What is Spinal Anesthesia? : Benefits and Side Effects


A spinal anesthetic is an alternative to a general anesthetic in many surgeries operations. Under this anesthetic, the patient stays awake while being operated, sensing no pain.

All You Need to Know About Spinal Anesthesia

What is Spinal Anesthesia?

Subarachnoid anesthesia is another name for spinal anesthesia. It is used as a local or regional anesthetic. The anesthetic drug is injected in the subarachnoid cerebrospinal fluid found surrounding the spinal cord of the body. It is injected usually at the levels of L2-L3 or L3-L4 in lumbar space. It will numb the nerve supply of the belly, hips, bottom as well as legs. Once the action of local anesthesia is at the peak, the patient won’t feel any pain due to operation. During this phase, any other medication injected will provide instant and excellent relief in pain for longer hours after the operation.

spinal anesthesia complications

How is Spinal Anesthesia Given?

Spinal anesthesia is performed in an anesthetic room or operation theatre. It requires operating department practitioners as assistants to the anesthetist and other members of the OT team to support and help in the procedure. Before giving spinal anesthesia, a drip is put on the hand of the patient through the cannula and is attached to the monitor (providing ECG, blood pressure, and oxygen saturation). The majority of spinal anesthetic will be performed while the patient is awake. The anesthetist will instruct the patient to get in position in which the procedure is to do. The two of the positions are :

  1. In a sitting position with the patient slumping forward, chin over the chest, shoulders down, and the bottom is curled under.
  2.  Lying on the side with the knees curled touching the chest.

These positions help in opening the space between the spinal vertebrae, where the spinal anesthesia is to be injected. Once the patient acquires the correct position, his back is cleaned with an antiseptic to minimize the chance of infection.

Now the anesthetist will feel the back firmly, to exactly locate the space where to inject the spinal anesthesia. The anesthesia injected will numb the skin first and then the fine spinal needle is inserted. During this moment, the patient needs to stay still. Usually, the patient feels no significant pain but in rare cases, the needle may end up near nerves supply the legs and thus the patient may have shooting pain down one of his legs.


In this case, the patient has to stay still and let the anesthetist know about the pain. As soon as the drug is injected warm sensation is felt at very first in the bottom as well as legs get numb. Spinal anesthesia doesn’t work instantly, it requires a little more time for almost 5 to 15 mins. Initially patient will feel difficult to move legs and end up not able to move legs at all.

How Does It Work?

Spinal anesthesia is rapid and comprehensive for surgery. It reversibly blocks the nerves in the spinal cord. By this, the transmission of pain is interrupted to the brain. Hence, pain stimuli are not sensed by the brain. During childbirth, if spinal anesthesia is given require a midwife or medical staff for 20 minutes after each side for recording the maternal blood pressure, pulse, and fetal heart rate every 5 minutes. In other surgeries also, after spinal anesthesia patients need close monitoring of his respiration, blood pressure.

Who Should Avoid Taking Spinal Anesthesia?

As such there are no absolute contraindications of spinal anesthesia. Some of the relative contraindications are :

  • Patient’s refusal
  • Local infection
  • Bleeding problems like, thrombocytopenia or hematoma risks
  • Severe aortic stenosis
  • Increased intracranial pressure
  • Hypovolemic shock
  • Allergy
  • Ehlers Danlos Syndrome


Following are some of the benefits of spinal anesthesia over general anesthesia:

  • Minimal risk of a chest infection after surgery.
  • No dangerous effect on the breathing and lungs
  • Provide excellent pain relief soon after the surgery
  • Minimize the use of strong analgesics which cause nausea, vomiting, and constipation in patients.
  • No hangover effects like seen in general anesthesia patients.
  • Patient able to drink and eat soon after the surgery.


Some of the commonly occurring side-effects are :

  • Hypotension
  • Difficulty in urination, often seen in male patients

Rarely occurring side-effects are :

  • Severe headache which gets worse on standing or sitting.
  • A high block which leads to difficulty in breathing or weakening of the arms.
  • Nerve damage. This can be permanent or temporary. Temporary damage may last for a few days to weeks and then be resolved.

How Long Does The Spinal Anesthesia Last For?

Usually, spinal anesthesia lasts for about 1 to 3 hours. After that, the effect wears off. The anesthetist is there to regulate the level of the drug throughout the surgery to ensure it’s the effect on the patient’s body.

Is One Awake During Spinal Anesthesia?

Yes, the patient is awake during surgery but the doctor may intravenously inject medicine to make him sleepy. The lower body of the patient is completely numb and he cannot move his legs and also experiences no pain during the surgery.


Spinal Anaesthesia is very useful in the medical field and provides 100 percent compliance of the patient during any surgery. Although it is important to monitor the vitals of the patient during the surgery in case spinal anesthesia is used.