Download Intravenous conscious sedation for dental treatment: am I my

Anaesthesia, 2007, 62, pages 645–647
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Editorial
Intravenous conscious
sedation for dental treatment:
am I my brother’s keeper?
Before 2002, both dentists and doctors
administered general anaesthetics for
dental treatment to large numbers of
patients [1] outside a hospital setting.
Many of these practitioners had an
almost magical belief that somehow this
type of anaesthesia was different from
that in hospital and was without harm
[2]. Unfortunately this was not the case
[1, 3]. There was a small but regular
litany of deaths, some almost certainly
precipitated by the arrhythmogenic
property of halothane [4] and then
compounded by failure to follow any
recognisable resuscitation protocol. In
addition, considerable morbidity went
unreported. Much of this morbidity
reflected general anaesthesia techniques
well outside recognised practice [2]. In
1990, the report by Professor Poswillo
[5] led to the Department of Health
providing funds for monitoring equipment, defibrillators and resuscitation
drugs for all dental practices. The report
also urged practitioners to reduce the
use of general anaesthesia and consider
conscious sedation instead. However,
the deaths and morbidity continued [6].
‘A Conscious Decision’, published by
The Department of Health in July 2000
[7], noted that ‘standards aimed at
protecting patients from the effects of
serious complications of general anaesthesia or conscious sedation administered during dental treatment are not
rigorously applied or enforced’; and
‘despite a large number of expert reports
which have been aimed at improving
standards, it seems that patients are still
vulnerable to unexpected death or nonfatal complications occurring outside
hospital which seem to be avoidable’.
By early 2002, general anaesthesia for
dental treatment in the United Kingdom was confined to a hospital setting.
Thus conscious sedation and the use of
local anaesthesia are now the only
therapies approved of by the General
Dental Council (GDC) for dental treatment outside hospital [8, 9].
Conscious sedation was defined by
the GDC [8] as:
‘A technique in which the use of a
drug or drugs 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 should
carry a margin of safety wide enough
to render loss of consciousness
unlikely’.
In the past 5 years there has been
a proliferation of centres outside the
hospital setting hospital offering sedation for dental treatment to both adults
and children. Some centres advertise on
the internet and often proclaim that
their sedation is given by a consultant
anaesthetist. There is rarely any mention
of the principles of conscious sedation
or the use of local anaesthesia. The
impression is given that patients will not
remember their treatment. Patients may
interpret this as a general anaesthetic
and it seems unlikely that many understand the concept of conscious sedation.
Since 2001, in addition to the published Standards of the GDC [8, 9],
other bodies have issued guidelines on
conscious sedation for dental treatment
[10–13]. The guidelines are all agreed
on conscious sedation as defined and on
the principle of minimal intervention,
and give guidance on intravenous drug
usage. In addition, there is also guidance
on the management of any complication [11, 14] which requires the whole
dental team to be:
‘fully trained in the appropriate procedure to take in the event of the
patient losing consciousness, aware of
complications, appropriately trained
and regularly rehearsed in emergency
procedures including defibrillation
when advanced conscious sedation
Ó 2007 The Author
Journal compilation Ó 2007 The Association of Anaesthetists of Great Britain and Ireland
techniques are used, fully equipped
with appropriate means of airway
protection, oxygen delivery and
drugs for emergency use. It is essential that these are carefully checked,
that the oxygen supply is secure and
adequate and that the drugs are
in-date with all requisite means for
immediate administration at all times.
It is vitally important for the whole
team to be prepared and that it
rehearses the routine regularly’ [11].
For adults, the standard technique for
intravenous conscious sedation [11, 13]
is the use of a titrated dose of a single
drug, for example the current use of
the benzodiazepine, midazolam. Drugs
used in combination (sometimes called
‘alternative techniques’) are said to be
appropriate in specially selected circumstances, although these have never been
defined in any standard or guideline. Do
the special circumstances reflect the
needs of the patient or that the administration of drug combinations must be
restricted to an experienced practitioner
and team fully trained in their use
working in an appropriate environment? In any event, the use of fixed
doses or bolus techniques is unacceptable as success is directly related to
titration of the dose according to the
individual patient’s needs [11, 13].
The UK National Clinical Guidelines
in Paediatric Dentistry 2002 [10], from
The Faculty of Dental Surgery, Royal
College of Surgeons, specifically addresses the use of conscious sedation in
children. The only form of conscious
sedation recommended without reserve
for children, outside hospital, is titrated
nitrous oxide inhalation. The guidelines
caution that the use of intravenous
midazolam in children may cause disinhibition rather than sedation. The
guidelines also state that ‘intravenous
sedation for children below the age of
14 should be carried out in a hospital
facility’. The guidelines are also clear
that potent opioids such as fentanyl and
alfentanil, and drugs such as propofol
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Editorial
Anaesthesia, 2007, 62, pages 645–647
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and ketamine ‘should only be administered by a qualified anaesthetist in a
hospital environment’. It is noted further that ‘the use of multiple drugs
increases the risk of complication and is
not recommended’. The Scottish Intercollegiate Guidelines Network (SIGN
58) document [12] states: ‘There is
insufficient scientific evidence to support the routine use of intravenous (IV)
sedation for dentistry in children under
the age of 16 years. General anaesthetic
agents such as propofol and potent
opioids such as fentanyl, alfentanil and
remifentanil should only be administered by an appropriately trained anaesthetist in a hospital setting with full back
up facilities’. It seems clear therefore
that intravenous conscious sedation in
children is not recommended, except
on rare occasions, and that it should
preferably be carried out in hospital.
Has this plethora of advice created a
safe environment, outside hospital, for
patients undergoing conscious sedation
for dental treatment? Unfortunately not.
Cases adjudicated recently by the Professional Conduct Committee (PCC) of
the GDC and others (both adults and
children) which are still sub judice
indicate that there are considerable
problems.
In one case that came before the
GDC, a female adult patient weighing
50 kg, received 4 mg midazolam, 50 lg
fentanyl, 10 mg ketamine and 5 mg
propofol given by a staff grade anaesthetist, for a 15-min procedure to
remove two teeth. This was followed
by a period of unconsciousness in the
recovery area, accompanied by vomiting and several days for the patient to
recover fully. The judgement (April
2007) of the PCC of the GDC was that
‘the care provided to Mrs A in the
recovery period was poor’. The dentist
was found not guilty of serious professional misconduct. However, he did
volunteer, while under oath giving
evidence, that he would not be undertaking any dentistry in the future under
conscious sedation.
The pharmacological rationale and
the concept of titrating a mixture of a
benzodiazepine, a potent opioid and
two intravenous anaesthetics is difficult
to interpret. For example, should the
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drugs be mixed together, and if so in
what doses or which drug should be
given first; in addition, how are the
patient’s requirements determined? At
present there are no peer-reviewed
publications to provide guidance on
these matters.
A further difficulty is whether the
concept of conscious sedation applies if
patients are sedated in a hospital setting.
A review of sedation provided in hospital [15], for a variety of procedures,
makes it clear that, if patients are not in
a state of conscious sedation, then all the
safeguards for general anaesthesia should
apply. The mode of sedation used in
these circumstances will not be applicable outside hospital for dental treatment under current GDC Standards.
In another case, a 6-year-old boy,
weighing 17 kg, received in bolus fashion 2 mg midazolam, 4 mg ketamine
and 250 lg alfentanil intravenously,
given by a consultant anaesthetist. Local
anaesthesia was injected by the dentist,
who then removed six teeth. The
procedure lasted 10 min. When the
nasal oxygen was discontinued after
the extractions, the oxygen saturation
fell. By the time the patient reached
the recovery area in a head-up position,
he was unconscious, cyanosed and his
oxygen saturation and pulse rate were
extremely low; blood pressure was not
measured. Ventilation with 100% oxygen could not be carried out in the
recovery area as the equipment was not
available. The patient was returned to
the treatment area, his trachea was
intubated and he was ventilated with
100% oxygen. An ambulance was called
and the patient was transferred to hospital. Although the patient survived, he
now has brain damage and may require
considerable care in the future. The
dental and anaesthetic management of
this child did not conform to any of the
published guidelines.
The judgement of the PCC of the
GDC (October 2006) was to find the
dentist guilty of serious professional
misconduct and his name has been
removed from the GDC Register. The
GDC has no jurisdiction over doctors
and it will be up to the General Medical
Council (GMC) to assess the liability of
the anaesthetists in cases like this. Why
then did the GDC strike off the dentist
even though he did not administer the
sedation? The answer lies firstly in the
GDC Standards [8] at the time this case
occurred, which state: ‘where a second
dental or medical practitioner is providing conscious sedation for a patient,
the treating dentist must ensure that the
person acting as the sedationist has
undertaken a relevant postgraduate education and training, accepts the definition of conscious sedation given and the
principle of minimum intervention, and
has specific experience of the use of
conscious sedation in dentistry’. Second, it was by no means clear that
informed consent for intravenous conscious sedation had been obtained from
the patient’s parents. No apparent consideration was given to any alternative
and nitrous oxide was allegedly not
available. Third, the dental record was
deemed to be unacceptable. The PCC
of the GDC took the view that what
occurred was part of the dentist’s
responsibility.
The mixture of drugs used in this
case was presented to a meeting of
The Dental Sedation Teachers Group
(DSTG) and published without comment in their Autumn 2005 newsletter
[16]. The article describes a review of
6000 sedated children, a remarkably
large number for something (intravenous sedation) which every guideline
describes as a rare event. There is some
confusion in the article over titration vs
bolus intravenous injections and potency
vs length of action of the drugs used.
Onset time of the drugs is not mentioned. Although having eschewed
titration as ‘theoretically illogical’ based
on this confusion, the article concludes
that, ‘titration of midazolam alone or the
entire mixture gives an added safety
margin against the tendency towards
deep sedation’. Deep sedation is deemed
to be general anaesthesia by the GDC
and therefore not acceptable outside a
hospital setting [8]. It is interesting that,
in the DTSG Autumn 2006 newsletter,
the following appears: ‘The opinions
expressed in this and previous Newsletters are those of the authors and are not
necessarily those of the Editor or of
the Dental Sedation Teachers Group’ –
hardly a vote of confidence.
Ó 2007 The Author
Journal compilation Ó 2007 The Association of Anaesthetists of Great Britain and Ireland
Anaesthesia, 2007, 62, pages 645–647
Editorial
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Anaesthetists and dentists involved in
conscious sedation for dental treatment
outside hospital should not perpetuate
the magical belief, as occurred with
general anaesthesia, that sedative techniques as described above are risk-free.
Common sense would indicate that
they are not. Why then are they given?
One wonders whether financial expediency plays a part. Only some 20 min
were scheduled for each case described
above. This allegedly included patient
assessment by both the dentist and the
sedationist, discussing the options for
conscious sedation and obtaining
informed consent as well as the dental
treatment required. Titration of midazolam in adults or titrating nitrous oxide
in children may be time-consuming,
requires an appropriate ambience and is
not always successful as a first option. It
may therefore seem easier to take a
chance and administer by bolus a mixture of intravenous drugs. Although the
risk of something going wrong is low,
this increases the possibility that when it
does occur, the people present have not
trained as a team in dealing with
complications [11] and do not know
what to do. Under these circumstances,
as the cases above illustrate, tragedy may
not be far away.
Patients attending for dental treatment outside hospital are unlikely to
have serious co-morbidities and their
dental problems are not life-threatening.
Therefore, we should do everything we
can to avoid adverse outcomes. It is
worth emphasising that conscious sedation alone, as defined, regardless of
which drug or drugs are used to achieve
the state, is unlikely to provide the
necessary analgesia for most dental
treatment. Therefore, the purpose of
conscious sedation is to provide sufficient pain and anxiety control to
encourage the patient to accept a properly administered local anaesthetic.
Regrettably, this prime concept is
hardly mentioned by some of those
engaged in teaching conscious sedation
for dental treatment [17].
A simple step, in future, would be
that all those involved in conscious
sedation for dental treatment follow the
published guidelines [7–14]. The cases
described here should remind anaesthetists, acting as sedationists, that if
they deviate from the guidelines not
only are they putting their patients at
risk, but also the professional standing of
themselves and their dental colleagues.
In this instance the anaesthetist is indeed
his brother’s keeper.
L. Strunin
Emeritus Professor of Anaesthesia
Barts and The London
Queen Mary’s School of Medicine and
Dentistry University of London, UK
The Grange, Firsby, Spilsby
Lincolnshire PE23 5QL, UK
E-mail: [email protected]
References
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Journal 1982; 153: 357–63.
2 The Royal College of Anaesthetists.
Standards and Guidelines for General
Anaesthesia for Dentistry, February.
London: The Royal College of
Anaesthetists, 1999.
3 Coplans MP, Curson I. Deaths associated with dentistry and dental disease. Anaesthesia 1993; 48: 435–8.
4 Worthington LM, Flynn PJ, Strunin
L. Death in the dental chair: an
avoidable catastrophe? British Journal
of Anaesthesia 1998; 80: 131–2.
5 Poswillo D. General Anaesthesia, Sedation and Resuscitation in Dentistry.
Report of an Expert Working Party for the
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London: Department of Health, 1990.
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on Professional and Personal Conduct
Ó 2007 The Author
Journal compilation Ó 2007 The Association of Anaesthetists of Great Britain and Ireland
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