Anesthesia

Anesthesia for the obstetrical patient has evolved rapidly the past several years. The important difference in this group of patients is that each patient is really two patients, mother and child. Also, the pregnant mother is herself a different patient physiologically from a non-pregnant female, with necessary special considerations. Together, these issues have been the reason for the direction that obstetrical anesthesia has taken.

Mothers have been having babies without anesthesia for most of the history of humankind. It has only been since the mid 1800's that a scientifically based approach to relieve the pain of labor has been attempted. These early attempts started in England, and involved the mother breathing the vapor of ether or chloroform from a soaked cloth held over the face by a physician. While effective in the relief of labor pain, complications from the use of this approach led to the search for safer techniques. One of the important complications centered on the fact that pregnant moms retain food and fluid in their stomachs, not emptying their stomachs as non-pregnant adults do. When made unconscious under anesthesia, mothers were placed at risk for regurgitation and aspiration of stomach contents, sometimes with severe consequences. In addition, the process making the mother unconscious often resulted in a sleepy or depressed baby.

These considerations still hold true today even with our more modern and safer anesthetic drugs and techniques. While general anesthesia is safely and effectively given to pregnant patients today, the fact that these risks remain has led to the refinement of regional anesthetic techniques for labor, delivery, and cesarean section. Anesthesia falls roughly into three approaches for labor and delivery. The first is essentially the non-pharmacological approach. Many mothers select this feeling that it is best for them and their babies. Also, Lamaze and other techniques have become more popular as methods for dealing with the pain of labor, and in some women, may be enough. Certainly, the pain of labor can vary from one patient to another. For many, the pain of labor is something they choose not to suffer if it can be safely dealt with, and it can.

The next approach would be to give mom some pain relieving medication, usually a narcotic, by the intra-muscular or intravenous route. This approach has been used successfully for many years. It has some drawbacks. It is a systemic approach in that the drugs are distributed to the mother's entire system. Consequently, they can also effect the baby, again potentially resulting in a sleepy or depressed baby. The dosage and frequency of these drugs has been adjusted over the years to minimize effects on the baby. The mothers frequently become sleepy, and may have less or no memory of this important first experience with their new child.

The most sophisticated and direct approach is regional anesthesia. And this is where an anesthesiologist becomes involved. He or she will evaluate the patient (with the patient's obstetrician) to determine that epidural anesthesia is appropriate and to choose the best timing for starting an epidural. Epidural anesthesia is a technique for blocking the pain sensations in the appropriate nerves directly, specifically to avoid systemic effects on mother or baby. It involves using a needle to place a very small plastic tube (called a catheter) into the mother's epidural space in her back. The needle is removed and only the soft plastic tube remains. Medications can then be given in a controlled fashion as needed to relieve pain without making mother or baby sleepy or unconscious. Also, the catheter can remain in place for hours or even days to continue to give relief. Frequently, a small pump with a reservoir of medication is attached to give continuous pain relief without interruption. An added benefit is that should the patient require C-section, the epidural can be used for anesthesia for that as well by simply giving a larger, stronger dose of local anesthetic. The risks of this procedure are well defined, very low, and avoidable. This makes epidural anesthesia for labor and delivery the standard all across the nation if not the civilized world.

If C-section is necessary in a patient who has not chosen an epidural for labor, a regional anesthetic technique is still the prefered approach. Most commonly, this is late in labor and there may be some urgency. A similar technique called a subarachnoid or spinal block is most commonly used. It is easier and much quicker to perform, using a smaller needle and less medication, and having a more rapid onset of action. Again, the risk is very low, causing this to also become a standard practice in obstetrical care.

This summary is an overview of the available options. Many variations of these techniques exist and your anesthesiologist may feel that one of these approaches or even another not specifically mentioned here would be best for you. Contact your anesthesiologist in the Anesthesia Department of your hospital to have your questions answered.