Specific Surgeries and Procedures

An arterial line is a drip that is inserted into a peripheral artery (usually in your wrist) and allows beat-to-beat analysis of your blood pressure and cardiovascular function. It gives us the ability to rapidly titrate the anaesthetic dose and various blood pressure and cardiovascular medications to ensure a safer anaesthetic for you. It also allows us to sample arterial blood and measure oxygen, carbon dioxide and acid base balance.

Arterial lines are usually inserted while you are asleep but for various (usually emergency) procedures, they may need to be done while you are awake.

Arterial lines have a very low complication rate (3.4 per 10 000 {surgical and patient risk factors for severe arterial line complications in adults – Gregory Nuttall et al}). Most reported complications are minor and require no therapy (temporary thrombosis or occlusion of vessel, haematoma, local sepsis).

Severe complications (including downstream ischaemia (lack of blood and oxygen) and tissue death comprise a very small proportion of the already low complication rate.

A central venous line is a long drip which is inserted into a large blood vessel (usually under the clavicle, in the neck or in the groin).

This line is used to administer many cardiovascular and advanced blood pressure medications as well as fluids and other medications.

Additionally the CVP can be used to sample blood for blood tests and may also be used to monitor venous pressure near the heart for certain procedures (eg liver surgery).

CVP lines allow us to rapidly and accurately titrate medication to make your anaesthetic safer. They are also used very commonly in the ICU, for many of the same reasons and also occasionally for administering intravenous food (TPN).

CVP’s are associated with the following complications:
Minor: Arterial puncture (up to 9%), haematoma (1-4%), infection, device malfunction
Major: Pneumothorax (up to 1% depending on insertion site), arrhythmias, other (<0.1%) {Central line complications, Craig Kornbau et al}
Should you develop a pneumothorax (“deflated lung”) during CVP insertion, you may require a chest drain which allows the lung to re-expand.

An epidural is a procedure where a needle which is inserted into the epidural space (a potential space surrounding the brain and spinal cord). Nerves which run from your spinal cord through this space are anaesthetized by the medication which is administered through this needle. Epidurals can be performed at any level of the spine but are most commonly placed in the lower back.

A caudal anaesthetic is an epidural when the needle is passed through a ligament at the very bottom of your spine and into the same epidural space. This is most commonly done in paediatric anaesthesia.

Spinal anaesthesia is when a different needle is inserted past the epidural space and into the spinal space. This is always done in the lower back.

Spinal and Epidural anaesthetics are usually done while you are awake or lightly sedated, with the assistance of local anaesthetic applied to the back to limit any pain. If you are coming for a surgery which already requires a general anaesthetic, the injection may be done while you are asleep.

The advantages of these types of anaesthetic are numerous. Most prominently, they provide excellent analgesia without the complications associated with high doses of systemic analgesics and are thus a very useful part of major surgery, especially to the lower chest and abdomen.

When used for various back pain conditions, they may be sufficient (in conjunction with physiotherapy) to treat the condition without undergoing more invasive surgery.

There are also side effects associated with their use:

• Common:
  1. Inability (or limited ability) to move legs: this is an effect of a successful block of the nerves to the legs. Movement will come back to normal as soon as the block wears off (usually about 4 hours)
  2. Inability to pass urine: this is as a result of a successful block of the nerves supplying the bladder and will pass in the same timeframe.
  3. Low blood pressure: Usually a very minor drop, but occasionally requires treatment by your anaesthesiologist
  4. Itching, nausea: this may occur as a result of one class of medication administered. It too will pass with time, but it may require medication until it does
• Uncommon:(0.3-1.3%)
  1. Dural puncture headache: This is a very specific type of headache which only occurs in certain positions and with certain actions. It is caused by the accidental advancement of an epidural needle into the spinal space and a resultant leak of cerebrospinal fluid out of the spinal space. It is different to a regular day-to-day headache and is thus easily diagnosed if it does occur. The most effective treatment for this is a second epidural injection where a blood patch is placed.
• Very Uncommon: (<1:100 000 to <1:300 000)
  1. Local anaesthetic systemic toxicity, nerve injury from a needle or medication, epidural haematoma and epidural abscess (which if left too long may result in paraplegia)

A peripheral nerve block is when your anaesthetist injects a solution of local anaesthetic very close to a nerve in order to block the transmission of pain signals carried by that nerve, greatly decreasing or abolishing the pain caused by the surgery. There are a multitude of different nerves that can be blocked, but peripheral nerve blockade is usually performed for surgeries of the shoulder, forearm or hand, hip or knee.

There are numerous advantages associated with peripheral nerve blockade, most notably diminished pain and decreased doses of systemic analgesics, meaning a reduction in the side effects of those drugs. Studies have even shown better limb function after some joint replacement surgeries when nerve blocks have been used.

There are also side effects associated with their use:

• Common:
  1. Inability to move or feel pain in “blocked” limb until the local anaesthetic agent wears off. It is important to note that standing or walking after leg blockade should only be done with care and after ensuring your leg has regained enough power to enable to you support yourself without falling. Furthermore, extra care should be taken to protect the anaesthetized limb as the inability to feel pain means that you can injure yourself without knowing it
  2. Bleeding or localized inflammation at the site is usually minimal and self-limiting.
• Uncommon:
  1. Block failure. Even with adequate visualization of the nerve and the needle with the use of ultrasound, there may be partial or complete failure of nerve blockade in up to 4% of cases. If this occurs, your anaesthetist will provide extra systemic analgesia to cover the pain of the surgery
• Very Uncommon:
  1. Nerve injury. This occurs as a result of inadvertent needle placement, toxicity of the local anaesthstic solution or pressure in the surrounding tissue resulting in diminished blood supply to the nerve. Many precautions will be taken by your anaesthetist to prevent this from occurring, but the risk cannot be eliminated completely. Nerve injury is difficult to study because of its rarity, but reported incidences range from around 3% for interscalene blocks (for shoulder surgery) in one study to less than 0.01% in other more recent studies.
  2. Nerve injury may result in pain, numbness or even rarely movement abnormalities in the nerve distribution. The vast majority of cases will recover completely, although recovery may be slow (6 weeks to 6 months). It is important to note that the surgery itself is probably a more common cause of nerve injuries than peripheral nerve blockade; and that various other factors also contribute to injury (patient positioning, tourniquet use, diabetes, advanced age, pre-existing nerve damage, extremes of body habitus).

Local anaesthetic systemic toxicity, systemic sepsis and intravascular injection are all fleetingly rare in modern anaesthetic practice.

Peripheral nerve blockade is usually an adjunct to a general anaesthetic and thus the surgery can often continue even if you choose not to have a block done. If your anaesthetist offers you a peripheral nerve block, he has already weighed up the benefits and risks and believes that the procedure remains worthwhile. Nonetheless if you have reservations about it, feel free to discuss these beforehand.

If you have decided or are still considering Bariatric surgery in the near future and have questions regarding the anaesthetic, this serves to provide you with some information. All people are at least a little nervous about receiving an anaesthetic and some are just terrified! Hopefully by providing you with some information it may help to relieve some of the anxiety associated with having surgery.

Weight loss surgery requires you to have a general anaesthetic to enable the surgeon to perform the procedure. In many ways, the anaesthetic is similar to what you may have had for other procedures, especially if it involved abdominal surgery. There are however, some important differences in the techniques and drugs we use to reduce the risks involved for very overweight patients. All anaesthesia comes with some risks but fortunately, it is becoming safer as the medicines and equipment improve. We have access to the latest technology available.

Once you have decided to proceed with the operation you will meet one of our anaesthesiologist partners in our rooms for a pre-operative evaluation. This forms part of the multi-disciplinary evaluation to ensure the best possible outcome for you. When you come for your appointment, please bring a complete list of any current medications you are taking. Your anaesthetic plan, and any risks specific to the surgery or to your medical conditions will be explained to you. This consultation will also provide you with an opportunity to ask any questions you may have regarding the anaesthetic.

You will be admitted to hospital on the afternoon before your surgery and will meet the anaesthesiologist assigned to you, who will again discuss everything you can expect from the upcoming surgery and hospital stay.

Please also remember to bring along all your current medications, in their original packaging.

On the morning of the surgery you will be brought to our theatre and transferred to the operating table. Our monitors will be attached to you, and an intravenous cannula will be placed in a vein so that the medications can be injected to make you sleep. You will then undergo a general anaesthetic, which involves making you completely unconscious and managing your pain during and after the surgery. During your anaesthetic you are very carefully monitored and the anaesthetic is adjusted specifically to your needs at the time. You will also be given a muscle relaxant to help the surgeon perform the surgery under optimal conditions.

The procedure takes between 2 and 4 hours to perform, after which you will be taken to the recovery area to wake up. Once you are awake and comfortable, you will go back to your ward or, rarely (in higher risk cases), to the High Care Unit.

After your surgery you will most likely be sleepy and somewhat disorientated for a short time. You may also have some discomfort or pain, but it is usually mild to moderate in nature. Other common side effects include a sore throat, abdominal pain/cramping, or pain between the shoulder blades. Occasionally you may also be nauseous. Medications will be prescribed to treat these symptoms.

Once you are back in the ward you will be encouraged to get out of bed as soon as possible to promote the blood circulation in your legs and reduce the risks of developing blood clots in the deep leg veins. You should expect to stay in hospital for at least 2 nights post-operatively assuming all goes well.

Every step of the way you will be cared for by experienced and trained professionals who have your best interests at heart.