The selection of the type of anesthesia for hip or knee surgery is an important issue to discuss with your surgeon and anesthesiologist. They will determine the most suitable type based of several factors e.g. your general health condition, the duration of surgery, the risks involved and your preferences.
Type of anesthesia
In this type of anesthesia, the nerves supplying an area of the body are blocked, so that the patient cannot feel any pain from this region. The patient may stay awake during surgery or may be given a light sedative to help him relax and may be allow him to sleep lightly.
The three common types of regional anesthesia are:
- Epidural block: in this type the doctors inserts a needle in the back and through the lumen of this needle he inserts a very thin tube (catheter) that will enter the area adjacent to the nerves emerging from the spinal cord. The doctor will then inject the anesthetic drug through this tube. The tube can be left in place after surgery so that the anesthetic drug can be injected in smaller doses during recovery to relieve the pain.
- Spinal anesthesia: the doctor inserts a needle in the lower back reaching the fluid around the spinal cord. He then injects the anesthetic drug and removes the needle. The effect of this drug usually lasts for about 3 hours.
- Peripheral nerve block: in this type the doctor will inject the anesthetic drug around large nerves found in the thigh e.g. sciatic or femoral nerves.
Regional anesthesia is usually very safe. It helps prevent excessive blood loss as it lowers the blood pressure of the patient during surgery. There is no drowsiness or nausea as in general anesthesia. However, it may cause some headache which resolves within days.
In contrast to regional anesthesia, general anesthesia affects the whole body e.g. the heart and lungs. In this case the doctor gives the patient an injection that will make the patient unconscious within seconds from injection. Then he inserts a tube down the throat through which he administers the anesthetic gases and oxygen to assist your breathing.