Anesthetic Injections

Trigger Point Injections

Trigger point injections are used to relieve pain that is associated with the muscles of the body. There are many different muscle groups in our body and some of these muscles can spasm. When they do this you can actually feel them tighten up under the skin into little bands, which produces the patient’s pain on palpation. This can be associated with muscle pain itself called myofascial pain syndrome or these muscles can be in spasm in response to a deeper underlying problem such as a herniated disc or facet inflammation. It is not unusual for patient’s to have a series of these injections to see if the pain can be relieved over a period of several weeks. Injections are very simple and are preceded by consent, of course. There is an alcohol prep on the skin and then placement of very thin needles just under the skin and into the muscles with injection of local anesthetic or local anesthetic and steroid.

Complications: The risk is very minimal, depending upon the area of the body. It usually includes infection and/or bleeding. Patients need to be off all blood thinners before any needle injections can be given, which they must do with permission of the physician who put them on the blood thinner to begin with.

Intermediate Joint and Bursa Injections and Major Joint Injections Involving the Shoulder, Hip and Knee

These injections also involve small needles, which are placed into the joint usually under x-ray guidance. Most of these injections are done with steroid to help shrink any swelling or inflammation within the joint itself that might be causing pain. Once again, these are done with local anesthetic and are not done on patients who are on blood thinners. A series of three injections with steroid are usually done, one every two weeks over a period within six months.

Sacroiliac Joint Injections

These injections are done for pain coming from inflammation of the sacroiliac joints on either the left or right side of the pelvis. This pain can start in the lumbar or buttock region and is usually exacerbated with pressure on this joint either from sitting or from deep palpation on physical examination. This pain can radiate down the buttocks to just behind the left or right knee. It is very similar in pain to herniated disc pain. It usually does not go past the knee unless there is a large amount of muscle spasm in the buttock region.

The Injection: These injections are done with local anesthetic with x-ray guidance in the surgery center. The patient is brought into the operating room, placed in the face down position on the operating room table, and the x-ray machine is brought in to find the sacroiliac joint under fluoroscopy. Once this is done an antiseptic is placed over the lumbar region or buttock region on the left or right under sterile technique. Then a large amount of local anesthetic is placed with a very thin needle over the sacroiliac joint. This is followed with a second needle under x-ray guidance until the tip of it enters the sacroiliac joint. If the patient’s pain is coming from this region the patient will feel reproduction of that pain for several seconds before local anesthetic with steroid is injected into the joint. This will relieve the patient’s pain almost immediately over the next 10 to 15 minutes and is a good sign that this is the etiology of the patient’s problem. Then the patient is observed for 30 minutes in the surgery center.

Complications: There may be some weakness in that lower extremity that was worked on due to very large amounts of local anesthetic that is used in the region of the sciatic nerve, which lies close to the sacroiliac joint. This usually wears off within about an hour, but the patient does need to have a driver to take them home after the injection. Complications are rare, but they include infection and bleeding. This is true any time a needle is placed in the body. Therefore, once again, patients would need to have permission to be off their blood thinning agents if this injection was contemplated.

Diagnostic Spinal Tap

Diagnostic spinal taps are procedures that are done in the radiology department or in the operating room with the use of a fluoroscopy machine. Patients who come to the pain clinic for this procedure usually have already been to see the neurologist or another specialist who tried to do the spinal tap without use of fluoroscopy. This can sometimes be very difficult in patients who cannot lie still or who are very large in size and it is difficult to find the landmarks on the body to do the lumbar spinal tap. They come to us because we can use the fluoroscopy unit to see all of the bones in the lower back and this indeed makes the procedure much quicker and simpler to perform.

The Injection: After consent is given, the patient is brought into the operating room. The procedure is usually done in a sitting position or lying with the left or right side down. The x-ray machine is then brought in. The low back is prepped with antiseptic solution and wiped. Then a large amount of local anesthetic is placed in between the bones of the lower back so that the spinal needle cannot be felt. The spinal needle is a very thin needle, which can be seen on the x-ray machine and under fluoroscopic guidance it is guided into the sac that holds the spinal cord. At the level that this is done the spinal cord itself is nowhere near the tip of the needle. Once the needle is placed the pressure of the spinal fluid is measured and then a sample of the spinal fluid is taken and sent to the laboratory for whatever the referring physician would like it tested, i.e. cell types, signs of infection, etc. The entire procedure takes approximately 30 minutes. The actual injection itself usually takes 5 minutes. The patient is kept with us for 30 minutes following the injection and is advised to drink a lot of fluids over the next several days to help prevent spinal headaches. Living in Arizona it is very easy to become dehydrated, and by taking in fluid this helps the body replenish the fluid that was taken for inspection by the laboratory.

Complications: Some portion of patients do develop spinal headaches, which is the most common complication from a spinal tap and we go over what the patient needs to be looking for and conservative treatment of spinal headaches before the patient leaves. Other complications include infection and bleeding, and once again this procedure is not done if the patient is on anticoagulants, i.e. blood thinners.

Blood Patch Injections for Spinal Headaches

These are procedures that are done if the patient develops a spinal headache after a lumbar puncture is performed and conservative treatment did not help the patient. Blood patch injections are very similar to epidural steroid injections except that we use the patient’s own blood instead of steroids for injection. Please see Epidural Steroid Procedure.

The Injection: The patient is brought into the operating room or procedure room, placed in the left or right side down position, and asked to bring their knees up to their chest with their chin down to their chest to curl up into a ball. This opens up the spaces between the big bones of the lower back. If your pain physician feels fluoroscopic guidance is necessary we can use an x-ray machine to expedite the process. In general, local anesthetic is used liberally between the big bones of the lower back at the site of the original spinal tap. Then a second needle is advanced until the tip of it is in the epidural space. At this point the patient will have their blood drawn from an IV site, which was placed prior to the procedure, or directly from a vein. Approximately 10 to 12 cc of the patient’s own blood is drawn under sterile technique and handed to the pain physician who then places this into the epidural space. This is done to clot off the original hole made by the spinal tap needle. This is very similar to the way a patch is placed on a tire with a hole in it. It takes 24-48 hours before this patch is solidly in place. Therefore, it is important to follow your physician’s instructions for that time frame.

Complications: Complications include infection and bleeding, and once again a patient on blood thinners cannot have this procedure performed. Other complications include a worse headache from the second hole that may inadvertently be placed into the same sac that the first hole was placed in and low back pain for the next several days. Most patients get low back pain from the placement of their own blood in the epidural space. It is a temporary, yet common, finding as the blood is a foreign body in that space. It does take several days for it to start to be absorbed into the body. This is what causes the back pain. This is usually treated with non-steroid antiinflammatories, rest, and a heating pad. The patient is told to expect this to happen. Most patients feel that the back pain is extremely minimal compared to the pain that they were having from the spinal headache. The patient’s are asked to go home and lie in bed for the next 24 hours with just bathroom privileges. This is done to help the blood patch solidify. After 24 hours they can stand up and start moving around their household, but no bending, twisting, turning or lifting should occur before 48 hours is up. Any of these can break open the blood patch and immediate cause the spinal headache to recur.

Neurolytic (i.e. Nerve Destroying) Injections

Neurolytic injections can be done in may regions of the body. They are usually deferred as one of the last remedies for pain after all other treatments have been tried. This is because they actually destroy the nerves that they are placed next to. These injections are usually done with either Alcohol or Phenol liquids, which have been shown to destroy nerves. These injections are always done under fluoroscopic guidance and in a surgery center operating room setting. Before a neurolytic block is considered diagnostic blocks are usually performed. These are done in the exact same location only with local anesthetic to see if the pain can be eliminated. There are several steps that are done to carefully select patients for this injection. These include documentation that the pain is extremely severe and that it cannot be relieved by any other therapy. We also document that the pain is localized and that the distribution of a nerve that we can identify is made. At this point we confirm with a diagnostic block that local anesthetic can indeed relieve the pain and that there are no undesirable deficits seen after the local anesthetic block. This is because many of the nerves in our bodies are mixed nerves, which carry not only sensory information but motor function as well.

Complications: Potential side effects of neurolytic blocks can be severe and dangerous and include neuritis and worsening pain from the dead nerve. This is called deafferentation pain. Motor deficits can also be seen when mixed nerves are targeted, and since a liquid is used unintentional damage to nontargeted tissue can also occur. All of these lists are explained for the specific block for the specific person that will be receiving it and they differ depending upon the block and the problem. Many of these blocks are reserved for patients with cancer.

Trigeminal Nerve Injections

These are injections that involve the nerves of the face such as the facial nerve and it’s branches. Trigeminal nerve blocks are the injections that are placed after conservative treatment has failed for trigeminal neuralgia. These injections are also used for terminal cancer or multiple sclerosis patients. These injections are performed in the operating room with fluoroscopic guidance and IV sedation can be used, but the patient needs to be alert at the time of testing. These needles are very carefully placed in the face and are directed towards the front of the ear. They are placed with fluoroscopic guidance very carefully and then a diagnostic block is usually performed with local anesthetic. If all goes well, the patient’s pain is relieved at that point. Phenol and alcohol have also been used in the past as has radiofrequency lesioning.

Complications: Any time needles are placed infection and bleeding are always a consideration, and of course these injections cannot be done in patients who are on blood thinners. Depending upon the type of injection, i.e. local anesthetic, neurolytic agent, or radiofrequency, there are different complications and it is best you talk to your pain physician very carefully about these complications before the procedure.