Regional anesthesia for surgery

With regional anesthesia, your anesthesiologist injects medication near a cluster of nerves to numb only the area of your body that requires surgery. You may remain awake or you may be given a sedative. Spinal and epidural blocks involve interrupting sensation from the legs or abdomen by injecting local anesthetic medication in or near the spinal canal. Other blocks can be performed for surgery on your extremities, or limbs, blocking sensations from the arm or leg.

1. How is regional anesthesia different from general anesthesia?

In general anesthesia, you are unconscious and have no awareness or other sensations. In regional anesthesia, your anesthesiologist makes an injection near a cluster of nerves to numb the area of your body that requires surgery.

2. If I choose regional anesthesia, does that mean I am awake during the surgery? 

You may remain awake, or you may be given a sedative. You do not see or feel the actual surgery take place. Your anesthesiologist, after reviewing your individual situation, will discuss the appropriate amount of sedation for you. Although this sedation analgesia was once referred to as "twilight sleep", the term "conscious sedation" has become more popular to describe a semi-conscious state that allows patients to be comfortable during certain surgical procedures.

During minimal sedation, you will feel relaxed, and you may be awake. You can understand and answer questions and will be able to follow your physician's instructions. When receivingmoderate sedation, you will feel drowsy and may even sleep through much of the procedure, but will be easily awakened when spoken to. You may or may not remember being in the operating room. During deep sedation, you will sleep through the procedure with little or no memory of the procedure room. Your breathing can slow, and you might be sleeping until the medications wear off.

While you receive sedation during surgery, your vital signs, including heart rate, blood pressure and oxygen level, will be watched closely in order to avoid sudden changes or complications. You may also receive supplemental oxygen during the surgery.

3. What are the different types of blocks performed for regional anesthesia? 

In regional anesthesia, your anesthesiologist makes an injection near a cluster of nerves to numb the area of your body that requires surgery. There are several kinds of regional anesthesia. Two of the most frequently used are spinal anesthesia and epidural anesthesia, which are produced by injections made with great exactness in the appropriate areas of the back. They are frequently preferred for childbirth and prostate surgery. Another common type of regional anesthesia is a peripheral nerve block, which is produced by injections made with great exactness near a cluster of nerves to numb the appropriate area of your body extremity (arm, leg, head) that requires surgery. Two of the most frequently used are femoral nerve block, which is produced by injection in the leg region, and brachial plexus block, which is produced by injection in the arm and shoulder region. These blocks are frequently performed for surgery in the knee, shoulder, or arm.

4. May I request what type of anesthesia I will receive?

Yes, in certain situations. Some operations can be performed using different anesthetic procedures. Your anesthesiologist, after reviewing your individual situation, will discuss any available options with you. If there is more than one type of anesthetic procedure available, your preference should be discussed with your anesthesiologist in order for the most appropriate anesthetic plan to be made.

5. What types of surgical procedures would be amenable for regional anesthesia? 

If there are no medical contraindications, anesthesiologists are able to perform regional anesthesia techniques (with either sedation or general anesthesia) for a wide variety of surgical procedures. Some examples of surgeries utilizing regional techniques are:

  • Gastrointestinal (stomach)/hepatic (liver): epidural, spinal or paravertebral nerve blocks and catheters may provide effective anesthesia and analgesia for colon resections and surgeries of the stomach, intestines, or liver.
  • Gynecology (female reproductive organ): epidural, spinal or paravertebral nerve blocks and catheters may provide effective anesthesia and analgesia for hysterectomy, pelvic procedures, Cesarean sections, and other gynecologic procedures.
  • Ophthalmology (eye): injection of local anesthetics may provide anesthesia and analgesia for many types of eye procedures.
  • Orthopedics (bone and joint): epidural, spinal, and many types of peripheral nerve blocks and catheters may be used depending on the limb/joint being operated upon.
  • Thoracic surgery (chest): epidural, paravertebral or intercostal nerve blocks and catheters may be especially useful in controlling pain following procedures of the chest or esophagus.
  • Urology (kidney, prostate, and bladder): epidural, spinal or paravertebral nerve blocks and catheters may provide effective anesthesia and analgesia for radical prostatectomy, nephrectomy, and other procedures involving the kidneys, prostate, or bladder.
  • Vascular surgery (blood vessel): cervical (neck) blocks may be used for incisional pain for carotid surgeries; epidural or paravertebral nerve blocks may be used for abdominal aortic endovascular procedures or lower extremity graft bypass procedures.

As with any other medical procedure, each type of regional/local block carries with it its own risks and benefits, which should be carefully considered and discussed with your anesthesiologist each time an anesthetic plan is chosen for a particular procedure.

6. How is the epidural or spinal block performed? 

An epidural or spinal block is given in the back. You will either be sitting up or lying on your side. Before the block is performed, your skin will be cleansed with an antiseptic solution. The anesthesiologist will use local anesthesia to numb an area of your back.

For the epidural block, a special needle is placed in the epidural space just outside the spinal sac. A tiny flexible tube called an epidural catheter is inserted through this needle. Occasionally, the catheter will touch a nerve, causing a brief tingling sensation down one leg. Once the catheter is positioned properly, the needle is removed and the catheter is taped in place. Additional medications are given as needed through the epidural catheter without another needle being inserted. The medication bathes the nerves and blocks out the pain. This produces epidural anesthesia and analgesia.

For the spinal block, a small needle is placed in spinal sac. Occasionally, the needle will touch a nerve, causing a brief tingling sensation down one leg. Once the needle is positioned properly, medication is administered. The medication bathes the nerves and blocks out the pain. This produces spinal anesthesia and analgesia.

7. How is a peripheral nerve block performed? 

Depending on the location of surgery, a peripheral nerve block can be given in the shoulder-arm, back or leg regions. Typically, you will either be lying flat on your back (supine) or lying on your side (lateral) but occasionally may even be on your stomach (prone). The block is administered at an appropriate location to provide anesthesia for the surgery. Before the block is performed, your skin will be cleansed with an antiseptic solution. The anesthesiologist will use local anesthesia to numb an area of where the peripheral nerve block will be administered.

For peripheral nerve blocks, a special needle or catheter is placed near the cluster of nerves that need to be numbed for surgery. Occasionally, the needle will touch a nerve, causing a brief tingling sensation down the extremity where the regional block is being performed. The needle may also be used to temporarily obtain muscle twitches in the extremity where surgery will occur.

8. Specific Nerve Blocks 

This section will provide you with more detail on specific nerve blocks that can be used for anesthesia and analgesia.

Spinal and Epidural Anesthesia

Spinal and epidural blocks are forms of anesthesia that temporarily interrupt sensation from the trunk (chest and abdomen) and legs by injection of local anesthetic medication in the vertebral canal, which contains the spinal cord and spinal nerves. The spinal cord and spinal nerves are contained within a fluid-filled sac. The fluid-filled sac is called the dural sac and the fluid is known as cerebrospinal or spinal fluid

Prior to performing a spinal or epidural block, your anesthesiologist may place monitors to watch your vitals signs. You will be placed either on your side with your knees and chin pulled as close to your chest as possible or sit with your arms and head resting on a small table. At this time, your anesthesiologist may choose to inject a small amount of relaxing medicine into your intravenous line if you require sedation. The anesthesiologist will feel your back, clean your skin with an antiseptic (bacteria-killing) solution, and place a sterile drape around the area. Your anesthesiologist may first inject some local anesthesia into the skin and then into the deeper tissues of the lower back - this may cause a slight burning or pressure sensation. Your anesthesiologist will then carefully insert the needle and advance it into the space between your vertebrae (backbones). Occasionally, you may feel a brief tingling sensation (paresthesia) during the procedure.

For spinal anesthesia, the anesthesiologist advances the needle until he or she is able to inject some local anesthesia into the spinal fluid. Since a spinal block typically involves a one-time injection, the duration of your spinal anesthesia will depend on the type and amount of local anesthetic medication administered by your anesthesiologist.

For epidural anesthesia, the anesthesiologist advances the needle into the epidural space which is located just outside of the dural sac containing the spinal fluid. Your anesthesiologist may insert a small flexible catheter to allow for continuous injections or infusions of local anesthesia. The needle is removed and only the catheter remains at the end of the procedure. Epidural analgesia is most commonly used to provide pain relief during childbirth or after painful surgical procedures of the chest, abdomen, and lower extremities.

After your anesthesiologist has performed the spinal or epidural block, you will generally feel numbness and may notice that your legs will become weak to the point where you may not be able to move them. This is normal. The surgery will be allowed to start only when your anesthesiologist is certain that the site of surgery is completely numb. During the surgery, you will have the option of being awake or sedated. If you choose to be sedated, the anesthesiologist will administer sedatives through your intravenous line to help you sleep lightly during the operation.

After surgery, you will be taken to the recovery room and monitored closely by recovery room nurse until your spinal or epidural block wears off. Typically, a spinal block lasts 2-6 hours depending the type and amount of local anesthetic given by the anesthesiologist. If you received an epidural catheter, it can be left in place for several days after surgery to allow a continuous infusion of pain relieving medications. Your epidural catheter is generally removed once you are able to keep down oral pain-relieving medications.

Brachial Plexus Block

The brachial plexus is the major nerve bundle going to the shoulder and arm. Depending on the level of surgery, your anesthesiologist will decide at what level he wants to block the brachial plexus. For example if you have surgery at the shoulder, your anesthesiologist may choose a nerve block (interscalene or cervical paravertebral block) performed at a location above the clavicle. For surgeries below the shoulder joint or clavicle, an infraclavicular or axillary technique may be used. Your anesthesiologist may use ultrasound, a nerve stimulator or other techniques to help identify the appropriate location along the brachial plexus to inject the local anesthetic. If a nerve stimulator is used, you may feel the muscles in your shoulder or arm twitch. This is normal. If you experience any sharp pain or any type of paresthesia ("shock-like" sensation similar to if you were to hit your "funny-bone" in your elbow) shortly before or during the injection you should notify your anesthesiologist immediately. You should also notify your anesthesiologist before performing any brachial plexus block if you have any type of pain below the elbow, preexisting pain, or preexisting nerve injury. If you have serious respiratory (lung, breathing) problems you should notify your anesthesiologist before proceeding with the block. Your anesthesiologist will then decide whether a brachial plexus block is safe for you and will provide adequate analgesia for the surgery.

Paravertebral Block

Paravertebral blocks can be utilized to numb a specific area in one part of the body depending on where the block is performed. For example, paravertebral blocks at the level of the neck can be used for thyroid gland or carotid artery surgery. Paravertebral blocks at the level of the chest and abdomen can be used for many types of breast, thoracic, and abdominal surgery. Paravertebral blocks at the level of the hip can be used for surgeries involving the hip, knee, and the front of the thigh.

In general, all paravertebral blocks are performed with a similar technique. Your anesthesiologist will feel your back, clean your skin with an antiseptic (bacteria-killing) solution, and may inject some local anesthesia into the skin and then into the deeper tissues of the back - this may cause a slight burning or pressure sensation. Your anesthesiologist will then carefully insert and advance a needle and inject local anesthesia to numb the nerves. If a nerve stimulator is used to help locate the nerves, you may feel the muscles in your chest, abdomen, or legs twitch. This is normal. If paravertebral blocks are utilized for thoracic and abdominal surgery, more than one injection may be needed to provide achieve adequate anesthesia. Your anesthesiologist may insert a small flexible catheter to allow for continuous injections or infusions of local anesthesia. The needle is removed and only the catheter remains at the end of the procedure if this is the case. As with other blocks, always let your anesthesiologist know if you experience any sharp or radiating pain during the procedure or injecting of the local anesthetic. Always notify your anesthesiologist if you experience sudden numbness, bilateral numbness or warmness with the injection of your local anesthetic

Femoral Nerve Block

The femoral nerve provides sensation and motor function to the front of the thigh and knee. This block is commonly used for procedures that cover the knee. If you receive a femoral nerve block, you will be positioned on lying on your back. Your anesthesiologist will clean your groin area with an antiseptic (bacteria-killing) solution. If using an ultrasound, the anesthesiologist will place the ultrasound probe on your skin. An image of the femoral nerve will be obtained by scanning the area. Once the nerve is identified, the anesthesiologist will inject local anesthesia (“numbing medicine”) into the skin—this may cause a slight burning or pressure sensation. Your anesthesiologist will then carefully insert and advance a needle toward the femoral nerve. The ultrasound is used to visualize the needle as it approaches the nerve. The needle does not touch the nerve; it is stopped when it is near the nerve. Once the needle is in proper position relative to the nerve, local anesthetic is injected through the needle to numb the nerve. The local anesthetic can be seen surrounding the nerve with ultrasound. Sometimes a nerve stimulator is also used to help your anesthesiologist determine the appropriate location to inject the local anesthetic. If a nerve stimulator is used, you may feel the muscles in your leg twitch—this is normal. Your anesthesiologist may insert a small flexible catheter to allow for continuous injections or infusions of local anesthesia. The needle is removed and only the catheter remains at the end of the procedure if this is the case. As with other blocks, always let your anesthesiologist know if you experience any sharp or radiating pain during the procedure or injecting of the local anesthetic. You may have difficulty with weight bearing on the blocked leg, and you should have help in attempting to get up. Care should be taken to prevent falls.

Sciatic and Popliteal Nerve Block

This sciatic nerve provides sensation and motor function to the back of the thigh and most of the leg below the knee. This block is commonly used for surgery on the knee, calf, Achilles tendon, ankle, and foot. If you receive a sciatic nerve block, you generally will be place on your belly or side but occasionally you may be lying on your back. Your anesthesiologist will clean your skin with an antiseptic (bacteria-killing) solution. If using an ultrasound, the anesthesiologist will place the ultrasound probe on your skin. An image of the sciatic nerve will be obtained by scanning the area. Once the nerve is identified, the anesthesiologist will inject local anesthesia (“numbing medicine”) into the skin—this may cause a slight burning or pressure sensation. Your anesthesiologist will then carefully insert and advance a needle toward the sciatic nerve. The ultrasound is used to visualize the needle as it approaches the nerve. The needle does not touch the nerve; it is stopped when it is near the nerve. Once the needle is in proper position relative to the nerve, local anesthetic is injected through the needle to numb the nerve. The local anesthetic can be seen surrounding the nerve with ultrasound. A nerve stimulator is sometimes used as well to help your anesthesiologist determine the appropriate location to inject the local anesthetic. You may feel the muscles in your leg twitch—this is normal. As with other blocks, always let your anesthesiologist know if you experience any sharp or radiating pain during the procedure or injecting of the local anesthetic. As with other blocks, always let your anesthesiologist know if you experience any sharp or radiating pain during the procedure or injecting of the local anesthetic. You may have difficulty with weight bearing on the blocked leg, and you should have help in attempting to get up. Care should be taken to prevent falls.