dental surgery on patients on anticoagulant therapy

1. Presented by,
Dr Saqba Alam
J of IMAB. 2013, vol. 19, issue 4

2.  The aim of oral anticoagulant therapy is
to reduce blood coagulability to an
optimal therapeutic range within which
the patient is provided some degree of
protection from thromboembolic events.
This is achieved at the cost of a minor risk
of haemorrhage.

3. Oral anticoagulant therapy is prescribed for :
 prophylaxis and treatment of pulmonary
embolism
 venous thromboembolism
 deep vein thrombosis, DVT
 For the prevention of postoperative venous
thromboembolism after orthopaedic surgical
procedures as hip fracture and prosthetic total
hip or knee joint replacement,thromboembolic
complications associated with atrial fibrillation
and/or prosthetic replacement of cardiac
valves.

4.  INDIRECT ACTING ANTICOAGS (Coumarin
derivatives)
 Acenocoumarol - derivative of
coumarin
 MOA vitamin K antagonist
 Peak of action with oral intake occurs 12 h
after administration. After discontinuation,
the action persists for 48 - 72 h.

5.  Atrial fibrillation and mitral stenosis
 history of embolism
 age over 65
 hypertension; diabetes or expressed left
ventricular hypertrophy
 intramural thrombus of the heart after a
infarction or aneurysm (3-6 months)
 artificial heart valves, with a limited left
ventricular function

6.  Coumarin derivative
 MOA : Acts on extrinsic clotting pathway by
preventing the reduction of vitamin K into its
active form.
 Depending on the reason for the
anticoagulation (cardiovascular thrombo-
embolic risk), the patient’s target INR
therapeutic ranges will be different.
 Patients with atrial fibrillation, DVT, or stroke
have a target INR of 2.0 to 3.0, whereas after
undergoing cardiac valve replacement
surgery, patients have a target range of 2.5
to3.5.

7.  Patients taking warfarin may require
bridging anticoagulation around the
time of major surgery.
 This involves replacing the warfarin
with unfractionated or low molecular
weight heparin. Consultation with a
cardiologist is particularly
recommended if a patient with a
coronary stent requires surgery.

9.  Bridging anticoagulation refers to giving a
short-acting blood thinner, usually low-
molecular-weight heparin given by
subcutaneous injection for 10 to 12 days
around the time of the surgery/procedure,
when warfarin is interrupted and its
anticoagulant effect is outside a
therapeutic range.
 Bridging anticoagulation aims to reduce
patients' risk for developing blood clots,
such as stroke, but may also increase
patients' risk for developing potentially
serious bleeding complications after
surgery.

10.  Dabigatran is a selective, reversible
direct thrombin inhibitor currently used in Europe and
North America for stroke prevention in nonvalvular AF and
in Europe for VTE prophylaxis in orthopedic patients.
 Rapid onset of action.
 It is able to provide stable anticoagulation at a fixed dose
without the need for routine laboratory monitoring of INR
and associated dosage adjustments.
 No specific antidote or reversal agent exists.
 However, owing to dabigatran’s short half-life (12-14 hours
(14-17 hours in the elderly)), merely discontinuing the
administration of the drug is thought to be sufficient to
resolve minor bleeding in most circumstances.

11.  Rivaroxaban is approved in Europe and North
America as a highly selective Direct Factor Xa a Inhibitor.

 MOA- Rivaroxaban interrupts the intrinsic and extrinsic
pathway of the blood coagulation cascade, inhibiting
both thrombin formation and development of thrombi.
Rivaroxaban does not inhibit thrombin and no effects on
platelets have been demonstrated.
 It also provides stable anticoagulation at a fixed dose
without the need for routine INR monitoring.
 There is no specific reversal agent or antidote for
rivaroxaban, but its short half-life means that the
discontinuation of the drug is likely be adequate to
correct most bleeding problems caused by its use.

13. Tests for anticoagulation assessment
 The prothrombin time ratio (PTR), defined as the
patient’s prothrombin time (PT) was used to
monitor anticoagulant therapy for many years.
 INR as an (ISI )index.
 PT INR ratio INR =(PT test/PT normal)ISI
 BY ( the International Committee on Thrombosis
and Homeostasis 1985)
It is now widely used for monitoring anticoagulant
therapy and dosage planning. The INR for a
healthy patient is 1 and the therapeutic INR for
those on anticoagulant therapy typically ranges
from 2 to 4, depending on the reason for
anticoagulation.

14.  BCSH (British Committee for Standards
in Haematology), the British Society for
Haematology Committee, the British
Dental Association (BDA), the National
Patient Safety Agency (NPSA)
presented a guideline in after
reviewing in the year 2011, whose
summary was…….

15.  In pts with INR <4 (LOW) no need to discontinue oral
anticoags as the risk of thrombosis is increased.
GRADE A (LEVEL IB)
 For patients stably anticoagulated on warfarin (INR
2-4) and who are prescribed a single dose of
antibiotics as prophylaxis against endocarditis,
there is no necessity to alter their anticoagulant
(grade C, level IV).
 For patients who are stably anticoagulated on
warfarin, a check INR is recommended 72 hours
prior to dental surgery.
 PTS with co-existing medical problems e.g. liver
disease, renal disease, thrombocytopenia .Such
patients may have an increased risk of bleeding.

16. NONE of these approaches is risk free
for the pt and the surgeon must make
a clinical judgement of the risk benefit
ratio between management
strategies and adverse complications.

17.  Wahl reviewed 26 papers comprising 2014
dental surgical procedures in 774 patients
receiving continuous warfarin therapy,
THE CONCLUSION WAS….
 Twelve patients (<2%) had postoperative
bleeding problems that were not controlled
by local measures
 Major bleeding was rare (4/2012, 0.2%) for
patients with a therapeutic INR (<4)
undergoing dental surgery.THERE WERE NO
DEATHS……

18.  The risk for FATAL pulmonary embolism
after discontinuing anticoagulant
therapy is 0.19 to 0.49 events per 100
person years for patients undergoing
anticoagulant therapy.
 The case fatality rate from recurrent PE is
4% TO 9%

20. Specific consideration must be
given to the issue of whether oral
anticoagulant treatment should
be unaltered,modified, or
stopped according to possible
bleeding complications.

21.  Hong C. et al. reported a study with 122
patients who had a total of 240 dental
extractions. 35 patients (29%) were on
concomitant medications thought to
potentate bleeding.7 patients were on
multiple antithrombotic
medications(excluding warfarin); 2 were
taking a combination of aspirin,cilastazol,
and nonsteroidal analgesic medication; 3
were on a combination of aspirin and
clopidogrel; and 2 were on acombination
of aspirin and enoxaparin.

22.  The results of this retrospective study
suggest that the overall prevalence of
persistent bleeding after dental
procedures in patients on warfarin
therapy is low (2%).
 Additionally, most complications
experienced were controlled with local
hemostatic measures

23.  INR values should be obtained within 24
hours before the dental procedure. For
patients with INR in the therapeutic range 2-
4 or below, therapy need not be modified
or discontinued for simple single dental
extractions. More complicated and invasive
oral surgical procedures for patients with an
INR on the high end of the scale or greater
than 3.5 should be referred to physician for
dose adjust mentor therapy alteration
before invasive dental procedures

24. (Ref : OCT 24,2003 GRACE REGISTRY EUR.HEART.J)

26.  Local hemostatic measures are shown to
suffice to control the possible bleeding
secondary to dental treatments.

27. The risk of bleeding may be minimized by:
 a.Pressure and Packing !!!....
 b.The use of oxidized cellulose (Surgical) or
collagen sponges and
 c.sutures (grade B, level IIb).
 d. 5% tranexamic acid mouthwashes used four
times a day for 2 days (grade A, level Ib).
Ref : (Sept 2011Guidelines for the management
of patients on oral anticoagulants requiring
dental surgery
British Committee for Standards in Haematology)

29. .
BLEEDING
VS
THROMBOSIS

30. It is necessary to carefully evaluate the
bleeding risk of the planned
treatment, as well as the thrombotic
risk of suppressing the anticoagulant
or antiplatelet medication, on an
individualized basis for each patient,
with a view to providing optimum and
personalized care.

31. THANK YOU  !!