Services 801.662.3500 Rev. 08/07 © Primary Children’s Medical Center 2007 All of the information contained in the Let’s Talk About… series is for educational purposes only. This educational information is not a substitute for medical advice or for care from a physician or other health care professional. If you have questions about your child’s health, contact your health care provider.
