What Is spinal anesthesia ?

Spinal anesthesia involves injecting a local anesthetic into the spinal canal to induce a single sleep. The injection is performed in the lower back, in an area without a spinal cord. It anesthetizes the nerves that control the lower part of the body. The technique is similar to the epidural anesthesia used during childbirth.

Spinal anesthesia is used for many interventions in urology, surgery of the lower limbs, "lower" abdominal surgery (proctology...), varicose vein surgery, gynecology, obstetrics and for the majority of scheduled caesarean sections. As the effect of anesthesia is limited, operations should last less than 2 to 3 hours.

How Does It Work?

The spinal space is located within the spine and surrounds the spinal cord to its termination at the very bottom of the back. Spinal anaesthesia consists of injecting a dose of anaesthetic into the liquid in contact with the nerves that innervate the area to be treated. The injected medication will stop the transmission of nerve messages to this area, allowing the pain to stop.

‍How is Spinal Anesthesia Performed?

1. Spinal anesthesia is performed in either a sitting or side-lying position.
2. You will be fitted with a venous infusion and monitored at a monitoring device to track your heart and respiratory status during the procedure. A nasal mask with oxygen may also be placed on you.
3. After local anesthesia of the skin, the anesthesiologist inserts a fine needle to inject the anesthetic drug into the nerve area.
4. You will soon feel a warm sensation and tingling in your legs.
5. Then, the lower body area will completely "go to sleep" and become insensitive to pain.
6. The procedure will begin once insensitivity has been verified. Sometimes the anesthesia is not sufficient and can be supplemented by a general anesthesia.

What to Expect ?

The 7 steps of rachianesthesia administration :

1. An intravenous infusion is placed in your arm;
2. You are asked to sit on the bed;
3. You will be helped to lean forward and bend your back as much as possible;
4. A local anesthetic is given to numb the area where the epidural will be given;
5. The procedure is done in sterile conditions: the anesthesiologist will dress as if for surgery, clean your back and place a sterile field on it;
6. A needle is used to insert and inject the anesthetic drug. In case of significant pain, inform your anesthesiologist so that he/she can correct his/her action;
7. The needle is removed.

Benefits

Rachianesthesia has several advantages, including the following:

• Less drowsiness than other painkillers, which allows you to do your rehabilitation and even get out of bed;
• Fewer side effects such as nausea and vomiting;
• Fewer painkillers are needed, which means there are fewer side effects and you rehabilitate faster

Contraindications

A contraindication is a specific situation in which a drug, type of surgery or procedure (such as an epidural) should not be used because it could cause harm. The contraindications are:

• Taking anticoagulants or having a blood clotting problem;
• Having an allergy to local anesthetics;
• ‍Infection in progress: untreated fever or infection localized to the area where the puncture should be performed.

Be sure to talk to your anesthesiologist about these issues during the pre-anesthetic consultation.

NB: Tattooing, scoliosis, or other back problems are not contraindications to epidural. These are situations that require adaptations and that sometimes make the procedure more difficult.

Potential risks and side effects

Rachianesthesia are generally very safe and the risk of serious adverse events is low. But as with any other anesthetic procedure, some risks exist and side effects are expected.

Expected side effects

• Back pain: You may feel pain where the needle was inserted. This discomfort is temporary. Back pain lasting several days is mostly seen during rachianesthesia performed for childbirth. Indeed, in the event of prolonged work, the epidural decreasing even removing the pains, it is very frequent to take bad positions involving contractures with the back.

• Drop of tension: it is a frequent but not systematic undesirable effect. The product administered in spinal anaesthesia can lower the blood pressure and more rarely slow down the heartbeat temporarily. This is a temporary side effect and is expected by your anesthesiologist who will take the necessary measures to relieve you.

• Inability to urinate: the nerves of the bladder being affected by spinal anesthesia, transient difficulties to urinate are possible in the hours following the procedure.

Potential risks

• Headaches and dura mater breach: this is a complication related to a technical difficulty in the placement of spinal anesthesia. These headaches occur after the spinal anesthesia is administered and persist for several days. Medication is necessary and most often sufficient for the pain to disappear. If the pain persists, an epidural can be performed in order to inject your own blood into the epidural space and thus seal the breach. This risk occurs in about 0.5% of patients. ‍

• ‍Infection: it occurs in the spine (spondylodiscitis) or in the head (meningitis). These are exceptional cases which concern 0.00069% of patients, i.e. 1/145,000 patients.

• Paralysis: this incident is very rare. During childbirth, the paralysis most often concerns the nerve that allows the foot to be raised and is linked to the patient's position (in the stirrups) during delivery. When the epidural is responsible (1/500 000 patients in maternity wards), it most often affects an isolated nerve and requires specialized treatment. High epidurals for surgery (outside maternity wards) are more likely to affect the spinal cord, but this risk remains very exceptional.