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A sedative is a drug used to calm someone down, make them more comfortable and help them sleep. For people who find certain tests or treatments frightening or uncomfortable, sedation can help them relax or stay still for a test or treatment (such as imaging tests). For example, if you are afraid of enclosed spaces or have a hard time being still, sedation may be helpful when having an MRI.

Sedation almost always includes analgesics and anesthetics. Analgesics are drugs that relieve pain. Anesthetics are drugs that cause a loss of feeling or awareness.

Levels of sedation

Depending on the situation and the test or treatment, different levels of sedation can be used.

During minimal sedation, you are relaxed and awake. You can understand and answer questions and follow instructions.

Under moderate sedation, you are drowsy and may sleep through much of the procedure. You can be easily awakened when spoken to or touched and may or may not remember the procedure.

During deep sedation, you will sleep through the procedure and have little or no memory of it. Your breathing can slow and you may sleep until the medicines wear off. You are often given oxygen while under deep sedation.

How sedation is given

You may need to prepare for sedation by not taking certain medicines, and you will probably be told to not drink or eat anything for a certain time before sedation is given. Sedation can be given as a drink, a pill, by breathing it in (inhalation) or through a needle into a vein (intravenous, or IV, injection).

During sedation, the healthcare team will monitor you closely. A small probe that fits on your finger or toe is attached to a machine called a pulse oximeter. This machine monitors your heart rate and the amount of oxygen in the blood.

Side effects

After sedation, the healthcare team monitors you closely for possible side effects. These will go away as the sedation wears off. Some common side effects include:

  • drowsiness
  • nausea
  • vomiting
  • dizziness
  • mood changes (feeling angry or sad)

Sometimes sedation can make you overly active and upset instead of making you sleepy. Serious side effects such as allergic reaction or breathing problems are rare, but they are possible. The healthcare team is trained to deal with these problems if they happen and will watch you very closely for them.

Special considerations for children

Preparing a child for sedation can help lower their anxiety, make them more cooperative and help them develop coping skills. Parents and caregivers can help prepare children by explaining to them what will happen, including what they will see, feel, hear, taste or smell during sedation and the test.

A child’s age and development can affect their fears about sedation. Most kids are concerned about getting a needle. Sedation is often given by mouth and does not require a needle.

Younger kids may be afraid of being separated from their parents. Talk to the healthcare team about whether you can stay with your child for the test or treatment.

To help prepare children for sedation:

  • Let your child know where you will be during the test or treatment if you can’t be with them.
  • Explain to them in a way they can understand that the doctor will give them medicine to help them to relax or feel sleepy during the test.
  • Try to create a calm, supportive and soothing environment for your child before and after the test.

Preparing a child for sedation depends on the age and experience of the child. Find out more about helping your child cope with tests and treatments.