General Anaesthesia

General Anaesthesia (GA) refers to being “put to sleep”. During GA, you are unconscious.

Has general anaesthesia for dental treatment gone out of fashion?

General Anaesthesia is rarely used for dental treatment nowadays. One of the reasons for this is that IV sedation with midazolam works so well for nearly everyone, and is extremely safe. Each general anaesthetic carries a certain amount of risk.

In the U.K., it is recommended that general anaesthesia for dental treatment in adults is used as a last resort, where there is no other method of pain and anxiety management appropriate for the person in question. The report “A Conscious Decision”, which was published in 2000 by the Department of Health, recommended that when a GA is considered necessary, it should be given in the safest way possible.  This means that GA nowadays is only available in hospitals or specialist clinics where the necessary safety equipment is available.

This policy change has resulted in far fewer GAs being given, and an increase in the use of IV conscious sedation.

Any technique resulting in the loss of consciousness is defined as GA and in the UK ‘deep sedation’ is considered to be in this category. Some of the techniques mentioned on the IV sedation page are actually general anaesthesia – for example, propofol is classed as a GA drug and therefore is usually given in a hospital setting.

Disadvantages of General Anaesthesia

Apart from the risk of serious complications (which, while very small, is still much higher than for conscious IV sedation), general anesthesia has a few major disadvantages:

  • GA depresses the cardiovascular and respiratory systems. For some groups of medically compromised patients, it is contraindicated for elective procedures.
  • It’s not recommended for routine dental work like fillings. The potential risk involved is too high to warrant the use of GA. For things like fillings, a breathing tube must be inserted, because otherwise, little bits of tooth, other debris or saliva could enter the airway and produce airway obstruction or cause illnesses like pneumonia.
  • Laboratory tests, chest x-rays and ECG are often required before having elective GA, because of the greater risks involved.
  • Very advanced training and an anesthesia team are required, and special equipment and facilities are needed. GA introduces a number of technical problems for the operator (i. e. dentist), especially when a “breathing tube” is involved: the tongue is brought forward more into the dentist’s way by the airway tubing, the muscles are paralysed so the operator is working against a dead weight all the time and there are postural problems because the patient can’t be moved about much. The operator can get very tired very quickly when doing a session. It’s physically the most demanding kind of dentistry (usually standing, hot lights, compromised patient position).
  • You can’t drink or eat for 6 hours before the procedure (otherwise, vomiting is possible and this would be very dangerous during GA).
  • It’s expensive.
  • GA does nothing to reduce dental anxiety.

When is general anaesthesia used?

GA can be useful or even indicated for certain situations.

  • Conscious IV sedation works for about 97% of extremely anxious people. But there will always be a few people for whom it doesn’t work, either because you find it impossible to cooperate even when sedated and/or because you have a very high tolerance to the drugs used for IV sedation. This appears to be more common if you’ve been taking similar drugs long-term for other mental health conditions. In this case, GA may be the best option.
  • For short or longer potentially traumatic procedures, such as the removal of wisdom teeth which are completely covered in bone, or certain other types of oral surgery. While there may be alternatives like multiple shorter appointments, in some cases GA may be preferable. If it’s extractions that really terrify you, it may be possible to be put to sleep for the extractions and then have fillings etc. done under conscious sedation with local anaesthetic.

How is it administered?

GA is usually started off with an injection in the hand or arm. It can be supplemented by a face mask but if a face mask is used you probably won’t remember it.

If post-op pain is expected, the normal practice is to inject a long acting local anaesthetic during the GA, so that when you wake up everything is nice and numb for a good few hours afterwards, which should give you time to take some painkillers and allow them to kick in. It’s much better to prevent pain than it is to try to deal with it once it has started.

Will I wake up?

“I need to have severely impacted wisdom teeth taken out, and the oral surgeon strongly recommends GA – but I’m scared to death of being ‘put to sleep’ and not waking up!”

If GA has actually been recommended to you because the dentist or oral surgeon anticipates that the surgery will be too unpleasant otherwise, general anesthesia will make things much easier for you. Provided that a qualified anaesthesist oversees the procedure, the risk of death is extremely small. A study from 1982 entitled “Deaths asociated with dentistry” (British Dental Journal) put the mortality rate at 1:338,536 for outpatient general anaesthesia (bear in mind that this was nearly 30 years ago).

What is it like? First-hand accounts of General Anesthesia

“My appt. was at 8am, so luckily I didn’t have to wait long at all. Practically as soon as I signed in and paid, they called me back. I was brought into the OR room. I rewmoved my sweatshirt and sat in the chair. They put a sterile hat on me and a blue napkin/cover thing. They put a pulse ox and blood pressure cuff on me. I’m not going to lie, sitting in that chair waiting was the most scared I have ever been. I have never had surgery before. I kept looking at the monitor which was non-stop beeping because my heart rate was in the 140′s due to being so nervous. They were all like, “Wow, you really are nervous, aren’t you?” I was like, “Duh.”

Anyway, so I tried to focus on my breathing to bring my heart rate down, which helped some. They put the IV in, which was no big deal. Just a little pinch. They started a saline drip, I think. Then they put this thing over my nose and said it was oxygen. By this point, I was just ready for them to put me to sleep because of how nervous I was.

I closed my eyes because when I went to sleep I wanted make it as natural as possible. I remember sitting there a few more moments with my eyes closed…

Then I woke up. And it was all over. I didn’t feel/hear anything during the surgery, which is what my silly brain thought was going to happen.”

“I’m 34 years old and had two impacted lower wisdom teeth and normal uppers. My oral surgeon was fantastic and suggested GA due to having all four removed. I was totally trepidacious, not sleeping the night before and pacing the waiting room just before the procedure. That said, this was the easiest and most painless surgery I’ve ever had. First they get you a little nitrous to calm you down, then they spray some sort of light freezing concoction on your arm before the IV….didn’t even feel the needle. 15 seconds later, you’re feeling fantastic. Next thing you know, you’re waking up. I had no pain whatsoever. I was alert soon after and able to leave.”

 

Is it possible to be put to sleep using gas instead of an iv? I have a fear of needles.

  1. You need to distinguish between sedation and anaesthesia. Sedation means you can sort of communicate and your protective reflexes are intact. Anaesthesia means you can’t do either.
  2. You can get to anaesthesia in 2 ways, with IV agents or with gasses. This is called “Induction”. Once anaesthesia is established, it’s usual practice to maintain it with gas.
  3. It used to be very unpleasant to induce with gas, they smelled pretty bad and it was a fairly slow process especially for adults. There’s a newer agent out now called Sevofluorane which doesn’t smell too bad (a bit like wet fur coats!) and works very quickly.
  4. All anaesthetists will want IV access during the GA for an adult, most will want it for children too.
  5. Some anaesthetists are happy to induce anaesthesia with Sevo but they’ll want to put an IV in right after the patient is asleep, which is fine as far as most patients are concerned.
  6. For short GAs such as kids extractions then most anaesthetists are happy to manage the airway (see 1 about reflexes) for a couple of minutes. For anything more than 5 mins, then they need to use additional hardware to keep the patient breathing (this is usually considered a good thing ).

So the normal chain of events for a very needle phobic patient would be: Induce GA with Sevo, establish IV access, insert breathing equipment, maintain GA with gasses, carry out treatment.
(from our message board. Answer courtesy of Gordon Laurie, BDS)

Further information:

A Conscious Decision: A review of the use of general anaesthesia and conscious sedation in primary dental care (2000) (PDF)

Conscious sedation in the provision of dental care: report of an Expert Group on Sedation for Dentistry, Standing Dental Advisory Committee (2003) (PDF)