King Abdullah Arabic Health Encyclopedia

 Intrathecal Injections

Intrathecal Injections - All Many people have pain in their back and legs because of problems with the spine. An intrathecal injection can be effective in relieving this kind of pain. If your doctor recommends an intrathecal injection, the decision whether or not to have this procedure is yours. Nerves pass from the body to the brain through the spine. Pressure on the nerves caused by a bone, ligament, or disk may also cause the sensation of pain. An intrathecal injection of morphine is made to reduce the sensations of pain carried to the brain by the nerves. This results in a decrease of overall sensation of pain. A long needle is used during the procedure to deliver the medicine to the area directly around the nerves. Your doctor will give you instructions on what you can and cannot do for a few days following this procedure.

Introduction

Many people have pain in their back and legs because of problems with the spine. An intrathecal injection can be effective in relieving this kind of pain. If your doctor recommends an intrathecal injection, the decision whether or not to have this procedure is also yours. This module will explain the benefits and risks of this procedure.

Anatomy

The spine is formed of vertebrae, or small bones. The vertebrae are separated and cushioned by softer disks. This allows the spine to flex and bend. Nerves pass from the body to the brain through the spine. Nerves carry sensations including the sensation of pain to the brain. Pressure on the nerves caused by a bone, ligament, or disk may also cause the sensation of pain. The nerves in the back are located in a bag of fluid called the thecal sac, which can be seen in this cross section of the spine.

Intrathecal Injections

An intrathecal injection of morphine is made to reduce the sensations of pain carried to the brain by the nerves. This results in a decrease of overall sensation of pain. The medications are put in the fluid that bathes the nerves inside the thecal sac, a space called the ‘intrathecal space.’ A needle is used to deliver the medication. Sometimes this is done under x-ray control. Initially, an IV is placed in your arm or hand to give you medications that help you relax and that treat blood pressure changes if necessary.

The Procedure

Before the injection, the skin is disinfected and numbed with local anesthesia so that you will not feel the pain of the intrathecal injection. A minute or so later the intrathecal medication is injected through a longer needle directly around the nerves. This is usually not painful, although it may be uncomfortable. During this part of the procedure, you should let your doctor know if you have any pain, especially in the legs. Pain may mean the needle is touching a nerve. After injection of the medications, the needle is taken out and the procedure is completed.

Risks and Complications

This procedure is very safe. There are, however, several possible risks and complications. These are unlikely but possible. You need to know about them just in case they happen. By being informed you may be able to help your doctor detect complications early. Nerves could be injured during this procedure, but this is extremely rare. Because the thecal sac is entered and spinal fluid is withdrawn, some patients develop severe headaches. If this happens, let your doctor know. In very rare cases, infections may occur. Therefore, it is important to report to your doctor any worsening pain or fever. Patients may have reactions to the medications injected. Increased sleepiness, decreased respiration, inability to empty the bladder, and generalized itching, nausea, and vomiting are rare side effects of the medication used. Allergic reactions could very rarely lead to death. Therefore, it is very important to inform your doctor about the allergies that you know you have, especially drug allergies. A serious side effect may mean that you should not have further injections. The injection may cause internal bleeding, which puts pressure on the nerves. The chance of this happening is again extremely rare, but if you develop a new weakness or a bladder problem you should tell you doctor. It is also very important to tell your doctor if you are on any blood thinners such as Coumadin® or aspirin. This type of medication may have to be stopped for a few days to prevent the risk of severe complications, including paralysis. You should tell your doctor if you develop any new weakness, any new bladder problems, or any worsening of pain or fever. You may need to be admitted to the hospital to watch your breathing and blood pressure after the injection. Because of the drowsiness you have after the injection, be sure to have someone with you to drive you home. X-Rays may be used during this procedure. The amount of radiation during this test is deemed safe. However this same amount could be dangerous for a fetus. Drugs used during this procedure may not be safe for a pregnancy. It is therefore very important to make sure you are not pregnant prior to this procedure. Be sure to tell your doctor before the procedure is performed if there is any chance you may be pregnant. You should not consume alcoholic beverages for three to seven days after this procedure. Alcoholic beverages after this procedure may make you extremely drowsy and may even stop your breathing. Ask your doctor for how long you should not drink alcoholic beverages. Because intrathecal injections of morphine alter mental status, you should not drive a motor vehicle, ride a bicycle, or make important decisions for three to seven days following the injection. To learn more about when you can resume driving, ask your doctor.

Summary

Intrathecal injections are a very safe procedure that can significantly help reduce or end your pain. However, as you have learned, complications may happen. Learning about them will help you and your doctor detect and treat them early if they happen.

 

Last modified: May 15, 2012