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Coagulopathies & Oral Surgery
Introduction

Dental procedures, such as dental extractions &
periodontal surgery (treatment of ‘gum’ disease /
pyorrhoea), are among the most common ‘invasive’
(surgical) procedures carried out worldwide.

Many oral surgical / dental procedures are associated with
post-operative bleeding, which, in most cases, is self-
limiting & non-problematic.

However, a small but significant segment of the population
has an increased risk of bleeding due to inherited bleeding
disorders (such as
hæmophila), hæmatological conditions
(such as
leukæmia or thrombocytopænia) or various drug-
induced
coagulopathies (such as with warfarin or aspirin),
in which even relatively minor invasive procedures can
precipitate a prolonged bleeding episode.

Excessive bleeding in these patients is not only distressing
for the patient but also hinders the completion of the
procedure (e.g. suturing) & can compromise wound
healing.  More common are patients with
hæmostatic
defects
secondary to underlying disease or medication.

The dental management of such patients can present a
significant challenge; however, the onus is very much on
the dentist / oral surgeon to maintain clear & frequent
communication with the patient’s primary doctor,
hæmatologist or both to assess the risk & plan appropriate
management.
When a bleeding disorder is suspected, the usual screening tests include the PT or
INR to test the activity of the extrinsic & final common pathways & the activated
partial thromboplastin time
to test the intrinsic & final common pathways.

Platelet counts may be important when
thrombocytopenia is suspected and
bleeding time is prolonged.

If a factor deficiency is known of or suspected, the factor levels will need to be
measured and if needs be, augmented.

Patients with multiple or more severe single coagulopathies are best managed by
oral surgeons familiar with these disorders & in settings where blood products are
available, should they become necessary.


What follows are principles of patient management that relate to the underlying
disease process, & which have varying scientific support.


Dialysis Patients

The degree to which kidney, liver & bone marrow disease interfere with coagulation
following oral surgical procedures is not well understood.  Although there are no
randomised, prospective studies, it is unlikely that individuals whose kidney failure
is well managed with
dialysis would be at increased risk for clinically significant
bleeding, even from multiple dental extractions.

In the case of dialysis for Chronic Renal Failure, patients are
heparinised for the
time they are receiving
dialysis, & they could be anti-coagulated to some degree
for several hours thereafter.

Heparinisation, along with chronic anti-coagulation (eg aspirin, warfarin), creates a
multi-factorial
coagulopathy that puts a patient at higher risk for bleeding from oral
surgical procedures immediately following
dialysis.  Although the half-life of heparin
is approximately 4 hours,
dialysis is a long & fatiguing procedure, & for this reason
patients are better able to tolerate dental care on a
non-dialysis day.  On the other
hand, the longer a patient is from their last
dialysis, the more likely they are to
have a
coagulopathy from uræmia.
Useful Article:

Med Oral Patol Oral Cir Bucal 2008.  Dental Management in Renal Failure -
Patients on Dialysis



Patients on Anti-Coagulation & Anti-Thrombotic Medications

An increasing number of patients are taking “blood thinners” for various medical
conditions.

These drugs interfere with the body’s normal clotting mechanism. There are 2 main
processes by which the body normally forms a
blood clot at the site of tissue injury.

The 1st involves small blood cells called
platelets which clump together at the
wound to form a mechanical
plug. This plug slows the flow of blood through the
vessel and forms a matrix for the next phase of
coagulation. During coagulation,
chemicals in the blood interact with each other to fill in the spaces between the
platelets, stabilise the clot, & make it more solid until the process stops the
bleeding.

Anti-platelet drugs such as
aspirin, ticlopidine & clopidogrel target this phase of
clot formation by preventing platelets from sticking together and adhering to blood
vessels. These drugs do this by creating permanent changes in the
platelets which
last for the lifetime of the
platelet (7 - 10 days). These effects can only be
countered as the body produces new
platelets that have not been exposed to the
drug.

Anti-coagulant agents such as
warfarin inhibit the 2nd phase of clotting by blocking
production of proteins that stabilise the
clot.  Warfarin can only affect these blood
proteins when they are being made.
Useful Articles:

Austral Dental J 2003.  Current Concepts of the Management of Dental Extractions
for Patients taking Warfarin

BDJ 2003.  Antibacterial Prescribing & Warfarin.  A Review

BDJ 2003.  Dental Management Considerations for the Patient with an Acquired
Coagulopathy.  Part 2. Coagulopathies from Drugs

American Academy of Oral Medicine 2007. Patient Information Sheet.  Blood
Thinners Dental Care

J Oral Sciences 2007.  Dental Management of patients recieving anti-coagulation
or anti-platelet treatment

Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007.  Management of Dental
Patients taking Common Hemostasis-Altering Medications

Evidence-Based Dentistry 2008.  Guidelines for the Management of Patients who
are taking Oral Anticoagulants & who require Dental Surgery

Evidence-Based Dentistry 2009.  Continuing Warfarin Therapy does not Increased
Risk of Bleeding for Patients undergoing Minor Dental Procedures

JOMS 2011.  Comparison of the Effects of Warfarin & Heparin on Bleeding
Caused by Dental Extraction.  A Clinical Study

JOMS 2011.  Delayed Complications of Tooth Extraction in Patients Taking
Warfarin, Antibiotics and Other Medications

JOMS 2011.  Risk Factors Affecting Postoperative Hemorrhage After Tooth
Extraction in Patients Receiving Oral Antithrombotic Therapy

Dental Update 2012.  Bleeding Disorders seen in the Dental Practice

Dental Update 2012.  Management of Bleeding Disorders in the Dental Practice -
Managing Patients on Anticoagulants

BDJ 2012.  Letter to Editor.  New Anticoagulants
Patients with Hæmophilia (Factors VIII & IX Deficiencies) & Von Willebrand's
Disease

Hæmophilia is a group of hereditary genetic disorders that impair the body's ability
to control
coagulation (blood clotting).

Hæmophilia A (Clotting Factor VIII deficiency) is the most common form of the
disorder (1 in 5,000 – 10,000 male births).

Hæmophilia B (Clotting Factor IX deficiency) is rarer than Hæmophilia A, occuring
in around 1 in about 20,000 – 34,000 male births.

Hæmophilia lowers blood plasma clotting factor levels of the coagulation factors
needed for normal
coagulation.  When a blood vessel is injured, a clot does form
but the missing
coagulation factors prevent fibrin formation, which is necessary to
maintain the blood
clot.

A
hæmophiliac does not bleed more intensely than a person without it but can
bleed for a much longer time.  In severe cases, even a minor injury can result in
bleeding that can last days - weeks or there is incomplete healing.  In areas such
as the brain or inside joints, this can be fatal or permanently debilitating.
Useful Articles:

St James Hospital, Dublin.  Haemophilia & Dental Care

Austral Dental J 2001.  A Protocol for the Dental Management of Von Willebrand's
Disease, Hæmophilia A & Hæmophilia B.

Haemophilia 2004.  Management of Von Willebrand Disease.  A Guideline from the
UK Haemophilia Centre Doctors’ Organization

Haemophilia 2005.  Dental Procedures in Adult Patients with Hereditary Bleeding
Disorders.  10 Years Experience in 3 Italian Hemophilia Centers

J Dent Res 2005.  Hereditary Blood Coagulation Disorders -  Management and
Dental Treatment

World Federation of Hæmophilia 2005.  Guidelines for the Management of
Hæmophilia

Treatment of Hæmophilia 2006.  Guidelines for Dental Treatment of Patients with
Inherited Bleeding Disorders

Canadian Hæmophilia Society 2007.  All About von Willebrand Disease

Treatment of Hæmophilia 2008.  Dental Management of Patients with Inhibitors to
Factor VIII or Factor IX

Treatment of Hæmophilia 2008.  Oral Care for People with Hæmophilia or a
Hereditary Bleeding Tendency

N Engl J Med 2009.  Clinical Problem Solving.  A Bloody Mystery (Acquired von
Willebrand’s Disease)

Barts & the London NHS Trust 2010.  Dental Management of Haemophilia Patients

N Engl J Med 2012.  Factor XIII in the Treatment of Hemophilia A
Patients with Rare Clotting Factor Deficiencies

Clotting / Coagulation Factors are proteins in the blood that control bleeding.

If any of the
clotting factors are deficient or defective, the coagulation cascade is
blocked.  When this happens, the blood
clot does not form & bleeding continues
longer than it should.

Rare
clotting factor deficiencies are bleeding disorders in where clotting factors
other than those of
Factors VIII & IX (otherwise known as Hæmophilias) are
deficient / defective.  These are
Factors I, II, V, VII, X, XI, XII & XIII.
Useful Articles:

Canadian Hæmophilia Society 2001.  Factor VII Deficiency.  An inherited bleeding
disorder

Canadian Hæmophilia Society 2001.  Factor XIII Deficiency.  An Inherited Bleeding
Disorder

Canadian Hæmophilia Society 2004.  Factor I Deficiency (Fibrinogen).  An Inherited
Bleeding Disorder

Canadian Hæmophilia Society 2006.  Factor V Deficiency (Parahæmophilia).  An
Inherited Bleeding Disorder

Canadian Hæmophilia Society 2006.  Factor X Deficiency.  An inherited bleeding
disorder

Treatment of Hæmophilia 2006.  The Rare Coagulation Disorders

Canadian Hæmophilia Society 2007.  Factor XI Deficiency.  An inherited bleeding
disorder

Med Oral Patol Oral Cir Bucal 2007.  Dental Treatment of Patients with
Coagulation Factor Alterations.  An Update

Treatment of Hæmophilia 2008.  Factor XI Deficiency & Its Management

World Federation of Hæmophilia 2009.  What are Rare Clotting Factor Deficiencies
Useful (General) Articles:

Burket’s Oral Medicine.  Diagnosis & Treatment.  Chapter 17.  Bleeding & Clotting
Disorders

Canadian Hæmophilia Society.  Desmopressin.  DDAVP, Octostim, Octostim
spray.  A Guide for Patients & their Caregivers

Canadian Hæmophilia Society.  Tranexamic Acid.  Cyklokapron

J Can Dent Assoc 2006.  Bleeding Disorders - Characterization, Dental
Considerations & Management

J Can Dent Assoc 2007.  Bleeding Disorders of Importance in Dental Care &
Related Patient Management

Dental Update 2014.  Haemostasis Part 1.  The Management of Post-Extraction
Haemorrhage

Dental Update 2014.  Haemostasis Part 2.  Medications that Affect Haemostasis
Patients with Platelet Disorders & Deficiencies

Platelets are cell fragments that function in the clotting / coagulation system.

Platelets circulate for 7 - 10 days.  About one third are always transiently
sequestered in the
spleen.

The
platelet count is normally 140,000 - 440,000/μL.  However, the count can vary
slightly according to menstrual cycle phase, decrease during near-term pregnancy
(
gestational thrombocytopænia) & increase in response to inflammatory cytokines
(secondary or reactive thrombocytosis).

Platelets are eventually destroyed, primarily by the spleen.

Platelet disorders include:

  • Abnormal increase in platelets (thrombocythæmia)
  • Decrease in platelets (thrombocytopænia)
  • Platelet dysfunction

Any of these conditions, even those in which
platelets are increased, may cause
defective formation of
hæmostatic plugs & bleeding.

The risk of bleeding is inversely proportional to the
platelet count.

When the
platelet count is < 50,000/μL, minor bleeding occurs easily & the risk of
major bleeding increases.

Counts between 20,000 - 50,000/μL predispose to bleeding with trauma, even
minor trauma.

With counts < 20,000/μL, spontaneous bleeding may occur.

With counts < 5000/μL, severe spontaneous bleeding is more likely.

However, patients with counts < 10,000/μL may be asymptomatic for years.
Useful Articles:

Canadian Hæmophilia Society 2001.  Glanzmann Thrombasthenia.  An inherited
bleeding disorder

J Oral Maxillofac Surg 2001.  Management of the Oral and Maxillofacial Surgery
Patient With Thrombocytopenia

Canadian Children's Platelet Study Group 2002.  Disorders of Platelet Function

Treatment of Hæmophilia 2008.  Platelet Function Disorders
Patients with Hæmatological Disorders
Useful Articles:

Oral Surgery 1979.  Dental Management of Leukaemic Patients

JOMS 1982.  Dental Extractions in Patients with Acute Non-Lymphocytic
Leukaemia

BDJ 2010.  General Medicine & Surgery for Dental Practitioners.  Part 6 – Cancer,
Radiotherapy & Chemotherapy

J Clin Exp Dent 2011.  Dental treatment considerations in the chemotherapy patient

J Clin Exp Dent 2011.  Oral manifestations & dental management of patient with
leukocyte alterations
Last Updated 20th May 2015
Clinical Assessment

A careful history regarding bleeding problems is essential prior to surgery.  
Excessive bleeding may result from a variety of causes.

For instance, drugs such as
acetyl-salicylic acid (Aspirin) & other non-selective
Non-Steroidal Anti-Inflammatory (NSAID’s such as Ibuprofen) analgesics may
inhibit platelet function.

Liver disease may decrease the production of
clotting factors.

To help uncover previously unrecognised bleeding disorders prior to major oral
surgery, it has been recommended that pre-operative laboratory assessment of
hæmostasis be carried out.  However, a large number of studies concluded that
routine
hæmostatic testing of asymptomatic patients does not significantly alter
treatment & is not cost-effective for its low ‘yield’.