How spinal anesthesia works
Spinal anesthesia refers to injections within the spinal canal that produce loss of sensation in the lower half of the body. More specifically, a small amount of local anesthetic is injected into the fluid that surrounds the spinal cord. The injection is made in the lower lumbar area of the back, well above the point at which the spinal cord ends. The result is the rapid onset of numbness in the lower half of the body.
Northeastern Anesthesia Services uses spinals for orthopedic, urologic, gynecologic and obstetric procedures
This type of anesthesia is appropriate for a wide variety of surgeries. Northeastern Anesthesia Services, PC (NEA) will typically use spinals for various orthopedic, urologic, gynecologic and obstetric procedures. NEA anesthesiologists typically accompany the spinal anesthesia with an intravenous sedative to make sure patients are comfortable and relaxed during surgery. After the administration of the sedative, many patients do not recall the administration of the spinal.
How epidural anesthesia works
Epidural injections also occur within the spinal canal, though in this instance an NEA anesthesiologist carefully places the needle just outside the protective outer layers of the spinal cord. An injection of local anesthetics into the epidural space also produces numbness, although the onset is more gradual than that of a spinal injection. An NEA anesthesiologist will often place a thin flexible tube, or catheter, into the epidural space to allow for the continuous infusion of pain relieving medications. This technique allows for very effective post-operative pain control after certain types of chest and abdominal procedures. NEA also commonly uses the epidural catheter for pain relief in childbirth since the amount of time a woman will need pain relief is often unpredictable.
The procedure for spinals and epidurals
After an NEA doctor carefully reviews a patient's medical history, a mild sedative is administered. An antiseptic solution is then applied to the lower back and the skin in this area is numbed with a local anesthesia. The remainder of the procedure is relatively painless, although it may take the anesthesiologist a few minutes to locate the precise region for injection.
The NEA anesthesiologist working with you will be in constant communication, asking you what you do and do not feel. At the conclusion of the procedure, you will lie down and let the anesthetic take effect. The anesthesiologist will then make certain that the anesthetic is having a satisfactory numbing effect before the surgeon is allowed to begin. Many patients are agreeable to a spinal/epidural but are concerned that they will be wide awake during surgery. In most cases, NEA anesthesiologists will administer sedatives that will allow the patient to sleep during their surgery. Many tell us they forget having been taken into the operating room.
Why choose a spinal or epidural over a general anesthetic?
In NEA's experience, there are several reasons why a patient prefers a spinal/epidural over a general anesthetic:
- Some patients like to maintain a sense of control and choose to have minimal sedation during surgery. Spinal/epidural anesthesia allows for this choice while keeping the patient completely pain-free during the procedure.
- The likelihood of nausea is minimized with spinal/epidural versus general anesthesia.
- Some studies have shown that for prostate and vascular bypass procedures, spinal/epidural anesthesia may result in less blood loss and a lower likelihood of developing blood clots in the legs.
- For cesarean sections, spinal anesthesia is almost universally accepted as the anesthetic of choice because it is safer for both the mother and the baby.
- Spinal/epidural may be chosen for patients who have a medical history that makes general anesthesia riskier. For instance, a spinal anesthetic for a knee arthroscopy may be a better choice in an asthmatic patient to avoid triggering asthma during the administration of a general anesthetic.
Spinal and epidural anesthetics are as safe as general anesthesia
Spinal and epidural anesthetics are widely used and have been shown to be as safe as general anesthesia. Some of the potential complications are headaches, bleeding and infection, however these responses are extremely rare. In the past, patients used to regularly get headaches from spinals and would be asked to lie flat after a spinal injection to minimize the chance of getting a headache. With the improvement of spinal needle design, the occurrence of nerve injury and headache has been drastically reduced.
It is no longer necessary to lie flat until the spinal wears off. In the rare event that a spinal headache occurs, there is a treatment called an epidural blood patch that NEA may administer. The blood patch has an extremely high success rate.
If you're interested in learning more about spinal and epidural anesthetics, please contact Northeastern Anesthesia Services.