Undergoing Spinal Anaesthesia

Spinal Anaesthesia (SA), Spinal Anaesthetic, Subarachnoid Block (SAB) is the most common type of regional anaesthesia in modern anaesthetic practice. This anaesthetic technique makes the lower part of the body- the abdomen, hips and lower limbs, numb. The local anaesthetic medicine is injected, into your lower back (between the bones of your spine) using a very thin needle, directly into the cerebrospinal fluid that surrounds the spinal cord. This numbs the nerves that come in contact with the medicine and the lower part of your abdomen, pelvis and both legs become numb and immobile.

You will be alert and conscious and will be free of pain. You can choose to be sedated during the procedure.

A spinal anaesthetic can be used on its own or with an epidural anaesthetic or a general anaesthetic for:

• Urology: surgeries on the prostate, bladder, genitalia, stone removal.
• General Surgery: surgeries for hernia repair, varicose veins, piles
• Vascular surgery on the blood vessels in the leg
• Obstetrics & Gynaecology: Caesarian Sections (LSCS), prolapse repairs, hysteroscopy, hysterectomy
• Orthopaedic surgery of the hip & leg

Usually, a spinal lasts around 2-3 hours.

How is the Spinal performed?

The spinal anaesthetic will be given to you in the operation theatre after you have been hooked up to the monitors and an IV cannula has been placed and a drip started.

Position: you can be sitting up on the OT table with your legs on a low stool or lying on your side with your legs tucked up towards your chest while receiving your spinal. You will be
helped to bend forwards, curving your lower back as much as you can. You will be requested to relax and leave your body loose. The anaesthetic team will help you into the position.

Your anaesthesiologist will scrub up and wear sterile attire. They will then clean your back with an antiseptic solution (can feel cold) and cover it with a sterile sheet. The skin over the injection site and the anticipated path of the spinal needle will be infiltrated with a local anaesthetic to make it numb. This may sting a little. Then the spinal injection will be given after this. You will need to be still for this to be done. The anaesthetic team will explain what is happening and you will be aware of what is going on.

What will you feel?

A spinal injection is typically no more painful than having a blood sample withdrawn or an IV cannula inserted. It takes a few minutes to perform though, if you have any back problems or obesity the duration maybe longer.

Generally, the more relaxed you let yourself be, the faster the procedure goes and the lesser the discomfort you may face.

• As the injection is given, you may feel a pins and needles like sensation or a sharp pain in one of your legs. If this happens, please try to remain still, and tell your anaesthesiologist.
• Once the injection is given, you will be asked to lie down flat. The effect begins within a few minutes.
• At first you will feel warm, then numb to touch and gradually your legs will become heavier and more difficult to move.
• Once the injected drug is working fully you will be unable to lift your legs or feel any pain in the lower part of your body.
• You may feel pressure but you will not feel pain

How do we know that your spinal is working? 

To check if your anaesthetic is working, the Anaesthesiologist may:

• Apply a cold liquid to your skin and ask if you can feel it as cold

• Brush a swab or a probe on your skin and asking what you can feel
• Ask you to lift your legs.

Your surgery will begin only after your anaesthesiologist is satisfied that the anaesthetic is working.

During the operation under a spinal anaesthetic (alone)

• Our anaesthetic team will treat you with immense care while you are being operated under a spinal anaesthetic.
• We will monitor your heart rate, blood pressure, breathing, and other vital signs to make sure they are normal and steady. Your anaesthetist will stay near to you all the time.
• You will be positioned for the surgery. Your anaesthesiologist will make you as comfortable as possible.
• You may be given oxygen to breathe, through a plastic mask or a nasal cannula, to improve oxygen levels in your blood.
• You will be aware of your surroundings and what is happening. You will be able to relax while the anaesthesiologist looks after you.
• You may be able to listen to music during the surgery. We will try to accommodate your musical requests as much as safely possible.
• You can talk to your anaesthesiologist and anaesthetic technician during the surgery.
• You can choose to be sedated while being operated- if so, you will be relaxed and may be sleepy during the surgery. You may remember all or parts or none of your time in the OT.

After the operation

It takes 4-5 hours for sensation to return to completely normal after receiving a spinal anaesthetic. As it returns you may feel a tingling sensation.

Usually, the pain medication is prescribed for you is timed in such a manner as to have the pain killers in effect by the time the spinal wears off. Nevertheless, if you experience pain, please do not hesitate to ask for pain relief.

You may feel a little bit lightheaded if your blood pressure is on the lower side and unsteady on your feet when the spinal first wears off. Please ask for help from the staff looking after you when you first get out of bed.

Usually, you can eat and drink much sooner after a spinal anaesthetic than after a general anaesthetic.

What are the advantages of having a spinal?

• A lower risk of a chest infection after surgery.
• Less effect on the lungs and the breathing.
• Good pain relief immediately after surgery.
• Less need for strong pain-relieving drugs that can have side effects.
• Less sickness and vomiting.
• Earlier return to drinking and eating after surgery.

Side Effects and Complications

As with all anaesthetic techniques, the possibility of unwanted side effects or complications exists with a spinal anaesthetic.

• Very common events and common side effects
  • Low blood pressure– the effect of the anaesthetic will lower your blood pressure. You may feel uneasy or sick or faint. Your anaesthesiologist will prevent and treat this with IV fluids and drugs to increase your BP.
  • Itching– when morphine-like drugs (opioid) have also been used in the spinal anaesthetic. Medicines can be given to help.
  • Difficulty passing urine (urinary retention) or loss of bladder control (incontinence)– Your bladder function will return to normal after the spinal wears off. You may need to have a catheter placed in your bladder temporarily, while the spinal wears off and for a short time afterwards. Your bowel function is not affected by the spinal.
  • Pain during the injection- if you feel pain in places other than where the needle is – you should immediately tell your anaesthetist. This might be in your legs or bottom, and might be due to the needle touching a nerve. The needle will be repositioned.
  • Post-dural puncture headache –Uncommonly (1 in 200 spinals), after a spinal it is possible to develop a more severe, persistent headache called a post-dural puncture headache (PDPH), for which there is specific treatment. This happens on average about 1 in 200 spinal injections. This headache is usually worse if you sit up and is better if you lie flat. The headache may be accompanied by loss of hearing or muffling or distortion of hearing. It is usually responds to paracetamol and other pain killers and increasing fluid intake.
• Rare complications:
  • Nerve damage- Permanent nerve damage is rare (approximately 1 in 50,000 spinals).

Causes-

• Direct injury caused by the needle or the catheter- temporary.
• Haematoma (a blood clot)- A very rare problem that happens if your blood does not clot normally due to diseases like haemophilia, or if you are on medication such as warfarin, heparin or clopidogrel. You must tell your anaesthesiologist if you have such a condition beforehand. Emergency surgery is needed to remove the clot.
• Infection: Very rare. Severe infections causing nerve damage require urgent treatment with antibiotics and/or surgery to prevent permanent nerve damage. Local skin infections can be related to a spinal injection or an epidural are rare and do not cause nerve damage.
  You may not be offered an epidural or spinal injection if you already have a significant infection elsewhere, or if you have a weak immune system.
• Inadequate blood supply causing nerve damage. Anaesthetists are
  well aware of this risk and use drugs and intravenous fluid to prevent large drops in blood pressure.

Can I eat and drink before my spinal?

The instructions regarding eating and drinking before your spinal and those before undergoing a general anaesthetic are the same. This is so because, sometimes it becomes necessary to change from a spinal to a general anaesthetic. We will provide you with clear instructions during your preoperative work up.

Do I have to stay fully conscious?

You can choose between staying awake and being sedated during your operation. The level of sedation will be such that you will be aware but not anxious and may feel a bit sleepy. You may be able to hear sounds and conversation. If you sleep, then you will be easily woken up from it when needed.

Will I see what is happening to me?

A screen is placed across your body at the level of the chest that limits your view of the surgery.

Can I choose my anaesthetic?

Yes, your anaesthesiologist will discuss your choices with you. The final plan depends upon

1. The nature of your operation.
2. Your physical status
3. Your anaesthesiologists’ best judgement
4. Your choice

As much as is feasible, your choice shall be accommodated.

There are some uncommon reasons why you may not be able to have, or may be advised not to have, a spinal anaesthetic. These include having:

• Certain abnormalities of your spine or previous surgery on your back.
• ‘Blood thinning drugs’ that cannot be stopped or abnormalities of your blood clotting
• Infection in the skin of your back or a high temperature
• Certain heart conditions.

Can I refuse to have a spinal?

Yes. If, after you have had a discussion with your anaesthesiologist, you decide that you do not want a spinal, you can refuse to have the spinal.

Will I feel anything during the operation?

You should not feel pain during the operation. You may feel pressure as the surgical team carries out their work.

You will be able to hear sounds and conversation.

Should I tell the anaesthesiologist anything during the operation?

Yes, your anaesthetist will want to know about any sensations or other feelings you experience during the operation; this is part of their monitoring of the anaesthetic.

Is a spinal the same as an epidural?

No. while the two techniques involve the injection of local anaesthetics between the bones of the spine, they work in slightly different ways. Following an epidural, a fine plastic tube (epidural catheter) remains in your back that allows the injection of more anaesthetic as necessary during the surgery and for pain relief afterwards.

If you want more details about having a spinal, you can speak to our anaesthesiologists any time.