By Sally Robertson, BSc
A cesarean section or C-section is an abdominal surgery that is performed to deliver a baby via an incision made in the abdomen and womb. Sometimes this is the safest option in cases where a normal vaginal birth may pose a risk to the mother or baby. Some examples of when a C-section may be needed include the following:
- When the labour has not progressed naturally
- When there is a history of two or more caesarean sections
- When the baby is in the breech or bottom first position
- When there is a complication called praevia, where the placenta lies inside the lower segment of the womb
- When the mother is expecting twins or triplets
A C-section may be performed as an urgent procedure when complications have developed during pregnancy or labour or as an elective procedure, where the surgery has been planned in advance. When a C-section is carried out, anesthesia may be local, where the mother is awake but sensation in the lower body is numbed, or general, where the mother is unconscious during the delivery.
Most C-sections are performed under local or regional anesthesia, which is usually a safer option than general anesthesia. Delivery of the baby takes around 5 to 10 minutes and the whole procedure is usually over within 40 or 50 minutes. There are three types of regional anesthesia that may be administered and these are described below.
Spinal anesthesia or spinal block is a common form of anesthesia used for both urgent and elective procedures. A single dose of regional anesthetic is injected into the fluid around the spinal cord using a needle. This numbs the nerves in the lower body, from the waist down to the toes, for around two to three hours. The benefit of spinal anesthesia is that it blocks pain quickly, with only a small dose of anesthetic being used. Spinal anesthesia is also referred to as saddle block anesthesia because it numbs the area of the body that would come into contact with a saddle if a person was on a horse.
Here, a sterile guide needle and a catheter are inserted into the epidural space, the space around the spinal nerves present in the lower back. The catheter is placed at or below waist level and area where the needle will be inserted is numbed with a local anesthetic. The needle is then inserted and removed, while the catheter stays in place, taped along the centre of the back. The anesthetic is then administered via the catheter, as required to numb the body above and below the injection point. An epidural requires a larger does of anesthetic than spinal anesthesia and it can take longer to work.
Combined spinal-epidural (CSE)
Here, a combination of spinal and epidural anesthesia is used. The spinal is used for the C-section and the epidural is used to keep the level of anesthetic topped up, if required, and also to deliver pain relief after the procedure.
In the case of general anesthesia, the mother is completely unconscious throughout the C-section. Nowadays, this form of anesthesia is less common and only around 10% of C-sections are performed using this method. General anesthesia is less safe than regional anesthesia, but may be used in emergency situations or when the mother has a health condition that means regional anesthesia cannot be administered.
Prior to the C-section, an anesthetist reviews the mother’s medical history and may carry out a physical assessment and further tests. Once the mother is in theatre, her blood pressure, heart rate and blood oxygen level are measured and using a local anesthetic, the anesthetist inserts an intravenous drip to provide the mother with fluids and administer the anesthetic.
The anesthetic works very quickly and once the mother is asleep, a tube is inserted into the windpipe to ensure fluid from the stomach does not enter the lungs. The tube is also connected to a breathing machine. The anesthetist continues delivering the anesthetic, while the obstetrician safely delivers the baby.
Regional versus general anesthesia
Spinal or epidural anesthetic is safer than a general anesthetic. The mother can be awake when the baby is born and can hold and feed the baby immediately after birth. The mother’s partner can also be present during the birth. In the case of general anesthetic, the mother remains unconscious for the duration of the C-section and can only see the baby once she has woken up. It is also unlikely that the birth partner can be present.
On the other hand, regional anesthesia can lower the mother’s blood pressure and it can take longer to set up compared with general anesthesia. Occasionally, regional anesthetics do not work properly and a general anesthetic needs to be used.
Last Updated: Aug 4, 2015