Inhalation sedation using nitrous oxide
(nitrous oxide) is very safe and harmless. It has long been used
in medicine and dentistry. The method is not yet known in
Poland, hence you will certainly not have heard anything
earlier about it. Inhalation sedation using nitrous oxide
is especially suitable for children and adults who are
very afraid of dental treatment or of injections (anaesthesia).
SEDATION is achieved by inhaling the
laughing gas with the help of a mask placed over the nose.
The patient then feels a very pleasant sense of
bewilderment. Due to the pleasure of being in this state
the patient does not feel any dread or fear. Very
frequently patients (mainly children and young people)
begin to dream. Their dreams are also very pleasant and
usually involve a sensation of floating, flying or
drifting in water, the air, on clouds or in space.
Apart from clearly improving the patient’s mood, nitrous oxide also
has an anesthetising effect, thanks to which small fillings can be
made without the need for an anaesthetic, as nitrous oxide alone
suffices for this purpose. The advantages of using laughing gas are
most evident when treating children. If you want to find out more
about this form of inhalation sedation you will find a separate
brochure on this subject in our waiting room or you can ask our
Everyone can receive treatment free of fear and pain!
Feel free to familiarise yourself with our inhalation
sedative technique based on a mixture of nitrous oxide and
oxygen. This is a very pleasant and safe method for
combating fear and pain. It is used in dentistry as well
as in various other areas of medicine (e.g. ENT-therapy,
Inhalation sedation is a little known technique, mainly
due to the fact that it only made its first appearance in
1995. In addition, compared with Poland during the
communist period, dentists have adopted a more pleasant
approach to their patients and show more empathy.
Standards of treatment have likewise evolved. Whereas once
treatment without anaesthetic was the norm, now
anaesthesia is the standard.
Dental surgeries equipped with inhalation sedation
apparatus certainly put great emphasis not only on the
quality of treatment but also on ensuring pain-free
What is inhalation sedation?
Nitrous oxide sedation can be defined as a state of
physical relaxation, a pleasant feeling of bewilderment as
well as a being distanced from reality as a result of
inhaling a mixture of nitrous oxide and oxygen. In
addition, the patient becomes susceptible to hypnotic
suggestion while at the same time maintaining basic
movement and consciousness. The patient always receives a
large amount of oxygen (approx. 60%). Nitrous oxide is not
administered independently in 100% dose, nor in pre-set
doses (e.g. 66% N2O and 33% O2). Rather, the dose is
adjusted in accordance with the reactions of the patient.
You will find the details in the description of the method.
Indications for using N2O/O2 inhalation
- In clinical situations where the use of sedation ensures
the best results.
- The patient exhibits considerable fear of any kind of
- In cases of children and adults who are afraid of
needles being inserted in them.
- Strong vomiting reactions.
- Overexcitement, nervous hyperactivity.
- For long, monotonous or especially unpleasant surgical
procedures, prosthetic procedures,
impression taking in
the case of people with strong vomiting reactions.
- Removal of calculus.
- Opening up teeth featuring gangrenous decomposition of
- Preparation of initial caries lesions.
Medical conditions for
which inhalation sedation is the recommended choice:
- Asthma - N2O does not irritate the respiratory system.
Reducing stress helps lower the risk of an
respiratory mixture administered to the patient includes
approx. 60% oxygen.
This improves efficacy of breathing
and the patient’s mental state.
- Epilepsy - reducing stress helps reduce the risk of an
- Heart and circulatory diseases – N2O has no clear effect
on the cardiovascular system.
- The patient receives a higher concentration of oxygen (approx.
60%). The pulse oximeter then
has a reading of approx.
More oxygen reaches the coronary vessels. Moreover,
because there is no stress there is no
increased need for oxygen.
- Hypertension – N2O has no effect on the vascular system.
It reduces fear and stress and
safeguards against any
increase in blood pressure during surgical procedures.
- Haemophilia – in certain cases N2O can help circumvent
the need for needle injections.
Contraindications for using N2O/O2
- a cold, swelling of tonsils - obstruction of upper
- First third of pregnancy.
- Mental disorders.
- Multiple sclerosis, porphyria, myasthenia gravis.
- Bronchiectasia, emphesyma.
- Non-compliant patients.
Behaviour of patient under
The first period of the anaesthesia process can be divided into
three phases of sedation. Below is a description of the
behaviour of the patient during sedation.
Phase 1 – a moderate state of sedation as well as a mild
anaesthetic effect (5-25% N2O). The patient can feel a very slight
tingling sensation in his or her fingers, cheeks, tongue, back, head
and chest. The patient clearly relaxes and calms, his or pain
threshold rises and both fear and nervous tension are reduced. The
patient quickly and effectively reacts to instructions and answers
questions. Their sense of touch, hearing and sight may be slightly
impaired. Pupils react properly to light.
Phase 2 - dissociation and partial
anaesthesia (20-55% N2O). A state of dissociation is observed - this
is one of the key factors facilitating the surgical procedure.
Dissociation is an unusual state which takes the form of the
patient’s consciousness becoming detached to a lesser or greater
extent from surrounding reality. The patient is aware of the place
he or she is in and the actions being performed by the dental
surgeon, but everything seems to be very distant. The patient has no
power of resistance, all the more so as the state of sedation is a
very pleasant sensation. Advanced states of dissociation result in
the appearance of very vivid hallucinations similar to dreams. Hence
patients are then also peaceful and mentally relaxed. The tingling
sensation in different parts of the body intensifies. (A very
characteristic feature of phase 2.) Eyelid movement is reduced.
Verbal contact is still maintained. The patient reacts with delayed
answers to questions or with answers unrelated to the question.
Dream states occur, especially in the case of children. Adults do
not so easily lose control over the situation Suggesting to the
patient what the content of these dreams should be is advisable.
A feeling of floating, flying or drifting in water, air, clouds or
space. (A very characteristic feature of phase 2.) In such
situations the dentist can stop increasing the concentration and
leave N2O at the achieved level.
Partial amnesia – the patient does not remember what happened during
the operation and remembers only the dream, the contents of which he
or she can tell immediately after the surgical procedure. The
patient may also have a similar feeling to that of alcohol
The patient’s sensitivity to, e.g. the pain of an injected needle,
is then considerably reduced.
Physical relaxation involves the loosening of the muscles and the
casual arrangement of both upper and lower limbs.
The most important sign that the patient remains in the dissociation
phase is when the patient keeps his mouth wide open at the request
of the dental surgeon (the Lang symptom). This is proof that the
patient is still conscious.
Cough reflex functioning fully.
- status of being completely pain free (50-70% N2O). In this
phase all of the above symptoms intensify. Often the patient suffers
from total amnesia. The patient’s cough reflex is slightly impaired.
The patient’s ability to open his or her mouth at the request of the
dental surgeon still remains the basic controlled symptom.
Effectiveness of inhalation
sedation depends on several factors. These are as follows:
The experience of the dental surgeon – the more experienced a
dental surgeon is the more he or she can ensure that the
patient is effectively sedated. The patient’s
susceptibility to nitrous oxide - roughly 10% of patients
are insensitive to the effects of laughing gas. The
patient’s previous experiences - the greater the trauma
suffered by patients in earlier visits, the more difficult
it will be to sedate the patient. Sometimes it is
impossible and the patient is recommended for surgery
under general anaesthesia. The age of the patient – the
younger the child the more difficult it is to sedate,
owing to a lack of co-operation. The psycho-physical
structure of the patient - patients (especially children)
that are afraid of every action performed by the dentist
frequently also refuse to take inhalation sedation. Gender
– women less frequently consent to inhalation sedation,
fearing loss of self control. The average effectiveness of
inhalation sedation, i.e. patients who are successfully
sedated – is roughly 80%.
N2O/O2 inhalation sedation in the dental
treatment of “difficult children”. Author: Jolanta
Children are among the most difficult patients that any clinic
must deal with, and this is not only true of dental
surgeries. Why are children so difficult to treat? The
basic barrier facing dentists is the child’s intolerance
to stress and pain. The primary trigger of stress among
children is the unknown as well as those things they do
know, but which, unfortunately, they consider to be
painful. Coping with the first is relatively easy. The
latter poses a serious problem. The tolerance of most
children to pain is for all sense and purposes zero. There
are obviously “polite” children who endure even painful
treatment on live pulp. Children can obviously become
accustomed to dental visits and slightly painful
prophylactic check-ups, but eventually the child must
eventually confront the real crux of the matter, i.e. the
treatment itself, which they know will be painful. Well,
here the problems begin. To be sure the biggest problem
when treating children is choosing the right method for
the child patient that removes stress and any feeling of
pain. How can this be achieved? How can we make sure we
don’t lose the child’s trust? Everyone copes with this
problem as they can. Dental surgeons have developed their
own procedural methods. In Poland, stress-free methods of
treating children,, e.g. premedication through oral
sedatives, still remains little known. The most popular
method for Polish dentists when treating difficult
children is holding the child and inserting a metal finger
between the teeth. On the other hand, dental surgeons in
the USA and many other western countries make use of
needleless syringes, Cito-Ject and Paro-Ject syringes,
Wand syringes and N2O/O2 sedation. The basic rule of thumb
when treating children is to apply many methods in
different combinations. With experience the dental surgeon
can choose the right selection of methods. Even when all
known methods are used, an operation can still fail
because the child is terrified of injections. With no
anaesthesia the visit comes for all sense and purposes to
an end. Even when the anaesthetic is administered it does
not guarantee success. Children hate the feeling of
numbness of the anaesthetised tissue, which they perceive
as a kind of pain. The child’s fear of painful actions due
to past experiences is stronger than their trust in the
dentist and this fear is often impossible to overcome.
Many dentists thus prefer to carry out operations without
an anaesthetic, taking the young patient by surprise.
To make the operation possible, it is important to proceed
in such a way that the child’s stress is reduced to a
minimum. One of the best methods for controlling stress is
inhalation sedation using NO2. Combining inhalation
sedation with other methods is a very good approach to
combating pain. Inhalation sedation helps limit the
patient’s awareness and partially reduces the pain
threshold. Contact is maintained with the child at all
times – this is very important from the point of view of
the little patient’s safety. It is very easy to control
the dose of nitrous oxide, deepening or reducing the
sedation when necessary. N2O is an effective means of
reducing the patient’s fear. Under the influence of the
gas the child is calm, passive and indifferent to the
surrounding reality. Moreover, children are highly
susceptible to dream states, imagining themselves floating
in water, flying by plane, by balloon, by space rocket,
dancing at a ball with Cinderella, or riding in a carousel.
Before beginning the operation we carry out a preliminary
examination of the child, primarily with regard to its age.
Inhalation sedation is very rarely used on children below
three years of age as they are uncooperative. It is very
important to know whether the child has already been
treated "by force", for there are some children who have
suffer such serious psychological trauma that further
dental treatment is only possible under general
A detailed medical history should be taken in an interview
with the parents regarding the child’s health. It is very
important to ask them about the meals that the child has
eaten. A child should refrain from eating at least two
hours before the operation. Once we have obtained written
consent for the operation we can familiarise the little
patient with the apparatus for administering the N2O gas.
It is not always possible to get the child to agree to
have the mask placed over its nose. Of course, they smell
nice and they get a dinosaur sticker as a reward, but that
does not always suffice. When the child still resists the
operation should be postponed until the next visit. They
could be given a mask to take home. The process of
familiarising the child with inhalation sedation is
frequently a long one which may be drawn out over several
visits. We are certain that devoting more time to
convincing a difficult patient to take laughing gas will
pay off in the end.
It is no longer necessary then to get the child fully
acquainted with particular stages of treatment. Under the
influence of a mix of N2O/O2, they have limited awareness
of being in the dental surgery (during the dissociation
phase most children are dreaming), and are indifferent to
the work being performed by the dentist. It should be
admitted, however, that children who have had major
traumatic experiences when treated “by force” in the past
are not so easily affected by nitrous oxide. In many such
cases, even when in a state of bewilderment, they remain
in control of the situation and are unwilling to
co-operate and eagerly await the moment when the dentist
reaches for the "drilling machine". The operation must
then be interrupted and another attempt made at the next
visit, when the child has more trust in the dentist. If no
improvement is seen in later visits, then an operation
under general anaesthetic should be recommended. It is
important to stress in particular that the best patients
for laughing gas sedation are first timers. Those children
who have been treated with N2O ever since their first trip
to the dentist regard the experience as pleasant and look
forward to future visits. Very often, however, children
come to my clinic who have been referred to me by other
dentists who have tried to treat them using traditional
methods without resorting to any kind of anaesthesia. In
many cases they have endured treatment on several of their
teeth without an anaesthesia up to the moment of the
trepanation of the tooth chamber with vital pulp. After
this they refuse to allow the treatment to go on.
N2O has an anesthetising effect, albeit a weak one.
Nevertheless, many operations treating superficial or even
medium dental caries (depending on the child’s sensitivity)
can be carried out without an anaesthetic. This then
considerably shortens the duration of the procedure. If
the child complains about pain, I interrupt the procedure
and administer an anaesthetic. After the child is suitably
sedated it is possible to apply other methods for
controlling pain. A number of approaches are possible, e.g.
topical anaesthesia or anaesthesia with ethyl chloride, a
local anaesthetic with a standard syringe, a needle-less
injection, or nerve block anaesthesia. All these methods
can be applied simultaneously. Using the thinnest possible
needle, i.e. 0.3 mm, facilitates the work. Another fairly
good method is to use a needle-less syringe – this is
especially useful for anesthetising patients before
infiltration anaesthesia or block anaesthesia.
Administering an anaesthetic solely with a needle-less
syringe is often insufficient. Using a Cito-Ject or
Paro-Ject syringe or a computer guided Wand syringe often
helps control the pain when administering the anaesthesia.
In general, it is much easier to administer anaesthesia
using laughing gas. The same is true when performing
operations. In such cases children are calmer or do not
move at all. Using children’s music, fairy tales in
headphones also facilitates the operation since it
distracts the child from the unpleasant sound of the
turbine drill, the low speed drill or the sound of
cracking when a tooth is extracted. Music makes the state
of sedation much more pleasant. During inhalation sedation,
dramatic noises and loud conversations or shouts should be
avoided as it is easy to awaken the child from its
In addition, inhalation sedation using N2O/O2 is very
effective when carrying out short procedures that require
opening up the chamber of teeth whose pulp is undergoing
gangrenous decomposition. It is not easy to convince a
child that "drilling" into a tooth that is causing so much
suffering will not hurt. Moreover, the smell during
trepanation is often unbearable. Laughing gas removes
their fear of the operation, and the nose mask in turn
completely cuts them off from the smell.
A very interesting effect of laughing gas is amnesia,
although not all children experience this. Amnesia is very
beneficial. Children simply do not remember what happened
in the dentist’s chair and for many of them everything
there is alien and terrifying.
Those children that are regular patients of mine and have
been receiving treatment in my surgery for years
eventually no longer need N2O. Those toddlers who had once
been “dragged” onto the dentist’s chair in tears, become
normal, self-controlled patients. However, they still need
to be treated with extra special care. Some of them simply
grow up to be brave patients, completely trusting their
dentist and willingly accept treatment. This state of mind
is achieved by gradually reducing the amount of time they
spend under the influence of N2O. Initially children
receive the gas for the entire duration of the operation.
In subsequent visits the gas is cut off earlier and is
used only until the anaesthesia is administered.
I must admit that although I do not use laughing gas with
every child I cannot imagine working without it. I often
decide whether or not to use N2O/O2 inhalation sedation on
the spot during a check-up. Provided that the child has
not eaten within two hours of the visit the gas can be
administered right away. If the child clearly refuses to
take the usual pain-killing methods (topical, infiltration
and block anaesthesia, instead of wasting time convincing
them that it really does not hurt, I persuade the child to
put on the nose mask. This is a very simple and completely
safe method. The dental surgeon can administer a mixture
of N2O/O2 with the help of special apparatus. There are no
longer any special restrictions when buying N2O, and
having oxygen in the surgery is very beneficial.
Inhalation sedation and the dental surgeon
An ordinance of the Minister of Health and Social Welfare of 27
February 1998 "Regarding standards of procedure and
medical procedures for providing health care in the fields
of anaesthesiology and intensive therapy in health care
units" does not mention inhalation sedation as a form of
health care which can be provided by an anaesthesiologist.
Dentists can use inhalation sedation on their own but only
with suitable safe apparatus. It is very unwise for a
dental surgeon to independently operate apparatus for
general anaesthesia. Such apparatus may only be operated
by an anaesthesiologist.
Dentists’ use of laughing gas varies from country to
country, varying from extremely unfavourable attitudes in
France, where N2O can only be used in hospitals, to an
extremely liberal approach in the USA, where even firemen
can use N2O on victims of accidents. One might ask here
why Americans, normally so cautious and fearful of
litigation, are so willing to allow medically trained
firemen to administer N2O while the French restrict this
right to anaesthesiologists. But France is an exception in
Europe. Dentists in other European countries can use
inhalation sedation techniques without any problem.
In Poland these two viewpoints collide. One advocate of
the liberal approach to dentists’ use of nitrous oxide was
the late renowned Polish anaesthesiologist Dr. Janusz
Kącki. Thanks to this attitude dentists can use inhalation
sedation in Poland.