Types of Anesthesia

There are three major types of anesthesia: general, regional, and local. General anesthesia is defined as a state characterized by deep sleep, analgesia, muscle relaxation and depression of reflexes. Under general anesthesia, you will have no awareness of the surgical procedure. With regional or local anesthesia, an anesthetic drug is used to numb the surgical area. Regional anesthesia includes spinal and epidural anesthesia as well as specific nerve blocks. Often intravenous sedatives are given in addition to your regional anesthetic to provide added comfort and relaxation during your surgery. MAC or Monitored Anesthesia Care is local anesthesia with intravenous sedation. Your anesthesiologist will determine the type of anesthesia that is best suited for you and your operation and will explain this to you on the day of your surgery.

General Anesthesia

Induction of general anesthesia begins in the operating room with an intravenous injection of medication. The anesthetic state is maintained by a combination of inhalation gases and intravenous narcotics which are dosed as needed. Commonly, a small breathing tube (endotracheal tube) is inserted into your windpipe through your mouth after you are asleep. Inhalation anesthetics are delivered through this tube. Sometimes the anesthetic is delivered through a special face mask. Once surgery is complete, the anesthetic gases are discontinued and a return to the awakened state occurs shortly thereafter. The breathing tube is usually removed in the operating room.

Regional Anesthesia

Regional anesthesia includes spinal anesthesia, epidural anesthesia as well as specific nerve blocks.

Spinal anesthesia is administered by placing a special needle in your lower back below the level of your spinal cord. A spinal provides a rapid dense numbness. A small amount of local anesthetic is administered through the needle and the numbness begins almost immediately. The needle is removed after the injection of medication.

Often intravenous sedatives are given in addition to your regional anesthetic to provide added comfort and relaxation during your surgery.

Your surgeon and anesthesiologist may recommend a dose of a long acting narcotic be given through the spinal needle along with the local anesthetic (intrathecal administration of narcotic). The purpose of this additional medication is to provide pain relief during the immediate post operative period which may last up to 24 hours. This technique works well for certain types of surgeries, but is not appropriate in all situations.

Although uncommon, a headache may develop after spinal or epidural anesthetic. If this occurs, the headache may last a few days and there are several types of treatment available.

Epidural anesthesia is administered by placing a needle in the epidural space, just outside the sac that holds the spinal fluid. Next, a tiny flexible tube is inserted through the needle. This tube will be left in place during your surgery; however the needle is removed once the tube is in place. A narcotic solution, local anesthetic or a combination of narcotic and local is administered through the tube. This anesthetic solution can be changed as needed to effectively manage different levels of pain. Epidural anesthesia is typically used along with sedating medications or a general anesthetic. Based on the type of surgery the catheter may be removed at the end of the surgery or left in place to manage post operative pain.

In less than 1% of patients a headache may develop following an epidural anesthetic. This occurs if the needle nicks the sac that holds the spinal fluid. If a headache occurs there are several types of treatments available and will be determined by your anesthesiologist when necessary.

A nerve block interrupts the pain signal from the area of surgery to the brain, therefore decreasing the feeling of pain. Patients are given oxygen and a small amount of intravenous sedation prior to the nerve block. An ultrasound machine is used to visualize the blood vessels, nerves and muscles so that a needle may be inserted by the anesthesiologist. Once the nerve is located, local anesthetic is injected into the area. The nerve block takes effect in approximately 10-20 minutes and can last up to 24 hours. This technique is used along with sedating medications or general anesthesia. Nerve blocks are usually used for surgical procedures on the extremities. Temporary nerve injury can occur, however is very rare.

Local Anesthesia

Monitored Anesthesia Care (MAC) involves the administration of intravenous sedatives by your anesthesiologist and administration of local anesthetics by your surgeon.

Care During Procedure

With all types of anesthesia, a member of the anesthesia care team (Anesthesiologist and/or CRNA) is with you at all times in the operating room. During your surgery, the anesthesia team member directs the anesthetic and monitors all vital functions, such as heart rate and blood pressure. Many important medications such as antiemetics and pain medications are given during this time.