Anaesthesia
Anaesthesia for Hip Replacement
1. Spinal Anaesthesia (Or Epidural Anaesthesia OR Combined Spinal & Epidural Anaesthesia) with OR without Sedation
OR
2. General Anaesthesia (GA)
Spinal Anaesthesia (OR Epidural OR Combined Spinal & Epidural Anaesthesia) with or without Sedation
A Hip Replacement can be done under Spinal Anaesthetic, where an injection is placed in your back, which makes you numb waist downwards. It is currently the preferred choice for a Hip Replacement, as immediate recovery is considered better compared to General Anaesthesia.
Advantages of Spinal Anaesthesia:
- Least effect on Lungs and breathing
- Excellent pain relief during and for few hours after the operation
- Less need for stronger painkillers like Morphine
- Less sickness (nausea & vomiting) compared to General Anaesthetic
- Ability to eat and drink soon after the operation
- Spinal Anaesthetic might decrease the chances of developing blood clots (deep vein thrombosis)
Technique
Your Anaesthetist will insert an intravenous cannula (IV Cannula) generally at the back of your hand and connects you to routine monitors (ECG, Blood Pressure and Pulse Oximetry). You will then be asked to sit at the edge of the bed. Spinal Anaesthetic technique is a completely sterile procedure and your back is sprayed with an anti-septic spray. A small dose of Local Anaesthetic is injected to the skin (at the lower part of your back) to make it numb and then the needle is passed through the space in your back to the correct depth. Once the anaesthetic drug is injected, it takes about 5-7 minutes for spinal anaesthetic to take effect. At this point you will not be able to feel touch sensation or be able to move your legs. You will also lose sensation of lower part
of your abdomen. (Sometimes up to lower part of your ribcage). Spinal effect can last up to 3-4 hours.
You will then be transferred into the operating theatre where you will be securely positioned on your side. You will be re-connected to monitor and oxygen mask. At this point your Anaesthetist will administer sedative drug to keep you calm and comfortable throughout the operation.
Sedation:
Sedation is routinely offered to all patients who have Spinal/ Epidural anaesthesia. Sedative drugs are given through intravenous cannula, which makes you calm, comfortable and (may be) slightly sleepy. Sedatives will NOT result in complete sleep. You will be able to hear the noises arising from the operating theatre including the conversations. You can also talk to your Anaesthetist or Surgeon during the procedure (and vice versa).
Complications of Spinal/Epidural Anaesthesia
Spinal/Epidural Anaesthesia is generally considered safe. The significant side effects are as follows:
Nerve damage:
There is 1 in 12,000 chance of temporary nerve damage in the spine that can cause numbness or weakness in your legs, which can last from 6 weeks to 6 months. Permanent nerve damage is very rare.
Drop in Blood Pressure:
(BP) can make you feel ‘dizzy’. Your Anaesthetist will monitor it continuously and manage any drop in BP.
Shivering:
Occasional, quite often not related to body temperature.
Itching:
Uncommon and can be treated
Headache:
Up to 1 in 300 due to spinal fluid leak. You should report to Anaesthetist if headache is persistent or worsening.
Backache for a few days:
You may not notice backache, as you will be taking painkillers. Spinal Anaesthetic is not known to cause long-term backache.
Urinary retention
Can happen in up to 10 percent of patients and may require urinary catheterisation.
Infection of spine causing meningitis
Extremely rare.
Bleeding into spine causing spinal haematoma:
Extremely rare.
Complete paralysis (Paraplegia) or death
Extremely rare (1:50,000- 1:140,000)
Failure of the Spinal Anaesthetic
If the spinal anaesthetic doesn’t work, you will be offered general anaesthetic If you are having any of the complications of the spinal anaesthetic mentioned above, you should report it to your Ward doctor as soon as possible who may request an assessment from the Anaesthetic Team if necessary.
General Anaesthesia (GA)
General Anaesthesia (or simply called GA) involves administration of anaesthetic drugs through intravenous cannula (IV cannula or drip).
Your Anaesthetist will insert an IV cannula first. You will be connected to routine monitors (ECG, Blood Pressure (BP) and Pulse Oximetry). The Anaesthetist will then inject the anaesthetic drugs directly into your vein through the IV cannula. As soon as the drugs are injected, you will fall asleep.
After that you will NOT know, see, hear or feel any sensation until the procedure is over. The Anaesthetist will also insert an airway device into your throat (Laryngeal Mask) or into your windpipe (Tracheal tube) when you are asleep.
At the end of the operation, the Anaesthetist will switch off/reverse the anaesthetic drugs and you will begin to wake up. You may still feel sleepy as you recover in the Recovery Room.
A recovery nurse will monitor you until you are completely awake, comfortable and fit to go back to the Ward. Your Anaesthetist will also prescribe combination of painkillers, anti-emetics, laxative and IV fluids. You will be able to eat and drink as soon as possible provided your recovery is straightforward.
Modern anaesthetic drugs are much safer, short acting and have fewer side effects. However, you can still have complications from general anaesthetic.
Complications/side effects of General Anaesthesia (GA)
Spinal/Epidural Anaesthesia is generally considered safe. The significant side effects are as follows:
Pain:
On injection of anaesthetic drugs into your vein- common
Nausea and Vomiting:
Common but manageable with routine anti-emetics
Damage to teeth/crowns/caps/dentures/lips/tongue
Uncommon, but can happen when the airway device is inserted or removed.
Fluctuations in Blood Pressure (BP) and Heart Rate (HR)
Your Anaesthetist will monitor you continuously and manage any fluctuations in BP or HR.
Drowsiness:
Is common until anaesthetic drugs wear off completely. Painkillers like Morphine can also make you drowsy and tired.
Shivering:
Occasional, either due to exposure to cold in operation theatre or sometime not related to your body temperature.
Itching:
Is a common side effect of analgesics like Morphine. It can also be caused by an allergy to anything you have been in contact with, including drugs, sterilising fluids, stitch material, latex and dressings. It can be treated with drugs
Breathing difficulties:
Some people wake up after GA with slow or slightly difficult breathing. If this happens to you, you will be cared for in the Recovery Room until your breathing is better.
Sore throat:
Can happen due to airway intervention. It can last a few days and usually responds to simple painkillers.
Damage to Eyes:
It is possible that surgical drapes or other equipment can rub the cornea (clear surface of the eye) and cause a graze. Anaesthetists take care to prevent this. Serious and permanent loss of vision can happen, but it is very rare.
Nerve damage (paralysis or numbness):
Has a number of causes during local, regional or GA. Temporary nerve damage can happen due to pressure points, but full recovery often follows. Permanent nerve damage is uncommon
Bladder Problems:
Difficulty passing urine, or leaking urine, can happen after most kinds of moderate or major surgery. If this happens, the team looking after you will consider whether you need a urinary catheter
Confusion or Memory Loss:
This is common among older people who have had a GA. It may also be due to an illness developing such as chest or urine infection. There are other causes, which the team looking after you will take care of. It usually recovers but this can take some days, weeks or months.
Postoperative Delirium:
Can happen especially in elderly patient population
Postoperative Cognitive Dysfunction:
Has been reported after GA. However, it generally affects elderly patients
Serious allergy to drugs:
Difficult to predict
Equipment failure:
Difficult to predict
Chest infection:
Is more likely to happen after major surgery on the chest or abdomen, after emergency surgery and after surgery in people who smoke. Occasionally severe chest infections develop which may need treatment in the intensive-care unit. These infections can be life threatening.
Awareness under General Anaesthesia (GA)
Extremely rare, about 1 in 20,000 Anaesthetics
Death due to General Anaesthesia:
Is extremely rare in healthy patients undergoing non-emergency surgery (about 1 in 100,000 general anaesthetics) If you are having any complications of General Anaesthesia, please report it to your ward Doctor who will contact Anaesthetic Team if necessary. Death due to General Anaesthesia is extremely rare in healthy patients undergoing non-emergency surgery (about 1 in 100,000 general anaesthetics) If you are having any complications of General Anaesthesia, please report it to your ward Doctor who will contact Anaesthetic Team if necessary.
General Information
- Your Anaesthetist (Consultant or a junior Doctor) will see you on the day of the operation. This is your opportunity to discuss any issues related to your Anaesthesia & ask any questions you may have regarding your anaesthetic.
- Irrespective of the anaesthesia technique, the Surgeon will generally inject local anaesthetic drug around your joint and wound at the end of the operation. This will help you with pain relief.
- You may need more blood tests, X-rays or scans whilst in the hospital if necessary
For more information about your anaesthetic please go to https://www.rcoa.ac.uk/patientinfo/anaesthesia-information-leaflets
