Q. What is the preferred type of anesthesia for a planned cesarean and why?
A. Planned cesarean deliveries are virtually always done with some type of regional anesthesia, meaning a certain region of the body is anesthetized, in contrast to general anesthesia, where you are unconscious. Types of regional anesthesia include spinal and epidural.
The main differences are as follows:
Spinal is one "shot", which lasts a relatively standard length of time, typically 1-3 hours. Epidural involves the insertion of a catheter, which allows repeated doses of anesthetic drugs to be administered, thus allowing the anesthetic to be extended for an almost unlimited amount of time.
The onset of anesthesia with spinal is fast, typically within 5 minutes after injection the block is complete. The onset of anesthesia with an epidural is slower, typically between 15-30 minutes.
Spinal uses a very small needle, as only a very small amount of medication needs to be injected. Epidural anesthesia uses a slightly larger needle, as the catheter needs to be inserted through the needle. The amount of medication injected with an epidural is greater than with spinal anesthesia. However, very little of the epidural drug is absorbed into either the mother's or baby's blood.
There is often more decline in blood pressure with a spinal than an epidural, although this is variable, and easily and rapidly treated by the anesthesiologist.
If an epidural catheter has already been inserted for use during labor, and a cesarean is then needed, then a stronger type of anesthetic medication will be injected through the epidural and used for the cesarean.
If the cesarean is done without any prior use of anesthesia, as is the case with most planned, elective cesareans, then several factors determine which type of regional anesthesia will be used. If there is any concern that the operation may take a longer than usual amount of time, then an epidural may be used to allow for extension of the anesthetic by repeated administration of the anesthetic medications through the catheter. Certain types of medical conditions in the mother, such as some kinds of heart or lung problems, may make the epidural preferred, as the slower onset of anesthesia may be more easily tolerated.
However, in most women, who have no major medical problems nor is there any reason to suspect the cesarean may take more than the usual 45 minutes - 1 hour, a spinal is the most commonly performed anesthetic. The spinal injection is quick, technically easy, uses a very small needle, and the anesthetic is very effective and reliable. In some cases, (this is very unusual!) an epidural may not be as "solid", in other words, small areas of patchy sensation can remain.
Finally, some anesthesiologists have a personal preference for either spinal or epidural, so be sure to discuss this with him/her in your pre-anesthetic interview.