page49
Allergy
Patients should be asked about any history of
allergy;
those with a history of atopic allergy (asthma,
eczema,
hay fever, etc.) are at special risk. Those with a history of
a severe allergy or of anaphylactic reactions are at high
risk—it is essential to confirm that they are not allergic
to any medication,
or to any dental materials or equip-
ment (including latex gloves).
See also Anaphylaxis on
p.
26.
Arrhythmias
Patients,
especially those who suffer from heart failure
or
who have sustained a myocardial
infarction,
may
have irregular
cardiac rhythm.
Atrial
fibrillation is
a
common arrhythmia
even in patients
with normal
hearts and is of
little concern except
that
dental
sur-
geons
should be aware that
such patients
may be
receiving anticoagulant
therapy.
The patient’s medical
practitioner should be asked whether any special
pre-
cautions are necessary.
Premedication (e.g.
with tem-
azepam)
may be useful
in some instances
for
very
anxious patients.
See also Cardiac emergencies, p.
27 and Dental Anaes-
thesia,
p.
794.
Cardiac prostheses
For an account of
the risk of
infective endocarditis in
patients
with prosthetic
heart
valves,
see
Infective
Endocarditis,
below.
For
advice on patients receiving
anticoagulants,
see Thromboembolic disease,
below.
Coronary artery disease
Patients are vulnerable for at least 4 weeks following a
myocardial infarction or following any sudden increase
in the symptoms of
angina.
It
would be advisable to
check with the patient’s
medical
practitioner
before
commencing treatment.
See also Cardiac Emergencies
on p.
27.
Treatment with low-dose aspirin (75 mg daily), clopido-
grel,
or dipyridamole should not
be stopped routinely
nor should the dose be altered before dental procedures.
A Working Party of the British Society for Antimicrobial
Chemotherapy
has
not
recommended
antibiotic
prophylaxis
for
patients
following
coronary
artery
bypass surgery.
Cyanotic heart disease
Patients with cyanotic heart
disease are at
risk in the
dental chair, particularly if they have pulmonary hyper-
tension.
In such patients a syncopal
reaction increases
the shunt away from the lungs,
causing more hypoxia
which worsens the syncopal
reaction—a vicious circle
that
may prove fatal.
The advice of
the cardiologist
should be sought on any patient with congenital cyano-
tic heart disease.
Treatment in hospital
is more appro-
priate for some patients with this condition.
Hypertension
Patients with hypertension are likely to be receiving
antihypertensive drugs such as those described in sec-
tion 2.5. Their blood pressure may fall dangerously low
under general anaesthesia, see also under Dental Anaes-
thesia on p.
794.
Immunosuppression and indwelling
intraperitoneal catheters
See Table 2,
section 5.1
Infective endocarditis
While almost
any dental
procedure can cause bacter-
aemia,
there is no clear association with the develop-
ment
of
infective endocarditis.
Routine daily activities
such as tooth brushing also produce a bacteraemia and
may present a greater risk of infective endocarditis than
a single dental procedure.
Antibacterial prophylaxis and chlorhexidine mouthwash
are not recommended for the prevention of endocarditis
in patients undergoing dental procedures. Such prophy-
laxis
may expose patients
to the adverse effects
of
antimicrobials when the evidence of
benefit
has not
been proven.
Reduction of oral
bacteraemia
Patients at
risk of
endocarditis
1
should be advised to maintain the highest
possible standards of
oral
hygiene in order to reduce
the:
.
need for dental extractions or other surgery;
.
chances of severe bacteraemia if dental
surgery is
needed;
.
possibility of ‘spontaneous’
bacteraemia.
Postoperative care
Patients at risk of
endocarditis
1
should be warned to report
to the doctor
or
dental
surgeon any unexplained illness
that
develops
after
dental
treatment.
Any infection in patients at
risk of
endocarditis
1
should be investigated promptly and trea-
ted appropriately to reduce the risk of endocarditis.
Patients on anticoagulant
therapy
For
general
advice on dental surgery in patients receiving oral anti-
coagulant therapy see Thromboembolic Disease, below.
Joint prostheses
See Table 2,
section 5.1
Pacemakers
Pacemakers
prevent
asystole or
severe bradycardia.
Some ultrasonic scalers,
electronic apex locators,
elec-
tro-analgesic devices,
and electrocautery devices inter-
fere with the normal function of pacemakers (including
shielded pacemakers)
and should not
be used.
The
manufacturer’s literature should be consulted whenever
possible. If severe bradycardia occurs in a patient fitted
with
a
pacemaker,
electrical
equipment
should be
switched off
and the patient
placed supine with the
legs elevated.
If
the patient
loses consciousness and
the pulse remains slow or is absent,
cardiopulmonary
resuscitation (see inside back cover)
may be needed.
Call
immediately for medical
assistance and an ambu-
lance,
as appropriate.
1.
Patients at
risk of
endocarditis include those with valve
replacement, acquired valvular heart disease with stenosis
or
regurgitation,
structural
congenital
heart
disease (in-
cluding surgically corrected or palliated structural
condi-
tions,
but
excluding isolated atrial
septal
defect,
fully
repaired ventricular
septal
defect,
fully repaired patent
ductus arteriosus,
and closure devices considered to be
endothelialised),
hypertrophic cardiomyopathy,
or
a pre-
vious episode of infective endocarditis
BNF 61
Prescribing in dental practice
29
Prescribing in dental practice