There are several forms of anesthesia. The type of anesthesia you receive will depend on the type of surgery and your medical condition.
The different types of anesthesia include the following:
Local anesthesia is an anesthetic agent given to temporarily stop the sense of pain in a particular area of the body. For minor surgery, a local anesthetic can be administered via injection to the site, while the patient is awake or under some degree of sedation. However, when a large area needs to be numbed, or if a local anesthetic injection will not penetrate deep enough, a regional anesthetic may be indicated.
Monitored Anesthesia Care (MAC): Monitored anesthesia care encompasses the use of a variety of medications, usually given intravenously, to produce varying levels of sedation during surgical procedures. Because this is not considered true general anesthesia, patients may or may not experience awareness and memory of aspects of intra-operative events. An anesthesia provider will be with you at all times to monitor your well-being, and adjust the level of sedation as needed. In addition to the sedation, your surgeon will often use local anesthetics in the body region where you are being operated upon. The advantage of this type of anesthesia, as opposed to general anesthesia, is that there are typically fewer side-effects such as nausea, sore throat, and memory impairment, as well as the ability to avoid the use of a breathing tube. It is important to remember that the level of anesthesia you receive is tailored to your changing needs during your surgery, and at some point, it may become necessary to institute full general anesthesia. Possible side effects include nausea/vomiting, temporary memory impairment and respiratory depression which may necessitate general anesthesia.
Regional anesthesia is used to numb only the portion of the body which will receive the surgical procedure. Usually an injection of local anesthetic is given in the area of nerves that provide feeling to that part of the body. There are several forms of regional anesthetics, which include:
Spinal/Epidural: Also known as neuraxial anesthesia, a spinal or epidural anesthetic is used for lower abdominal, pelvic, rectal, or lower extremity surgery. This type of anesthetic involves injecting anesthetic medication into the spinal or epidural space, which surrounds the spinal cord. The injection causes numbness in an area of the body supplied by the nerves that are blocked by the anesthetic. Usually, but not always, a spinal anesthetic involves a single injection of a medication, while an epidural anesthetic involves placement of a small catheter (hollow tube). Epidural anesthesia may also be used for the purpose of controlling pain both during and after surgical procedures, including those involving the upper abdomen or chest, or for management of labor pain. Possible side effects include headache, back pain, convulsions, infection, persistent numbness, weakness or pain, or unconsciousness necessitating general anesthesia.
Nerve Block: Nerve block involves the injection of local anesthetic near the location of a nerve or group of nerves that provide sensation to a specific region of the body, usually one of the limbs. In addition to the injection of local anesthetic, a small catheter may be inserted to provide additional pain relief after the initial injection of medicine has worn off. Depending on the type of medicine administered, you may expect the affected body part to be numb for several hours and up to 24 hours after the surgery, or even longer if a catheter is placed.
Some examples of surgery which might involve the use of a nerve block are: total knee replacements, anterior cruciate ligament (ACL) reconstructions, shoulder surgery as well as many fracture repairs.
At Berkshire Health Systems, the use of ultrasound-guidance has improved the quality, effectiveness and safety of many nerve blocks. Possible side effects include infection, convulsions, persistent weakness, numbness or pain, injury to blood vessels or nerves, or unconsciousness necessitating general anesthesia.
Ultrasound-Guided Nerve Blocks The advantages of using ultrasound are greater accuracy, increased safety, decreased need for narcotic pain medications post-operatively, and faster recovery times. Many patients who might otherwise be admitted to the hospital for the purpose of pain control are now able to be discharged on the same day of their surgery.
Some of the procedures for which an ultrasound-guided block may be performed include total joint replacement, shoulder surgery, anterior cruciate ligament (ACL) reconstruction, arteriovenous (AV) fistula creation, and fracture repairs of the upper and lower extremities. Depending on the type of medicine administered, you may expect the affected body part to be numb for several hours after the surgery, or even longer if a catheter is placed.
As a patient, your options will be discussed with you by your anesthesia provider prior to your surgery, and if you are a candidate for a nerve block, it most likely will be performed in the pre-surgical area immediately prior to going into the operating room. An intravenous (IV) line will be placed, as well as appropriate monitors (blood pressure cuff, EKG, and pulse oximetry) and supplemental oxygen. You will be given some form of sedation through your IV, and an ultrasound probe will be used to visualize the nerve to be blocked as well as adjacent structures. Since the ultrasound provides a "real-time" image of the nerves to be blocked, the result is a more accurate and effective nerve block with increased safety.
For some procedures, such as joint replacement, a small catheter may be placed at the time of the nerve block, which may remain in place for several days after your procedure. This catheter will be used to deliver a local anesthetic at a controlled rate for as long as the catheter remains in place (usually less than five days). If you are discharged from the hospital with a catheter in place, full instructions for the care of the catheter will be given to you upon discharge.
IV Regional Block: Also known as a Bier Block, an IV regional block is used for surgical procedures of the lower arm or hand. The block involves placement of a tourniquet, similar to a blood pressure cuff, on the upper arm to be blocked, and injection of local anesthetic into an IV placed in the hand or forearm. This type of block is appropriate for surgical procedures lasting less than one hour. In addition to the local anesthetic, you may also receive some form of sedation to keep you comfortable. Possible side effects include infection, convulsions, persistent weakness, numbness or pain, injury to blood vessels, loss of limb, or unconsciousness necessitating general anesthesia.
General Anesthesia involves the use of medication to induce unconsciousness during surgery. Medications to provide general anesthesia are either inhaled through a breathing mask or tube, or administered through an intravenous line. After you are asleep, a breathing tube may be inserted into the windpipe to maintain proper breathing during surgery. Once the surgery is complete, the anesthetic is discontinued and the patient wakes up in the operating room or the recovery room. Possible side effects include nausea/vomiting, sore throat, hoarseness, headache, mouth or teeth injury, awareness under anesthesia, injury to blood vessels, temporary memory loss and aspiration possibly leading to pneumonia.