“Can’t
you just put me to sleep to do that?”
Try to stay awake for this week’s topic…sedation. Insert
drum and symbol noise here post awful joke.
There is a lot of confusion over methods of pain and
anxiety relief used by dentists. This mainly comes from back in t’ day when
regular high street dentists, officially known as General Dental Practitioners
or GDP’s happily knocked people out to carry out dental treatment.
In 1998 the General Dental Council acted
to construct more stringent standards for the use of general anaesthetic for
dental treatment as sadly, several people popped their clogs in the dental
chair. It endorsed the need for Conscious Sedation provision rather than the
continuing provision of General Anaesthesia as a demand led service
i.e. for everyone who came in needing a tooth out, a filling, a check up, would
no longer automatically receive general anaesthetic as standard.
Although the publication of the GDC
regulations was followed by a
substantial reduction in the use of general anaesthesia for dental treatment,
two further deaths occurred outside hospital following general anaesthesia for
dental treatment. Following several more rather tedious but nevertheless
important reports, a final set of regulations were developed which state that “by
31 December 2001, all general anaesthesia for dental treatment should be
administered in a hospital setting with critical care facilities.
This led, positively, to an increase in the use of
sedation. Sadly, the dentists of yesteryear – yes even as recently as 2001 –
were not so good on the communication front and either through this or through
lack of knowledge themselves did not adequately explain to patients the
difference between general anaesthetic, aka being knocked out, being put to
sleep, and sedation.
For this reason we still on a daily basis see patients
booked in on clinics to receive sedation for their dental treatment who either
a) are unsuitable for sedation (I will explain further below, these people are
usually weeded out at the consultation appointment but some still manage to
wiggle through the net) OR b) believe they are going to be asleep i.e. have general
anaesthetic for the procedure,
Why does it
matter? I hear you ask. Well in some cases you are right. Why some people feel
the need to be asleep to have a filling when others will happily have half their
face hacked off without even a local anaesthetic is a mystery however our
friends at the GDC state “dentists have a duty to provide and patients have a
right to expect adequate and appropriate pain and anxiety control”. In some
cases, due to general or mental health issues, or in fact the nature of the
dental procedure alone, local anaesthetic simply is not enough.
Therefore
there are several options ON TOP OF local anaesthetic than can be considered.
The reason I slipped onto the old caps lock button is because sedation is not
the be all and end all. It helps you relax, stay calm, prevent certain
stress-related illnesses from escalating during treatment, it does not however
provide complete pain relief and so local anaesthetic – yes the one via the
needle – is still vital and patients need to be made aware of this otherwise
you will find yourself in front of the not-so-friendly GDC being accused of
assault.
How we can
help
Here is the
wordy bit. In order to eliminate confusion caused by the aforementioned poor
communicators, we now refer to sedation as “conscious sedation” purely because
you remain fully conscious for the entire time. Yes that’s right, you are not asleep,
in a coma, and in fact remain fully in control of your body movements including
the very important (if not slightly annoying) gag reflex, ability to open and
close the mouth etc.
Here is
exactly what I said above but in nice technical terms;
“conscious sedation
is a technique in which the use of a drug…produces a state of
depression of the central nervous system enabling treatment to be carried out,
but during which verbal contact with the patient is maintained throughout the
period of sedation. The drugs and techniques used to provide conscious sedation
for dental treatment should carry a margin of safety wide enough to render loss
of consciousness unlikely.”
Delivery of
conscious sedation comes in several forms – inhalation i.e. you breathe in the
drug, or intravenous i.e. the drug is given directly into the bloodstream.
Inhalation Sedation
The drug
you inhale is the same thing they give pregnant women when giving birth –
laughing gas known as Nitrous Oxide. This chemical has the added quality over
intravenous sedation of providing pain relief when inhaled. The American
Academy of Paediatric Dentistry (AAPD) helpfully describe it as a colourless gas with
a faint, sweet smell. It is an effective analgesic (pain relieving)/anxiolytic
(anxiety relieving) agent causing central nervous system (CNS) depression and
euphoria with little effect on the respiratory system. Translation: it makes
you calm and happy without compromising any breathing reflexes or causing harm
to the lungs or airways which is particularly important in people with things
like asthma, where irritation of the airways can cause problems.
Pros
|
Cons
|
Quickly excreted
from lungs – so effects wear off rapidly
|
Need for flow of
pure oxygen after delivery of nitrous oxide as it leaves the blood stream
much quicker than oxygen can replace it. Not really a disadvantage as 100%
oxygen feels awesome and is automatically available wherever inhalation
sedation is being given
|
No airway
irritation
|
Feeling of loss of
control
|
Nitrous oxide is absorbed
rapidly, allowing for both rapid onset (two to three minutes)
|
You have to wear a
mask in order to breathe the gas, anyone suffering from claustrophobia may
struggle with this
|
It causes minimal impairment
of any reflexes, thus protecting the cough reflex however has the added
benefit of reducing very strong gag reflexes allowing certain treatment to be
carried out that otherwise the patient may not be able to tolerate e.g.
impressions
|
You need to be able
to breathe through your nose, therefore if you have trouble with this e.g.
broken nose, a cold, then you are unsuitable for this type of sedation
|
Extremely safe when
used correctly
|
For the same reason
as above, if treatment required needs us to be near your top front teeth, the
mask gets in the way and so is not suitable
|
Extremely effective
at reducing anxiety/ increasing tolerance to dental procedures particularly
long or more difficult treatment.
|
It does not work
alone. That is to say, the drug is not powerful enough used by itself to
relieve all anxiety. It requires reassurance and “behavioural management” to
be effective.
|
Who is
it suitable for:
1.
Anxious
patients. It is important to ascertain the reason for anxiety. As I mentioned
above, it is still necessary to have local anaesthetic injections (yes, the
dreaded needle) with ALL types of sedation and so while you care less when you
under conscious sedation, if the fear of needles is extensive then the patient
will be unsuitable for treatment under sedation.
2.
A
patient whose gag reflex interferes with dental care;
3.
Patients
where good, effective local anaesthesia cannot be achieved e.g. heavily
infected teeth, low pain threshold
4.
A
cooperative child undergoing a lengthy dental procedure.
5.
Patients
will well controlled diseases that can be worsened by stress e.g. angina,
asthma
Contraindications for use of nitrous
oxide/oxygen inhalation may include:
1.
some
patients with chronic obstructive pulmonary diseases (COPD) – certain tests
will be performed before placing a patient on a list for inhalation sedation,
and the results of these tests will determine whether or not patients are
suitable
2.
severe
emotional disturbances. As mentioned above, the inhalation sedation does not
work alone in reducing anxiety or making a patient feel like what you are about
to do to their teeth is within the realms of something they can tolerate.
Certain mental health disorders are too difficult to manage using the
techniques of inhalation sedation
3.
drug-related
dependencies. This includes alcohol as the metabolism of the drug, i.e. the way
it works is affected heavily by certain drugs and alcohol.
4.
first
trimester of pregnancy. Ideally we avoid inhalation sedation but it is still preferred
over general anaesthetic so it is taken on a case by case basis.
5.
Severe
heart disease, again, as with the respiratory problems, the results of pre-op
tests will give us an idea of the level of disease and therefore whether
sedation is appropriate
6.
Blood
problems – Including factor deficiencies e.g. haemophilia, nutrient
deficiencies e.g. anaemia
7.
As
mentioned before , anything that prevents or makes it difficult for a patient
to breathe through their nose which could be as simple as a current or recent
cold.
Now we have gone through all that,
which involves enough paperwork to fell a small forest, if you are deemed
suitable for sedation there are certain things that you must or must not do.
Oh by the way, this is what it looks
like
See, even children can do it. You just
breathe in through the nose, and out usually through the mouth because it is
open for us to do the treatment. It is quite tight fitting and you feel a bit
like a horse with a nose bag, but you are being pumped with the wonder that is
nitrous oxide, so you couldn’t care less.
Some people would describe the feeling
of receiving the sedation as like “being a bit drunk”. As a health professional
I of course cannot comment on this but a friend told me a the warm glow after a
few glasses of wine comes pretty close to the feeling of sedation.
Dos and
Don’ts
- Don’t starve but don’t stuff yourself either. Some people say that inhalation sedation makes them feel a bit sick and a full stomach won’t help with this feeling. A light meal a few hours before treatment is perfect.
- A responsible adult escort must accompany the patient home from the dental surgery and assume responsibility for the patient’s post-sedation care.
- Wherever possible arrangements should be made for the patient and escort to travel home by private car or taxi rather than public transport. Where this is not possible, the escort must be made aware of the added responsibilities of caring for the patient during the journey home.
- No alcohol 24 hours before AND after the sedation.
- Take your regular medication as normal as this will have been factored into the decision of whether you a patient is suitable for sedation and so there is no need to stop if you have been deemed appropriate.
Intravenous Sedation
This involves use of drug called
Midazolam, and less frequently Propofol. This I suppose could be considered as a
slightly stronger form of conscious sedation and is often the culprit which
causes confusion between sedation and general anaesthetic. The drug/magic
potion is given via a cannula in the back of the hand/inside of the elbow which
is the same as with general anaesthetic, hence the mix up.
Despite the needle only being present
for a matter of seconds, a severe needle phobia will also rule out intravenous
sedation alone. As with inhalation sedation, local anaesthetic injections will
also be required after the sedation agent is given. Usually by the point people
are happy for you to take a pneumatic drill to their face but the inserting of
the cannula on someone particularly anxious can be very stressful and if this
is the case then they are unsuitable for this form of anaesthesia. In some
cases, inhalation or oral sedation (a tablet) can be given prior to the
insertion of the cannula and this can often be enough to alleviate the patient’s
worries about needles enough for sedation to be given.
Because of the drug given for IV
sedation, there are a few more contraindications for this type of sedation vs
Inhalation.
The same reasons for giving inhalation
sedation also apply for IV sedation however a few more can be added, for
example, patients suffering from epilepsy or Parkinsons disease would benefit
from treatment under IV sedation as the drug given for sedation has strong
action against involuntary movements for instance those that occur during an
epileptic seizure.
Who IV
sedation is NOT suitable for.
1.
Very
young or very old patients. The reason for this is that the drug is broken down
by the liver, kidneys etc and if these are not functioning at the correct level
the patient can have a very unpredictable level of sedation. The same applies
for patients with severe liver or kidney disease (including alcoholics who may
have a poorly functioning liver without knowing it)
2.
Pregnancy
(you literally cannot do ANYTHING fun when pregnant)
3.
Severe
hormone issues e.g. thyroid disease, poorly controlled diabetes, adrenal
insuffiency treated with steroids
Whilst this does not rule out patients
from receiving IV sedation, certain medications amplify the effects of sedation
and so the delivery of the drug will need to be modified. The list of drugs is
fairly extensive but includes:
1.
Antihistamines
(e.g. for allergies including hayfever)
2.
Antihypertensives
(blood pressure)
3.
Alcohol
4.
Opioid
drugs – the legal or illegal kind
5.
Anti
epileptic drugs – because they often have the same action as midazolam used for
sedation
6.
Anti
depressants
7.
Obesity.
For several reasons.
a.
Finding
a vein
b.
Unpredictable
metabolism (breaking down and using )of the drug by the body
c.
Difficult
monitoring of breathing rate, heart rate etc which is VITAL throughout sedation
d.
Difficulty
in treating medical emergencies e.g. if CPR is required
8.
Blood
disorders – haemophilia, thalassemia, sickle cell anaemia etc
IV sedation makes you feel a bit more
drunk than with inhalation sedation, but again, all within the boundaries of
the nice happy warm place before you decide late night karaoke/snogging your
boss is a good idea.
The added benefit of IV sedation is
that is SOME people it causes loss of memory for the time that the sedation was
given. Whilst this is beneficial sometimes because it means the patient may not
remember a possibly not so nice bit of dental treatment, it also means that the
patient may not remember how well they coped/how calm they felt, and so every time
they have sedation, their fears remain the same because it feels like the first
time even after 50 attempts. I must stress that whilst this amnesia occurs a
lot, it cannot be promised, and some people remember everything.
The Dos and Don’ts remain relatively the
same. No alcohol. Escort is required. However because IV sedation takes much
longer to wear off and be completely eradicated from the body, extra care has
to be taken for 24 hours. This means no signing of important documents, no
cooking (beyond a microwave ready meal), no looking after children, no driving.
Therefore, the responsibilities of the escort that a patient chooses are
greater than with inhalation sedation.
As with inhalation sedation,
starvation is not recommended before IV sedation however we recommend not to
eat for 2 hours prior to Midazolam sedation, or 6 hours before use of Propofol.
Again, whilst there seems to be a long
list of dos and don’ts in summary. Conscious sedation implies that the patient
has:
• Minimally depressed consciousness
• Ability to maintain open airway
• Protective reflexes maintained
• Response to physical and verbal stimulation (European
Archives of Paediatric Dentistry)
i.e.
YOU ARE NOT ASLEEP. NOT EVEN A BIT. NOPE. NOT EVEN DOZING.
Sedation is an extremely useful tool
in treating lots of different people for lots of different reasons. For most of
us it is given as an option for taking out wisdom teeth because this can often
be a more extensive procedure than having a scale and polish so do not be
afraid to ask to be referred for it!
Where I borrowed stuff from
General Anaesthesia for
Dental Treatment in a Hospital Setting with Critical Care Facilities, Chief
Dental Officer, 31 May 2001
GENERAL DENTAL COUNCIL, Maintaining Standards,
paragraph 4.8
Scottish Dental Clinical Effectiveness
Programme Conscious Sedation in Dentistry Dental Clinical Guidance Second Edition
