FAQ: Anesthesia and Pain Relief
 Anesthesia and Pain Relief
The patient's preferences and medical condition(s) and the surgeon are all factors in selecting the type of anesthesia and pain relief patients receive.
The anesthesiologist, in consultation with the surgeon, will determine the best type of anesthesia and pain relief for each patient. The anesthesiologist will take the patient's preferences into consideration whenever possible. All options will be discussed the day of surgery during the pre-operative interview.
The patient's pain-relief preferences also will be discussed.
Anesthesia
There are two types of anesthesia used in total joint surgery - general and regional.
- General anesthesia is the loss of consciousness, pain sensation and protective
airway responses.
- Regional anesthesia includes spinal blocks, epidural blocks or peripheral nerve
blocks. With regional anesthesia, the anesthesiologist places medication
near a cluster of nerves to numb only the area of the body that requires surgery.
Spinal and epidural blocks involve interrupting sensation from the legs or
abdomen by placing local anesthetic medication in or near the spinal canal.
The preferred form of anesthesia for joint surgery is regional anesthesia.
With regional anesthesia, is the patient awake during the surgery?
The patient may remain awake or may be given a sedative, but the patient does not see or feel the actual surgery take place. The anesthesiologist, after reviewing individual situation, will
discuss the appropriate amount of sedation with the patient.
The term “conscious sedation” is used to describe a semi-conscious state that allows patients to be comfortable during certain surgical procedures. Sedation can be light, moderate or deep. During deep sedation, patients sleep through the procedure with little or no memory of the procedure
room, and may continue to sleep until the medications wear off.
How is the epidural or spinal block performed?
A spinal or epidural block is given in the spine. The patient is either sitting up or lying on his/her side. Before the block is performed, the skin will be cleansed with an antiseptic (bacteria-killing) solution. The anesthesiologist will use local anesthesia to numb an area of the spine. Another needle is then used to introduce either an anesthetic (in the case of a spinal) or a small plastic tube (in case of an epidural). The needle is removed after the anesthetic or catheter is in place. The medication bathes the nerves and blocks out the pain. After the anesthesiologist has performed the spinal or epidural block, there generally is a feeling of numbness and the legs become weak to the point of not being able to move them. This is normal.
How is a peripheral nerve block performed?
The block is administered at an appropriate location to provide pain relief after surgery. Before the block is performed, the skin will be cleansed with an antiseptic solution. The anesthesiologist will use local anesthesia to numb the area where the peripheral nerve block will be administered. A special needle or catheter is placed near the cluster of nerves that need to be numbed. The needle is used to temporarily obtain muscle twitches where surgery has occurred. Local anesthetic is used to bathe the nerves and block out pain. If the patient requires pain control for more than 24 hours after surgery, the anesthesiologist can place a continuous catheter to allow the continuous delivery of pain-relieving medications. After the catheter is removed, sensations will return to normal, typically within a few hours.
Femoral nerve block
The femoral nerve provides sensation and motor functions to the front of the thigh and knee. This block commonly is used for procedures that cover this area (such as surgery of the knee or hip). To receive a femoral nerve block, the patient is positioned lying on his or her back. The anesthesiologist cleans the groin area with an antiseptic solution, and may inject some local anesthesia into the skin – this may cause a slight burning or pressure sensation. The anesthesiologist will then carefully insert and advance a needle and inject local anesthesia to numb the nerves. A nerve stimulator generally is used to help the anesthesiologist determine the appropriate location to inject the local anesthetic. Muscles in the leg may twitch - this is normal. The 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.
What are the benefits of a regional block?
Frequently, there is less nausea from regional blocks and patients generally awaken faster after regional blocks. Regional blocks also can be used to reduce the pain after surgery. Generally, regional nerve blocks and catheters will provide better pain control than intravenous or oral narcotics.
What are the risks of a regional anesthesia block?
Like any other medical procedure, there are risks associated with regional anesthesia. Complications or side effects can occur, even though the patient is monitored carefully and the anesthesiologist takes special precautions to avoid them. To help prevent a decrease in blood pressure, fluids may be administered intravenously. Although not common, a headache may develop following the block procedure. By holding as still as possible while the needle is placed, the patient may help to decrease the likelihood of a headache. The area where the nerve block was administered may be sore and tender for a few days. These discomforts, if they do occur, often disappear within a few days. If there do not disappear or become severe, additional treatments are available.
How common is nerve injury after a regional block?
Nerve injury after a regional block is a rare occurrence, which can occur anywhere from 1 in 4,000 blocks to 1 in 200,000 blocks, depending on the type of block and specific risk factors. It can be related to direct-needle injury of the nerve or to secondary complications like bleeding or infection. To prevent nerve injury, inform the anesthesiologist if the patient experiences any sharp or radiating pain during needle placement or injection. If the patient experiences any new symptoms like tingling, numbness or motor dysfunction after a nerve block already has worn off, seek medical attention immediately as this can be a sign of secondary damage by hematoma or infection. Because recovery of nerve function depends on timely initiation of diagnosis and treatment, do not take any unexpected changes lightly.
Can the epidural or regional block catheter become infected?
Every time a foreign body like a needle or catheter is introduced into the body, there is the risk of infection. Bacteria can enter the body through the primary puncture or along the catheter site. The risk of infection increases over time but the chance of a serious infection leading to abscess formation and requiring surgical intervention or damage to the nerve secondary to an infection is extremely rare. The catheter will be removed two days after surgery to minimize the risk of infection.
Pain Relief
What are the choices for pain relief after surgery?
- IV or oral pain medications: Pain-relieving medications that are injected into a
vein or taken by mouth will help to dull the pain but may not eliminate it
completely. These medications usually are prescribed by the surgeon.
- Local anesthesia: Other pain-relieving medications may be injected into the
surgical incision by the surgeon. These medications are local anesthetics. They
provide numbness or loss of sensation in one specific area.
- Peripheral nerve blocks: Single injection or nerve catheters can be used to
reduce the pain after surgery. Local anesthetics and other drugs are used for these
procedures to reduce or “block” pain and other sensation over a wider region of
the body.
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